Redis 5.0.5

CLIENT PAUSE may be used, in other contexts, for a long time making all
the slaves time out. Better for now to be more specific about what
should disable senidng PINGs.

An alternative to that would be to virtually refresh the slave
interactions when clients are paused, however for now I went for this
more conservative solution.

CONTRIBUTING

@@ -14,9 +14,7 @@ each source file that you contribute.
 
   PLEASE DO NOT POST GENERAL QUESTIONS that are not about bugs or suspected
   bugs in the Github issues system. We'll be very happy to help you and provide
-  all the support at the Reddit sub:
-
-      http://reddit.com/r/redis
+  all the support in the mailing list.
 
   There is also an active community of Redis users at Stack Overflow:
 
@@ -24,7 +22,12 @@ each source file that you contribute.
 
 # How to provide a patch for a new feature
 
-1. If it is a major feature or a semantical change, please post it as a new submission in r/redis on Reddit at http://reddit.com/r/redis. Try to be passionate about why the feature is needed, make users upvote your proposal to gain traction and so forth. Read feedbacks about the community. But in this first step **please don't write code yet**.
+1. If it is a major feature or a semantical change, please don't start coding
+straight away: if your feature is not a conceptual fit you'll lose a lot of
+time writing the code without any reason. Start by posting in the mailing list
+and creating an issue at Github with the description of, exactly, what you want
+to accomplish and why. Use cases are important for features to be accepted.
+Here you'll see if there is consensus about your idea.
 
 2. If in step 1 you get an acknowledgment from the project leaders, use the
    following procedure to submit a patch:
@@ -35,6 +38,13 @@ each source file that you contribute.
     d. Initiate a pull request on github ( https://help.github.com/articles/creating-a-pull-request/ )
     e. Done :)
 
-For minor fixes just open a pull request on Github.
+3. Keep in mind that we are very overloaded, so issues and PRs sometimes wait
+for a *very* long time. However this is not lack of interest, as the project
+gets more and more users, we find ourselves in a constant need to prioritize
+certain issues/PRs over others. If you think your issue/PR is very important
+try to popularize it, have other users commenting and sharing their point of
+view and so forth. This helps.
+
+4. For minor fixes just open a pull request on Github.
 
 Thanks!

MANIFESTO

@@ -34,7 +34,21 @@ Redis Manifesto
     so that the complexity is obvious and more complex operations can be
     performed as the sum of the basic operations.
 
-4 - Code is like a poem; it's not just something we write to reach some
+4 - We believe in code efficiency. Computers get faster and faster, yet we
+    believe that abusing computing capabilities is not wise: the amount of
+    operations you can do for a given amount of energy remains anyway a
+    significant parameter: it allows to do more with less computers and, at
+    the same time, having a smaller environmental impact. Similarly Redis is
+    able to "scale down" to smaller devices. It is perfectly usable in a
+    Raspberry Pi and other small ARM based computers. Faster code having
+    just the layers of abstractions that are really needed will also result,
+    often, in more predictable performances. We think likewise about memory
+    usage, one of the fundamental goals of the Redis project is to
+    incrementally build more and more memory efficient data structures, so that
+    problems that were not approachable in RAM in the past will be perfectly
+    fine to handle in the future.
+
+5 - Code is like a poem; it's not just something we write to reach some
     practical result. Sometimes people that are far from the Redis philosophy
     suggest using other code written by other authors (frequently in other
     languages) in order to implement something Redis currently lacks. But to us
@@ -45,23 +59,48 @@ Redis Manifesto
     when needed. At the same time, when writing the Redis story we're trying to
     write smaller stories that will fit in to other code.
 
-5 - We're against complexity. We believe designing systems is a fight against
+6 - We're against complexity. We believe designing systems is a fight against
     complexity. We'll accept to fight the complexity when it's worthwhile but
     we'll try hard to recognize when a small feature is not worth 1000s of lines
     of code. Most of the time the best way to fight complexity is by not
-    creating it at all.
+    creating it at all. Complexity is also a form of lock-in: code that is
+    very hard to understand cannot be modified by users in an independent way
+    regardless of the license. One of the main Redis goals is to remain
+    understandable, enough for a single programmer to have a clear idea of how
+    it works in detail just reading the source code for a couple of weeks.
 
-6 - Two levels of API. The Redis API has two levels: 1) a subset of the API fits
+7 - Threading is not a silver bullet. Instead of making Redis threaded we
+    believe on the idea of an efficient (mostly) single threaded Redis core.
+    Multiple of such cores, that may run in the same computer or may run
+    in multiple computers, are abstracted away as a single big system by
+    higher order protocols and features: Redis Cluster and the upcoming
+    Redis Proxy are our main goals. A shared nothing approach is not just
+    much simpler (see the previous point in this document), is also optimal
+    in NUMA systems. In the specific case of Redis it allows for each instance
+    to have a more limited amount of data, making the Redis persist-by-fork
+    approach more sounding. In the future we may explore parallelism only for
+    I/O, which is the low hanging fruit: minimal complexity could provide an
+    improved single process experience.
+
+8 - Two levels of API. The Redis API has two levels: 1) a subset of the API fits
     naturally into a distributed version of Redis and 2) a more complex API that
     supports multi-key operations. Both are useful if used judiciously but
     there's no way to make the more complex multi-keys API distributed in an
     opaque way without violating our other principles. We don't want to provide
     the illusion of something that will work magically when actually it can't in
     all cases. Instead we'll provide commands to quickly migrate keys from one
-    instance to another to perform multi-key operations and expose the tradeoffs
-    to the user.
+    instance to another to perform multi-key operations and expose the
+    trade-offs to the user.
 
-7 - We optimize for joy. We believe writing code is a lot of hard work, and the
+9 - We optimize for joy. We believe writing code is a lot of hard work, and the
     only way it can be worth is by enjoying it. When there is no longer joy in
     writing code, the best thing to do is stop. To prevent this, we'll avoid
     taking paths that will make Redis less of a joy to develop.
+
+10 - All the above points are put together in what we call opportunistic
+     programming: trying to get the most for the user with minimal increases
+     in complexity (hanging fruits). Solve 95% of the problem with 5% of the
+     code when it is acceptable. Avoid a fixed schedule but follow the flow of
+     user requests, inspiration, Redis internal readiness for certain features
+     (sometimes many past changes reach a critical point making a previously
+     complex feature very easy to obtain).

README.md

@@ -119,7 +119,7 @@ parameter (the path of the configuration file):
 It is possible to alter the Redis configuration by passing parameters directly
 as options using the command line. Examples:
 
-    % ./redis-server --port 9999 --slaveof 127.0.0.1 6379
+    % ./redis-server --port 9999 --replicaof 127.0.0.1 6379
     % ./redis-server /etc/redis/6379.conf --loglevel debug
 
 All the options in redis.conf are also supported as options using the command
@@ -216,7 +216,7 @@ Inside the root are the following important directories:
 
 * `src`: contains the Redis implementation, written in C.
 * `tests`: contains the unit tests, implemented in Tcl.
-* `deps`: contains libraries Redis uses. Everything needed to compile Redis is inside this directory; your system just needs to provide `libc`, a POSIX compatible interface and a C compiler. Notably `deps` contains a copy of `jemalloc`, which is the default allocator of Redis under Linux. Note that under `deps` there are also things which started with the Redis project, but for which the main repository is not `anitrez/redis`. An exception to this rule is `deps/geohash-int` which is the low level geocoding library used by Redis: it originated from a different project, but at this point it diverged so much that it is developed as a separated entity directly inside the Redis repository.
+* `deps`: contains libraries Redis uses. Everything needed to compile Redis is inside this directory; your system just needs to provide `libc`, a POSIX compatible interface and a C compiler. Notably `deps` contains a copy of `jemalloc`, which is the default allocator of Redis under Linux. Note that under `deps` there are also things which started with the Redis project, but for which the main repository is not `antirez/redis`. An exception to this rule is `deps/geohash-int` which is the low level geocoding library used by Redis: it originated from a different project, but at this point it diverged so much that it is developed as a separated entity directly inside the Redis repository.
 
 There are a few more directories but they are not very important for our goals
 here. We'll focus mostly on `src`, where the Redis implementation is contained,
@@ -227,7 +227,7 @@ of complexity incrementally.
 Note: lately Redis was refactored quite a bit. Function names and file
 names have been changed, so you may find that this documentation reflects the
 `unstable` branch more closely. For instance in Redis 3.0 the `server.c`
-and `server.h` files were named to `redis.c` and `redis.h`. However the overall
+and `server.h` files were named `redis.c` and `redis.h`. However the overall
 structure is the same. Keep in mind that all the new developments and pull
 requests should be performed against the `unstable` branch.
 
@@ -245,7 +245,7 @@ A few important fields in this structure are:
 * `server.db` is an array of Redis databases, where data is stored.
 * `server.commands` is the command table.
 * `server.clients` is a linked list of clients connected to the server.
-* `server.master` is a special client, the master, if the instance is a slave.
+* `server.master` is a special client, the master, if the instance is a replica.
 
 There are tons of other fields. Most fields are commented directly inside
 the structure definition.
@@ -323,7 +323,7 @@ Inside server.c you can find code that handles other vital things of the Redis s
 networking.c
 ---
 
-This file defines all the I/O functions with clients, masters and slaves
+This file defines all the I/O functions with clients, masters and replicas
 (which in Redis are just special clients):
 
 * `createClient()` allocates and initializes a new client.
@@ -390,16 +390,16 @@ replication.c
 
 This is one of the most complex files inside Redis, it is recommended to
 approach it only after getting a bit familiar with the rest of the code base.
-In this file there is the implementation of both the master and slave role
+In this file there is the implementation of both the master and replica role
 of Redis.
 
-One of the most important functions inside this file is `replicationFeedSlaves()` that writes commands to the clients representing slave instances connected
-to our master, so that the slaves can get the writes performed by the clients:
+One of the most important functions inside this file is `replicationFeedSlaves()` that writes commands to the clients representing replica instances connected
+to our master, so that the replicas can get the writes performed by the clients:
 this way their data set will remain synchronized with the one in the master.
 
 This file also implements both the `SYNC` and `PSYNC` commands that are
 used in order to perform the first synchronization between masters and
-slaves, or to continue the replication after a disconnection.
+replicas, or to continue the replication after a disconnection.
 
 Other C files
 ---

redis.conf

@@ -264,59 +264,64 @@ dir ./
 
 ################################# REPLICATION #################################
 
-# Master-Slave replication. Use slaveof to make a Redis instance a copy of
+# Master-Replica replication. Use replicaof to make a Redis instance a copy of
 # another Redis server. A few things to understand ASAP about Redis replication.
 #
+#   +------------------+      +---------------+
+#   |      Master      | ---> |    Replica    |
+#   | (receive writes) |      |  (exact copy) |
+#   +------------------+      +---------------+
+#
 # 1) Redis replication is asynchronous, but you can configure a master to
 #    stop accepting writes if it appears to be not connected with at least
-#    a given number of slaves.
-# 2) Redis slaves are able to perform a partial resynchronization with the
+#    a given number of replicas.
+# 2) Redis replicas are able to perform a partial resynchronization with the
 #    master if the replication link is lost for a relatively small amount of
 #    time. You may want to configure the replication backlog size (see the next
 #    sections of this file) with a sensible value depending on your needs.
 # 3) Replication is automatic and does not need user intervention. After a
-#    network partition slaves automatically try to reconnect to masters
+#    network partition replicas automatically try to reconnect to masters
 #    and resynchronize with them.
 #
-# slaveof <masterip> <masterport>
+# replicaof <masterip> <masterport>
 
 # If the master is password protected (using the "requirepass" configuration
-# directive below) it is possible to tell the slave to authenticate before
+# directive below) it is possible to tell the replica to authenticate before
 # starting the replication synchronization process, otherwise the master will
-# refuse the slave request.
+# refuse the replica request.
 #
 # masterauth <master-password>
 
-# When a slave loses its connection with the master, or when the replication
-# is still in progress, the slave can act in two different ways:
+# When a replica loses its connection with the master, or when the replication
+# is still in progress, the replica can act in two different ways:
 #
-# 1) if slave-serve-stale-data is set to 'yes' (the default) the slave will
+# 1) if replica-serve-stale-data is set to 'yes' (the default) the replica will
 #    still reply to client requests, possibly with out of date data, or the
 #    data set may just be empty if this is the first synchronization.
 #
-# 2) if slave-serve-stale-data is set to 'no' the slave will reply with
+# 2) if replica-serve-stale-data is set to 'no' the replica will reply with
 #    an error "SYNC with master in progress" to all the kind of commands
-#    but to INFO, SLAVEOF, AUTH, PING, SHUTDOWN, REPLCONF, ROLE, CONFIG,
+#    but to INFO, replicaOF, AUTH, PING, SHUTDOWN, REPLCONF, ROLE, CONFIG,
 #    SUBSCRIBE, UNSUBSCRIBE, PSUBSCRIBE, PUNSUBSCRIBE, PUBLISH, PUBSUB,
 #    COMMAND, POST, HOST: and LATENCY.
 #
-slave-serve-stale-data yes
+replica-serve-stale-data yes
 
-# You can configure a slave instance to accept writes or not. Writing against
-# a slave instance may be useful to store some ephemeral data (because data
-# written on a slave will be easily deleted after resync with the master) but
+# You can configure a replica instance to accept writes or not. Writing against
+# a replica instance may be useful to store some ephemeral data (because data
+# written on a replica will be easily deleted after resync with the master) but
 # may also cause problems if clients are writing to it because of a
 # misconfiguration.
 #
-# Since Redis 2.6 by default slaves are read-only.
+# Since Redis 2.6 by default replicas are read-only.
 #
-# Note: read only slaves are not designed to be exposed to untrusted clients
+# Note: read only replicas are not designed to be exposed to untrusted clients
 # on the internet. It's just a protection layer against misuse of the instance.
-# Still a read only slave exports by default all the administrative commands
+# Still a read only replica exports by default all the administrative commands
 # such as CONFIG, DEBUG, and so forth. To a limited extent you can improve
-# security of read only slaves using 'rename-command' to shadow all the
+# security of read only replicas using 'rename-command' to shadow all the
 # administrative / dangerous commands.
-slave-read-only yes
+replica-read-only yes
 
 # Replication SYNC strategy: disk or socket.
 #
@@ -324,25 +329,25 @@ slave-read-only yes
 # WARNING: DISKLESS REPLICATION IS EXPERIMENTAL CURRENTLY
 # -------------------------------------------------------
 #
-# New slaves and reconnecting slaves that are not able to continue the replication
+# New replicas and reconnecting replicas that are not able to continue the replication
 # process just receiving differences, need to do what is called a "full
-# synchronization". An RDB file is transmitted from the master to the slaves.
+# synchronization". An RDB file is transmitted from the master to the replicas.
 # The transmission can happen in two different ways:
 #
 # 1) Disk-backed: The Redis master creates a new process that writes the RDB
 #                 file on disk. Later the file is transferred by the parent
-#                 process to the slaves incrementally.
+#                 process to the replicas incrementally.
 # 2) Diskless: The Redis master creates a new process that directly writes the
-#              RDB file to slave sockets, without touching the disk at all.
+#              RDB file to replica sockets, without touching the disk at all.
 #
-# With disk-backed replication, while the RDB file is generated, more slaves
+# With disk-backed replication, while the RDB file is generated, more replicas
 # can be queued and served with the RDB file as soon as the current child producing
 # the RDB file finishes its work. With diskless replication instead once
-# the transfer starts, new slaves arriving will be queued and a new transfer
+# the transfer starts, new replicas arriving will be queued and a new transfer
 # will start when the current one terminates.
 #
 # When diskless replication is used, the master waits a configurable amount of
-# time (in seconds) before starting the transfer in the hope that multiple slaves
+# time (in seconds) before starting the transfer in the hope that multiple replicas
 # will arrive and the transfer can be parallelized.
 #
 # With slow disks and fast (large bandwidth) networks, diskless replication
@@ -351,140 +356,140 @@ repl-diskless-sync no
 
 # When diskless replication is enabled, it is possible to configure the delay
 # the server waits in order to spawn the child that transfers the RDB via socket
-# to the slaves.
+# to the replicas.
 #
 # This is important since once the transfer starts, it is not possible to serve
-# new slaves arriving, that will be queued for the next RDB transfer, so the server
-# waits a delay in order to let more slaves arrive.
+# new replicas arriving, that will be queued for the next RDB transfer, so the server
+# waits a delay in order to let more replicas arrive.
 #
 # The delay is specified in seconds, and by default is 5 seconds. To disable
 # it entirely just set it to 0 seconds and the transfer will start ASAP.
 repl-diskless-sync-delay 5
 
-# Slaves send PINGs to server in a predefined interval. It's possible to change
-# this interval with the repl_ping_slave_period option. The default value is 10
+# Replicas send PINGs to server in a predefined interval. It's possible to change
+# this interval with the repl_ping_replica_period option. The default value is 10
 # seconds.
 #
-# repl-ping-slave-period 10
+# repl-ping-replica-period 10
 
 # The following option sets the replication timeout for:
 #
-# 1) Bulk transfer I/O during SYNC, from the point of view of slave.
-# 2) Master timeout from the point of view of slaves (data, pings).
-# 3) Slave timeout from the point of view of masters (REPLCONF ACK pings).
+# 1) Bulk transfer I/O during SYNC, from the point of view of replica.
+# 2) Master timeout from the point of view of replicas (data, pings).
+# 3) Replica timeout from the point of view of masters (REPLCONF ACK pings).
 #
 # It is important to make sure that this value is greater than the value
-# specified for repl-ping-slave-period otherwise a timeout will be detected
-# every time there is low traffic between the master and the slave.
+# specified for repl-ping-replica-period otherwise a timeout will be detected
+# every time there is low traffic between the master and the replica.
 #
 # repl-timeout 60
 
-# Disable TCP_NODELAY on the slave socket after SYNC?
+# Disable TCP_NODELAY on the replica socket after SYNC?
 #
 # If you select "yes" Redis will use a smaller number of TCP packets and
-# less bandwidth to send data to slaves. But this can add a delay for
-# the data to appear on the slave side, up to 40 milliseconds with
+# less bandwidth to send data to replicas. But this can add a delay for
+# the data to appear on the replica side, up to 40 milliseconds with
 # Linux kernels using a default configuration.
 #
-# If you select "no" the delay for data to appear on the slave side will
+# If you select "no" the delay for data to appear on the replica side will
 # be reduced but more bandwidth will be used for replication.
 #
 # By default we optimize for low latency, but in very high traffic conditions
-# or when the master and slaves are many hops away, turning this to "yes" may
+# or when the master and replicas are many hops away, turning this to "yes" may
 # be a good idea.
 repl-disable-tcp-nodelay no
 
 # Set the replication backlog size. The backlog is a buffer that accumulates
-# slave data when slaves are disconnected for some time, so that when a slave
+# replica data when replicas are disconnected for some time, so that when a replica
 # wants to reconnect again, often a full resync is not needed, but a partial
-# resync is enough, just passing the portion of data the slave missed while
+# resync is enough, just passing the portion of data the replica missed while
 # disconnected.
 #
-# The bigger the replication backlog, the longer the time the slave can be
+# The bigger the replication backlog, the longer the time the replica can be
 # disconnected and later be able to perform a partial resynchronization.
 #
-# The backlog is only allocated once there is at least a slave connected.
+# The backlog is only allocated once there is at least a replica connected.
 #
 # repl-backlog-size 1mb
 
-# After a master has no longer connected slaves for some time, the backlog
+# After a master has no longer connected replicas for some time, the backlog
 # will be freed. The following option configures the amount of seconds that
-# need to elapse, starting from the time the last slave disconnected, for
+# need to elapse, starting from the time the last replica disconnected, for
 # the backlog buffer to be freed.
 #
-# Note that slaves never free the backlog for timeout, since they may be
+# Note that replicas never free the backlog for timeout, since they may be
 # promoted to masters later, and should be able to correctly "partially
-# resynchronize" with the slaves: hence they should always accumulate backlog.
+# resynchronize" with the replicas: hence they should always accumulate backlog.
 #
 # A value of 0 means to never release the backlog.
 #
 # repl-backlog-ttl 3600
 
-# The slave priority is an integer number published by Redis in the INFO output.
-# It is used by Redis Sentinel in order to select a slave to promote into a
+# The replica priority is an integer number published by Redis in the INFO output.
+# It is used by Redis Sentinel in order to select a replica to promote into a
 # master if the master is no longer working correctly.
 #
-# A slave with a low priority number is considered better for promotion, so
-# for instance if there are three slaves with priority 10, 100, 25 Sentinel will
+# A replica with a low priority number is considered better for promotion, so
+# for instance if there are three replicas with priority 10, 100, 25 Sentinel will
 # pick the one with priority 10, that is the lowest.
 #
-# However a special priority of 0 marks the slave as not able to perform the
-# role of master, so a slave with priority of 0 will never be selected by
+# However a special priority of 0 marks the replica as not able to perform the
+# role of master, so a replica with priority of 0 will never be selected by
 # Redis Sentinel for promotion.
 #
 # By default the priority is 100.
-slave-priority 100
+replica-priority 100
 
 # It is possible for a master to stop accepting writes if there are less than
-# N slaves connected, having a lag less or equal than M seconds.
+# N replicas connected, having a lag less or equal than M seconds.
 #
-# The N slaves need to be in "online" state.
+# The N replicas need to be in "online" state.
 #
 # The lag in seconds, that must be <= the specified value, is calculated from
-# the last ping received from the slave, that is usually sent every second.
+# the last ping received from the replica, that is usually sent every second.
 #
 # This option does not GUARANTEE that N replicas will accept the write, but
-# will limit the window of exposure for lost writes in case not enough slaves
+# will limit the window of exposure for lost writes in case not enough replicas
 # are available, to the specified number of seconds.
 #
-# For example to require at least 3 slaves with a lag <= 10 seconds use:
+# For example to require at least 3 replicas with a lag <= 10 seconds use:
 #
-# min-slaves-to-write 3
-# min-slaves-max-lag 10
+# min-replicas-to-write 3
+# min-replicas-max-lag 10
 #
 # Setting one or the other to 0 disables the feature.
 #
-# By default min-slaves-to-write is set to 0 (feature disabled) and
-# min-slaves-max-lag is set to 10.
+# By default min-replicas-to-write is set to 0 (feature disabled) and
+# min-replicas-max-lag is set to 10.
 
 # A Redis master is able to list the address and port of the attached
-# slaves in different ways. For example the "INFO replication" section
+# replicas in different ways. For example the "INFO replication" section
 # offers this information, which is used, among other tools, by
-# Redis Sentinel in order to discover slave instances.
+# Redis Sentinel in order to discover replica instances.
 # Another place where this info is available is in the output of the
 # "ROLE" command of a master.
 #
-# The listed IP and address normally reported by a slave is obtained
+# The listed IP and address normally reported by a replica is obtained
 # in the following way:
 #
 #   IP: The address is auto detected by checking the peer address
-#   of the socket used by the slave to connect with the master.
+#   of the socket used by the replica to connect with the master.
 #
-#   Port: The port is communicated by the slave during the replication
-#   handshake, and is normally the port that the slave is using to
-#   list for connections.
+#   Port: The port is communicated by the replica during the replication
+#   handshake, and is normally the port that the replica is using to
+#   listen for connections.
 #
 # However when port forwarding or Network Address Translation (NAT) is
-# used, the slave may be actually reachable via different IP and port
-# pairs. The following two options can be used by a slave in order to
+# used, the replica may be actually reachable via different IP and port
+# pairs. The following two options can be used by a replica in order to
 # report to its master a specific set of IP and port, so that both INFO
 # and ROLE will report those values.
 #
 # There is no need to use both the options if you need to override just
 # the port or the IP address.
 #
-# slave-announce-ip 5.5.5.5
-# slave-announce-port 1234
+# replica-announce-ip 5.5.5.5
+# replica-announce-port 1234
 
 ################################## SECURITY ###################################
 
@@ -518,7 +523,7 @@ slave-priority 100
 # rename-command CONFIG ""
 #
 # Please note that changing the name of commands that are logged into the
-# AOF file or transmitted to slaves may cause problems.
+# AOF file or transmitted to replicas may cause problems.
 
 ################################### CLIENTS ####################################
 
@@ -547,15 +552,15 @@ slave-priority 100
 # This option is usually useful when using Redis as an LRU or LFU cache, or to
 # set a hard memory limit for an instance (using the 'noeviction' policy).
 #
-# WARNING: If you have slaves attached to an instance with maxmemory on,
-# the size of the output buffers needed to feed the slaves are subtracted
+# WARNING: If you have replicas attached to an instance with maxmemory on,
+# the size of the output buffers needed to feed the replicas are subtracted
 # from the used memory count, so that network problems / resyncs will
 # not trigger a loop where keys are evicted, and in turn the output
-# buffer of slaves is full with DELs of keys evicted triggering the deletion
+# buffer of replicas is full with DELs of keys evicted triggering the deletion
 # of more keys, and so forth until the database is completely emptied.
 #
-# In short... if you have slaves attached it is suggested that you set a lower
-# limit for maxmemory so that there is some free RAM on the system for slave
+# In short... if you have replicas attached it is suggested that you set a lower
+# limit for maxmemory so that there is some free RAM on the system for replica
 # output buffers (but this is not needed if the policy is 'noeviction').
 #
 # maxmemory <bytes>
@@ -602,25 +607,25 @@ slave-priority 100
 #
 # maxmemory-samples 5
 
-# Starting from Redis 5, by default a slave will ignore its maxmemory setting
+# Starting from Redis 5, by default a replica will ignore its maxmemory setting
 # (unless it is promoted to master after a failover or manually). It means
 # that the eviction of keys will be just handled by the master, sending the
-# DEL commands to the slave as keys evict in the master side.
+# DEL commands to the replica as keys evict in the master side.
 #
-# This behavior ensures that masters and slaves stay consistent, and is usually
-# what you want, however if your slave is writable, or you want the slave to have
+# This behavior ensures that masters and replicas stay consistent, and is usually
+# what you want, however if your replica is writable, or you want the replica to have
 # a different memory setting, and you are sure all the writes performed to the
-# slave are idempotent, then you may change this default (but be sure to understand
+# replica are idempotent, then you may change this default (but be sure to understand
 # what you are doing).
 #
-# Note that since the slave by default does not evict, it may end using more
+# Note that since the replica by default does not evict, it may end using more
 # memory than the one set via maxmemory (there are certain buffers that may
-# be larger on the slave, or data structures may sometimes take more memory and so
-# forth). So make sure you monitor your slaves and make sure they have enough
+# be larger on the replica, or data structures may sometimes take more memory and so
+# forth). So make sure you monitor your replicas and make sure they have enough
 # memory to never hit a real out-of-memory condition before the master hits
 # the configured maxmemory setting.
 #
-# slave-ingore-maxmemory yes
+# replica-ignore-maxmemory yes
 
 ############################# LAZY FREEING ####################################
 
@@ -657,7 +662,7 @@ slave-priority 100
 #    or SORT with STORE option may delete existing keys. The SET command
 #    itself removes any old content of the specified key in order to replace
 #    it with the specified string.
-# 4) During replication, when a slave performs a full resynchronization with
+# 4) During replication, when a replica performs a full resynchronization with
 #    its master, the content of the whole database is removed in order to
 #    load the RDB file just transferred.
 #
@@ -669,7 +674,7 @@ slave-priority 100
 lazyfree-lazy-eviction no
 lazyfree-lazy-expire no
 lazyfree-lazy-server-del no
-slave-lazy-flush no
+replica-lazy-flush no
 
 ############################## APPEND ONLY MODE ###############################
 
@@ -819,13 +824,7 @@ aof-use-rdb-preamble yes
 lua-time-limit 5000
 
 ################################ REDIS CLUSTER  ###############################
-#
-# ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
-# WARNING EXPERIMENTAL: Redis Cluster is considered to be stable code, however
-# in order to mark it as "mature" we need to wait for a non trivial percentage
-# of users to deploy it in production.
-# ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
-#
+
 # Normal Redis instances can't be part of a Redis Cluster; only nodes that are
 # started as cluster nodes can. In order to start a Redis instance as a
 # cluster node enable the cluster support uncommenting the following:
@@ -846,42 +845,42 @@ lua-time-limit 5000
 #
 # cluster-node-timeout 15000
 
-# A slave of a failing master will avoid to start a failover if its data
+# A replica of a failing master will avoid to start a failover if its data
 # looks too old.
 #
-# There is no simple way for a slave to actually have an exact measure of
+# There is no simple way for a replica to actually have an exact measure of
 # its "data age", so the following two checks are performed:
 #
-# 1) If there are multiple slaves able to failover, they exchange messages
-#    in order to try to give an advantage to the slave with the best
+# 1) If there are multiple replicas able to failover, they exchange messages
+#    in order to try to give an advantage to the replica with the best
 #    replication offset (more data from the master processed).
-#    Slaves will try to get their rank by offset, and apply to the start
+#    Replicas will try to get their rank by offset, and apply to the start
 #    of the failover a delay proportional to their rank.
 #
-# 2) Every single slave computes the time of the last interaction with
+# 2) Every single replica computes the time of the last interaction with
 #    its master. This can be the last ping or command received (if the master
 #    is still in the "connected" state), or the time that elapsed since the
 #    disconnection with the master (if the replication link is currently down).
-#    If the last interaction is too old, the slave will not try to failover
+#    If the last interaction is too old, the replica will not try to failover
 #    at all.
 #
-# The point "2" can be tuned by user. Specifically a slave will not perform
+# The point "2" can be tuned by user. Specifically a replica will not perform
 # the failover if, since the last interaction with the master, the time
 # elapsed is greater than:
 #
-#   (node-timeout * slave-validity-factor) + repl-ping-slave-period
+#   (node-timeout * replica-validity-factor) + repl-ping-replica-period
 #
-# So for example if node-timeout is 30 seconds, and the slave-validity-factor
-# is 10, and assuming a default repl-ping-slave-period of 10 seconds, the
-# slave will not try to failover if it was not able to talk with the master
+# So for example if node-timeout is 30 seconds, and the replica-validity-factor
+# is 10, and assuming a default repl-ping-replica-period of 10 seconds, the
+# replica will not try to failover if it was not able to talk with the master
 # for longer than 310 seconds.
 #
-# A large slave-validity-factor may allow slaves with too old data to failover
+# A large replica-validity-factor may allow replicas with too old data to failover
 # a master, while a too small value may prevent the cluster from being able to
-# elect a slave at all.
+# elect a replica at all.
 #
-# For maximum availability, it is possible to set the slave-validity-factor
-# to a value of 0, which means, that slaves will always try to failover the
+# For maximum availability, it is possible to set the replica-validity-factor
+# to a value of 0, which means, that replicas will always try to failover the
 # master regardless of the last time they interacted with the master.
 # (However they'll always try to apply a delay proportional to their
 # offset rank).
@@ -889,22 +888,22 @@ lua-time-limit 5000
 # Zero is the only value able to guarantee that when all the partitions heal
 # the cluster will always be able to continue.
 #
-# cluster-slave-validity-factor 10
+# cluster-replica-validity-factor 10
 
-# Cluster slaves are able to migrate to orphaned masters, that are masters
-# that are left without working slaves. This improves the cluster ability
+# Cluster replicas are able to migrate to orphaned masters, that are masters
+# that are left without working replicas. This improves the cluster ability
 # to resist to failures as otherwise an orphaned master can't be failed over
-# in case of failure if it has no working slaves.
+# in case of failure if it has no working replicas.
 #
-# Slaves migrate to orphaned masters only if there are still at least a
-# given number of other working slaves for their old master. This number
-# is the "migration barrier". A migration barrier of 1 means that a slave
-# will migrate only if there is at least 1 other working slave for its master
-# and so forth. It usually reflects the number of slaves you want for every
+# Replicas migrate to orphaned masters only if there are still at least a
+# given number of other working replicas for their old master. This number
+# is the "migration barrier". A migration barrier of 1 means that a replica
+# will migrate only if there is at least 1 other working replica for its master
+# and so forth. It usually reflects the number of replicas you want for every
 # master in your cluster.
 #
-# Default is 1 (slaves migrate only if their masters remain with at least
-# one slave). To disable migration just set it to a very large value.
+# Default is 1 (replicas migrate only if their masters remain with at least
+# one replica). To disable migration just set it to a very large value.
 # A value of 0 can be set but is useful only for debugging and dangerous
 # in production.
 #
@@ -923,7 +922,7 @@ lua-time-limit 5000
 #
 # cluster-require-full-coverage yes
 
-# This option, when set to yes, prevents slaves from trying to failover its
+# This option, when set to yes, prevents replicas from trying to failover its
 # master during master failures. However the master can still perform a
 # manual failover, if forced to do so.
 #
@@ -931,7 +930,7 @@ lua-time-limit 5000
 # data center operations, where we want one side to never be promoted if not
 # in the case of a total DC failure.
 #
-# cluster-slave-no-failover no
+# cluster-replica-no-failover no
 
 # In order to setup your cluster make sure to read the documentation
 # available at http://redis.io web site.
@@ -1165,7 +1164,7 @@ activerehashing yes
 # The limit can be set differently for the three different classes of clients:
 #
 # normal -> normal clients including MONITOR clients
-# slave  -> slave clients
+# replica  -> replica clients
 # pubsub -> clients subscribed to at least one pubsub channel or pattern
 #
 # The syntax of every client-output-buffer-limit directive is the following:
@@ -1186,12 +1185,12 @@ activerehashing yes
 # asynchronous clients may create a scenario where data is requested faster
 # than it can read.
 #
-# Instead there is a default limit for pubsub and slave clients, since
-# subscribers and slaves receive data in a push fashion.
+# Instead there is a default limit for pubsub and replica clients, since
+# subscribers and replicas receive data in a push fashion.
 #
 # Both the hard or the soft limit can be disabled by setting them to zero.
 client-output-buffer-limit normal 0 0 0
-client-output-buffer-limit slave 256mb 64mb 60
+client-output-buffer-limit replica 256mb 64mb 60
 client-output-buffer-limit pubsub 32mb 8mb 60
 
 # Client query buffers accumulate new commands. They are limited to a fixed

runtest-moduleapi

@@ -0,0 +1,16 @@
+#!/bin/sh
+TCL_VERSIONS="8.5 8.6"
+TCLSH=""
+
+for VERSION in $TCL_VERSIONS; do
+	TCL=`which tclsh$VERSION 2>/dev/null` && TCLSH=$TCL
+done
+
+if [ -z $TCLSH ]
+then
+    echo "You need tcl 8.5 or newer in order to run the Redis test"
+    exit 1
+fi
+
+make -C tests/modules && \
+$TCLSH tests/test_helper.tcl --single unit/moduleapi/commandfilter "${@}"

sentinel.conf

@@ -73,11 +73,11 @@ dir /tmp
 # be elected by the majority of the known Sentinels in order to
 # start a failover, so no failover can be performed in minority.
 #
-# Slaves are auto-discovered, so you don't need to specify slaves in
+# Replicas are auto-discovered, so you don't need to specify replicas in
 # any way. Sentinel itself will rewrite this configuration file adding
-# the slaves using additional configuration options.
+# the replicas using additional configuration options.
 # Also note that the configuration file is rewritten when a
-# slave is promoted to master.
+# replica is promoted to master.
 #
 # Note: master name should not include special characters or spaces.
 # The valid charset is A-z 0-9 and the three characters ".-_".
@@ -85,11 +85,11 @@ sentinel monitor mymaster 127.0.0.1 6379 2
 
 # sentinel auth-pass <master-name> <password>
 #
-# Set the password to use to authenticate with the master and slaves.
+# Set the password to use to authenticate with the master and replicas.
 # Useful if there is a password set in the Redis instances to monitor.
 #
-# Note that the master password is also used for slaves, so it is not
-# possible to set a different password in masters and slaves instances
+# Note that the master password is also used for replicas, so it is not
+# possible to set a different password in masters and replicas instances
 # if you want to be able to monitor these instances with Sentinel.
 #
 # However you can have Redis instances without the authentication enabled
@@ -104,7 +104,7 @@ sentinel monitor mymaster 127.0.0.1 6379 2
 
 # sentinel down-after-milliseconds <master-name> <milliseconds>
 #
-# Number of milliseconds the master (or any attached slave or sentinel) should
+# Number of milliseconds the master (or any attached replica or sentinel) should
 # be unreachable (as in, not acceptable reply to PING, continuously, for the
 # specified period) in order to consider it in S_DOWN state (Subjectively
 # Down).
@@ -112,11 +112,11 @@ sentinel monitor mymaster 127.0.0.1 6379 2
 # Default is 30 seconds.
 sentinel down-after-milliseconds mymaster 30000
 
-# sentinel parallel-syncs <master-name> <numslaves>
+# sentinel parallel-syncs <master-name> <numreplicas>
 #
-# How many slaves we can reconfigure to point to the new slave simultaneously
-# during the failover. Use a low number if you use the slaves to serve query
-# to avoid that all the slaves will be unreachable at about the same
+# How many replicas we can reconfigure to point to the new replica simultaneously
+# during the failover. Use a low number if you use the replicas to serve query
+# to avoid that all the replicas will be unreachable at about the same
 # time while performing the synchronization with the master.
 sentinel parallel-syncs mymaster 1
 
@@ -128,18 +128,18 @@ sentinel parallel-syncs mymaster 1
 #   already tried against the same master by a given Sentinel, is two
 #   times the failover timeout.
 #
-# - The time needed for a slave replicating to a wrong master according
+# - The time needed for a replica replicating to a wrong master according
 #   to a Sentinel current configuration, to be forced to replicate
 #   with the right master, is exactly the failover timeout (counting since
 #   the moment a Sentinel detected the misconfiguration).
 #
 # - The time needed to cancel a failover that is already in progress but
 #   did not produced any configuration change (SLAVEOF NO ONE yet not
-#   acknowledged by the promoted slave).
+#   acknowledged by the promoted replica).
 #
-# - The maximum time a failover in progress waits for all the slaves to be
-#   reconfigured as slaves of the new master. However even after this time
-#   the slaves will be reconfigured by the Sentinels anyway, but not with
+# - The maximum time a failover in progress waits for all the replicas to be
+#   reconfigured as replicas of the new master. However even after this time
+#   the replicas will be reconfigured by the Sentinels anyway, but not with
 #   the exact parallel-syncs progression as specified.
 #
 # Default is 3 minutes.
@@ -200,7 +200,7 @@ sentinel failover-timeout mymaster 180000
 # <role> is either "leader" or "observer"
 # 
 # The arguments from-ip, from-port, to-ip, to-port are used to communicate
-# the old address of the master and the new address of the elected slave
+# the old address of the master and the new address of the elected replica
 # (now a master).
 #
 # This script should be resistant to multiple invocations.
@@ -228,12 +228,17 @@ sentinel deny-scripts-reconfig yes
 #
 # In such case it is possible to tell Sentinel to use different command names
 # instead of the normal ones. For example if the master "mymaster", and the
-# associated slaves, have "CONFIG" all renamed to "GUESSME", I could use:
+# associated replicas, have "CONFIG" all renamed to "GUESSME", I could use:
 #
-# sentinel rename-command mymaster CONFIG GUESSME
+# SENTINEL rename-command mymaster CONFIG GUESSME
 #
 # After such configuration is set, every time Sentinel would use CONFIG it will
 # use GUESSME instead. Note that there is no actual need to respect the command
 # case, so writing "config guessme" is the same in the example above.
 #
 # SENTINEL SET can also be used in order to perform this configuration at runtime.
+#
+# In order to set a command back to its original name (undo the renaming), it
+# is possible to just rename a command to itsef:
+#
+# SENTINEL rename-command mymaster CONFIG CONFIG

src/Makefile

@@ -21,6 +21,11 @@ NODEPS:=clean distclean
 
 # Default settings
 STD=-std=c99 -pedantic -DREDIS_STATIC=''
+ifneq (,$(findstring clang,$(CC)))
+ifneq (,$(findstring FreeBSD,$(uname_S)))
+  STD+=-Wno-c11-extensions
+endif
+endif
 WARN=-Wall -W -Wno-missing-field-initializers
 OPT=$(OPTIMIZATION)
 
@@ -41,6 +46,10 @@ endif
 # To get ARM stack traces if Redis crashes we need a special C flag.
 ifneq (,$(filter aarch64 armv,$(uname_M)))
         CFLAGS+=-funwind-tables
+else
+ifneq (,$(findstring armv,$(uname_M)))
+        CFLAGS+=-funwind-tables
+endif
 endif
 
 # Backwards compatibility for selecting an allocator
@@ -93,10 +102,20 @@ else
 ifeq ($(uname_S),OpenBSD)
 	# OpenBSD
 	FINAL_LIBS+= -lpthread
+	ifeq ($(USE_BACKTRACE),yes)
+	    FINAL_CFLAGS+= -DUSE_BACKTRACE -I/usr/local/include
+	    FINAL_LDFLAGS+= -L/usr/local/lib
+	    FINAL_LIBS+= -lexecinfo
+    	endif
+
 else
 ifeq ($(uname_S),FreeBSD)
 	# FreeBSD
-	FINAL_LIBS+= -lpthread
+	FINAL_LIBS+= -lpthread -lexecinfo
+else
+ifeq ($(uname_S),DragonFly)
+	# FreeBSD
+	FINAL_LIBS+= -lpthread -lexecinfo
 else
 	# All the other OSes (notably Linux)
 	FINAL_LDFLAGS+= -rdynamic
@@ -106,6 +125,7 @@ endif
 endif
 endif
 endif
+endif
 # Include paths to dependencies
 FINAL_CFLAGS+= -I../deps/hiredis -I../deps/linenoise -I../deps/lua/src
 
@@ -144,7 +164,7 @@ endif
 
 REDIS_SERVER_NAME=redis-server
 REDIS_SENTINEL_NAME=redis-sentinel
-REDIS_SERVER_OBJ=adlist.o quicklist.o ae.o anet.o dict.o server.o sds.o zmalloc.o lzf_c.o lzf_d.o pqsort.o zipmap.o sha1.o ziplist.o release.o networking.o util.o object.o db.o replication.o rdb.o t_string.o t_list.o t_set.o t_zset.o t_hash.o config.o aof.o pubsub.o multi.o debug.o sort.o intset.o syncio.o cluster.o crc16.o endianconv.o slowlog.o scripting.o bio.o rio.o rand.o memtest.o crc64.o bitops.o sentinel.o notify.o setproctitle.o blocked.o hyperloglog.o latency.o sparkline.o redis-check-rdb.o redis-check-aof.o geo.o lazyfree.o module.o evict.o expire.o geohash.o geohash_helper.o childinfo.o defrag.o siphash.o rax.o t_stream.o listpack.o localtime.o
+REDIS_SERVER_OBJ=adlist.o quicklist.o ae.o anet.o dict.o server.o sds.o zmalloc.o lzf_c.o lzf_d.o pqsort.o zipmap.o sha1.o ziplist.o release.o networking.o util.o object.o db.o replication.o rdb.o t_string.o t_list.o t_set.o t_zset.o t_hash.o config.o aof.o pubsub.o multi.o debug.o sort.o intset.o syncio.o cluster.o crc16.o endianconv.o slowlog.o scripting.o bio.o rio.o rand.o memtest.o crc64.o bitops.o sentinel.o notify.o setproctitle.o blocked.o hyperloglog.o latency.o sparkline.o redis-check-rdb.o redis-check-aof.o geo.o lazyfree.o module.o evict.o expire.o geohash.o geohash_helper.o childinfo.o defrag.o siphash.o rax.o t_stream.o listpack.o localtime.o lolwut.o lolwut5.o
 REDIS_CLI_NAME=redis-cli
 REDIS_CLI_OBJ=anet.o adlist.o dict.o redis-cli.o zmalloc.o release.o anet.o ae.o crc64.o siphash.o crc16.o
 REDIS_BENCHMARK_NAME=redis-benchmark
@@ -290,3 +310,6 @@ install: all
 	$(REDIS_INSTALL) $(REDIS_CHECK_RDB_NAME) $(INSTALL_BIN)
 	$(REDIS_INSTALL) $(REDIS_CHECK_AOF_NAME) $(INSTALL_BIN)
 	@ln -sf $(REDIS_SERVER_NAME) $(INSTALL_BIN)/$(REDIS_SENTINEL_NAME)
+
+uninstall:
+	rm -f $(INSTALL_BIN)/{$(REDIS_SERVER_NAME),$(REDIS_BENCHMARK_NAME),$(REDIS_CLI_NAME),$(REDIS_CHECK_RDB_NAME),$(REDIS_CHECK_AOF_NAME),$(REDIS_SENTINEL_NAME)}

src/aof.c

@@ -197,6 +197,12 @@ ssize_t aofRewriteBufferWrite(int fd) {
  * AOF file implementation
  * ------------------------------------------------------------------------- */
 
+/* Return true if an AOf fsync is currently already in progress in a
+ * BIO thread. */
+int aofFsyncInProgress(void) {
+    return bioPendingJobsOfType(BIO_AOF_FSYNC) != 0;
+}
+
 /* Starts a background task that performs fsync() against the specified
  * file descriptor (the one of the AOF file) in another thread. */
 void aof_background_fsync(int fd) {
@@ -333,10 +339,24 @@ void flushAppendOnlyFile(int force) {
     int sync_in_progress = 0;
     mstime_t latency;
 
-    if (sdslen(server.aof_buf) == 0) return;
+    if (sdslen(server.aof_buf) == 0) {
+        /* Check if we need to do fsync even the aof buffer is empty,
+         * because previously in AOF_FSYNC_EVERYSEC mode, fsync is
+         * called only when aof buffer is not empty, so if users
+         * stop write commands before fsync called in one second,
+         * the data in page cache cannot be flushed in time. */
+        if (server.aof_fsync == AOF_FSYNC_EVERYSEC &&
+            server.aof_fsync_offset != server.aof_current_size &&
+            server.unixtime > server.aof_last_fsync &&
+            !(sync_in_progress = aofFsyncInProgress())) {
+            goto try_fsync;
+        } else {
+            return;
+        }
+    }
 
     if (server.aof_fsync == AOF_FSYNC_EVERYSEC)
-        sync_in_progress = bioPendingJobsOfType(BIO_AOF_FSYNC) != 0;
+        sync_in_progress = aofFsyncInProgress();
 
     if (server.aof_fsync == AOF_FSYNC_EVERYSEC && !force) {
         /* With this append fsync policy we do background fsyncing.
@@ -468,6 +488,7 @@ void flushAppendOnlyFile(int force) {
         server.aof_buf = sdsempty();
     }
 
+try_fsync:
     /* Don't fsync if no-appendfsync-on-rewrite is set to yes and there are
      * children doing I/O in the background. */
     if (server.aof_no_fsync_on_rewrite &&
@@ -482,10 +503,14 @@ void flushAppendOnlyFile(int force) {
         redis_fsync(server.aof_fd); /* Let's try to get this data on the disk */
         latencyEndMonitor(latency);
         latencyAddSampleIfNeeded("aof-fsync-always",latency);
+        server.aof_fsync_offset = server.aof_current_size;
         server.aof_last_fsync = server.unixtime;
     } else if ((server.aof_fsync == AOF_FSYNC_EVERYSEC &&
                 server.unixtime > server.aof_last_fsync)) {
-        if (!sync_in_progress) aof_background_fsync(server.aof_fd);
+        if (!sync_in_progress) {
+            aof_background_fsync(server.aof_fd);
+            server.aof_fsync_offset = server.aof_current_size;
+        }
         server.aof_last_fsync = server.unixtime;
     }
 }
@@ -677,6 +702,7 @@ int loadAppendOnlyFile(char *filename) {
     int old_aof_state = server.aof_state;
     long loops = 0;
     off_t valid_up_to = 0; /* Offset of latest well-formed command loaded. */
+    off_t valid_before_multi = 0; /* Offset before MULTI command loaded. */
 
     if (fp == NULL) {
         serverLog(LL_WARNING,"Fatal error: can't open the append log file for reading: %s",strerror(errno));
@@ -689,6 +715,7 @@ int loadAppendOnlyFile(char *filename) {
      * operation is received. */
     if (fp && redis_fstat(fileno(fp),&sb) != -1 && sb.st_size == 0) {
         server.aof_current_size = 0;
+        server.aof_fsync_offset = server.aof_current_size;
         fclose(fp);
         return C_ERR;
     }
@@ -777,16 +804,28 @@ int loadAppendOnlyFile(char *filename) {
         /* Command lookup */
         cmd = lookupCommand(argv[0]->ptr);
         if (!cmd) {
-            serverLog(LL_WARNING,"Unknown command '%s' reading the append only file", (char*)argv[0]->ptr);
+            serverLog(LL_WARNING,
+                "Unknown command '%s' reading the append only file",
+                (char*)argv[0]->ptr);
             exit(1);
         }
 
+        if (cmd == server.multiCommand) valid_before_multi = valid_up_to;
+
         /* Run the command in the context of a fake client */
         fakeClient->cmd = cmd;
-        cmd->proc(fakeClient);
+        if (fakeClient->flags & CLIENT_MULTI &&
+            fakeClient->cmd->proc != execCommand)
+        {
+            queueMultiCommand(fakeClient);
+        } else {
+            cmd->proc(fakeClient);
+        }
 
         /* The fake client should not have a reply */
-        serverAssert(fakeClient->bufpos == 0 && listLength(fakeClient->reply) == 0);
+        serverAssert(fakeClient->bufpos == 0 &&
+                     listLength(fakeClient->reply) == 0);
+
         /* The fake client should never get blocked */
         serverAssert((fakeClient->flags & CLIENT_BLOCKED) == 0);
 
@@ -801,7 +840,12 @@ int loadAppendOnlyFile(char *filename) {
      * If the client is in the middle of a MULTI/EXEC, handle it as it was
      * a short read, even if technically the protocol is correct: we want
      * to remove the unprocessed tail and continue. */
-    if (fakeClient->flags & CLIENT_MULTI) goto uxeof;
+    if (fakeClient->flags & CLIENT_MULTI) {
+        serverLog(LL_WARNING,
+            "Revert incomplete MULTI/EXEC transaction in AOF file");
+        valid_up_to = valid_before_multi;
+        goto uxeof;
+    }
 
 loaded_ok: /* DB loaded, cleanup and return C_OK to the caller. */
     fclose(fp);
@@ -810,6 +854,7 @@ loaded_ok: /* DB loaded, cleanup and return C_OK to the caller. */
     stopLoading();
     aofUpdateCurrentSize();
     server.aof_rewrite_base_size = server.aof_current_size;
+    server.aof_fsync_offset = server.aof_current_size;
     return C_OK;
 
 readerr: /* Read error. If feof(fp) is true, fall through to unexpected EOF. */
@@ -1121,25 +1166,47 @@ int rewriteStreamObject(rio *r, robj *key, robj *o) {
     streamID id;
     int64_t numfields;
 
-    /* Reconstruct the stream data using XADD commands. */
-    while(streamIteratorGetID(&si,&id,&numfields)) {
-        /* Emit a two elements array for each item. The first is
-         * the ID, the second is an array of field-value pairs. */
+    if (s->length) {
+        /* Reconstruct the stream data using XADD commands. */
+        while(streamIteratorGetID(&si,&id,&numfields)) {
+            /* Emit a two elements array for each item. The first is
+             * the ID, the second is an array of field-value pairs. */
 
-        /* Emit the XADD <key> <id> ...fields... command. */
-        if (rioWriteBulkCount(r,'*',3+numfields*2) == 0) return 0;
+            /* Emit the XADD <key> <id> ...fields... command. */
+            if (rioWriteBulkCount(r,'*',3+numfields*2) == 0) return 0;
+            if (rioWriteBulkString(r,"XADD",4) == 0) return 0;
+            if (rioWriteBulkObject(r,key) == 0) return 0;
+            if (rioWriteBulkStreamID(r,&id) == 0) return 0;
+            while(numfields--) {
+                unsigned char *field, *value;
+                int64_t field_len, value_len;
+                streamIteratorGetField(&si,&field,&value,&field_len,&value_len);
+                if (rioWriteBulkString(r,(char*)field,field_len) == 0) return 0;
+                if (rioWriteBulkString(r,(char*)value,value_len) == 0) return 0;
+            }
+        }
+    } else {
+        /* Use the XADD MAXLEN 0 trick to generate an empty stream if
+         * the key we are serializing is an empty string, which is possible
+         * for the Stream type. */
+        if (rioWriteBulkCount(r,'*',7) == 0) return 0;
         if (rioWriteBulkString(r,"XADD",4) == 0) return 0;
         if (rioWriteBulkObject(r,key) == 0) return 0;
-        if (rioWriteBulkStreamID(r,&id) == 0) return 0;
-        while(numfields--) {
-            unsigned char *field, *value;
-            int64_t field_len, value_len;
-            streamIteratorGetField(&si,&field,&value,&field_len,&value_len);
-            if (rioWriteBulkString(r,(char*)field,field_len) == 0) return 0;
-            if (rioWriteBulkString(r,(char*)value,value_len) == 0) return 0;
-        }
+        if (rioWriteBulkString(r,"MAXLEN",6) == 0) return 0;
+        if (rioWriteBulkString(r,"0",1) == 0) return 0;
+        if (rioWriteBulkStreamID(r,&s->last_id) == 0) return 0;
+        if (rioWriteBulkString(r,"x",1) == 0) return 0;
+        if (rioWriteBulkString(r,"y",1) == 0) return 0;
     }
 
+    /* Append XSETID after XADD, make sure lastid is correct,
+     * in case of XDEL lastid. */
+    if (rioWriteBulkCount(r,'*',3) == 0) return 0;
+    if (rioWriteBulkString(r,"XSETID",6) == 0) return 0;
+    if (rioWriteBulkObject(r,key) == 0) return 0;
+    if (rioWriteBulkStreamID(r,&s->last_id) == 0) return 0;
+
+
     /* Create all the stream consumer groups. */
     if (s->cgroups) {
         raxIterator ri;
@@ -1195,7 +1262,7 @@ int rewriteModuleObject(rio *r, robj *key, robj *o) {
     RedisModuleIO io;
     moduleValue *mv = o->ptr;
     moduleType *mt = mv->type;
-    moduleInitIOContext(io,mt,r);
+    moduleInitIOContext(io,mt,r,key);
     mt->aof_rewrite(&io,key,mv->value);
     if (io.ctx) {
         moduleFreeContext(io.ctx);
@@ -1694,6 +1761,7 @@ void backgroundRewriteDoneHandler(int exitcode, int bysignal) {
             server.aof_selected_db = -1; /* Make sure SELECT is re-issued */
             aofUpdateCurrentSize();
             server.aof_rewrite_base_size = server.aof_current_size;
+            server.aof_current_size = server.aof_current_size;
 
             /* Clear regular AOF buffer since its contents was just written to
              * the new AOF from the background rewrite buffer. */

src/atomicvar.h

@@ -1,7 +1,7 @@
 /* This file implements atomic counters using __atomic or __sync macros if
  * available, otherwise synchronizing different threads using a mutex.
  *
- * The exported interaface is composed of three macros:
+ * The exported interface is composed of three macros:
  *
  * atomicIncr(var,count) -- Increment the atomic counter
  * atomicGetIncr(var,oldvalue_var,count) -- Get and increment the atomic counter

src/bio.c

@@ -17,7 +17,7 @@
  *
  * The design is trivial, we have a structure representing a job to perform
  * and a different thread and job queue for every job type.
- * Every thread wait for new jobs in its queue, and process every job
+ * Every thread waits for new jobs in its queue, and process every job
  * sequentially.
  *
  * Jobs of the same type are guaranteed to be processed from the least
@@ -204,14 +204,14 @@ void *bioProcessBackgroundJobs(void *arg) {
         }
         zfree(job);
 
-        /* Unblock threads blocked on bioWaitStepOfType() if any. */
-        pthread_cond_broadcast(&bio_step_cond[type]);
-
         /* Lock again before reiterating the loop, if there are no longer
          * jobs to process we'll block again in pthread_cond_wait(). */
         pthread_mutex_lock(&bio_mutex[type]);
         listDelNode(bio_jobs[type],ln);
         bio_pending[type]--;
+
+        /* Unblock threads blocked on bioWaitStepOfType() if any. */
+        pthread_cond_broadcast(&bio_step_cond[type]);
     }
 }
 

src/bitops.c

@@ -994,12 +994,18 @@ void bitfieldCommand(client *c) {
         /* Lookup for read is ok if key doesn't exit, but errors
          * if it's not a string. */
         o = lookupKeyRead(c->db,c->argv[1]);
-        if (o != NULL && checkType(c,o,OBJ_STRING)) return;
+        if (o != NULL && checkType(c,o,OBJ_STRING)) {
+            zfree(ops);
+            return;
+        }
     } else {
         /* Lookup by making room up to the farest bit reached by
          * this operation. */
         if ((o = lookupStringForBitCommand(c,
-            highest_write_offset)) == NULL) return;
+            highest_write_offset)) == NULL) {
+            zfree(ops);
+            return;
+        }
     }
 
     addReplyMultiBulkLen(c,numops);

src/blocked.c

@@ -126,12 +126,37 @@ void processUnblockedClients(void) {
          * the code is conceptually more correct this way. */
         if (!(c->flags & CLIENT_BLOCKED)) {
             if (c->querybuf && sdslen(c->querybuf) > 0) {
-                processInputBuffer(c);
+                processInputBufferAndReplicate(c);
             }
         }
     }
 }
 
+/* This function will schedule the client for reprocessing at a safe time.
+ *
+ * This is useful when a client was blocked for some reason (blocking opeation,
+ * CLIENT PAUSE, or whatever), because it may end with some accumulated query
+ * buffer that needs to be processed ASAP:
+ *
+ * 1. When a client is blocked, its readable handler is still active.
+ * 2. However in this case it only gets data into the query buffer, but the
+ *    query is not parsed or executed once there is enough to proceed as
+ *    usually (because the client is blocked... so we can't execute commands).
+ * 3. When the client is unblocked, without this function, the client would
+ *    have to write some query in order for the readable handler to finally
+ *    call processQueryBuffer*() on it.
+ * 4. With this function instead we can put the client in a queue that will
+ *    process it for queries ready to be executed at a safe time.
+ */
+void queueClientForReprocessing(client *c) {
+    /* The client may already be into the unblocked list because of a previous
+     * blocking operation, don't add back it into the list multiple times. */
+    if (!(c->flags & CLIENT_UNBLOCKED)) {
+        c->flags |= CLIENT_UNBLOCKED;
+        listAddNodeTail(server.unblocked_clients,c);
+    }
+}
+
 /* Unblock a client calling the right function depending on the kind
  * of operation the client is blocking for. */
 void unblockClient(client *c) {
@@ -152,12 +177,7 @@ void unblockClient(client *c) {
     server.blocked_clients_by_type[c->btype]--;
     c->flags &= ~CLIENT_BLOCKED;
     c->btype = BLOCKED_NONE;
-    /* The client may already be into the unblocked list because of a previous
-     * blocking operation, don't add back it into the list multiple times. */
-    if (!(c->flags & CLIENT_UNBLOCKED)) {
-        c->flags |= CLIENT_UNBLOCKED;
-        listAddNodeTail(server.unblocked_clients,c);
-    }
+    queueClientForReprocessing(c);
 }
 
 /* This function gets called when a blocked client timed out in order to
@@ -195,7 +215,7 @@ void disconnectAllBlockedClients(void) {
         if (c->flags & CLIENT_BLOCKED) {
             addReplySds(c,sdsnew(
                 "-UNBLOCKED force unblock from blocking operation, "
-                "instance state changed (master -> slave?)\r\n"));
+                "instance state changed (master -> replica?)\r\n"));
             unblockClient(c);
             c->flags |= CLIENT_CLOSE_AFTER_REPLY;
         }

src/cluster.c

@@ -1230,7 +1230,7 @@ void clearNodeFailureIfNeeded(clusterNode *node) {
         serverLog(LL_NOTICE,
             "Clear FAIL state for node %.40s: %s is reachable again.",
                 node->name,
-                nodeIsSlave(node) ? "slave" : "master without slots");
+                nodeIsSlave(node) ? "replica" : "master without slots");
         node->flags &= ~CLUSTER_NODE_FAIL;
         clusterDoBeforeSleep(CLUSTER_TODO_UPDATE_STATE|CLUSTER_TODO_SAVE_CONFIG);
     }
@@ -1589,6 +1589,12 @@ void clusterUpdateSlotsConfigWith(clusterNode *sender, uint64_t senderConfigEpoc
         }
     }
 
+    /* After updating the slots configuration, don't do any actual change
+     * in the state of the server if a module disabled Redis Cluster
+     * keys redirections. */
+    if (server.cluster_module_flags & CLUSTER_MODULE_FLAG_NO_REDIRECTION)
+        return;
+
     /* If at least one slot was reassigned from a node to another node
      * with a greater configEpoch, it is possible that:
      * 1) We are a master left without slots. This means that we were
@@ -2059,7 +2065,7 @@ int clusterProcessPacket(clusterLink *link) {
         server.cluster->mf_end = mstime() + CLUSTER_MF_TIMEOUT;
         server.cluster->mf_slave = sender;
         pauseClients(mstime()+(CLUSTER_MF_TIMEOUT*2));
-        serverLog(LL_WARNING,"Manual failover requested by slave %.40s.",
+        serverLog(LL_WARNING,"Manual failover requested by replica %.40s.",
             sender->name);
     } else if (type == CLUSTERMSG_TYPE_UPDATE) {
         clusterNode *n; /* The node the update is about. */
@@ -2873,7 +2879,7 @@ void clusterLogCantFailover(int reason) {
     switch(reason) {
     case CLUSTER_CANT_FAILOVER_DATA_AGE:
         msg = "Disconnected from master for longer than allowed. "
-              "Please check the 'cluster-slave-validity-factor' configuration "
+              "Please check the 'cluster-replica-validity-factor' configuration "
               "option.";
         break;
     case CLUSTER_CANT_FAILOVER_WAITING_DELAY:
@@ -3025,6 +3031,7 @@ void clusterHandleSlaveFailover(void) {
         if (server.cluster->mf_end) {
             server.cluster->failover_auth_time = mstime();
             server.cluster->failover_auth_rank = 0;
+	    clusterDoBeforeSleep(CLUSTER_TODO_HANDLE_FAILOVER);
         }
         serverLog(LL_WARNING,
             "Start of election delayed for %lld milliseconds "
@@ -3054,7 +3061,7 @@ void clusterHandleSlaveFailover(void) {
             server.cluster->failover_auth_time += added_delay;
             server.cluster->failover_auth_rank = newrank;
             serverLog(LL_WARNING,
-                "Slave rank updated to #%d, added %lld milliseconds of delay.",
+                "Replica rank updated to #%d, added %lld milliseconds of delay.",
                 newrank, added_delay);
         }
     }
@@ -3210,7 +3217,8 @@ void clusterHandleSlaveMigration(int max_slaves) {
      * the natural slaves of this instance to advertise their switch from
      * the old master to the new one. */
     if (target && candidate == myself &&
-        (mstime()-target->orphaned_time) > CLUSTER_SLAVE_MIGRATION_DELAY)
+        (mstime()-target->orphaned_time) > CLUSTER_SLAVE_MIGRATION_DELAY &&
+       !(server.cluster_module_flags & CLUSTER_MODULE_FLAG_NO_FAILOVER))
     {
         serverLog(LL_WARNING,"Migrating to orphaned master %.40s",
             target->name);
@@ -3563,7 +3571,8 @@ void clusterCron(void) {
 
     if (nodeIsSlave(myself)) {
         clusterHandleManualFailover();
-        clusterHandleSlaveFailover();
+        if (!(server.cluster_module_flags & CLUSTER_MODULE_FLAG_NO_FAILOVER))
+            clusterHandleSlaveFailover();
         /* If there are orphaned slaves, and we are a slave among the masters
          * with the max number of non-failing slaves, consider migrating to
          * the orphaned masters. Note that it does not make sense to try
@@ -3869,6 +3878,11 @@ int verifyClusterConfigWithData(void) {
     int j;
     int update_config = 0;
 
+    /* Return ASAP if a module disabled cluster redirections. In that case
+     * every master can store keys about every possible hash slot. */
+    if (server.cluster_module_flags & CLUSTER_MODULE_FLAG_NO_REDIRECTION)
+        return C_OK;
+
     /* If this node is a slave, don't perform the check at all as we
      * completely depend on the replication stream. */
     if (nodeIsSlave(myself)) return C_OK;
@@ -4187,7 +4201,7 @@ void clusterCommand(client *c) {
 "COUNT-failure-reports <node-id> -- Return number of failure reports for <node-id>.",
 "COUNTKEYSINSLOT <slot> - Return the number of keys in <slot>.",
 "DELSLOTS <slot> [slot ...] -- Delete slots information from current node.",
-"FAILOVER [force|takeover] -- Promote current slave node to being a master.",
+"FAILOVER [force|takeover] -- Promote current replica node to being a master.",
 "FORGET <node-id> -- Remove a node from the cluster.",
 "GETKEYSINSLOT <slot> <count> -- Return key names stored by current node in a slot.",
 "FLUSHSLOTS -- Delete current node own slots information.",
@@ -4197,11 +4211,11 @@ void clusterCommand(client *c) {
 "MYID -- Return the node id.",
 "NODES -- Return cluster configuration seen by node. Output format:",
 "    <id> <ip:port> <flags> <master> <pings> <pongs> <epoch> <link> <slot> ... <slot>",
-"REPLICATE <node-id> -- Configure current node as slave to <node-id>.",
+"REPLICATE <node-id> -- Configure current node as replica to <node-id>.",
 "RESET [hard|soft] -- Reset current node (default: soft).",
 "SET-config-epoch <epoch> - Set config epoch of current node.",
 "SETSLOT <slot> (importing|migrating|stable|node <node-id>) -- Set slot state.",
-"SLAVES <node-id> -- Return <node-id> slaves.",
+"REPLICAS <node-id> -- Return <node-id> replicas.",
 "SLOTS -- Return information about slots range mappings. Each range is made of:",
 "    start, end, master and replicas IP addresses, ports and ids",
 NULL
@@ -4578,7 +4592,7 @@ NULL
 
         /* Can't replicate a slave. */
         if (nodeIsSlave(n)) {
-            addReplyError(c,"I can only replicate a master, not a slave.");
+            addReplyError(c,"I can only replicate a master, not a replica.");
             return;
         }
 
@@ -4597,7 +4611,8 @@ NULL
         clusterSetMaster(n);
         clusterDoBeforeSleep(CLUSTER_TODO_UPDATE_STATE|CLUSTER_TODO_SAVE_CONFIG);
         addReply(c,shared.ok);
-    } else if (!strcasecmp(c->argv[1]->ptr,"slaves") && c->argc == 3) {
+    } else if ((!strcasecmp(c->argv[1]->ptr,"slaves") ||
+                !strcasecmp(c->argv[1]->ptr,"replicas")) && c->argc == 3) {
         /* CLUSTER SLAVES <NODE ID> */
         clusterNode *n = clusterLookupNode(c->argv[2]->ptr);
         int j;
@@ -4651,10 +4666,10 @@ NULL
 
         /* Check preconditions. */
         if (nodeIsMaster(myself)) {
-            addReplyError(c,"You should send CLUSTER FAILOVER to a slave");
+            addReplyError(c,"You should send CLUSTER FAILOVER to a replica");
             return;
         } else if (myself->slaveof == NULL) {
-            addReplyError(c,"I'm a slave but my master is unknown to me");
+            addReplyError(c,"I'm a replica but my master is unknown to me");
             return;
         } else if (!force &&
                    (nodeFailed(myself->slaveof) ||
@@ -4761,7 +4776,7 @@ NULL
 
 /* Generates a DUMP-format representation of the object 'o', adding it to the
  * io stream pointed by 'rio'. This function can't fail. */
-void createDumpPayload(rio *payload, robj *o) {
+void createDumpPayload(rio *payload, robj *o, robj *key) {
     unsigned char buf[2];
     uint64_t crc;
 
@@ -4769,7 +4784,7 @@ void createDumpPayload(rio *payload, robj *o) {
      * byte followed by the serialized object. This is understood by RESTORE. */
     rioInitWithBuffer(payload,sdsempty());
     serverAssert(rdbSaveObjectType(payload,o));
-    serverAssert(rdbSaveObject(payload,o));
+    serverAssert(rdbSaveObject(payload,o,key));
 
     /* Write the footer, this is how it looks like:
      * ----------------+---------------------+---------------+
@@ -4827,7 +4842,7 @@ void dumpCommand(client *c) {
     }
 
     /* Create the DUMP encoded representation. */
-    createDumpPayload(&payload,o);
+    createDumpPayload(&payload,o,c->argv[1]);
 
     /* Transfer to the client */
     dumpobj = createObject(OBJ_STRING,payload.io.buffer.ptr);
@@ -4900,7 +4915,7 @@ void restoreCommand(client *c) {
 
     rioInitWithBuffer(&payload,c->argv[3]->ptr);
     if (((type = rdbLoadObjectType(&payload)) == -1) ||
-        ((obj = rdbLoadObject(type,&payload)) == NULL))
+        ((obj = rdbLoadObject(type,&payload,c->argv[1])) == NULL))
     {
         addReplyError(c,"Bad data format");
         return;
@@ -5150,10 +5165,10 @@ try_again:
         serverAssertWithInfo(c,NULL,rioWriteBulkLongLong(&cmd,dbid));
     }
 
-    int expired = 0; /* Number of keys that we'll find already expired.
-                        Note that serializing large keys may take some time
-                        so certain keys that were found non expired by the
-                        lookupKey() function, may be expired later. */
+    int non_expired = 0; /* Number of keys that we'll find non expired.
+                            Note that serializing large keys may take some time
+                            so certain keys that were found non expired by the
+                            lookupKey() function, may be expired later. */
 
     /* Create RESTORE payload and generate the protocol to call the command. */
     for (j = 0; j < num_keys; j++) {
@@ -5163,11 +5178,16 @@ try_again:
         if (expireat != -1) {
             ttl = expireat-mstime();
             if (ttl < 0) {
-                expired++;
                 continue;
             }
             if (ttl < 1) ttl = 1;
         }
+
+        /* Relocate valid (non expired) keys into the array in successive
+         * positions to remove holes created by the keys that were present
+         * in the first lookup but are now expired after the second lookup. */
+        kv[non_expired++] = kv[j];
+
         serverAssertWithInfo(c,NULL,
             rioWriteBulkCount(&cmd,'*',replace ? 5 : 4));
 
@@ -5183,7 +5203,7 @@ try_again:
 
         /* Emit the payload argument, that is the serialized object using
          * the DUMP format. */
-        createDumpPayload(&payload,ov[j]);
+        createDumpPayload(&payload,ov[j],kv[j]);
         serverAssertWithInfo(c,NULL,
             rioWriteBulkString(&cmd,payload.io.buffer.ptr,
                                sdslen(payload.io.buffer.ptr)));
@@ -5195,6 +5215,9 @@ try_again:
             serverAssertWithInfo(c,NULL,rioWriteBulkString(&cmd,"REPLACE",7));
     }
 
+    /* Fix the actual number of keys we are migrating. */
+    num_keys = non_expired;
+
     /* Transfer the query to the other node in 64K chunks. */
     errno = 0;
     {
@@ -5236,7 +5259,7 @@ try_again:
      * command name itself. */
     if (!copy) newargv = zmalloc(sizeof(robj*)*(num_keys+1));
 
-    for (j = 0; j < num_keys-expired; j++) {
+    for (j = 0; j < num_keys; j++) {
         if (syncReadLine(cs->fd, buf2, sizeof(buf2), timeout) <= 0) {
             socket_error = 1;
             break;
@@ -5434,9 +5457,17 @@ clusterNode *getNodeByQuery(client *c, struct redisCommand *cmd, robj **argv, in
     multiCmd mc;
     int i, slot = 0, migrating_slot = 0, importing_slot = 0, missing_keys = 0;
 
+    /* Allow any key to be set if a module disabled cluster redirections. */
+    if (server.cluster_module_flags & CLUSTER_MODULE_FLAG_NO_REDIRECTION)
+        return myself;
+
     /* Set error code optimistically for the base case. */
     if (error_code) *error_code = CLUSTER_REDIR_NONE;
 
+    /* Modules can turn off Redis Cluster redirection: this is useful
+     * when writing a module that implements a completely different
+     * distributed system. */
+
     /* We handle all the cases as if they were EXEC commands, so we have
      * a common code path for everything */
     if (cmd->proc == execCommand) {

src/cluster.h

@@ -100,6 +100,13 @@ typedef struct clusterLink {
 #define CLUSTERMSG_TYPE_MODULE 9        /* Module cluster API message. */
 #define CLUSTERMSG_TYPE_COUNT 10        /* Total number of message types. */
 
+/* Flags that a module can set in order to prevent certain Redis Cluster
+ * features to be enabled. Useful when implementing a different distributed
+ * system on top of Redis Cluster message bus, using modules. */
+#define CLUSTER_MODULE_FLAG_NONE 0
+#define CLUSTER_MODULE_FLAG_NO_FAILOVER (1<<1)
+#define CLUSTER_MODULE_FLAG_NO_REDIRECTION (1<<2)
+
 /* This structure represent elements of node->fail_reports. */
 typedef struct clusterNodeFailReport {
     struct clusterNode *node;  /* Node reporting the failure condition. */

src/config.c

@@ -120,7 +120,7 @@ const char *configEnumGetName(configEnum *ce, int val) {
     return NULL;
 }
 
-/* Wrapper for configEnumGetName() returning "unknown" insetad of NULL if
+/* Wrapper for configEnumGetName() returning "unknown" instead of NULL if
  * there is no match. */
 const char *configEnumGetNameOrUnknown(configEnum *ce, int val) {
     const char *name = configEnumGetName(ce,val);
@@ -344,15 +344,19 @@ void loadServerConfigFromString(char *config) {
                 err = "lfu-decay-time must be 0 or greater";
                 goto loaderr;
             }
-        } else if (!strcasecmp(argv[0],"slaveof") && argc == 3) {
+        } else if ((!strcasecmp(argv[0],"slaveof") ||
+                    !strcasecmp(argv[0],"replicaof")) && argc == 3) {
             slaveof_linenum = linenum;
             server.masterhost = sdsnew(argv[1]);
             server.masterport = atoi(argv[2]);
             server.repl_state = REPL_STATE_CONNECT;
-        } else if (!strcasecmp(argv[0],"repl-ping-slave-period") && argc == 2) {
+        } else if ((!strcasecmp(argv[0],"repl-ping-slave-period") ||
+                    !strcasecmp(argv[0],"repl-ping-replica-period")) &&
+                    argc == 2)
+        {
             server.repl_ping_slave_period = atoi(argv[1]);
             if (server.repl_ping_slave_period <= 0) {
-                err = "repl-ping-slave-period must be 1 or greater";
+                err = "repl-ping-replica-period must be 1 or greater";
                 goto loaderr;
             }
         } else if (!strcasecmp(argv[0],"repl-timeout") && argc == 2) {
@@ -391,15 +395,24 @@ void loadServerConfigFromString(char *config) {
         } else if (!strcasecmp(argv[0],"masterauth") && argc == 2) {
             zfree(server.masterauth);
             server.masterauth = argv[1][0] ? zstrdup(argv[1]) : NULL;
-        } else if (!strcasecmp(argv[0],"slave-serve-stale-data") && argc == 2) {
+        } else if ((!strcasecmp(argv[0],"slave-serve-stale-data") ||
+                    !strcasecmp(argv[0],"replica-serve-stale-data"))
+                    && argc == 2)
+        {
             if ((server.repl_serve_stale_data = yesnotoi(argv[1])) == -1) {
                 err = "argument must be 'yes' or 'no'"; goto loaderr;
             }
-        } else if (!strcasecmp(argv[0],"slave-read-only") && argc == 2) {
+        } else if ((!strcasecmp(argv[0],"slave-read-only") ||
+                    !strcasecmp(argv[0],"replica-read-only"))
+                    && argc == 2)
+        {
             if ((server.repl_slave_ro = yesnotoi(argv[1])) == -1) {
                 err = "argument must be 'yes' or 'no'"; goto loaderr;
             }
-        } else if (!strcasecmp(argv[0],"slave-ignore-maxmemory") && argc == 2) {
+        } else if ((!strcasecmp(argv[0],"slave-ignore-maxmemory") ||
+                    !strcasecmp(argv[0],"replica-ignore-maxmemory"))
+                    && argc == 2)
+        {
             if ((server.repl_slave_ignore_maxmemory = yesnotoi(argv[1])) == -1) {
                 err = "argument must be 'yes' or 'no'"; goto loaderr;
             }
@@ -427,7 +440,9 @@ void loadServerConfigFromString(char *config) {
             if ((server.lazyfree_lazy_server_del = yesnotoi(argv[1])) == -1) {
                 err = "argument must be 'yes' or 'no'"; goto loaderr;
             }
-        } else if (!strcasecmp(argv[0],"slave-lazy-flush") && argc == 2) {
+        } else if ((!strcasecmp(argv[0],"slave-lazy-flush") ||
+                    !strcasecmp(argv[0],"replica-lazy-flush")) && argc == 2)
+        {
             if ((server.repl_slave_lazy_flush = yesnotoi(argv[1])) == -1) {
                 err = "argument must be 'yes' or 'no'"; goto loaderr;
             }
@@ -659,15 +674,17 @@ void loadServerConfigFromString(char *config) {
                 err = "cluster migration barrier must zero or positive";
                 goto loaderr;
             }
-        } else if (!strcasecmp(argv[0],"cluster-slave-validity-factor")
+        } else if ((!strcasecmp(argv[0],"cluster-slave-validity-factor") ||
+                    !strcasecmp(argv[0],"cluster-replica-validity-factor"))
                    && argc == 2)
         {
             server.cluster_slave_validity_factor = atoi(argv[1]);
             if (server.cluster_slave_validity_factor < 0) {
-                err = "cluster slave validity factor must be zero or positive";
+                err = "cluster replica validity factor must be zero or positive";
                 goto loaderr;
             }
-        } else if (!strcasecmp(argv[0],"cluster-slave-no-failover") &&
+        } else if ((!strcasecmp(argv[0],"cluster-slave-no-failover") ||
+                    !strcasecmp(argv[0],"cluster-replica-no-failover")) &&
                    argc == 2)
         {
             server.cluster_slave_no_failover = yesnotoi(argv[1]);
@@ -677,6 +694,8 @@ void loadServerConfigFromString(char *config) {
             }
         } else if (!strcasecmp(argv[0],"lua-time-limit") && argc == 2) {
             server.lua_time_limit = strtoll(argv[1],NULL,10);
+        } else if (!strcasecmp(argv[0],"lua-replicate-commands") && argc == 2) {
+            server.lua_always_replicate_commands = yesnotoi(argv[1]);
         } else if (!strcasecmp(argv[0],"slowlog-log-slower-than") &&
                    argc == 2)
         {
@@ -718,27 +737,37 @@ void loadServerConfigFromString(char *config) {
             if ((server.stop_writes_on_bgsave_err = yesnotoi(argv[1])) == -1) {
                 err = "argument must be 'yes' or 'no'"; goto loaderr;
             }
-        } else if (!strcasecmp(argv[0],"slave-priority") && argc == 2) {
+        } else if ((!strcasecmp(argv[0],"slave-priority") ||
+                    !strcasecmp(argv[0],"replica-priority")) && argc == 2)
+        {
             server.slave_priority = atoi(argv[1]);
-        } else if (!strcasecmp(argv[0],"slave-announce-ip") && argc == 2) {
+        } else if ((!strcasecmp(argv[0],"slave-announce-ip") ||
+                    !strcasecmp(argv[0],"replica-announce-ip")) && argc == 2)
+        {
             zfree(server.slave_announce_ip);
             server.slave_announce_ip = zstrdup(argv[1]);
-        } else if (!strcasecmp(argv[0],"slave-announce-port") && argc == 2) {
+        } else if ((!strcasecmp(argv[0],"slave-announce-port") ||
+                    !strcasecmp(argv[0],"replica-announce-port")) && argc == 2)
+        {
             server.slave_announce_port = atoi(argv[1]);
             if (server.slave_announce_port < 0 ||
                 server.slave_announce_port > 65535)
             {
                 err = "Invalid port"; goto loaderr;
             }
-        } else if (!strcasecmp(argv[0],"min-slaves-to-write") && argc == 2) {
+        } else if ((!strcasecmp(argv[0],"min-slaves-to-write") ||
+                    !strcasecmp(argv[0],"min-replicas-to-write")) && argc == 2)
+        {
             server.repl_min_slaves_to_write = atoi(argv[1]);
             if (server.repl_min_slaves_to_write < 0) {
-                err = "Invalid value for min-slaves-to-write."; goto loaderr;
+                err = "Invalid value for min-replicas-to-write."; goto loaderr;
             }
-        } else if (!strcasecmp(argv[0],"min-slaves-max-lag") && argc == 2) {
+        } else if ((!strcasecmp(argv[0],"min-slaves-max-lag") ||
+                    !strcasecmp(argv[0],"min-replicas-max-lag")) && argc == 2)
+        {
             server.repl_min_slaves_max_lag = atoi(argv[1]);
             if (server.repl_min_slaves_max_lag < 0) {
-                err = "Invalid value for min-slaves-max-lag."; goto loaderr;
+                err = "Invalid value for min-replicas-max-lag."; goto loaderr;
             }
         } else if (!strcasecmp(argv[0],"notify-keyspace-events") && argc == 2) {
             int flags = keyspaceEventsStringToFlags(argv[1]);
@@ -780,7 +809,7 @@ void loadServerConfigFromString(char *config) {
     if (server.cluster_enabled && server.masterhost) {
         linenum = slaveof_linenum;
         i = linenum-1;
-        err = "slaveof directive not allowed in cluster mode";
+        err = "replicaof directive not allowed in cluster mode";
         goto loaderr;
     }
 
@@ -864,6 +893,10 @@ void loadServerConfig(char *filename, char *options) {
 #define config_set_special_field(_name) \
     } else if (!strcasecmp(c->argv[2]->ptr,_name)) {
 
+#define config_set_special_field_with_alias(_name1,_name2) \
+    } else if (!strcasecmp(c->argv[2]->ptr,_name1) || \
+               !strcasecmp(c->argv[2]->ptr,_name2)) {
+
 #define config_set_else } else
 
 void configSetCommand(client *c) {
@@ -1009,8 +1042,8 @@ void configSetCommand(client *c) {
             int soft_seconds;
 
             class = getClientTypeByName(v[j]);
-            hard = strtoll(v[j+1],NULL,10);
-            soft = strtoll(v[j+2],NULL,10);
+            hard = memtoll(v[j+1],NULL);
+            soft = memtoll(v[j+2],NULL);
             soft_seconds = strtoll(v[j+3],NULL,10);
 
             server.client_obuf_limits[class].hard_limit_bytes = hard;
@@ -1023,7 +1056,9 @@ void configSetCommand(client *c) {
 
         if (flags == -1) goto badfmt;
         server.notify_keyspace_events = flags;
-    } config_set_special_field("slave-announce-ip") {
+    } config_set_special_field_with_alias("slave-announce-ip",
+                                          "replica-announce-ip")
+    {
         zfree(server.slave_announce_ip);
         server.slave_announce_ip = ((char*)o->ptr)[0] ? zstrdup(o->ptr) : NULL;
 
@@ -1039,6 +1074,8 @@ void configSetCommand(client *c) {
       "cluster-require-full-coverage",server.cluster_require_full_coverage) {
     } config_set_bool_field(
       "cluster-slave-no-failover",server.cluster_slave_no_failover) {
+    } config_set_bool_field(
+      "cluster-replica-no-failover",server.cluster_slave_no_failover) {
     } config_set_bool_field(
       "aof-rewrite-incremental-fsync",server.aof_rewrite_incremental_fsync) {
     } config_set_bool_field(
@@ -1049,10 +1086,16 @@ void configSetCommand(client *c) {
       "aof-use-rdb-preamble",server.aof_use_rdb_preamble) {
     } config_set_bool_field(
       "slave-serve-stale-data",server.repl_serve_stale_data) {
+    } config_set_bool_field(
+      "replica-serve-stale-data",server.repl_serve_stale_data) {
     } config_set_bool_field(
       "slave-read-only",server.repl_slave_ro) {
+    } config_set_bool_field(
+      "replica-read-only",server.repl_slave_ro) {
     } config_set_bool_field(
       "slave-ignore-maxmemory",server.repl_slave_ignore_maxmemory) {
+    } config_set_bool_field(
+      "replica-ignore-maxmemory",server.repl_slave_ignore_maxmemory) {
     } config_set_bool_field(
       "activerehashing",server.activerehashing) {
     } config_set_bool_field(
@@ -1080,6 +1123,8 @@ void configSetCommand(client *c) {
       "lazyfree-lazy-server-del",server.lazyfree_lazy_server_del) {
     } config_set_bool_field(
       "slave-lazy-flush",server.repl_slave_lazy_flush) {
+    } config_set_bool_field(
+      "replica-lazy-flush",server.repl_slave_lazy_flush) {
     } config_set_bool_field(
       "no-appendfsync-on-rewrite",server.aof_no_fsync_on_rewrite) {
     } config_set_bool_field(
@@ -1143,6 +1188,8 @@ void configSetCommand(client *c) {
       "latency-monitor-threshold",server.latency_monitor_threshold,0,LLONG_MAX){
     } config_set_numerical_field(
       "repl-ping-slave-period",server.repl_ping_slave_period,1,INT_MAX) {
+    } config_set_numerical_field(
+      "repl-ping-replica-period",server.repl_ping_slave_period,1,INT_MAX) {
     } config_set_numerical_field(
       "repl-timeout",server.repl_timeout,1,INT_MAX) {
     } config_set_numerical_field(
@@ -1151,14 +1198,24 @@ void configSetCommand(client *c) {
       "repl-diskless-sync-delay",server.repl_diskless_sync_delay,0,INT_MAX) {
     } config_set_numerical_field(
       "slave-priority",server.slave_priority,0,INT_MAX) {
+    } config_set_numerical_field(
+      "replica-priority",server.slave_priority,0,INT_MAX) {
     } config_set_numerical_field(
       "slave-announce-port",server.slave_announce_port,0,65535) {
+    } config_set_numerical_field(
+      "replica-announce-port",server.slave_announce_port,0,65535) {
     } config_set_numerical_field(
       "min-slaves-to-write",server.repl_min_slaves_to_write,0,INT_MAX) {
         refreshGoodSlavesCount();
+    } config_set_numerical_field(
+      "min-replicas-to-write",server.repl_min_slaves_to_write,0,INT_MAX) {
+        refreshGoodSlavesCount();
     } config_set_numerical_field(
       "min-slaves-max-lag",server.repl_min_slaves_max_lag,0,INT_MAX) {
         refreshGoodSlavesCount();
+    } config_set_numerical_field(
+      "min-replicas-max-lag",server.repl_min_slaves_max_lag,0,INT_MAX) {
+        refreshGoodSlavesCount();
     } config_set_numerical_field(
       "cluster-node-timeout",server.cluster_node_timeout,0,LLONG_MAX) {
     } config_set_numerical_field(
@@ -1169,6 +1226,8 @@ void configSetCommand(client *c) {
       "cluster-migration-barrier",server.cluster_migration_barrier,0,INT_MAX){
     } config_set_numerical_field(
       "cluster-slave-validity-factor",server.cluster_slave_validity_factor,0,INT_MAX) {
+    } config_set_numerical_field(
+      "cluster-replica-validity-factor",server.cluster_slave_validity_factor,0,INT_MAX) {
     } config_set_numerical_field(
       "hz",server.config_hz,0,INT_MAX) {
         /* Hz is more an hint from the user, so we accept values out of range
@@ -1189,7 +1248,7 @@ void configSetCommand(client *c) {
             if (server.maxmemory < zmalloc_used_memory()) {
                 serverLog(LL_WARNING,"WARNING: the new maxmemory value set via CONFIG SET is smaller than the current memory usage. This will result in key eviction and/or the inability to accept new write commands depending on the maxmemory-policy.");
             }
-            freeMemoryIfNeeded();
+            freeMemoryIfNeededAndSafe();
         }
     } config_set_memory_field(
       "proto-max-bulk-len",server.proto_max_bulk_len) {
@@ -1280,6 +1339,7 @@ void configGetCommand(client *c) {
     config_get_string_field("logfile",server.logfile);
     config_get_string_field("pidfile",server.pidfile);
     config_get_string_field("slave-announce-ip",server.slave_announce_ip);
+    config_get_string_field("replica-announce-ip",server.slave_announce_ip);
 
     /* Numerical values */
     config_get_numerical_field("maxmemory",server.maxmemory);
@@ -1332,19 +1392,25 @@ void configGetCommand(client *c) {
     config_get_numerical_field("tcp-backlog",server.tcp_backlog);
     config_get_numerical_field("databases",server.dbnum);
     config_get_numerical_field("repl-ping-slave-period",server.repl_ping_slave_period);
+    config_get_numerical_field("repl-ping-replica-period",server.repl_ping_slave_period);
     config_get_numerical_field("repl-timeout",server.repl_timeout);
     config_get_numerical_field("repl-backlog-size",server.repl_backlog_size);
     config_get_numerical_field("repl-backlog-ttl",server.repl_backlog_time_limit);
     config_get_numerical_field("maxclients",server.maxclients);
     config_get_numerical_field("watchdog-period",server.watchdog_period);
     config_get_numerical_field("slave-priority",server.slave_priority);
+    config_get_numerical_field("replica-priority",server.slave_priority);
     config_get_numerical_field("slave-announce-port",server.slave_announce_port);
+    config_get_numerical_field("replica-announce-port",server.slave_announce_port);
     config_get_numerical_field("min-slaves-to-write",server.repl_min_slaves_to_write);
+    config_get_numerical_field("min-replicas-to-write",server.repl_min_slaves_to_write);
     config_get_numerical_field("min-slaves-max-lag",server.repl_min_slaves_max_lag);
+    config_get_numerical_field("min-replicas-max-lag",server.repl_min_slaves_max_lag);
     config_get_numerical_field("hz",server.config_hz);
     config_get_numerical_field("cluster-node-timeout",server.cluster_node_timeout);
     config_get_numerical_field("cluster-migration-barrier",server.cluster_migration_barrier);
     config_get_numerical_field("cluster-slave-validity-factor",server.cluster_slave_validity_factor);
+    config_get_numerical_field("cluster-replica-validity-factor",server.cluster_slave_validity_factor);
     config_get_numerical_field("repl-diskless-sync-delay",server.repl_diskless_sync_delay);
     config_get_numerical_field("tcp-keepalive",server.tcpkeepalive);
 
@@ -1353,14 +1419,22 @@ void configGetCommand(client *c) {
             server.cluster_require_full_coverage);
     config_get_bool_field("cluster-slave-no-failover",
             server.cluster_slave_no_failover);
+    config_get_bool_field("cluster-replica-no-failover",
+            server.cluster_slave_no_failover);
     config_get_bool_field("no-appendfsync-on-rewrite",
             server.aof_no_fsync_on_rewrite);
     config_get_bool_field("slave-serve-stale-data",
             server.repl_serve_stale_data);
+    config_get_bool_field("replica-serve-stale-data",
+            server.repl_serve_stale_data);
     config_get_bool_field("slave-read-only",
             server.repl_slave_ro);
+    config_get_bool_field("replica-read-only",
+            server.repl_slave_ro);
     config_get_bool_field("slave-ignore-maxmemory",
             server.repl_slave_ignore_maxmemory);
+    config_get_bool_field("replica-ignore-maxmemory",
+            server.repl_slave_ignore_maxmemory);
     config_get_bool_field("stop-writes-on-bgsave-error",
             server.stop_writes_on_bgsave_err);
     config_get_bool_field("daemonize", server.daemonize);
@@ -1389,6 +1463,8 @@ void configGetCommand(client *c) {
             server.lazyfree_lazy_server_del);
     config_get_bool_field("slave-lazy-flush",
             server.repl_slave_lazy_flush);
+    config_get_bool_field("replica-lazy-flush",
+            server.repl_slave_lazy_flush);
     config_get_bool_field("dynamic-hz",
             server.dynamic_hz);
 
@@ -1462,10 +1538,14 @@ void configGetCommand(client *c) {
         addReplyBulkCString(c,buf);
         matches++;
     }
-    if (stringmatch(pattern,"slaveof",1)) {
+    if (stringmatch(pattern,"slaveof",1) ||
+        stringmatch(pattern,"replicaof",1))
+    {
+        char *optname = stringmatch(pattern,"slaveof",1) ?
+                        "slaveof" : "replicaof";
         char buf[256];
 
-        addReplyBulkCString(c,"slaveof");
+        addReplyBulkCString(c,optname);
         if (server.masterhost)
             snprintf(buf,sizeof(buf),"%s %d",
                 server.masterhost, server.masterport);
@@ -1574,12 +1654,11 @@ void rewriteConfigMarkAsProcessed(struct rewriteConfigState *state, const char *
  * If the old file does not exist at all, an empty state is returned. */
 struct rewriteConfigState *rewriteConfigReadOldFile(char *path) {
     FILE *fp = fopen(path,"r");
-    struct rewriteConfigState *state = zmalloc(sizeof(*state));
-    char buf[CONFIG_MAX_LINE+1];
-    int linenum = -1;
-
     if (fp == NULL && errno != ENOENT) return NULL;
 
+    char buf[CONFIG_MAX_LINE+1];
+    int linenum = -1;
+    struct rewriteConfigState *state = zmalloc(sizeof(*state));
     state->option_to_line = dictCreate(&optionToLineDictType,NULL);
     state->rewritten = dictCreate(&optionSetDictType,NULL);
     state->numlines = 0;
@@ -1621,8 +1700,20 @@ struct rewriteConfigState *rewriteConfigReadOldFile(char *path) {
         /* Now we populate the state according to the content of this line.
          * Append the line and populate the option -> line numbers map. */
         rewriteConfigAppendLine(state,line);
-        rewriteConfigAddLineNumberToOption(state,argv[0],linenum);
 
+        /* Translate options using the word "slave" to the corresponding name
+         * "replica", before adding such option to the config name -> lines
+         * mapping. */
+        char *p = strstr(argv[0],"slave");
+        if (p) {
+            sds alt = sdsempty();
+            alt = sdscatlen(alt,argv[0],p-argv[0]);;
+            alt = sdscatlen(alt,"replica",7);
+            alt = sdscatlen(alt,p+5,strlen(p+5));
+            sdsfree(argv[0]);
+            argv[0] = alt;
+        }
+        rewriteConfigAddLineNumberToOption(state,argv[0],linenum);
         sdsfreesplitres(argv,argc);
     }
     fclose(fp);
@@ -1809,15 +1900,14 @@ void rewriteConfigDirOption(struct rewriteConfigState *state) {
 }
 
 /* Rewrite the slaveof option. */
-void rewriteConfigSlaveofOption(struct rewriteConfigState *state) {
-    char *option = "slaveof";
+void rewriteConfigSlaveofOption(struct rewriteConfigState *state, char *option) {
     sds line;
 
     /* If this is a master, we want all the slaveof config options
      * in the file to be removed. Note that if this is a cluster instance
      * we don't want a slaveof directive inside redis.conf. */
     if (server.cluster_enabled || server.masterhost == NULL) {
-        rewriteConfigMarkAsProcessed(state,"slaveof");
+        rewriteConfigMarkAsProcessed(state,option);
         return;
     }
     line = sdscatprintf(sdsempty(),"%s %s %d", option,
@@ -1859,8 +1949,10 @@ void rewriteConfigClientoutputbufferlimitOption(struct rewriteConfigState *state
         rewriteConfigFormatMemory(soft,sizeof(soft),
                 server.client_obuf_limits[j].soft_limit_bytes);
 
+        char *typename = getClientTypeName(j);
+        if (!strcmp(typename,"slave")) typename = "replica";
         line = sdscatprintf(sdsempty(),"%s %s %s %s %ld",
-                option, getClientTypeName(j), hard, soft,
+                option, typename, hard, soft,
                 (long) server.client_obuf_limits[j].soft_limit_seconds);
         rewriteConfigRewriteLine(state,option,line,force);
     }
@@ -2038,7 +2130,7 @@ int rewriteConfig(char *path) {
     rewriteConfigOctalOption(state,"unixsocketperm",server.unixsocketperm,CONFIG_DEFAULT_UNIX_SOCKET_PERM);
     rewriteConfigNumericalOption(state,"timeout",server.maxidletime,CONFIG_DEFAULT_CLIENT_TIMEOUT);
     rewriteConfigNumericalOption(state,"tcp-keepalive",server.tcpkeepalive,CONFIG_DEFAULT_TCP_KEEPALIVE);
-    rewriteConfigNumericalOption(state,"slave-announce-port",server.slave_announce_port,CONFIG_DEFAULT_SLAVE_ANNOUNCE_PORT);
+    rewriteConfigNumericalOption(state,"replica-announce-port",server.slave_announce_port,CONFIG_DEFAULT_SLAVE_ANNOUNCE_PORT);
     rewriteConfigEnumOption(state,"loglevel",server.verbosity,loglevel_enum,CONFIG_DEFAULT_VERBOSITY);
     rewriteConfigStringOption(state,"logfile",server.logfile,CONFIG_DEFAULT_LOGFILE);
     rewriteConfigYesNoOption(state,"syslog-enabled",server.syslog_enabled,CONFIG_DEFAULT_SYSLOG_ENABLED);
@@ -2051,23 +2143,23 @@ int rewriteConfig(char *path) {
     rewriteConfigYesNoOption(state,"rdbchecksum",server.rdb_checksum,CONFIG_DEFAULT_RDB_CHECKSUM);
     rewriteConfigStringOption(state,"dbfilename",server.rdb_filename,CONFIG_DEFAULT_RDB_FILENAME);
     rewriteConfigDirOption(state);
-    rewriteConfigSlaveofOption(state);
-    rewriteConfigStringOption(state,"slave-announce-ip",server.slave_announce_ip,CONFIG_DEFAULT_SLAVE_ANNOUNCE_IP);
+    rewriteConfigSlaveofOption(state,"replicaof");
+    rewriteConfigStringOption(state,"replica-announce-ip",server.slave_announce_ip,CONFIG_DEFAULT_SLAVE_ANNOUNCE_IP);
     rewriteConfigStringOption(state,"masterauth",server.masterauth,NULL);
     rewriteConfigStringOption(state,"cluster-announce-ip",server.cluster_announce_ip,NULL);
-    rewriteConfigYesNoOption(state,"slave-serve-stale-data",server.repl_serve_stale_data,CONFIG_DEFAULT_SLAVE_SERVE_STALE_DATA);
-    rewriteConfigYesNoOption(state,"slave-read-only",server.repl_slave_ro,CONFIG_DEFAULT_SLAVE_READ_ONLY);
-    rewriteConfigYesNoOption(state,"slave-ignore-maxmemory",server.repl_slave_ignore_maxmemory,CONFIG_DEFAULT_SLAVE_IGNORE_MAXMEMORY);
-    rewriteConfigNumericalOption(state,"repl-ping-slave-period",server.repl_ping_slave_period,CONFIG_DEFAULT_REPL_PING_SLAVE_PERIOD);
+    rewriteConfigYesNoOption(state,"replica-serve-stale-data",server.repl_serve_stale_data,CONFIG_DEFAULT_SLAVE_SERVE_STALE_DATA);
+    rewriteConfigYesNoOption(state,"replica-read-only",server.repl_slave_ro,CONFIG_DEFAULT_SLAVE_READ_ONLY);
+    rewriteConfigYesNoOption(state,"replica-ignore-maxmemory",server.repl_slave_ignore_maxmemory,CONFIG_DEFAULT_SLAVE_IGNORE_MAXMEMORY);
+    rewriteConfigNumericalOption(state,"repl-ping-replica-period",server.repl_ping_slave_period,CONFIG_DEFAULT_REPL_PING_SLAVE_PERIOD);
     rewriteConfigNumericalOption(state,"repl-timeout",server.repl_timeout,CONFIG_DEFAULT_REPL_TIMEOUT);
     rewriteConfigBytesOption(state,"repl-backlog-size",server.repl_backlog_size,CONFIG_DEFAULT_REPL_BACKLOG_SIZE);
     rewriteConfigBytesOption(state,"repl-backlog-ttl",server.repl_backlog_time_limit,CONFIG_DEFAULT_REPL_BACKLOG_TIME_LIMIT);
     rewriteConfigYesNoOption(state,"repl-disable-tcp-nodelay",server.repl_disable_tcp_nodelay,CONFIG_DEFAULT_REPL_DISABLE_TCP_NODELAY);
     rewriteConfigYesNoOption(state,"repl-diskless-sync",server.repl_diskless_sync,CONFIG_DEFAULT_REPL_DISKLESS_SYNC);
     rewriteConfigNumericalOption(state,"repl-diskless-sync-delay",server.repl_diskless_sync_delay,CONFIG_DEFAULT_REPL_DISKLESS_SYNC_DELAY);
-    rewriteConfigNumericalOption(state,"slave-priority",server.slave_priority,CONFIG_DEFAULT_SLAVE_PRIORITY);
-    rewriteConfigNumericalOption(state,"min-slaves-to-write",server.repl_min_slaves_to_write,CONFIG_DEFAULT_MIN_SLAVES_TO_WRITE);
-    rewriteConfigNumericalOption(state,"min-slaves-max-lag",server.repl_min_slaves_max_lag,CONFIG_DEFAULT_MIN_SLAVES_MAX_LAG);
+    rewriteConfigNumericalOption(state,"replica-priority",server.slave_priority,CONFIG_DEFAULT_SLAVE_PRIORITY);
+    rewriteConfigNumericalOption(state,"min-replicas-to-write",server.repl_min_slaves_to_write,CONFIG_DEFAULT_MIN_SLAVES_TO_WRITE);
+    rewriteConfigNumericalOption(state,"min-replicas-max-lag",server.repl_min_slaves_max_lag,CONFIG_DEFAULT_MIN_SLAVES_MAX_LAG);
     rewriteConfigStringOption(state,"requirepass",server.requirepass,NULL);
     rewriteConfigNumericalOption(state,"maxclients",server.maxclients,CONFIG_DEFAULT_MAX_CLIENTS);
     rewriteConfigBytesOption(state,"maxmemory",server.maxmemory,CONFIG_DEFAULT_MAXMEMORY);
@@ -2093,10 +2185,10 @@ int rewriteConfig(char *path) {
     rewriteConfigYesNoOption(state,"cluster-enabled",server.cluster_enabled,0);
     rewriteConfigStringOption(state,"cluster-config-file",server.cluster_configfile,CONFIG_DEFAULT_CLUSTER_CONFIG_FILE);
     rewriteConfigYesNoOption(state,"cluster-require-full-coverage",server.cluster_require_full_coverage,CLUSTER_DEFAULT_REQUIRE_FULL_COVERAGE);
-    rewriteConfigYesNoOption(state,"cluster-slave-no-failover",server.cluster_slave_no_failover,CLUSTER_DEFAULT_SLAVE_NO_FAILOVER);
+    rewriteConfigYesNoOption(state,"cluster-replica-no-failover",server.cluster_slave_no_failover,CLUSTER_DEFAULT_SLAVE_NO_FAILOVER);
     rewriteConfigNumericalOption(state,"cluster-node-timeout",server.cluster_node_timeout,CLUSTER_DEFAULT_NODE_TIMEOUT);
     rewriteConfigNumericalOption(state,"cluster-migration-barrier",server.cluster_migration_barrier,CLUSTER_DEFAULT_MIGRATION_BARRIER);
-    rewriteConfigNumericalOption(state,"cluster-slave-validity-factor",server.cluster_slave_validity_factor,CLUSTER_DEFAULT_SLAVE_VALIDITY);
+    rewriteConfigNumericalOption(state,"cluster-replica-validity-factor",server.cluster_slave_validity_factor,CLUSTER_DEFAULT_SLAVE_VALIDITY);
     rewriteConfigNumericalOption(state,"slowlog-log-slower-than",server.slowlog_log_slower_than,CONFIG_DEFAULT_SLOWLOG_LOG_SLOWER_THAN);
     rewriteConfigNumericalOption(state,"latency-monitor-threshold",server.latency_monitor_threshold,CONFIG_DEFAULT_LATENCY_MONITOR_THRESHOLD);
     rewriteConfigNumericalOption(state,"slowlog-max-len",server.slowlog_max_len,CONFIG_DEFAULT_SLOWLOG_MAX_LEN);
@@ -2124,7 +2216,7 @@ int rewriteConfig(char *path) {
     rewriteConfigYesNoOption(state,"lazyfree-lazy-eviction",server.lazyfree_lazy_eviction,CONFIG_DEFAULT_LAZYFREE_LAZY_EVICTION);
     rewriteConfigYesNoOption(state,"lazyfree-lazy-expire",server.lazyfree_lazy_expire,CONFIG_DEFAULT_LAZYFREE_LAZY_EXPIRE);
     rewriteConfigYesNoOption(state,"lazyfree-lazy-server-del",server.lazyfree_lazy_server_del,CONFIG_DEFAULT_LAZYFREE_LAZY_SERVER_DEL);
-    rewriteConfigYesNoOption(state,"slave-lazy-flush",server.repl_slave_lazy_flush,CONFIG_DEFAULT_SLAVE_LAZY_FLUSH);
+    rewriteConfigYesNoOption(state,"replica-lazy-flush",server.repl_slave_lazy_flush,CONFIG_DEFAULT_SLAVE_LAZY_FLUSH);
     rewriteConfigYesNoOption(state,"dynamic-hz",server.dynamic_hz,CONFIG_DEFAULT_DYNAMIC_HZ);
 
     /* Rewrite Sentinel config if in Sentinel mode. */

src/config.h

@@ -62,7 +62,9 @@
 #endif
 
 /* Test for backtrace() */
-#if defined(__APPLE__) || (defined(__linux__) && defined(__GLIBC__))
+#if defined(__APPLE__) || (defined(__linux__) && defined(__GLIBC__)) || \
+    defined(__FreeBSD__) || (defined(__OpenBSD__) && defined(USE_BACKTRACE))\
+ || defined(__DragonFly__)
 #define HAVE_BACKTRACE 1
 #endif
 

src/db.c

@@ -38,6 +38,8 @@
  * C-level DB API
  *----------------------------------------------------------------------------*/
 
+int keyIsExpired(redisDb *db, robj *key);
+
 /* Update LFU when an object is accessed.
  * Firstly, decrement the counter if the decrement time is reached.
  * Then logarithmically increment the counter, and update the access time. */
@@ -102,7 +104,10 @@ robj *lookupKeyReadWithFlags(redisDb *db, robj *key, int flags) {
         /* Key expired. If we are in the context of a master, expireIfNeeded()
          * returns 0 only when the key does not exist at all, so it's safe
          * to return NULL ASAP. */
-        if (server.masterhost == NULL) return NULL;
+        if (server.masterhost == NULL) {
+            server.stat_keyspace_misses++;
+            return NULL;
+        }
 
         /* However if we are in the context of a slave, expireIfNeeded() will
          * not really try to expire the key, it only returns information
@@ -121,6 +126,7 @@ robj *lookupKeyReadWithFlags(redisDb *db, robj *key, int flags) {
             server.current_client->cmd &&
             server.current_client->cmd->flags & CMD_READONLY)
         {
+            server.stat_keyspace_misses++;
             return NULL;
         }
     }
@@ -206,7 +212,7 @@ void dbOverwrite(redisDb *db, robj *key, robj *val) {
  * 2) clients WATCHing for the destination key notified.
  * 3) The expire time of the key is reset (the key is made persistent).
  *
- * All the new keys in the database should be craeted via this interface. */
+ * All the new keys in the database should be created via this interface. */
 void setKey(redisDb *db, robj *key, robj *val) {
     if (lookupKeyWrite(db,key) == NULL) {
         dbAdd(db,key,val);
@@ -543,7 +549,7 @@ void keysCommand(client *c) {
 
         if (allkeys || stringmatchlen(pattern,plen,key,sdslen(key),0)) {
             keyobj = createStringObject(key,sdslen(key));
-            if (expireIfNeeded(c->db,keyobj) == 0) {
+            if (!keyIsExpired(c->db,keyobj)) {
                 addReplyBulk(c,keyobj);
                 numkeys++;
             }
@@ -1120,6 +1126,25 @@ void propagateExpire(redisDb *db, robj *key, int lazy) {
     decrRefCount(argv[1]);
 }
 
+/* Check if the key is expired. */
+int keyIsExpired(redisDb *db, robj *key) {
+    mstime_t when = getExpire(db,key);
+
+    if (when < 0) return 0; /* No expire for this key */
+
+    /* Don't expire anything while loading. It will be done later. */
+    if (server.loading) return 0;
+
+    /* If we are in the context of a Lua script, we pretend that time is
+     * blocked to when the Lua script started. This way a key can expire
+     * only the first time it is accessed and not in the middle of the
+     * script execution, making propagation to slaves / AOF consistent.
+     * See issue #1525 on Github for more information. */
+    mstime_t now = server.lua_caller ? server.lua_time_start : mstime();
+
+    return now > when;
+}
+
 /* This function is called when we are going to perform some operation
  * in a given key, but such key may be already logically expired even if
  * it still exists in the database. The main way this function is called
@@ -1140,32 +1165,17 @@ void propagateExpire(redisDb *db, robj *key, int lazy) {
  * The return value of the function is 0 if the key is still valid,
  * otherwise the function returns 1 if the key is expired. */
 int expireIfNeeded(redisDb *db, robj *key) {
-    mstime_t when = getExpire(db,key);
-    mstime_t now;
+    if (!keyIsExpired(db,key)) return 0;
 
-    if (when < 0) return 0; /* No expire for this key */
-
-    /* Don't expire anything while loading. It will be done later. */
-    if (server.loading) return 0;
-
-    /* If we are in the context of a Lua script, we pretend that time is
-     * blocked to when the Lua script started. This way a key can expire
-     * only the first time it is accessed and not in the middle of the
-     * script execution, making propagation to slaves / AOF consistent.
-     * See issue #1525 on Github for more information. */
-    now = server.lua_caller ? server.lua_time_start : mstime();
-
-    /* If we are running in the context of a slave, return ASAP:
+    /* If we are running in the context of a slave, instead of
+     * evicting the expired key from the database, we return ASAP:
      * the slave key expiration is controlled by the master that will
      * send us synthesized DEL operations for expired keys.
      *
      * Still we try to return the right information to the caller,
      * that is, 0 if we think the key should be still valid, 1 if
      * we think the key is expired at this time. */
-    if (server.masterhost != NULL) return now > when;
-
-    /* Return when this key has not expired */
-    if (now <= when) return 0;
+    if (server.masterhost != NULL) return 1;
 
     /* Delete the key */
     server.stat_expiredkeys++;

src/debug.c

@@ -37,7 +37,11 @@
 
 #ifdef HAVE_BACKTRACE
 #include <execinfo.h>
+#ifndef __OpenBSD__
 #include <ucontext.h>
+#else
+typedef ucontext_t sigcontext_t;
+#endif
 #include <fcntl.h>
 #include "bio.h"
 #include <unistd.h>
@@ -70,7 +74,7 @@ void xorDigest(unsigned char *digest, void *ptr, size_t len) {
         digest[j] ^= hash[j];
 }
 
-void xorObjectDigest(unsigned char *digest, robj *o) {
+void xorStringObjectDigest(unsigned char *digest, robj *o) {
     o = getDecodedObject(o);
     xorDigest(digest,o->ptr,sdslen(o->ptr));
     decrRefCount(o);
@@ -100,12 +104,151 @@ void mixDigest(unsigned char *digest, void *ptr, size_t len) {
     SHA1Final(digest,&ctx);
 }
 
-void mixObjectDigest(unsigned char *digest, robj *o) {
+void mixStringObjectDigest(unsigned char *digest, robj *o) {
     o = getDecodedObject(o);
     mixDigest(digest,o->ptr,sdslen(o->ptr));
     decrRefCount(o);
 }
 
+/* This function computes the digest of a data structure stored in the
+ * object 'o'. It is the core of the DEBUG DIGEST command: when taking the
+ * digest of a whole dataset, we take the digest of the key and the value
+ * pair, and xor all those together.
+ *
+ * Note that this function does not reset the initial 'digest' passed, it
+ * will continue mixing this object digest to anything that was already
+ * present. */
+void xorObjectDigest(redisDb *db, robj *keyobj, unsigned char *digest, robj *o) {
+    uint32_t aux = htonl(o->type);
+    mixDigest(digest,&aux,sizeof(aux));
+    long long expiretime = getExpire(db,keyobj);
+    char buf[128];
+
+    /* Save the key and associated value */
+    if (o->type == OBJ_STRING) {
+        mixStringObjectDigest(digest,o);
+    } else if (o->type == OBJ_LIST) {
+        listTypeIterator *li = listTypeInitIterator(o,0,LIST_TAIL);
+        listTypeEntry entry;
+        while(listTypeNext(li,&entry)) {
+            robj *eleobj = listTypeGet(&entry);
+            mixStringObjectDigest(digest,eleobj);
+            decrRefCount(eleobj);
+        }
+        listTypeReleaseIterator(li);
+    } else if (o->type == OBJ_SET) {
+        setTypeIterator *si = setTypeInitIterator(o);
+        sds sdsele;
+        while((sdsele = setTypeNextObject(si)) != NULL) {
+            xorDigest(digest,sdsele,sdslen(sdsele));
+            sdsfree(sdsele);
+        }
+        setTypeReleaseIterator(si);
+    } else if (o->type == OBJ_ZSET) {
+        unsigned char eledigest[20];
+
+        if (o->encoding == OBJ_ENCODING_ZIPLIST) {
+            unsigned char *zl = o->ptr;
+            unsigned char *eptr, *sptr;
+            unsigned char *vstr;
+            unsigned int vlen;
+            long long vll;
+            double score;
+
+            eptr = ziplistIndex(zl,0);
+            serverAssert(eptr != NULL);
+            sptr = ziplistNext(zl,eptr);
+            serverAssert(sptr != NULL);
+
+            while (eptr != NULL) {
+                serverAssert(ziplistGet(eptr,&vstr,&vlen,&vll));
+                score = zzlGetScore(sptr);
+
+                memset(eledigest,0,20);
+                if (vstr != NULL) {
+                    mixDigest(eledigest,vstr,vlen);
+                } else {
+                    ll2string(buf,sizeof(buf),vll);
+                    mixDigest(eledigest,buf,strlen(buf));
+                }
+
+                snprintf(buf,sizeof(buf),"%.17g",score);
+                mixDigest(eledigest,buf,strlen(buf));
+                xorDigest(digest,eledigest,20);
+                zzlNext(zl,&eptr,&sptr);
+            }
+        } else if (o->encoding == OBJ_ENCODING_SKIPLIST) {
+            zset *zs = o->ptr;
+            dictIterator *di = dictGetIterator(zs->dict);
+            dictEntry *de;
+
+            while((de = dictNext(di)) != NULL) {
+                sds sdsele = dictGetKey(de);
+                double *score = dictGetVal(de);
+
+                snprintf(buf,sizeof(buf),"%.17g",*score);
+                memset(eledigest,0,20);
+                mixDigest(eledigest,sdsele,sdslen(sdsele));
+                mixDigest(eledigest,buf,strlen(buf));
+                xorDigest(digest,eledigest,20);
+            }
+            dictReleaseIterator(di);
+        } else {
+            serverPanic("Unknown sorted set encoding");
+        }
+    } else if (o->type == OBJ_HASH) {
+        hashTypeIterator *hi = hashTypeInitIterator(o);
+        while (hashTypeNext(hi) != C_ERR) {
+            unsigned char eledigest[20];
+            sds sdsele;
+
+            memset(eledigest,0,20);
+            sdsele = hashTypeCurrentObjectNewSds(hi,OBJ_HASH_KEY);
+            mixDigest(eledigest,sdsele,sdslen(sdsele));
+            sdsfree(sdsele);
+            sdsele = hashTypeCurrentObjectNewSds(hi,OBJ_HASH_VALUE);
+            mixDigest(eledigest,sdsele,sdslen(sdsele));
+            sdsfree(sdsele);
+            xorDigest(digest,eledigest,20);
+        }
+        hashTypeReleaseIterator(hi);
+    } else if (o->type == OBJ_STREAM) {
+        streamIterator si;
+        streamIteratorStart(&si,o->ptr,NULL,NULL,0);
+        streamID id;
+        int64_t numfields;
+
+        while(streamIteratorGetID(&si,&id,&numfields)) {
+            sds itemid = sdscatfmt(sdsempty(),"%U.%U",id.ms,id.seq);
+            mixDigest(digest,itemid,sdslen(itemid));
+            sdsfree(itemid);
+
+            while(numfields--) {
+                unsigned char *field, *value;
+                int64_t field_len, value_len;
+                streamIteratorGetField(&si,&field,&value,
+                                           &field_len,&value_len);
+                mixDigest(digest,field,field_len);
+                mixDigest(digest,value,value_len);
+            }
+        }
+        streamIteratorStop(&si);
+    } else if (o->type == OBJ_MODULE) {
+        RedisModuleDigest md;
+        moduleValue *mv = o->ptr;
+        moduleType *mt = mv->type;
+        moduleInitDigestContext(md);
+        if (mt->digest) {
+            mt->digest(&md,mv->value);
+            xorDigest(digest,md.x,sizeof(md.x));
+        }
+    } else {
+        serverPanic("Unknown object type");
+    }
+    /* If the key has an expire, add it to the mix */
+    if (expiretime != -1) xorDigest(digest,"!!expire!!",10);
+}
+
 /* Compute the dataset digest. Since keys, sets elements, hashes elements
  * are not ordered, we use a trick: every aggregate digest is the xor
  * of the digests of their elements. This way the order will not change
@@ -114,7 +257,6 @@ void mixObjectDigest(unsigned char *digest, robj *o) {
  * a different digest. */
 void computeDatasetDigest(unsigned char *final) {
     unsigned char digest[20];
-    char buf[128];
     dictIterator *di = NULL;
     dictEntry *de;
     int j;
@@ -137,7 +279,6 @@ void computeDatasetDigest(unsigned char *final) {
         while((de = dictNext(di)) != NULL) {
             sds key;
             robj *keyobj, *o;
-            long long expiretime;
 
             memset(digest,0,20); /* This key-val digest */
             key = dictGetKey(de);
@@ -146,134 +287,8 @@ void computeDatasetDigest(unsigned char *final) {
             mixDigest(digest,key,sdslen(key));
 
             o = dictGetVal(de);
+            xorObjectDigest(db,keyobj,digest,o);
 
-            aux = htonl(o->type);
-            mixDigest(digest,&aux,sizeof(aux));
-            expiretime = getExpire(db,keyobj);
-
-            /* Save the key and associated value */
-            if (o->type == OBJ_STRING) {
-                mixObjectDigest(digest,o);
-            } else if (o->type == OBJ_LIST) {
-                listTypeIterator *li = listTypeInitIterator(o,0,LIST_TAIL);
-                listTypeEntry entry;
-                while(listTypeNext(li,&entry)) {
-                    robj *eleobj = listTypeGet(&entry);
-                    mixObjectDigest(digest,eleobj);
-                    decrRefCount(eleobj);
-                }
-                listTypeReleaseIterator(li);
-            } else if (o->type == OBJ_SET) {
-                setTypeIterator *si = setTypeInitIterator(o);
-                sds sdsele;
-                while((sdsele = setTypeNextObject(si)) != NULL) {
-                    xorDigest(digest,sdsele,sdslen(sdsele));
-                    sdsfree(sdsele);
-                }
-                setTypeReleaseIterator(si);
-            } else if (o->type == OBJ_ZSET) {
-                unsigned char eledigest[20];
-
-                if (o->encoding == OBJ_ENCODING_ZIPLIST) {
-                    unsigned char *zl = o->ptr;
-                    unsigned char *eptr, *sptr;
-                    unsigned char *vstr;
-                    unsigned int vlen;
-                    long long vll;
-                    double score;
-
-                    eptr = ziplistIndex(zl,0);
-                    serverAssert(eptr != NULL);
-                    sptr = ziplistNext(zl,eptr);
-                    serverAssert(sptr != NULL);
-
-                    while (eptr != NULL) {
-                        serverAssert(ziplistGet(eptr,&vstr,&vlen,&vll));
-                        score = zzlGetScore(sptr);
-
-                        memset(eledigest,0,20);
-                        if (vstr != NULL) {
-                            mixDigest(eledigest,vstr,vlen);
-                        } else {
-                            ll2string(buf,sizeof(buf),vll);
-                            mixDigest(eledigest,buf,strlen(buf));
-                        }
-
-                        snprintf(buf,sizeof(buf),"%.17g",score);
-                        mixDigest(eledigest,buf,strlen(buf));
-                        xorDigest(digest,eledigest,20);
-                        zzlNext(zl,&eptr,&sptr);
-                    }
-                } else if (o->encoding == OBJ_ENCODING_SKIPLIST) {
-                    zset *zs = o->ptr;
-                    dictIterator *di = dictGetIterator(zs->dict);
-                    dictEntry *de;
-
-                    while((de = dictNext(di)) != NULL) {
-                        sds sdsele = dictGetKey(de);
-                        double *score = dictGetVal(de);
-
-                        snprintf(buf,sizeof(buf),"%.17g",*score);
-                        memset(eledigest,0,20);
-                        mixDigest(eledigest,sdsele,sdslen(sdsele));
-                        mixDigest(eledigest,buf,strlen(buf));
-                        xorDigest(digest,eledigest,20);
-                    }
-                    dictReleaseIterator(di);
-                } else {
-                    serverPanic("Unknown sorted set encoding");
-                }
-            } else if (o->type == OBJ_HASH) {
-                hashTypeIterator *hi = hashTypeInitIterator(o);
-                while (hashTypeNext(hi) != C_ERR) {
-                    unsigned char eledigest[20];
-                    sds sdsele;
-
-                    memset(eledigest,0,20);
-                    sdsele = hashTypeCurrentObjectNewSds(hi,OBJ_HASH_KEY);
-                    mixDigest(eledigest,sdsele,sdslen(sdsele));
-                    sdsfree(sdsele);
-                    sdsele = hashTypeCurrentObjectNewSds(hi,OBJ_HASH_VALUE);
-                    mixDigest(eledigest,sdsele,sdslen(sdsele));
-                    sdsfree(sdsele);
-                    xorDigest(digest,eledigest,20);
-                }
-                hashTypeReleaseIterator(hi);
-            } else if (o->type == OBJ_STREAM) {
-                streamIterator si;
-                streamIteratorStart(&si,o->ptr,NULL,NULL,0);
-                streamID id;
-                int64_t numfields;
-
-                while(streamIteratorGetID(&si,&id,&numfields)) {
-                    sds itemid = sdscatfmt(sdsempty(),"%U.%U",id.ms,id.seq);
-                    mixDigest(digest,itemid,sdslen(itemid));
-                    sdsfree(itemid);
-
-                    while(numfields--) {
-                        unsigned char *field, *value;
-                        int64_t field_len, value_len;
-                        streamIteratorGetField(&si,&field,&value,
-                                                   &field_len,&value_len);
-                        mixDigest(digest,field,field_len);
-                        mixDigest(digest,value,value_len);
-                    }
-                }
-                streamIteratorStop(&si);
-            } else if (o->type == OBJ_MODULE) {
-                RedisModuleDigest md;
-                moduleValue *mv = o->ptr;
-                moduleType *mt = mv->type;
-                moduleInitDigestContext(md);
-                if (mt->digest) {
-                    mt->digest(&md,mv->value);
-                    xorDigest(digest,md.x,sizeof(md.x));
-                }
-            } else {
-                serverPanic("Unknown object type");
-            }
-            /* If the key has an expire, add it to the mix */
-            if (expiretime != -1) xorDigest(digest,"!!expire!!",10);
             /* We can finally xor the key-val digest to the final digest */
             xorDigest(final,digest,20);
             decrRefCount(keyobj);
@@ -289,6 +304,7 @@ void debugCommand(client *c) {
 "CHANGE-REPL-ID -- Change the replication IDs of the instance. Dangerous, should be used only for testing the replication subsystem.",
 "CRASH-AND-RECOVER <milliseconds> -- Hard crash and restart after <milliseconds> delay.",
 "DIGEST -- Output a hex signature representing the current DB content.",
+"DIGEST-VALUE <key-1> ... <key-N>-- Output a hex signature of the values of all the specified keys.",
 "ERROR <string> -- Return a Redis protocol error with <string> as message. Useful for clients unit tests to simulate Redis errors.",
 "LOG <message> -- write message to the server log.",
 "HTSTATS <dbid> -- Return hash table statistics of the specified Redis database.",
@@ -306,6 +322,7 @@ void debugCommand(client *c) {
 "SLEEP <seconds> -- Stop the server for <seconds>. Decimals allowed.",
 "STRUCTSIZE -- Return the size of different Redis core C structures.",
 "ZIPLIST <key> -- Show low level info about the ziplist encoding.",
+"STRINGMATCH-TEST -- Run a fuzz tester against the stringmatchlen() function.",
 NULL
         };
         addReplyHelp(c, help);
@@ -332,7 +349,6 @@ NULL
         zfree(ptr);
         addReply(c,shared.ok);
     } else if (!strcasecmp(c->argv[1]->ptr,"assert")) {
-        if (c->argc >= 3) c->argv[2] = tryObjectEncoding(c->argv[2]);
         serverAssertWithInfo(c,c->argv[0],1 == 2);
     } else if (!strcasecmp(c->argv[1]->ptr,"log") && c->argc == 3) {
         serverLog(LL_WARNING, "DEBUG LOG: %s", (char*)c->argv[2]->ptr);
@@ -345,7 +361,10 @@ NULL
             return;
         }
         emptyDb(-1,EMPTYDB_NO_FLAGS,NULL);
-        if (rdbLoad(server.rdb_filename,NULL) != C_OK) {
+        protectClient(c);
+        int ret = rdbLoad(server.rdb_filename,NULL);
+        unprotectClient(c);
+        if (ret != C_OK) {
             addReplyError(c,"Error trying to load the RDB dump");
             return;
         }
@@ -354,7 +373,10 @@ NULL
     } else if (!strcasecmp(c->argv[1]->ptr,"loadaof")) {
         if (server.aof_state != AOF_OFF) flushAppendOnlyFile(1);
         emptyDb(-1,EMPTYDB_NO_FLAGS,NULL);
-        if (loadAppendOnlyFile(server.aof_filename) != C_OK) {
+        protectClient(c);
+        int ret = loadAppendOnlyFile(server.aof_filename);
+        unprotectClient(c);
+        if (ret != C_OK) {
             addReply(c,shared.err);
             return;
         }
@@ -485,15 +507,28 @@ NULL
         }
         addReply(c,shared.ok);
     } else if (!strcasecmp(c->argv[1]->ptr,"digest") && c->argc == 2) {
+        /* DEBUG DIGEST (form without keys specified) */
         unsigned char digest[20];
         sds d = sdsempty();
-        int j;
 
         computeDatasetDigest(digest);
-        for (j = 0; j < 20; j++)
-            d = sdscatprintf(d, "%02x",digest[j]);
+        for (int i = 0; i < 20; i++) d = sdscatprintf(d, "%02x",digest[i]);
         addReplyStatus(c,d);
         sdsfree(d);
+    } else if (!strcasecmp(c->argv[1]->ptr,"digest-value") && c->argc >= 2) {
+        /* DEBUG DIGEST-VALUE key key key ... key. */
+        addReplyMultiBulkLen(c,c->argc-2);
+        for (int j = 2; j < c->argc; j++) {
+            unsigned char digest[20];
+            memset(digest,0,20); /* Start with a clean result */
+            robj *o = lookupKeyReadWithFlags(c->db,c->argv[j],LOOKUP_NOTOUCH);
+            if (o) xorObjectDigest(c->db,c->argv[j],digest,o);
+
+            sds d = sdsempty();
+            for (int i = 0; i < 20; i++) d = sdscatprintf(d, "%02x",digest[i]);
+            addReplyStatus(c,d);
+            sdsfree(d);
+        }
     } else if (!strcasecmp(c->argv[1]->ptr,"sleep") && c->argc == 3) {
         double dtime = strtod(c->argv[2]->ptr,NULL);
         long long utime = dtime*1000000;
@@ -585,6 +620,10 @@ NULL
         changeReplicationId();
         clearReplicationId2();
         addReply(c,shared.ok);
+    } else if (!strcasecmp(c->argv[1]->ptr,"stringmatch-test") && c->argc == 2)
+    {
+        stringmatchlen_fuzz_test();
+        addReplyStatus(c,"Apparently Redis did not crash: test passed");
     } else {
         addReplySubcommandSyntaxError(c);
         return;
@@ -723,6 +762,22 @@ static void *getMcontextEip(ucontext_t *uc) {
     #elif defined(__aarch64__) /* Linux AArch64 */
     return (void*) uc->uc_mcontext.pc;
     #endif
+#elif defined(__FreeBSD__)
+    /* FreeBSD */
+    #if defined(__i386__)
+    return (void*) uc->uc_mcontext.mc_eip;
+    #elif defined(__x86_64__)
+    return (void*) uc->uc_mcontext.mc_rip;
+    #endif
+#elif defined(__OpenBSD__)
+    /* OpenBSD */
+    #if defined(__i386__)
+    return (void*) uc->sc_eip;
+    #elif defined(__x86_64__)
+    return (void*) uc->sc_rip;
+    #endif
+#elif defined(__DragonFly__)
+    return (void*) uc->uc_mcontext.mc_rip;
 #else
     return NULL;
 #endif
@@ -864,6 +919,145 @@ void logRegisters(ucontext_t *uc) {
     );
     logStackContent((void**)uc->uc_mcontext.gregs[15]);
     #endif
+#elif defined(__FreeBSD__)
+    #if defined(__x86_64__)
+    serverLog(LL_WARNING,
+    "\n"
+    "RAX:%016lx RBX:%016lx\nRCX:%016lx RDX:%016lx\n"
+    "RDI:%016lx RSI:%016lx\nRBP:%016lx RSP:%016lx\n"
+    "R8 :%016lx R9 :%016lx\nR10:%016lx R11:%016lx\n"
+    "R12:%016lx R13:%016lx\nR14:%016lx R15:%016lx\n"
+    "RIP:%016lx EFL:%016lx\nCSGSFS:%016lx",
+        (unsigned long) uc->uc_mcontext.mc_rax,
+        (unsigned long) uc->uc_mcontext.mc_rbx,
+        (unsigned long) uc->uc_mcontext.mc_rcx,
+        (unsigned long) uc->uc_mcontext.mc_rdx,
+        (unsigned long) uc->uc_mcontext.mc_rdi,
+        (unsigned long) uc->uc_mcontext.mc_rsi,
+        (unsigned long) uc->uc_mcontext.mc_rbp,
+        (unsigned long) uc->uc_mcontext.mc_rsp,
+        (unsigned long) uc->uc_mcontext.mc_r8,
+        (unsigned long) uc->uc_mcontext.mc_r9,
+        (unsigned long) uc->uc_mcontext.mc_r10,
+        (unsigned long) uc->uc_mcontext.mc_r11,
+        (unsigned long) uc->uc_mcontext.mc_r12,
+        (unsigned long) uc->uc_mcontext.mc_r13,
+        (unsigned long) uc->uc_mcontext.mc_r14,
+        (unsigned long) uc->uc_mcontext.mc_r15,
+        (unsigned long) uc->uc_mcontext.mc_rip,
+        (unsigned long) uc->uc_mcontext.mc_rflags,
+        (unsigned long) uc->uc_mcontext.mc_cs
+    );
+    logStackContent((void**)uc->uc_mcontext.mc_rsp);
+    #elif defined(__i386__)
+    serverLog(LL_WARNING,
+    "\n"
+    "EAX:%08lx EBX:%08lx ECX:%08lx EDX:%08lx\n"
+    "EDI:%08lx ESI:%08lx EBP:%08lx ESP:%08lx\n"
+    "SS :%08lx EFL:%08lx EIP:%08lx CS:%08lx\n"
+    "DS :%08lx ES :%08lx FS :%08lx GS:%08lx",
+        (unsigned long) uc->uc_mcontext.mc_eax,
+        (unsigned long) uc->uc_mcontext.mc_ebx,
+        (unsigned long) uc->uc_mcontext.mc_ebx,
+        (unsigned long) uc->uc_mcontext.mc_edx,
+        (unsigned long) uc->uc_mcontext.mc_edi,
+        (unsigned long) uc->uc_mcontext.mc_esi,
+        (unsigned long) uc->uc_mcontext.mc_ebp,
+        (unsigned long) uc->uc_mcontext.mc_esp,
+        (unsigned long) uc->uc_mcontext.mc_ss,
+        (unsigned long) uc->uc_mcontext.mc_eflags,
+        (unsigned long) uc->uc_mcontext.mc_eip,
+        (unsigned long) uc->uc_mcontext.mc_cs,
+        (unsigned long) uc->uc_mcontext.mc_es,
+        (unsigned long) uc->uc_mcontext.mc_fs,
+        (unsigned long) uc->uc_mcontext.mc_gs
+    );
+    logStackContent((void**)uc->uc_mcontext.mc_esp);
+    #endif
+#elif defined(__OpenBSD__)
+    #if defined(__x86_64__)
+    serverLog(LL_WARNING,
+    "\n"
+    "RAX:%016lx RBX:%016lx\nRCX:%016lx RDX:%016lx\n"
+    "RDI:%016lx RSI:%016lx\nRBP:%016lx RSP:%016lx\n"
+    "R8 :%016lx R9 :%016lx\nR10:%016lx R11:%016lx\n"
+    "R12:%016lx R13:%016lx\nR14:%016lx R15:%016lx\n"
+    "RIP:%016lx EFL:%016lx\nCSGSFS:%016lx",
+        (unsigned long) uc->sc_rax,
+        (unsigned long) uc->sc_rbx,
+        (unsigned long) uc->sc_rcx,
+        (unsigned long) uc->sc_rdx,
+        (unsigned long) uc->sc_rdi,
+        (unsigned long) uc->sc_rsi,
+        (unsigned long) uc->sc_rbp,
+        (unsigned long) uc->sc_rsp,
+        (unsigned long) uc->sc_r8,
+        (unsigned long) uc->sc_r9,
+        (unsigned long) uc->sc_r10,
+        (unsigned long) uc->sc_r11,
+        (unsigned long) uc->sc_r12,
+        (unsigned long) uc->sc_r13,
+        (unsigned long) uc->sc_r14,
+        (unsigned long) uc->sc_r15,
+        (unsigned long) uc->sc_rip,
+        (unsigned long) uc->sc_rflags,
+        (unsigned long) uc->sc_cs
+    );
+    logStackContent((void**)uc->sc_rsp);
+    #elif defined(__i386__)
+    serverLog(LL_WARNING,
+    "\n"
+    "EAX:%08lx EBX:%08lx ECX:%08lx EDX:%08lx\n"
+    "EDI:%08lx ESI:%08lx EBP:%08lx ESP:%08lx\n"
+    "SS :%08lx EFL:%08lx EIP:%08lx CS:%08lx\n"
+    "DS :%08lx ES :%08lx FS :%08lx GS:%08lx",
+        (unsigned long) uc->sc_eax,
+        (unsigned long) uc->sc_ebx,
+        (unsigned long) uc->sc_ebx,
+        (unsigned long) uc->sc_edx,
+        (unsigned long) uc->sc_edi,
+        (unsigned long) uc->sc_esi,
+        (unsigned long) uc->sc_ebp,
+        (unsigned long) uc->sc_esp,
+        (unsigned long) uc->sc_ss,
+        (unsigned long) uc->sc_eflags,
+        (unsigned long) uc->sc_eip,
+        (unsigned long) uc->sc_cs,
+        (unsigned long) uc->sc_es,
+        (unsigned long) uc->sc_fs,
+        (unsigned long) uc->sc_gs
+    );
+    logStackContent((void**)uc->sc_esp);
+    #endif
+#elif defined(__DragonFly__)
+    serverLog(LL_WARNING,
+    "\n"
+    "RAX:%016lx RBX:%016lx\nRCX:%016lx RDX:%016lx\n"
+    "RDI:%016lx RSI:%016lx\nRBP:%016lx RSP:%016lx\n"
+    "R8 :%016lx R9 :%016lx\nR10:%016lx R11:%016lx\n"
+    "R12:%016lx R13:%016lx\nR14:%016lx R15:%016lx\n"
+    "RIP:%016lx EFL:%016lx\nCSGSFS:%016lx",
+        (unsigned long) uc->uc_mcontext.mc_rax,
+        (unsigned long) uc->uc_mcontext.mc_rbx,
+        (unsigned long) uc->uc_mcontext.mc_rcx,
+        (unsigned long) uc->uc_mcontext.mc_rdx,
+        (unsigned long) uc->uc_mcontext.mc_rdi,
+        (unsigned long) uc->uc_mcontext.mc_rsi,
+        (unsigned long) uc->uc_mcontext.mc_rbp,
+        (unsigned long) uc->uc_mcontext.mc_rsp,
+        (unsigned long) uc->uc_mcontext.mc_r8,
+        (unsigned long) uc->uc_mcontext.mc_r9,
+        (unsigned long) uc->uc_mcontext.mc_r10,
+        (unsigned long) uc->uc_mcontext.mc_r11,
+        (unsigned long) uc->uc_mcontext.mc_r12,
+        (unsigned long) uc->uc_mcontext.mc_r13,
+        (unsigned long) uc->uc_mcontext.mc_r14,
+        (unsigned long) uc->uc_mcontext.mc_r15,
+        (unsigned long) uc->uc_mcontext.mc_rip,
+        (unsigned long) uc->uc_mcontext.mc_rflags,
+        (unsigned long) uc->uc_mcontext.mc_cs
+    );
+    logStackContent((void**)uc->uc_mcontext.mc_rsp);
 #else
     serverLog(LL_WARNING,
         "  Dumping of registers not supported for this OS/arch");
@@ -1183,6 +1377,8 @@ void serverLogHexDump(int level, char *descr, void *value, size_t len) {
 void watchdogSignalHandler(int sig, siginfo_t *info, void *secret) {
 #ifdef HAVE_BACKTRACE
     ucontext_t *uc = (ucontext_t*) secret;
+#else
+    (void)secret;
 #endif
     UNUSED(info);
     UNUSED(sig);

src/defrag.c

@@ -47,7 +47,7 @@ int je_get_defrag_hint(void* ptr, int *bin_util, int *run_util);
 
 /* forward declarations*/
 void defragDictBucketCallback(void *privdata, dictEntry **bucketref);
-dictEntry* replaceSateliteDictKeyPtrAndOrDefragDictEntry(dict *d, sds oldkey, sds newkey, unsigned int hash, long *defragged);
+dictEntry* replaceSateliteDictKeyPtrAndOrDefragDictEntry(dict *d, sds oldkey, sds newkey, uint64_t hash, long *defragged);
 
 /* Defrag helper for generic allocations.
  *
@@ -355,7 +355,7 @@ long activeDefragSdsListAndDict(list *l, dict *d, int dict_val_type) {
         sdsele = ln->value;
         if ((newsds = activeDefragSds(sdsele))) {
             /* When defragging an sds value, we need to update the dict key */
-            unsigned int hash = dictGetHash(d, sdsele);
+            uint64_t hash = dictGetHash(d, sdsele);
             replaceSateliteDictKeyPtrAndOrDefragDictEntry(d, sdsele, newsds, hash, &defragged);
             ln->value = newsds;
             defragged++;
@@ -392,7 +392,7 @@ long activeDefragSdsListAndDict(list *l, dict *d, int dict_val_type) {
  * moved. Return value is the the dictEntry if found, or NULL if not found.
  * NOTE: this is very ugly code, but it let's us avoid the complication of
  * doing a scan on another dict. */
-dictEntry* replaceSateliteDictKeyPtrAndOrDefragDictEntry(dict *d, sds oldkey, sds newkey, unsigned int hash, long *defragged) {
+dictEntry* replaceSateliteDictKeyPtrAndOrDefragDictEntry(dict *d, sds oldkey, sds newkey, uint64_t hash, long *defragged) {
     dictEntry **deref = dictFindEntryRefByPtrAndHash(d, oldkey, hash);
     if (deref) {
         dictEntry *de = *deref;

src/evict.c

@@ -364,7 +364,7 @@ size_t freeMemoryGetNotCountedMemory(void) {
         }
     }
     if (server.aof_state != AOF_OFF) {
-        overhead += sdslen(server.aof_buf)+aofRewriteBufferSize();
+        overhead += sdsalloc(server.aof_buf)+aofRewriteBufferSize();
     }
     return overhead;
 }
@@ -444,8 +444,8 @@ int getMaxmemoryState(size_t *total, size_t *logical, size_t *tofree, float *lev
  * Otehrwise if we are over the memory limit, but not enough memory
  * was freed to return back under the limit, the function returns C_ERR. */
 int freeMemoryIfNeeded(void) {
-    /* By default slaves should ignore maxmemory and just be masters excat
-     * copies. */
+    /* By default replicas should ignore maxmemory
+     * and just be masters exact copies. */
     if (server.masterhost && server.repl_slave_ignore_maxmemory) return C_OK;
 
     size_t mem_reported, mem_tofree, mem_freed;
@@ -622,3 +622,14 @@ cant_free:
     return C_ERR;
 }
 
+/* This is a wrapper for freeMemoryIfNeeded() that only really calls the
+ * function if right now there are the conditions to do so safely:
+ *
+ * - There must be no script in timeout condition.
+ * - Nor we are loading data right now.
+ *
+ */
+int freeMemoryIfNeededAndSafe(void) {
+    if (server.lua_timedout || server.loading) return C_OK;
+    return freeMemoryIfNeeded();
+}

src/geo.c

@@ -659,7 +659,7 @@ void georadiusGeneric(client *c, int flags) {
             zsetConvertToZiplistIfNeeded(zobj,maxelelen);
             setKey(c->db,storekey,zobj);
             decrRefCount(zobj);
-            notifyKeyspaceEvent(NOTIFY_LIST,"georadiusstore",storekey,
+            notifyKeyspaceEvent(NOTIFY_ZSET,"georadiusstore",storekey,
                                 c->db->id);
             server.dirty += returned_items;
         } else if (dbDelete(c->db,storekey)) {

src/geohash.c

@@ -127,8 +127,8 @@ int geohashEncode(const GeoHashRange *long_range, const GeoHashRange *lat_range,
 
     /* Return an error when trying to index outside the supported
      * constraints. */
-    if (longitude > 180 || longitude < -180 ||
-        latitude > 85.05112878 || latitude < -85.05112878) return 0;
+    if (longitude > GEO_LONG_MAX || longitude < GEO_LONG_MIN ||
+        latitude > GEO_LAT_MAX || latitude < GEO_LAT_MIN) return 0;
 
     hash->bits = 0;
     hash->step = step;

src/help.h

@@ -98,6 +98,11 @@ struct commandHelp {
     "Get the current connection name",
     9,
     "2.6.9" },
+    { "CLIENT ID",
+    "-",
+    "Returns the client ID for the current connection",
+    9,
+    "5.0.0" },
     { "CLIENT KILL",
     "[ip:port] [ID client-id] [TYPE normal|master|slave|pubsub] [ADDR ip:port] [SKIPME yes/no]",
     "Kill the connection of a client",
@@ -123,6 +128,11 @@ struct commandHelp {
     "Set the current connection name",
     9,
     "2.6.9" },
+    { "CLIENT UNBLOCK",
+    "client-id [TIMEOUT|ERROR]",
+    "Unblock a client blocked in a blocking command from a different connection",
+    9,
+    "5.0.0" },
     { "CLUSTER ADDSLOTS",
     "slot [slot ...]",
     "Assign new hash slots to receiving node",
@@ -145,7 +155,7 @@ struct commandHelp {
     "3.0.0" },
     { "CLUSTER FAILOVER",
     "[FORCE|TAKEOVER]",
-    "Forces a slave to perform a manual failover of its master.",
+    "Forces a replica to perform a manual failover of its master.",
     12,
     "3.0.0" },
     { "CLUSTER FORGET",
@@ -178,9 +188,14 @@ struct commandHelp {
     "Get Cluster config for the node",
     12,
     "3.0.0" },
+    { "CLUSTER REPLICAS",
+    "node-id",
+    "List replica nodes of the specified master node",
+    12,
+    "5.0.0" },
     { "CLUSTER REPLICATE",
     "node-id",
-    "Reconfigure a node as a slave of the specified master node",
+    "Reconfigure a node as a replica of the specified master node",
     12,
     "3.0.0" },
     { "CLUSTER RESET",
@@ -205,7 +220,7 @@ struct commandHelp {
     "3.0.0" },
     { "CLUSTER SLAVES",
     "node-id",
-    "List slave nodes of the specified master node",
+    "List replica nodes of the specified master node",
     12,
     "3.0.0" },
     { "CLUSTER SLOTS",
@@ -690,12 +705,12 @@ struct commandHelp {
     "1.0.0" },
     { "READONLY",
     "-",
-    "Enables read queries for a connection to a cluster slave node",
+    "Enables read queries for a connection to a cluster replica node",
     12,
     "3.0.0" },
     { "READWRITE",
     "-",
-    "Disables read queries for a connection to a cluster slave node",
+    "Disables read queries for a connection to a cluster replica node",
     12,
     "3.0.0" },
     { "RENAME",
@@ -708,6 +723,11 @@ struct commandHelp {
     "Rename a key, only if the new key does not exist",
     0,
     "1.0.0" },
+    { "REPLICAOF",
+    "host port",
+    "Make the server a replica of another instance, or promote it as master.",
+    9,
+    "5.0.0" },
     { "RESTORE",
     "key ttl serialized-value [REPLACE]",
     "Create a key using the provided serialized value, previously obtained using DUMP.",
@@ -845,7 +865,7 @@ struct commandHelp {
     "1.0.0" },
     { "SLAVEOF",
     "host port",
-    "Make the server a slave of another instance, or promote it as master",
+    "Make the server a replica of another instance, or promote it as master. Deprecated starting with Redis 5. Use REPLICAOF instead.",
     9,
     "1.0.0" },
     { "SLOWLOG",
@@ -954,7 +974,7 @@ struct commandHelp {
     7,
     "2.2.0" },
     { "WAIT",
-    "numslaves timeout",
+    "numreplicas timeout",
     "Wait for the synchronous replication of all the write commands sent in the context of the current connection",
     0,
     "3.0.0" },
@@ -963,11 +983,36 @@ struct commandHelp {
     "Watch the given keys to determine execution of the MULTI/EXEC block",
     7,
     "2.2.0" },
+    { "XACK",
+    "key group ID [ID ...]",
+    "Marks a pending message as correctly processed, effectively removing it from the pending entries list of the consumer group. Return value of the command is the number of messages successfully acknowledged, that is, the IDs we were actually able to resolve in the PEL.",
+    14,
+    "5.0.0" },
     { "XADD",
     "key ID field string [field string ...]",
     "Appends a new entry to a stream",
     14,
     "5.0.0" },
+    { "XCLAIM",
+    "key group consumer min-idle-time ID [ID ...] [IDLE ms] [TIME ms-unix-time] [RETRYCOUNT count] [force] [justid]",
+    "Changes (or acquires) ownership of a message in a consumer group, as if the message was delivered to the specified consumer.",
+    14,
+    "5.0.0" },
+    { "XDEL",
+    "key ID [ID ...]",
+    "Removes the specified entries from the stream. Returns the number of items actually deleted, that may be different from the number of IDs passed in case certain IDs do not exist.",
+    14,
+    "5.0.0" },
+    { "XGROUP",
+    "[CREATE key groupname id-or-$] [SETID key id-or-$] [DESTROY key groupname] [DELCONSUMER key groupname consumername]",
+    "Create, destroy, and manage consumer groups.",
+    14,
+    "5.0.0" },
+    { "XINFO",
+    "[CONSUMERS key groupname] [GROUPS key] [STREAM key] [HELP]",
+    "Get information on streams and consumer groups",
+    14,
+    "5.0.0" },
     { "XLEN",
     "key",
     "Return the number of entires in a stream",
@@ -998,6 +1043,11 @@ struct commandHelp {
     "Return a range of elements in a stream, with IDs matching the specified IDs interval, in reverse order (from greater to smaller IDs) compared to XRANGE",
     14,
     "5.0.0" },
+    { "XTRIM",
+    "key MAXLEN [~] count",
+    "Trims the stream to (approximately if '~' is passed) a certain size",
+    14,
+    "5.0.0" },
     { "ZADD",
     "key [NX|XX] [CH] [INCR] score member [score member ...]",
     "Add one or more members to a sorted set, or update its score if it already exists",

src/hyperloglog.c

@@ -614,6 +614,7 @@ int hllSparseToDense(robj *o) {
         } else {
             runlen = HLL_SPARSE_VAL_LEN(p);
             regval = HLL_SPARSE_VAL_VALUE(p);
+            if ((runlen + idx) > HLL_REGISTERS) break; /* Overflow. */
             while(runlen--) {
                 HLL_DENSE_SET_REGISTER(hdr->registers,idx,regval);
                 idx++;
@@ -1013,7 +1014,12 @@ uint64_t hllCount(struct hllhdr *hdr, int *invalid) {
     double m = HLL_REGISTERS;
     double E;
     int j;
-    int reghisto[HLL_Q+2] = {0};
+    /* Note that reghisto size could be just HLL_Q+2, becuase HLL_Q+1 is
+     * the maximum frequency of the "000...1" sequence the hash function is
+     * able to return. However it is slow to check for sanity of the
+     * input: instead we history array at a safe size: overflows will
+     * just write data to wrong, but correctly allocated, places. */
+    int reghisto[64] = {0};
 
     /* Compute register histogram */
     if (hdr->encoding == HLL_DENSE) {
@@ -1088,6 +1094,7 @@ int hllMerge(uint8_t *max, robj *hll) {
             } else {
                 runlen = HLL_SPARSE_VAL_LEN(p);
                 regval = HLL_SPARSE_VAL_VALUE(p);
+                if ((runlen + i) > HLL_REGISTERS) break; /* Overflow. */
                 while(runlen--) {
                     if (regval > max[i]) max[i] = regval;
                     i++;

src/intset.c

@@ -123,7 +123,7 @@ static uint8_t intsetSearch(intset *is, int64_t value, uint32_t *pos) {
     } else {
         /* Check for the case where we know we cannot find the value,
          * but do know the insert position. */
-        if (value > _intsetGet(is,intrev32ifbe(is->length)-1)) {
+        if (value > _intsetGet(is,max)) {
             if (pos) *pos = intrev32ifbe(is->length);
             return 0;
         } else if (value < _intsetGet(is,0)) {

src/latency.c

@@ -560,12 +560,23 @@ sds latencyCommandGenSparkeline(char *event, struct latencyTimeSeries *ts) {
 
 /* LATENCY command implementations.
  *
- * LATENCY SAMPLES: return time-latency samples for the specified event.
+ * LATENCY HISTORY: return time-latency samples for the specified event.
  * LATENCY LATEST: return the latest latency for all the events classes.
- * LATENCY DOCTOR: returns an human readable analysis of instance latency.
+ * LATENCY DOCTOR: returns a human readable analysis of instance latency.
  * LATENCY GRAPH: provide an ASCII graph of the latency of the specified event.
+ * LATENCY RESET: reset data of a specified event or all the data if no event provided.
  */
 void latencyCommand(client *c) {
+    const char *help[] = {
+"DOCTOR              -- Returns a human readable latency analysis report.",
+"GRAPH   <event>     -- Returns an ASCII latency graph for the event class.",
+"HISTORY <event>     -- Returns time-latency samples for the event class.",
+"LATEST              -- Returns the latest latency samples for all events.",
+"RESET   [event ...] -- Resets latency data of one or more event classes.",
+"                       (default: reset all data for all event classes)",
+"HELP                -- Prints this help.",
+NULL
+    };
     struct latencyTimeSeries *ts;
 
     if (!strcasecmp(c->argv[1]->ptr,"history") && c->argc == 3) {
@@ -610,8 +621,10 @@ void latencyCommand(client *c) {
                 resets += latencyResetEvent(c->argv[j]->ptr);
             addReplyLongLong(c,resets);
         }
+    } else if (!strcasecmp(c->argv[1]->ptr,"help") && c->argc >= 2) {
+        addReplyHelp(c, help);
     } else {
-        addReply(c,shared.syntaxerr);
+        addReplySubcommandSyntaxError(c);
     }
     return;
 

src/listpack.c

@@ -707,6 +707,26 @@ unsigned char *lpInsert(unsigned char *lp, unsigned char *ele, uint32_t size, un
         }
     }
     lpSetTotalBytes(lp,new_listpack_bytes);
+
+#if 0
+    /* This code path is normally disabled: what it does is to force listpack
+     * to return *always* a new pointer after performing some modification to
+     * the listpack, even if the previous allocation was enough. This is useful
+     * in order to spot bugs in code using listpacks: by doing so we can find
+     * if the caller forgets to set the new pointer where the listpack reference
+     * is stored, after an update. */
+    unsigned char *oldlp = lp;
+    lp = lp_malloc(new_listpack_bytes);
+    memcpy(lp,oldlp,new_listpack_bytes);
+    if (newp) {
+        unsigned long offset = (*newp)-oldlp;
+        *newp = lp + offset;
+    }
+    /* Make sure the old allocation contains garbage. */
+    memset(oldlp,'A',new_listpack_bytes);
+    lp_free(oldlp);
+#endif
+
     return lp;
 }
 

src/lolwut.c

@@ -0,0 +1,56 @@
+/*
+ * Copyright (c) 2018, Salvatore Sanfilippo <antirez at gmail dot com>
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are met:
+ *
+ *   * Redistributions of source code must retain the above copyright notice,
+ *     this list of conditions and the following disclaimer.
+ *   * Redistributions in binary form must reproduce the above copyright
+ *     notice, this list of conditions and the following disclaimer in the
+ *     documentation and/or other materials provided with the distribution.
+ *   * Neither the name of Redis nor the names of its contributors may be used
+ *     to endorse or promote products derived from this software without
+ *     specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
+ * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
+ * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
+ * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
+ * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
+ * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
+ * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
+ * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
+ * POSSIBILITY OF SUCH DAMAGE.
+ *
+ * ----------------------------------------------------------------------------
+ *
+ * This file implements the LOLWUT command. The command should do something
+ * fun and interesting, and should be replaced by a new implementation at
+ * each new version of Redis.
+ */
+
+#include "server.h"
+
+void lolwut5Command(client *c);
+
+/* The default target for LOLWUT if no matching version was found.
+ * This is what unstable versions of Redis will display. */
+void lolwutUnstableCommand(client *c) {
+    sds rendered = sdsnew("Redis ver. ");
+    rendered = sdscat(rendered,REDIS_VERSION);
+    rendered = sdscatlen(rendered,"\n",1);
+    addReplyBulkSds(c,rendered);
+}
+
+void lolwutCommand(client *c) {
+    char *v = REDIS_VERSION;
+    if ((v[0] == '5' && v[1] == '.') ||
+        (v[0] == '4' && v[1] == '.' && v[2] == '9'))
+        lolwut5Command(c);
+    else
+        lolwutUnstableCommand(c);
+}

src/lolwut5.c

@@ -0,0 +1,282 @@
+/*
+ * Copyright (c) 2018, Salvatore Sanfilippo <antirez at gmail dot com>
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are met:
+ *
+ *   * Redistributions of source code must retain the above copyright notice,
+ *     this list of conditions and the following disclaimer.
+ *   * Redistributions in binary form must reproduce the above copyright
+ *     notice, this list of conditions and the following disclaimer in the
+ *     documentation and/or other materials provided with the distribution.
+ *   * Neither the name of Redis nor the names of its contributors may be used
+ *     to endorse or promote products derived from this software without
+ *     specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
+ * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
+ * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
+ * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
+ * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
+ * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
+ * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
+ * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
+ * POSSIBILITY OF SUCH DAMAGE.
+ *
+ * ----------------------------------------------------------------------------
+ *
+ * This file implements the LOLWUT command. The command should do something
+ * fun and interesting, and should be replaced by a new implementation at
+ * each new version of Redis.
+ */
+
+#include "server.h"
+#include <math.h>
+
+/* This structure represents our canvas. Drawing functions will take a pointer
+ * to a canvas to write to it. Later the canvas can be rendered to a string
+ * suitable to be printed on the screen, using unicode Braille characters. */
+typedef struct lwCanvas {
+    int width;
+    int height;
+    char *pixels;
+} lwCanvas;
+
+/* Translate a group of 8 pixels (2x4 vertical rectangle) to the corresponding
+ * braille character. The byte should correspond to the pixels arranged as
+ * follows, where 0 is the least significant bit, and 7 the most significant
+ * bit:
+ *
+ *   0 3
+ *   1 4
+ *   2 5
+ *   6 7
+ *
+ * The corresponding utf8 encoded character is set into the three bytes
+ * pointed by 'output'.
+ */
+#include <stdio.h>
+void lwTranslatePixelsGroup(int byte, char *output) {
+    int code = 0x2800 + byte;
+    /* Convert to unicode. This is in the U0800-UFFFF range, so we need to
+     * emit it like this in three bytes:
+     * 1110xxxx 10xxxxxx 10xxxxxx. */
+    output[0] = 0xE0 | (code >> 12);          /* 1110-xxxx */
+    output[1] = 0x80 | ((code >> 6) & 0x3F);  /* 10-xxxxxx */
+    output[2] = 0x80 | (code & 0x3F);         /* 10-xxxxxx */
+}
+
+/* Allocate and return a new canvas of the specified size. */
+lwCanvas *lwCreateCanvas(int width, int height) {
+    lwCanvas *canvas = zmalloc(sizeof(*canvas));
+    canvas->width = width;
+    canvas->height = height;
+    canvas->pixels = zmalloc(width*height);
+    memset(canvas->pixels,0,width*height);
+    return canvas;
+}
+
+/* Free the canvas created by lwCreateCanvas(). */
+void lwFreeCanvas(lwCanvas *canvas) {
+    zfree(canvas->pixels);
+    zfree(canvas);
+}
+
+/* Set a pixel to the specified color. Color is 0 or 1, where zero means no
+ * dot will be displyed, and 1 means dot will be displayed.
+ * Coordinates are arranged so that left-top corner is 0,0. You can write
+ * out of the size of the canvas without issues. */
+void lwDrawPixel(lwCanvas *canvas, int x, int y, int color) {
+    if (x < 0 || x >= canvas->width ||
+        y < 0 || y >= canvas->height) return;
+    canvas->pixels[x+y*canvas->width] = color;
+}
+
+/* Return the value of the specified pixel on the canvas. */
+int lwGetPixel(lwCanvas *canvas, int x, int y) {
+    if (x < 0 || x >= canvas->width ||
+        y < 0 || y >= canvas->height) return 0;
+    return canvas->pixels[x+y*canvas->width];
+}
+
+/* Draw a line from x1,y1 to x2,y2 using the Bresenham algorithm. */
+void lwDrawLine(lwCanvas *canvas, int x1, int y1, int x2, int y2, int color) {
+    int dx = abs(x2-x1);
+    int dy = abs(y2-y1);
+    int sx = (x1 < x2) ? 1 : -1;
+    int sy = (y1 < y2) ? 1 : -1;
+    int err = dx-dy, e2;
+
+    while(1) {
+        lwDrawPixel(canvas,x1,y1,color);
+        if (x1 == x2 && y1 == y2) break;
+        e2 = err*2;
+        if (e2 > -dy) {
+            err -= dy;
+            x1 += sx;
+        }
+        if (e2 < dx) {
+            err += dx;
+            y1 += sy;
+        }
+    }
+}
+
+/* Draw a square centered at the specified x,y coordinates, with the specified
+ * rotation angle and size. In order to write a rotated square, we use the
+ * trivial fact that the parametric equation:
+ *
+ *  x = sin(k)
+ *  y = cos(k)
+ *
+ * Describes a circle for values going from 0 to 2*PI. So basically if we start
+ * at 45 degrees, that is k = PI/4, with the first point, and then we find
+ * the other three points incrementing K by PI/2 (90 degrees), we'll have the
+ * points of the square. In order to rotate the square, we just start with
+ * k = PI/4 + rotation_angle, and we are done.
+ *
+ * Of course the vanilla equations above will describe the square inside a
+ * circle of radius 1, so in order to draw larger squares we'll have to
+ * multiply the obtained coordinates, and then translate them. However this
+ * is much simpler than implementing the abstract concept of 2D shape and then
+ * performing the rotation/translation transformation, so for LOLWUT it's
+ * a good approach. */
+void lwDrawSquare(lwCanvas *canvas, int x, int y, float size, float angle) {
+    int px[4], py[4];
+
+    /* Adjust the desired size according to the fact that the square inscribed
+     * into a circle of radius 1 has the side of length SQRT(2). This way
+     * size becomes a simple multiplication factor we can use with our
+     * coordinates to magnify them. */
+    size /= 1.4142135623;
+    size = round(size);
+
+    /* Compute the four points. */
+    float k = M_PI/4 + angle;
+    for (int j = 0; j < 4; j++) {
+        px[j] = round(sin(k) * size + x);
+        py[j] = round(cos(k) * size + y);
+        k += M_PI/2;
+    }
+
+    /* Draw the square. */
+    for (int j = 0; j < 4; j++)
+        lwDrawLine(canvas,px[j],py[j],px[(j+1)%4],py[(j+1)%4],1);
+}
+
+/* Schotter, the output of LOLWUT of Redis 5, is a computer graphic art piece
+ * generated by Georg Nees in the 60s. It explores the relationship between
+ * caos and order.
+ *
+ * The function creates the canvas itself, depending on the columns available
+ * in the output display and the number of squares per row and per column
+ * requested by the caller. */
+lwCanvas *lwDrawSchotter(int console_cols, int squares_per_row, int squares_per_col) {
+    /* Calculate the canvas size. */
+    int canvas_width = console_cols*2;
+    int padding = canvas_width > 4 ? 2 : 0;
+    float square_side = (float)(canvas_width-padding*2) / squares_per_row;
+    int canvas_height = square_side * squares_per_col + padding*2;
+    lwCanvas *canvas = lwCreateCanvas(canvas_width, canvas_height);
+
+    for (int y = 0; y < squares_per_col; y++) {
+        for (int x = 0; x < squares_per_row; x++) {
+            int sx = x * square_side + square_side/2 + padding;
+            int sy = y * square_side + square_side/2 + padding;
+            /* Rotate and translate randomly as we go down to lower
+             * rows. */
+            float angle = 0;
+            if (y > 1) {
+                float r1 = (float)rand() / RAND_MAX / squares_per_col * y;
+                float r2 = (float)rand() / RAND_MAX / squares_per_col * y;
+                float r3 = (float)rand() / RAND_MAX / squares_per_col * y;
+                if (rand() % 2) r1 = -r1;
+                if (rand() % 2) r2 = -r2;
+                if (rand() % 2) r3 = -r3;
+                angle = r1;
+                sx += r2*square_side/3;
+                sy += r3*square_side/3;
+            }
+            lwDrawSquare(canvas,sx,sy,square_side,angle);
+        }
+    }
+
+    return canvas;
+}
+
+/* Converts the canvas to an SDS string representing the UTF8 characters to
+ * print to the terminal in order to obtain a graphical representaiton of the
+ * logical canvas. The actual returned string will require a terminal that is
+ * width/2 large and height/4 tall in order to hold the whole image without
+ * overflowing or scrolling, since each Barille character is 2x4. */
+sds lwRenderCanvas(lwCanvas *canvas) {
+    sds text = sdsempty();
+    for (int y = 0; y < canvas->height; y += 4) {
+        for (int x = 0; x < canvas->width; x += 2) {
+            /* We need to emit groups of 8 bits according to a specific
+             * arrangement. See lwTranslatePixelsGroup() for more info. */
+            int byte = 0;
+            if (lwGetPixel(canvas,x,y)) byte |= (1<<0);
+            if (lwGetPixel(canvas,x,y+1)) byte |= (1<<1);
+            if (lwGetPixel(canvas,x,y+2)) byte |= (1<<2);
+            if (lwGetPixel(canvas,x+1,y)) byte |= (1<<3);
+            if (lwGetPixel(canvas,x+1,y+1)) byte |= (1<<4);
+            if (lwGetPixel(canvas,x+1,y+2)) byte |= (1<<5);
+            if (lwGetPixel(canvas,x,y+3)) byte |= (1<<6);
+            if (lwGetPixel(canvas,x+1,y+3)) byte |= (1<<7);
+            char unicode[3];
+            lwTranslatePixelsGroup(byte,unicode);
+            text = sdscatlen(text,unicode,3);
+        }
+        if (y != canvas->height-1) text = sdscatlen(text,"\n",1);
+    }
+    return text;
+}
+
+/* The LOLWUT command:
+ *
+ * LOLWUT [terminal columns] [squares-per-row] [squares-per-col]
+ *
+ * By default the command uses 66 columns, 8 squares per row, 12 squares
+ * per column.
+ */
+void lolwut5Command(client *c) {
+    long cols = 66;
+    long squares_per_row = 8;
+    long squares_per_col = 12;
+
+    /* Parse the optional arguments if any. */
+    if (c->argc > 1 &&
+        getLongFromObjectOrReply(c,c->argv[1],&cols,NULL) != C_OK)
+        return;
+
+    if (c->argc > 2 &&
+        getLongFromObjectOrReply(c,c->argv[2],&squares_per_row,NULL) != C_OK)
+        return;
+
+    if (c->argc > 3 &&
+        getLongFromObjectOrReply(c,c->argv[3],&squares_per_col,NULL) != C_OK)
+        return;
+
+    /* Limits. We want LOLWUT to be always reasonably fast and cheap to execute
+     * so we have maximum number of columns, rows, and output resulution. */
+    if (cols < 1) cols = 1;
+    if (cols > 1000) cols = 1000;
+    if (squares_per_row < 1) squares_per_row = 1;
+    if (squares_per_row > 200) squares_per_row = 200;
+    if (squares_per_col < 1) squares_per_col = 1;
+    if (squares_per_col > 200) squares_per_col = 200;
+
+    /* Generate some computer art and reply. */
+    lwCanvas *canvas = lwDrawSchotter(cols,squares_per_row,squares_per_col);
+    sds rendered = lwRenderCanvas(canvas);
+    rendered = sdscat(rendered,
+        "\nGeorg Nees - schotter, plotter on paper, 1968. Redis ver. ");
+    rendered = sdscat(rendered,REDIS_VERSION);
+    rendered = sdscatlen(rendered,"\n",1);
+    addReplyBulkSds(c,rendered);
+    lwFreeCanvas(canvas);
+}

src/lzf_d.c

@@ -52,6 +52,10 @@
 #endif
 #endif
 
+#if defined(__GNUC__) && __GNUC__ >= 5
+#pragma GCC diagnostic push
+#pragma GCC diagnostic ignored "-Wimplicit-fallthrough"
+#endif
 unsigned int
 lzf_decompress (const void *const in_data,  unsigned int in_len,
                 void             *out_data, unsigned int out_len)
@@ -86,8 +90,6 @@ lzf_decompress (const void *const in_data,  unsigned int in_len,
 #ifdef lzf_movsb
           lzf_movsb (op, ip, ctrl);
 #else
-#pragma GCC diagnostic push
-#pragma GCC diagnostic ignored "-Wimplicit-fallthrough"
           switch (ctrl)
             {
               case 32: *op++ = *ip++; case 31: *op++ = *ip++; case 30: *op++ = *ip++; case 29: *op++ = *ip++;
@@ -99,7 +101,6 @@ lzf_decompress (const void *const in_data,  unsigned int in_len,
               case  8: *op++ = *ip++; case  7: *op++ = *ip++; case  6: *op++ = *ip++; case  5: *op++ = *ip++;
               case  4: *op++ = *ip++; case  3: *op++ = *ip++; case  2: *op++ = *ip++; case  1: *op++ = *ip++;
             }
-#pragma GCC diagnostic pop
 #endif
         }
       else /* back reference */
@@ -185,4 +186,6 @@ lzf_decompress (const void *const in_data,  unsigned int in_len,
 
   return op - (u8 *)out_data;
 }
-
+#if defined(__GNUC__) && __GNUC__ >= 5
+#pragma GCC diagnostic pop
+#endif

src/modules/Makefile

@@ -13,7 +13,7 @@ endif
 
 .SUFFIXES: .c .so .xo .o
 
-all: helloworld.so hellotype.so helloblock.so testmodule.so hellocluster.so hellotimer.so
+all: helloworld.so hellotype.so helloblock.so testmodule.so hellocluster.so hellotimer.so hellodict.so
 
 .c.xo:
 	$(CC) -I. $(CFLAGS) $(SHOBJ_CFLAGS) -fPIC -c $< -o $@
@@ -43,6 +43,10 @@ hellotimer.xo: ../redismodule.h
 hellotimer.so: hellotimer.xo
 	$(LD) -o $@ $< $(SHOBJ_LDFLAGS) $(LIBS) -lc
 
+hellodict.xo: ../redismodule.h
+
+hellodict.so: hellodict.xo
+
 testmodule.xo: ../redismodule.h
 
 testmodule.so: testmodule.xo

src/modules/helloblock.c

@@ -77,7 +77,7 @@ void *HelloBlock_ThreadMain(void *arg) {
 /* An example blocked client disconnection callback.
  *
  * Note that in the case of the HELLO.BLOCK command, the blocked client is now
- * owned by the thread calling sleep(). In this speciifc case, there is not
+ * owned by the thread calling sleep(). In this specific case, there is not
  * much we can do, however normally we could instead implement a way to
  * signal the thread that the client disconnected, and sleep the specified
  * amount of seconds with a while loop calling sleep(1), so that once we

src/modules/hellocluster.c

@@ -69,7 +69,7 @@ int ListCommand_RedisCommand(RedisModuleCtx *ctx, RedisModuleString **argv, int
         RedisModule_ReplyWithLongLong(ctx,port);
     }
     RedisModule_FreeClusterNodesList(ids);
-    return RedisModule_ReplyWithSimpleString(ctx, "OK");
+    return REDISMODULE_OK;
 }
 
 /* Callback for message MSGTYPE_PING */
@@ -77,6 +77,7 @@ void PingReceiver(RedisModuleCtx *ctx, const char *sender_id, uint8_t type, cons
     RedisModule_Log(ctx,"notice","PING (type %d) RECEIVED from %.*s: '%.*s'",
         type,REDISMODULE_NODE_ID_LEN,sender_id,(int)len, payload);
     RedisModule_SendClusterMessage(ctx,NULL,MSGTYPE_PONG,(unsigned char*)"Ohi!",4);
+    RedisModule_Call(ctx, "INCR", "c", "pings_received");
 }
 
 /* Callback for message MSGTYPE_PONG. */
@@ -102,6 +103,15 @@ int RedisModule_OnLoad(RedisModuleCtx *ctx, RedisModuleString **argv, int argc)
         ListCommand_RedisCommand,"readonly",0,0,0) == REDISMODULE_ERR)
         return REDISMODULE_ERR;
 
+    /* Disable Redis Cluster sharding and redirections. This way every node
+     * will be able to access every possible key, regardless of the hash slot.
+     * This way the PING message handler will be able to increment a specific
+     * variable. Normally you do that in order for the distributed system
+     * you create as a module to have total freedom in the keyspace
+     * manipulation. */
+    RedisModule_SetClusterFlags(ctx,REDISMODULE_CLUSTER_FLAG_NO_REDIRECTION);
+
+    /* Register our handlers for different message types. */
     RedisModule_RegisterClusterMessageReceiver(ctx,MSGTYPE_PING,PingReceiver);
     RedisModule_RegisterClusterMessageReceiver(ctx,MSGTYPE_PONG,PongReceiver);
     return REDISMODULE_OK;

src/modules/hellodict.c

@@ -0,0 +1,132 @@
+/* Hellodict -- An example of modules dictionary API
+ *
+ * This module implements a volatile key-value store on top of the
+ * dictionary exported by the Redis modules API.
+ *
+ * -----------------------------------------------------------------------------
+ *
+ * Copyright (c) 2018, Salvatore Sanfilippo <antirez at gmail dot com>
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are met:
+ *
+ *   * Redistributions of source code must retain the above copyright notice,
+ *     this list of conditions and the following disclaimer.
+ *   * Redistributions in binary form must reproduce the above copyright
+ *     notice, this list of conditions and the following disclaimer in the
+ *     documentation and/or other materials provided with the distribution.
+ *   * Neither the name of Redis nor the names of its contributors may be used
+ *     to endorse or promote products derived from this software without
+ *     specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
+ * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
+ * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
+ * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
+ * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
+ * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
+ * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
+ * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
+ * POSSIBILITY OF SUCH DAMAGE.
+ */
+
+#define REDISMODULE_EXPERIMENTAL_API
+#include "../redismodule.h"
+#include <stdio.h>
+#include <stdlib.h>
+#include <ctype.h>
+#include <string.h>
+
+static RedisModuleDict *Keyspace;
+
+/* HELLODICT.SET <key> <value>
+ *
+ * Set the specified key to the specified value. */
+int cmd_SET(RedisModuleCtx *ctx, RedisModuleString **argv, int argc) {
+    if (argc != 3) return RedisModule_WrongArity(ctx);
+    RedisModule_DictSet(Keyspace,argv[1],argv[2]);
+    /* We need to keep a reference to the value stored at the key, otherwise
+     * it would be freed when this callback returns. */
+    RedisModule_RetainString(NULL,argv[2]);
+    return RedisModule_ReplyWithSimpleString(ctx, "OK");
+}
+
+/* HELLODICT.GET <key>
+ *
+ * Return the value of the specified key, or a null reply if the key
+ * is not defined. */
+int cmd_GET(RedisModuleCtx *ctx, RedisModuleString **argv, int argc) {
+    if (argc != 2) return RedisModule_WrongArity(ctx);
+    RedisModuleString *val = RedisModule_DictGet(Keyspace,argv[1],NULL);
+    if (val == NULL) {
+        return RedisModule_ReplyWithNull(ctx);
+    } else {
+        return RedisModule_ReplyWithString(ctx, val);
+    }
+}
+
+/* HELLODICT.KEYRANGE <startkey> <endkey> <count>
+ *
+ * Return a list of matching keys, lexicographically between startkey
+ * and endkey. No more than 'count' items are emitted. */
+int cmd_KEYRANGE(RedisModuleCtx *ctx, RedisModuleString **argv, int argc) {
+    if (argc != 4) return RedisModule_WrongArity(ctx);
+
+    /* Parse the count argument. */
+    long long count;
+    if (RedisModule_StringToLongLong(argv[3],&count) != REDISMODULE_OK) {
+        return RedisModule_ReplyWithError(ctx,"ERR invalid count");
+    }
+
+    /* Seek the iterator. */
+    RedisModuleDictIter *iter = RedisModule_DictIteratorStart(
+        Keyspace, ">=", argv[1]);
+
+    /* Reply with the matching items. */
+    char *key;
+    size_t keylen;
+    long long replylen = 0; /* Keep track of the amitted array len. */
+    RedisModule_ReplyWithArray(ctx,REDISMODULE_POSTPONED_ARRAY_LEN);
+    while((key = RedisModule_DictNextC(iter,&keylen,NULL)) != NULL) {
+        if (replylen >= count) break;
+        if (RedisModule_DictCompare(iter,"<=",argv[2]) == REDISMODULE_ERR)
+            break;
+        RedisModule_ReplyWithStringBuffer(ctx,key,keylen);
+        replylen++;
+    }
+    RedisModule_ReplySetArrayLength(ctx,replylen);
+
+    /* Cleanup. */
+    RedisModule_DictIteratorStop(iter);
+    return REDISMODULE_OK;
+}
+
+/* This function must be present on each Redis module. It is used in order to
+ * register the commands into the Redis server. */
+int RedisModule_OnLoad(RedisModuleCtx *ctx, RedisModuleString **argv, int argc) {
+    REDISMODULE_NOT_USED(argv);
+    REDISMODULE_NOT_USED(argc);
+
+    if (RedisModule_Init(ctx,"hellodict",1,REDISMODULE_APIVER_1)
+        == REDISMODULE_ERR) return REDISMODULE_ERR;
+
+    if (RedisModule_CreateCommand(ctx,"hellodict.set",
+        cmd_SET,"write deny-oom",1,1,0) == REDISMODULE_ERR)
+        return REDISMODULE_ERR;
+
+    if (RedisModule_CreateCommand(ctx,"hellodict.get",
+        cmd_GET,"readonly",1,1,0) == REDISMODULE_ERR)
+        return REDISMODULE_ERR;
+
+    if (RedisModule_CreateCommand(ctx,"hellodict.keyrange",
+        cmd_KEYRANGE,"readonly",1,1,0) == REDISMODULE_ERR)
+        return REDISMODULE_ERR;
+
+    /* Create our global dictionray. Here we'll set our keys and values. */
+    Keyspace = RedisModule_CreateDict(NULL);
+
+    return REDISMODULE_OK;
+}

src/modules/hellotimer.c

@@ -1,4 +1,4 @@
-/* Helloworld cluster -- A ping/pong cluster API example.
+/* Timer API example -- Register and handle timer events
  *
  * -----------------------------------------------------------------------------
  *
@@ -37,9 +37,6 @@
 #include <ctype.h>
 #include <string.h>
 
-#define MSGTYPE_PING 1
-#define MSGTYPE_PONG 2
-
 /* Timer callback. */
 void timerHandler(RedisModuleCtx *ctx, void *data) {
     REDISMODULE_NOT_USED(ctx);

src/multi.c

@@ -35,6 +35,7 @@
 void initClientMultiState(client *c) {
     c->mstate.commands = NULL;
     c->mstate.count = 0;
+    c->mstate.cmd_flags = 0;
 }
 
 /* Release all the resources associated with MULTI/EXEC state */
@@ -67,6 +68,7 @@ void queueMultiCommand(client *c) {
     for (j = 0; j < c->argc; j++)
         incrRefCount(mc->argv[j]);
     c->mstate.count++;
+    c->mstate.cmd_flags |= c->cmd->flags;
 }
 
 void discardTransaction(client *c) {
@@ -137,6 +139,21 @@ void execCommand(client *c) {
         goto handle_monitor;
     }
 
+    /* If there are write commands inside the transaction, and this is a read
+     * only slave, we want to send an error. This happens when the transaction
+     * was initiated when the instance was a master or a writable replica and
+     * then the configuration changed (for example instance was turned into
+     * a replica). */
+    if (!server.loading && server.masterhost && server.repl_slave_ro &&
+        !(c->flags & CLIENT_MASTER) && c->mstate.cmd_flags & CMD_WRITE)
+    {
+        addReplyError(c,
+            "Transaction contains write commands but instance "
+            "is now a read-only slave. EXEC aborted.");
+        discardTransaction(c);
+        goto handle_monitor;
+    }
+
     /* Exec all the queued commands */
     unwatchAllKeys(c); /* Unwatch ASAP otherwise we'll waste CPU cycles */
     orig_argv = c->argv;
@@ -158,7 +175,7 @@ void execCommand(client *c) {
             must_propagate = 1;
         }
 
-        call(c,CMD_CALL_FULL);
+        call(c,server.loading ? CMD_CALL_NONE : CMD_CALL_FULL);
 
         /* Commands may alter argc/argv, restore mstate. */
         c->mstate.commands[j].argc = c->argc;

src/networking.c

@@ -29,6 +29,7 @@
 
 #include "server.h"
 #include "atomicvar.h"
+#include <sys/socket.h>
 #include <sys/uio.h>
 #include <math.h>
 #include <ctype.h>
@@ -160,6 +161,32 @@ client *createClient(int fd) {
     return c;
 }
 
+/* This funciton puts the client in the queue of clients that should write
+ * their output buffers to the socket. Note that it does not *yet* install
+ * the write handler, to start clients are put in a queue of clients that need
+ * to write, so we try to do that before returning in the event loop (see the
+ * handleClientsWithPendingWrites() function).
+ * If we fail and there is more data to write, compared to what the socket
+ * buffers can hold, then we'll really install the handler. */
+void clientInstallWriteHandler(client *c) {
+    /* Schedule the client to write the output buffers to the socket only
+     * if not already done and, for slaves, if the slave can actually receive
+     * writes at this stage. */
+    if (!(c->flags & CLIENT_PENDING_WRITE) &&
+        (c->replstate == REPL_STATE_NONE ||
+         (c->replstate == SLAVE_STATE_ONLINE && !c->repl_put_online_on_ack)))
+    {
+        /* Here instead of installing the write handler, we just flag the
+         * client and put it into a list of clients that have something
+         * to write to the socket. This way before re-entering the event
+         * loop, we can try to directly write to the client sockets avoiding
+         * a system call. We'll only really install the write handler if
+         * we'll not be able to write the whole reply at once. */
+        c->flags |= CLIENT_PENDING_WRITE;
+        listAddNodeHead(server.clients_pending_write,c);
+    }
+}
+
 /* This function is called every time we are going to transmit new data
  * to the client. The behavior is the following:
  *
@@ -197,24 +224,9 @@ int prepareClientToWrite(client *c) {
 
     if (c->fd <= 0) return C_ERR; /* Fake client for AOF loading. */
 
-    /* Schedule the client to write the output buffers to the socket only
-     * if not already done (there were no pending writes already and the client
-     * was yet not flagged), and, for slaves, if the slave can actually
-     * receive writes at this stage. */
-    if (!clientHasPendingReplies(c) &&
-        !(c->flags & CLIENT_PENDING_WRITE) &&
-        (c->replstate == REPL_STATE_NONE ||
-         (c->replstate == SLAVE_STATE_ONLINE && !c->repl_put_online_on_ack)))
-    {
-        /* Here instead of installing the write handler, we just flag the
-         * client and put it into a list of clients that have something
-         * to write to the socket. This way before re-entering the event
-         * loop, we can try to directly write to the client sockets avoiding
-         * a system call. We'll only really install the write handler if
-         * we'll not be able to write the whole reply at once. */
-        c->flags |= CLIENT_PENDING_WRITE;
-        listAddNodeHead(server.clients_pending_write,c);
-    }
+    /* Schedule the client to write the output buffers to the socket, unless
+     * it should already be setup to do so (it has already pending data). */
+    if (!clientHasPendingReplies(c)) clientInstallWriteHandler(c);
 
     /* Authorize the caller to queue in the output buffer of this client. */
     return C_OK;
@@ -354,19 +366,13 @@ void addReplyErrorLength(client *c, const char *s, size_t len) {
      * Where the master must propagate the first change even if the second
      * will produce an error. However it is useful to log such events since
      * they are rare and may hint at errors in a script or a bug in Redis. */
-    if (c->flags & (CLIENT_MASTER|CLIENT_SLAVE)) {
-        char* to = c->flags & CLIENT_MASTER? "master": "slave";
-        char* from = c->flags & CLIENT_MASTER? "slave": "master";
+    if (c->flags & (CLIENT_MASTER|CLIENT_SLAVE) && !(c->flags & CLIENT_MONITOR)) {
+        char* to = c->flags & CLIENT_MASTER? "master": "replica";
+        char* from = c->flags & CLIENT_MASTER? "replica": "master";
         char *cmdname = c->lastcmd ? c->lastcmd->name : "<unknown>";
         serverLog(LL_WARNING,"== CRITICAL == This %s is sending an error "
                              "to its %s: '%s' after processing the command "
                              "'%s'", from, to, s, cmdname);
-        /* Here we want to panic because when a master is sending an
-         * error to some slave in the context of replication, this can
-         * only create some kind of offset or data desynchronization. Better
-         * to catch it ASAP and crash instead of continuing. */
-        if (c->flags & CLIENT_SLAVE)
-            serverPanic("Continuing is unsafe: replication protocol violation.");
     }
 }
 
@@ -623,6 +629,19 @@ void addReplySubcommandSyntaxError(client *c) {
     sdsfree(cmd);
 }
 
+/* Append 'src' client output buffers into 'dst' client output buffers. 
+ * This function clears the output buffers of 'src' */
+void AddReplyFromClient(client *dst, client *src) {
+    if (prepareClientToWrite(dst) != C_OK)
+        return;
+    addReplyString(dst,src->buf, src->bufpos);
+    if (listLength(src->reply))
+        listJoin(dst->reply,src->reply);
+    dst->reply_bytes += src->reply_bytes;
+    src->reply_bytes = 0;
+    src->bufpos = 0;
+}
+
 /* Copy 'src' client output buffers into 'dst' client output buffers.
  * The function takes care of freeing the old output buffers of the
  * destination client. */
@@ -790,6 +809,16 @@ void unlinkClient(client *c) {
             c->client_list_node = NULL;
         }
 
+        /* In the case of diskless replication the fork is writing to the
+         * sockets and just closing the fd isn't enough, if we don't also
+         * shutdown the socket the fork will continue to write to the slave
+         * and the salve will only find out that it was disconnected when
+         * it will finish reading the rdb. */
+        if ((c->flags & CLIENT_SLAVE) &&
+            (c->replstate == SLAVE_STATE_WAIT_BGSAVE_END)) {
+            shutdown(c->fd, SHUT_RDWR);
+        }
+
         /* Unregister async I/O handlers and close the socket. */
         aeDeleteFileEvent(server.el,c->fd,AE_READABLE);
         aeDeleteFileEvent(server.el,c->fd,AE_WRITABLE);
@@ -818,6 +847,13 @@ void unlinkClient(client *c) {
 void freeClient(client *c) {
     listNode *ln;
 
+    /* If a client is protected, yet we need to free it right now, make sure
+     * to at least use asynchronous freeing. */
+    if (c->flags & CLIENT_PROTECTED) {
+        freeClientAsync(c);
+        return;
+    }
+
     /* If it is our master that's beging disconnected we should make sure
      * to cache the state to try a partial resynchronization later.
      *
@@ -836,7 +872,7 @@ void freeClient(client *c) {
 
     /* Log link disconnection with slave */
     if ((c->flags & CLIENT_SLAVE) && !(c->flags & CLIENT_MONITOR)) {
-        serverLog(LL_WARNING,"Connection with slave %s lost.",
+        serverLog(LL_WARNING,"Connection with replica %s lost.",
             replicationGetSlaveName(c));
     }
 
@@ -1054,6 +1090,10 @@ int handleClientsWithPendingWrites(void) {
         c->flags &= ~CLIENT_PENDING_WRITE;
         listDelNode(server.clients_pending_write,ln);
 
+        /* If a client is protected, don't do anything,
+         * that may trigger write error or recreate handler. */
+        if (c->flags & CLIENT_PROTECTED) continue;
+
         /* Try to write buffers to the client socket. */
         if (writeToClient(c->fd,c,0) == C_ERR) continue;
 
@@ -1105,6 +1145,34 @@ void resetClient(client *c) {
     }
 }
 
+/* This funciton is used when we want to re-enter the event loop but there
+ * is the risk that the client we are dealing with will be freed in some
+ * way. This happens for instance in:
+ *
+ * * DEBUG RELOAD and similar.
+ * * When a Lua script is in -BUSY state.
+ *
+ * So the function will protect the client by doing two things:
+ *
+ * 1) It removes the file events. This way it is not possible that an
+ *    error is signaled on the socket, freeing the client.
+ * 2) Moreover it makes sure that if the client is freed in a different code
+ *    path, it is not really released, but only marked for later release. */
+void protectClient(client *c) {
+    c->flags |= CLIENT_PROTECTED;
+    aeDeleteFileEvent(server.el,c->fd,AE_READABLE);
+    aeDeleteFileEvent(server.el,c->fd,AE_WRITABLE);
+}
+
+/* This will undo the client protection done by protectClient() */
+void unprotectClient(client *c) {
+    if (c->flags & CLIENT_PROTECTED) {
+        c->flags &= ~CLIENT_PROTECTED;
+        aeCreateFileEvent(server.el,c->fd,AE_READABLE,readQueryFromClient,c);
+        if (clientHasPendingReplies(c)) clientInstallWriteHandler(c);
+    }
+}
+
 /* Like processMultibulkBuffer(), but for the inline protocol instead of RESP,
  * this function consumes the client query buffer and creates a command ready
  * to be executed inside the client structure. Returns C_OK if the command
@@ -1294,19 +1362,22 @@ int processMultibulkBuffer(client *c) {
 
             c->qb_pos = newline-c->querybuf+2;
             if (ll >= PROTO_MBULK_BIG_ARG) {
-                size_t qblen;
-
                 /* If we are going to read a large object from network
                  * try to make it likely that it will start at c->querybuf
                  * boundary so that we can optimize object creation
-                 * avoiding a large copy of data. */
-                sdsrange(c->querybuf,c->qb_pos,-1);
-                c->qb_pos = 0;
-                qblen = sdslen(c->querybuf);
-                /* Hint the sds library about the amount of bytes this string is
-                 * going to contain. */
-                if (qblen < (size_t)ll+2)
-                    c->querybuf = sdsMakeRoomFor(c->querybuf,ll+2-qblen);
+                 * avoiding a large copy of data.
+                 *
+                 * But only when the data we have not parsed is less than
+                 * or equal to ll+2. If the data length is greater than
+                 * ll+2, trimming querybuf is just a waste of time, because
+                 * at this time the querybuf contains not only our bulk. */
+                if (sdslen(c->querybuf)-c->qb_pos <= (size_t)ll+2) {
+                    sdsrange(c->querybuf,c->qb_pos,-1);
+                    c->qb_pos = 0;
+                    /* Hint the sds library about the amount of bytes this string is
+                     * going to contain. */
+                    c->querybuf = sdsMakeRoomFor(c->querybuf,ll+2);
+                }
             }
             c->bulklen = ll;
         }
@@ -1417,7 +1488,7 @@ void processInputBuffer(client *c) {
     }
 
     /* Trim to pos */
-    if (c->qb_pos) {
+    if (server.current_client != NULL && c->qb_pos) {
         sdsrange(c->querybuf,c->qb_pos,-1);
         c->qb_pos = 0;
     }
@@ -1425,6 +1496,25 @@ void processInputBuffer(client *c) {
     server.current_client = NULL;
 }
 
+/* This is a wrapper for processInputBuffer that also cares about handling
+ * the replication forwarding to the sub-slaves, in case the client 'c'
+ * is flagged as master. Usually you want to call this instead of the
+ * raw processInputBuffer(). */
+void processInputBufferAndReplicate(client *c) {
+    if (!(c->flags & CLIENT_MASTER)) {
+        processInputBuffer(c);
+    } else {
+        size_t prev_offset = c->reploff;
+        processInputBuffer(c);
+        size_t applied = c->reploff - prev_offset;
+        if (applied) {
+            replicationFeedSlavesFromMasterStream(server.slaves,
+                    c->pending_querybuf, applied);
+            sdsrange(c->pending_querybuf,applied,-1);
+        }
+    }
+}
+
 void readQueryFromClient(aeEventLoop *el, int fd, void *privdata, int mask) {
     client *c = (client*) privdata;
     int nread, readlen;
@@ -1444,7 +1534,9 @@ void readQueryFromClient(aeEventLoop *el, int fd, void *privdata, int mask) {
     {
         ssize_t remaining = (size_t)(c->bulklen+2)-sdslen(c->querybuf);
 
-        if (remaining < readlen) readlen = remaining;
+        /* Note that the 'remaining' variable may be zero in some edge case,
+         * for example once we resume a blocked client after CLIENT PAUSE. */
+        if (remaining > 0 && remaining < readlen) readlen = remaining;
     }
 
     qblen = sdslen(c->querybuf);
@@ -1492,18 +1584,7 @@ void readQueryFromClient(aeEventLoop *el, int fd, void *privdata, int mask) {
      * was actually applied to the master state: this quantity, and its
      * corresponding part of the replication stream, will be propagated to
      * the sub-slaves and to the replication backlog. */
-    if (!(c->flags & CLIENT_MASTER)) {
-        processInputBuffer(c);
-    } else {
-        size_t prev_offset = c->reploff;
-        processInputBuffer(c);
-        size_t applied = c->reploff - prev_offset;
-        if (applied) {
-            replicationFeedSlavesFromMasterStream(server.slaves,
-                    c->pending_querybuf, applied);
-            sdsrange(c->pending_querybuf,applied,-1);
-        }
-    }
+    processInputBufferAndReplicate(c);
 }
 
 void getClientsMaxBuffers(unsigned long *longest_output_list,
@@ -1641,10 +1722,10 @@ void clientCommand(client *c) {
 "kill <ip:port>         -- Kill connection made from <ip:port>.",
 "kill <option> <value> [option value ...] -- Kill connections. Options are:",
 "     addr <ip:port>                      -- Kill connection made from <ip:port>",
-"     type (normal|master|slave|pubsub)   -- Kill connections by type.",
+"     type (normal|master|replica|pubsub) -- Kill connections by type.",
 "     skipme (yes|no)   -- Skip killing current connection (default: yes).",
 "list [options ...]     -- Return information about client connections. Options:",
-"     type (normal|master|slave|pubsub)   -- Return clients of specified type.",
+"     type (normal|master|replica|pubsub) -- Return clients of specified type.",
 "pause <timeout>        -- Suspend all Redis clients for <timout> milliseconds.",
 "reply (on|off|skip)    -- Control the replies sent to the current connection.",
 "setname <name>         -- Assign the name <name> to the current connection.",
@@ -1940,15 +2021,8 @@ void rewriteClientCommandArgument(client *c, int i, robj *newval) {
     }
 }
 
-/* This function returns the number of bytes that Redis is virtually
+/* This function returns the number of bytes that Redis is
  * using to store the reply still not read by the client.
- * It is "virtual" since the reply output list may contain objects that
- * are shared and are not really using additional memory.
- *
- * The function returns the total sum of the length of all the objects
- * stored in the output list, plus the memory used to allocate every
- * list node. The static reply buffer is not taken into account since it
- * is allocated anyway.
  *
  * Note: this function is very fast so can be called as many time as
  * the caller wishes. The main usage of this function currently is
@@ -1978,6 +2052,7 @@ int getClientType(client *c) {
 int getClientTypeByName(char *name) {
     if (!strcasecmp(name,"normal")) return CLIENT_TYPE_NORMAL;
     else if (!strcasecmp(name,"slave")) return CLIENT_TYPE_SLAVE;
+    else if (!strcasecmp(name,"replica")) return CLIENT_TYPE_SLAVE;
     else if (!strcasecmp(name,"pubsub")) return CLIENT_TYPE_PUBSUB;
     else if (!strcasecmp(name,"master")) return CLIENT_TYPE_MASTER;
     else return -1;
@@ -2045,6 +2120,7 @@ int checkClientOutputBufferLimits(client *c) {
  * called from contexts where the client can't be freed safely, i.e. from the
  * lower level functions pushing data inside the client output buffers. */
 void asyncCloseClientOnOutputBufferLimitReached(client *c) {
+    if (c->fd == -1) return; /* It is unsafe to free fake clients. */
     serverAssert(c->reply_bytes < SIZE_MAX-(1024*64));
     if (c->reply_bytes == 0 || c->flags & CLIENT_CLOSE_ASAP) return;
     if (checkClientOutputBufferLimits(c)) {
@@ -2126,11 +2202,10 @@ int clientsArePaused(void) {
         while ((ln = listNext(&li)) != NULL) {
             c = listNodeValue(ln);
 
-            /* Don't touch slaves and blocked clients. The latter pending
-             * requests be processed when unblocked. */
+            /* Don't touch slaves and blocked clients.
+             * The latter pending requests will be processed when unblocked. */
             if (c->flags & (CLIENT_SLAVE|CLIENT_BLOCKED)) continue;
-            c->flags |= CLIENT_UNBLOCKED;
-            listAddNodeTail(server.unblocked_clients,c);
+            queueClientForReprocessing(c);
         }
     }
     return server.clients_paused;

src/object.c

@@ -185,7 +185,7 @@ robj *createStringObjectFromLongDouble(long double value, int humanfriendly) {
 /* Duplicate a string object, with the guarantee that the returned object
  * has the same encoding as the original one.
  *
- * This function also guarantees that duplicating a small integere object
+ * This function also guarantees that duplicating a small integer object
  * (or a string object that contains a representation of a small integer)
  * will always result in a fresh object that is unshared (refcount == 1).
  *
@@ -415,6 +415,18 @@ int isObjectRepresentableAsLongLong(robj *o, long long *llval) {
     }
 }
 
+/* Optimize the SDS string inside the string object to require little space,
+ * in case there is more than 10% of free space at the end of the SDS
+ * string. This happens because SDS strings tend to overallocate to avoid
+ * wasting too much time in allocations when appending to the string. */
+void trimStringObjectIfNeeded(robj *o) {
+    if (o->encoding == OBJ_ENCODING_RAW &&
+        sdsavail(o->ptr) > sdslen(o->ptr)/10)
+    {
+        o->ptr = sdsRemoveFreeSpace(o->ptr);
+    }
+}
+
 /* Try to encode a string object in order to save space */
 robj *tryObjectEncoding(robj *o) {
     long value;
@@ -484,11 +496,7 @@ robj *tryObjectEncoding(robj *o) {
      * We do that only for relatively large strings as this branch
      * is only entered if the length of the string is greater than
      * OBJ_ENCODING_EMBSTR_SIZE_LIMIT. */
-    if (o->encoding == OBJ_ENCODING_RAW &&
-        sdsavail(s) > len/10)
-    {
-        o->ptr = sdsRemoveFreeSpace(o->ptr);
-    }
+    trimStringObjectIfNeeded(o);
 
     /* Return the original object. */
     return o;
@@ -1011,13 +1019,13 @@ struct redisMemOverhead *getMemoryOverheadData(void) {
 
     mem = 0;
     if (server.aof_state != AOF_OFF) {
-        mem += sdslen(server.aof_buf);
+        mem += sdsalloc(server.aof_buf);
         mem += aofRewriteBufferSize();
     }
     mh->aof_buffer = mem;
     mem_total+=mem;
 
-    mem = 0;
+    mem = server.lua_scripts_mem;
     mem += dictSize(server.lua_scripts) * sizeof(dictEntry) +
         dictSlots(server.lua_scripts) * sizeof(dictEntry*);
     mem += dictSize(server.repl_scriptcache_dict) * sizeof(dictEntry) +
@@ -1175,7 +1183,7 @@ sds getMemoryDoctorReport(void) {
             s = sdscatprintf(s," * High process RSS overhead: This instance has non-allocator RSS memory overhead is greater than 1.1 (this means that the Resident Set Size of the Redis process is much larger than the RSS the allocator holds). This problem may be due to Lua scripts or Modules.\n\n");
         }
         if (big_slave_buf) {
-            s = sdscat(s," * Big slave buffers: The slave output buffers in this instance are greater than 10MB for each slave (on average). This likely means that there is some slave instance that is struggling receiving data, either because it is too slow or because of networking issues. As a result, data piles on the master output buffers. Please try to identify what slave is not receiving data correctly and why. You can use the INFO output in order to check the slaves delays and the CLIENT LIST command to check the output buffers of each slave.\n\n");
+            s = sdscat(s," * Big replica buffers: The replica output buffers in this instance are greater than 10MB for each replica (on average). This likely means that there is some replica instance that is struggling receiving data, either because it is too slow or because of networking issues. As a result, data piles on the master output buffers. Please try to identify what replica is not receiving data correctly and why. You can use the INFO output in order to check the replicas delays and the CLIENT LIST command to check the output buffers of each replica.\n\n");
         }
         if (big_client_buf) {
             s = sdscat(s," * Big client buffers: The clients output buffers in this instance are greater than 200K per client (on average). This may result from different causes, like Pub/Sub clients subscribed to channels bot not receiving data fast enough, so that data piles on the Redis instance output buffer, or clients sending commands with large replies or very large sequences of commands in the same pipeline. Please use the CLIENT LIST command in order to investigate the issue if it causes problems in your instance, or to understand better why certain clients are using a big amount of memory.\n\n");
@@ -1191,7 +1199,7 @@ sds getMemoryDoctorReport(void) {
 
 /* Set the object LRU/LFU depending on server.maxmemory_policy.
  * The lfu_freq arg is only relevant if policy is MAXMEMORY_FLAG_LFU.
- * The lru_idle and lru_clock args are only relevant if policy 
+ * The lru_idle and lru_clock args are only relevant if policy
  * is MAXMEMORY_FLAG_LRU.
  * Either or both of them may be <0, in that case, nothing is set. */
 void objectSetLRUOrLFU(robj *val, long long lfu_freq, long long lru_idle,
@@ -1202,16 +1210,20 @@ void objectSetLRUOrLFU(robj *val, long long lfu_freq, long long lru_idle,
             val->lru = (LFUGetTimeInMinutes()<<8) | lfu_freq;
         }
     } else if (lru_idle >= 0) {
-        /* Serialized LRU idle time is in seconds. Scale
+        /* Provided LRU idle time is in seconds. Scale
          * according to the LRU clock resolution this Redis
          * instance was compiled with (normally 1000 ms, so the
          * below statement will expand to lru_idle*1000/1000. */
         lru_idle = lru_idle*1000/LRU_CLOCK_RESOLUTION;
-        val->lru = lru_clock - lru_idle;
-        /* If the lru field overflows (since LRU it is a wrapping
-         * clock), the best we can do is to provide the maximum
-         * representable idle time. */
-        if (val->lru < 0) val->lru = lru_clock+1;
+        long lru_abs = lru_clock - lru_idle; /* Absolute access time. */
+        /* If the LRU field underflows (since LRU it is a wrapping
+         * clock), the best we can do is to provide a large enough LRU
+         * that is half-way in the circlular LRU clock we use: this way
+         * the computed idle time for this object will stay high for quite
+         * some time. */
+        if (lru_abs < 0)
+            lru_abs = (lru_clock+(LRU_CLOCK_MAX/2)) % LRU_CLOCK_MAX;
+        val->lru = lru_abs;
     }
 }
 
@@ -1285,9 +1297,18 @@ NULL
  *
  * Usage: MEMORY usage <key> */
 void memoryCommand(client *c) {
-    robj *o;
-
-    if (!strcasecmp(c->argv[1]->ptr,"usage") && c->argc >= 3) {
+    if (!strcasecmp(c->argv[1]->ptr,"help") && c->argc == 2) {
+        const char *help[] = {
+"DOCTOR - Return memory problems reports.",
+"MALLOC-STATS -- Return internal statistics report from the memory allocator.",
+"PURGE -- Attempt to purge dirty pages for reclamation by the allocator.",
+"STATS -- Return information about the memory usage of the server.",
+"USAGE <key> [SAMPLES <count>] -- Return memory in bytes used by <key> and its value. Nested values are sampled up to <count> times (default: 5).",
+NULL
+        };
+        addReplyHelp(c, help);
+    } else if (!strcasecmp(c->argv[1]->ptr,"usage") && c->argc >= 3) {
+        dictEntry *de;
         long long samples = OBJ_COMPUTE_SIZE_DEF_SAMPLES;
         for (int j = 3; j < c->argc; j++) {
             if (!strcasecmp(c->argv[j]->ptr,"samples") &&
@@ -1306,10 +1327,12 @@ void memoryCommand(client *c) {
                 return;
             }
         }
-        if ((o = objectCommandLookupOrReply(c,c->argv[2],shared.nullbulk))
-                == NULL) return;
-        size_t usage = objectComputeSize(o,samples);
-        usage += sdsAllocSize(c->argv[2]->ptr);
+        if ((de = dictFind(c->db->dict,c->argv[2]->ptr)) == NULL) {
+            addReply(c, shared.nullbulk);
+            return;
+        }
+        size_t usage = objectComputeSize(dictGetVal(de),samples);
+        usage += sdsAllocSize(dictGetKey(de));
         usage += sizeof(dictEntry);
         addReplyLongLong(c,usage);
     } else if (!strcasecmp(c->argv[1]->ptr,"stats") && c->argc == 2) {
@@ -1434,19 +1457,7 @@ void memoryCommand(client *c) {
         addReply(c, shared.ok);
         /* Nothing to do for other allocators. */
 #endif
-    } else if (!strcasecmp(c->argv[1]->ptr,"help") && c->argc == 2) {
-        addReplyMultiBulkLen(c,5);
-        addReplyBulkCString(c,
-"MEMORY DOCTOR                        - Outputs memory problems report");
-        addReplyBulkCString(c,
-"MEMORY USAGE <key> [SAMPLES <count>] - Estimate memory usage of key");
-        addReplyBulkCString(c,
-"MEMORY STATS                         - Show memory usage details");
-        addReplyBulkCString(c,
-"MEMORY PURGE                         - Ask the allocator to release memory");
-        addReplyBulkCString(c,
-"MEMORY MALLOC-STATS                  - Show allocator internal stats");
     } else {
-        addReplyError(c,"Syntax error. Try MEMORY HELP");
+        addReplyErrorFormat(c, "Unknown subcommand or wrong number of arguments for '%s'. Try MEMORY HELP", (char*)c->argv[1]->ptr);
     }
 }

src/quicklist.h

@@ -40,7 +40,7 @@
  * container: 2 bits, NONE=1, ZIPLIST=2.
  * recompress: 1 bit, bool, true if node is temporarry decompressed for usage.
  * attempted_compress: 1 bit, boolean, used for verifying during testing.
- * extra: 12 bits, free for future use; pads out the remainder of 32 bits */
+ * extra: 10 bits, free for future use; pads out the remainder of 32 bits */
 typedef struct quicklistNode {
     struct quicklistNode *prev;
     struct quicklistNode *next;

src/rax.c

@@ -1,6 +1,6 @@
 /* Rax -- A radix tree implementation.
  *
- * Copyright (c) 2017, Salvatore Sanfilippo <antirez at gmail dot com>
+ * Copyright (c) 2017-2018, Salvatore Sanfilippo <antirez at gmail dot com>
  * All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
@@ -51,14 +51,18 @@ void *raxNotFound = (void*)"rax-not-found-pointer";
 
 void raxDebugShowNode(const char *msg, raxNode *n);
 
-/* Turn debugging messages on/off. */
-#if 0
+/* Turn debugging messages on/off by compiling with RAX_DEBUG_MSG macro on.
+ * When RAX_DEBUG_MSG is defined by default Rax operations will emit a lot
+ * of debugging info to the standard output, however you can still turn
+ * debugging on/off in order to enable it only when you suspect there is an
+ * operation causing a bug using the function raxSetDebugMsg(). */
+#ifdef RAX_DEBUG_MSG
 #define debugf(...)                                                            \
-    do {                                                                       \
+    if (raxDebugMsg) {                                                         \
         printf("%s:%s:%d:\t", __FILE__, __FUNCTION__, __LINE__);               \
         printf(__VA_ARGS__);                                                   \
         fflush(stdout);                                                        \
-    } while (0);
+    }
 
 #define debugnode(msg,n) raxDebugShowNode(msg,n)
 #else
@@ -66,6 +70,16 @@ void raxDebugShowNode(const char *msg, raxNode *n);
 #define debugnode(msg,n)
 #endif
 
+/* By default log debug info if RAX_DEBUG_MSG is defined. */
+static int raxDebugMsg = 1;
+
+/* When debug messages are enabled, turn them on/off dynamically. By
+ * default they are enabled. Set the state to 0 to disable, and 1 to
+ * re-enable. */
+void raxSetDebugMsg(int onoff) {
+    raxDebugMsg = onoff;
+}
+
 /* ------------------------- raxStack functions --------------------------
  * The raxStack is a simple stack of pointers that is capable of switching
  * from using a stack-allocated array to dynamic heap once a given number of
@@ -134,12 +148,43 @@ static inline void raxStackFree(raxStack *ts) {
  * Radix tree implementation
  * --------------------------------------------------------------------------*/
 
+/* Return the padding needed in the characters section of a node having size
+ * 'nodesize'. The padding is needed to store the child pointers to aligned
+ * addresses. Note that we add 4 to the node size because the node has a four
+ * bytes header. */
+#define raxPadding(nodesize) ((sizeof(void*)-((nodesize+4) % sizeof(void*))) & (sizeof(void*)-1))
+
+/* Return the pointer to the last child pointer in a node. For the compressed
+ * nodes this is the only child pointer. */
+#define raxNodeLastChildPtr(n) ((raxNode**) ( \
+    ((char*)(n)) + \
+    raxNodeCurrentLength(n) - \
+    sizeof(raxNode*) - \
+    (((n)->iskey && !(n)->isnull) ? sizeof(void*) : 0) \
+))
+
+/* Return the pointer to the first child pointer. */
+#define raxNodeFirstChildPtr(n) ((raxNode**) ( \
+    (n)->data + \
+    (n)->size + \
+    raxPadding((n)->size)))
+
+/* Return the current total size of the node. Note that the second line
+ * computes the padding after the string of characters, needed in order to
+ * save pointers to aligned addresses. */
+#define raxNodeCurrentLength(n) ( \
+    sizeof(raxNode)+(n)->size+ \
+    raxPadding((n)->size)+ \
+    ((n)->iscompr ? sizeof(raxNode*) : sizeof(raxNode*)*(n)->size)+ \
+    (((n)->iskey && !(n)->isnull)*sizeof(void*)) \
+)
+
 /* Allocate a new non compressed node with the specified number of children.
  * If datafiled is true, the allocation is made large enough to hold the
  * associated data pointer.
  * Returns the new node pointer. On out of memory NULL is returned. */
 raxNode *raxNewNode(size_t children, int datafield) {
-    size_t nodesize = sizeof(raxNode)+children+
+    size_t nodesize = sizeof(raxNode)+children+raxPadding(children)+
                       sizeof(raxNode*)*children;
     if (datafield) nodesize += sizeof(void*);
     raxNode *node = rax_malloc(nodesize);
@@ -167,13 +212,6 @@ rax *raxNew(void) {
     }
 }
 
-/* Return the current total size of the node. */
-#define raxNodeCurrentLength(n) ( \
-    sizeof(raxNode)+(n)->size+ \
-    ((n)->iscompr ? sizeof(raxNode*) : sizeof(raxNode*)*(n)->size)+ \
-    (((n)->iskey && !(n)->isnull)*sizeof(void*)) \
-)
-
 /* realloc the node to make room for auxiliary data in order
  * to store an item in that node. On out of memory NULL is returned. */
 raxNode *raxReallocForData(raxNode *n, void *data) {
@@ -216,18 +254,17 @@ void *raxGetData(raxNode *n) {
 raxNode *raxAddChild(raxNode *n, unsigned char c, raxNode **childptr, raxNode ***parentlink) {
     assert(n->iscompr == 0);
 
-    size_t curlen = sizeof(raxNode)+
-                    n->size+
-                    sizeof(raxNode*)*n->size;
-    size_t newlen;
+    size_t curlen = raxNodeCurrentLength(n);
+    n->size++;
+    size_t newlen = raxNodeCurrentLength(n);
+    n->size--; /* For now restore the orignal size. We'll update it only on
+                  success at the end. */
 
     /* Alloc the new child we will link to 'n'. */
     raxNode *child = raxNewNode(0,0);
     if (child == NULL) return NULL;
 
     /* Make space in the original node. */
-    if (n->iskey) curlen += sizeof(void*);
-    newlen = curlen+sizeof(raxNode*)+1; /* Add 1 char and 1 pointer. */
     raxNode *newn = rax_realloc(n,newlen);
     if (newn == NULL) {
         rax_free(child);
@@ -235,14 +272,34 @@ raxNode *raxAddChild(raxNode *n, unsigned char c, raxNode **childptr, raxNode **
     }
     n = newn;
 
-    /* After the reallocation, we have 5/9 (depending on the system
-     * pointer size) bytes at the end, that is, the additional char
-     * in the 'data' section, plus one pointer to the new child:
+    /* After the reallocation, we have up to 8/16 (depending on the system
+     * pointer size, and the required node padding) bytes at the end, that is,
+     * the additional char in the 'data' section, plus one pointer to the new
+     * child, plus the padding needed in order to store addresses into aligned
+     * locations.
      *
-     * [numc][abx][ap][bp][xp]|auxp|.....
+     * So if we start with the following node, having "abde" edges.
+     *
+     * Note:
+     * - We assume 4 bytes pointer for simplicity.
+     * - Each space below corresponds to one byte
+     *
+     * [HDR*][abde][Aptr][Bptr][Dptr][Eptr]|AUXP|
+     *
+     * After the reallocation we need: 1 byte for the new edge character
+     * plus 4 bytes for a new child pointer (assuming 32 bit machine).
+     * However after adding 1 byte to the edge char, the header + the edge
+     * characters are no longer aligned, so we also need 3 bytes of padding.
+     * In total the reallocation will add 1+4+3 bytes = 8 bytes:
+     *
+     * (Blank bytes are represented by ".")
+     *
+     * [HDR*][abde][Aptr][Bptr][Dptr][Eptr]|AUXP|[....][....]
      *
      * Let's find where to insert the new child in order to make sure
-     * it is inserted in-place lexicographically. */
+     * it is inserted in-place lexicographically. Assuming we are adding
+     * a child "c" in our case pos will be = 2 after the end of the following
+     * loop. */
     int pos;
     for (pos = 0; pos < n->size; pos++) {
         if (n->data[pos] > c) break;
@@ -252,55 +309,81 @@ raxNode *raxAddChild(raxNode *n, unsigned char c, raxNode **childptr, raxNode **
      * so that we can mess with the other data without overwriting it.
      * We will obtain something like that:
      *
-     * [numc][abx][ap][bp][xp].....|auxp| */
-    unsigned char *src;
+     * [HDR*][abde][Aptr][Bptr][Dptr][Eptr][....][....]|AUXP|
+     */
+    unsigned char *src, *dst;
     if (n->iskey && !n->isnull) {
-        src = n->data+n->size+sizeof(raxNode*)*n->size;
-        memmove(src+1+sizeof(raxNode*),src,sizeof(void*));
+        src = ((unsigned char*)n+curlen-sizeof(void*));
+        dst = ((unsigned char*)n+newlen-sizeof(void*));
+        memmove(dst,src,sizeof(void*));
     }
 
-    /* Now imagine we are adding a node with edge 'c'. The insertion
-     * point is between 'b' and 'x', so the 'pos' variable value is
-     * To start, move all the child pointers after the insertion point
-     * of 1+sizeof(pointer) bytes on the right, to obtain:
+    /* Compute the "shift", that is, how many bytes we need to move the
+     * pointers section forward because of the addition of the new child
+     * byte in the string section. Note that if we had no padding, that
+     * would be always "1", since we are adding a single byte in the string
+     * section of the node (where now there is "abde" basically).
      *
-     * [numc][abx][ap][bp].....[xp]|auxp| */
-    src = n->data+n->size+sizeof(raxNode*)*pos;
-    memmove(src+1+sizeof(raxNode*),src,sizeof(raxNode*)*(n->size-pos));
+     * However we have padding, so it could be zero, or up to 8.
+     *
+     * Another way to think at the shift is, how many bytes we need to
+     * move child pointers forward *other than* the obvious sizeof(void*)
+     * needed for the additional pointer itself. */
+    size_t shift = newlen - curlen - sizeof(void*);
+
+    /* We said we are adding a node with edge 'c'. The insertion
+     * point is between 'b' and 'd', so the 'pos' variable value is
+     * the index of the first child pointer that we need to move forward
+     * to make space for our new pointer.
+     *
+     * To start, move all the child pointers after the insertion point
+     * of shift+sizeof(pointer) bytes on the right, to obtain:
+     *
+     * [HDR*][abde][Aptr][Bptr][....][....][Dptr][Eptr]|AUXP|
+     */
+    src = n->data+n->size+
+          raxPadding(n->size)+
+          sizeof(raxNode*)*pos;
+    memmove(src+shift+sizeof(raxNode*),src,sizeof(raxNode*)*(n->size-pos));
+
+    /* Move the pointers to the left of the insertion position as well. Often
+     * we don't need to do anything if there was already some padding to use. In
+     * that case the final destination of the pointers will be the same, however
+     * in our example there was no pre-existing padding, so we added one byte
+     * plus thre bytes of padding. After the next memmove() things will look
+     * like thata:
+     *
+     * [HDR*][abde][....][Aptr][Bptr][....][Dptr][Eptr]|AUXP|
+     */
+    if (shift) {
+        src = (unsigned char*) raxNodeFirstChildPtr(n);
+        memmove(src+shift,src,sizeof(raxNode*)*pos);
+    }
 
     /* Now make the space for the additional char in the data section,
-     * but also move the pointers before the insertion point in the right
-     * by 1 byte, in order to obtain the following:
+     * but also move the pointers before the insertion point to the right
+     * by shift bytes, in order to obtain the following:
      *
-     * [numc][ab.x][ap][bp]....[xp]|auxp| */
+     * [HDR*][ab.d][e...][Aptr][Bptr][....][Dptr][Eptr]|AUXP|
+     */
     src = n->data+pos;
-    memmove(src+1,src,n->size-pos+sizeof(raxNode*)*pos);
+    memmove(src+1,src,n->size-pos);
 
     /* We can now set the character and its child node pointer to get:
      *
-     * [numc][abcx][ap][bp][cp]....|auxp|
-     * [numc][abcx][ap][bp][cp][xp]|auxp| */
+     * [HDR*][abcd][e...][Aptr][Bptr][....][Dptr][Eptr]|AUXP|
+     * [HDR*][abcd][e...][Aptr][Bptr][Cptr][Dptr][Eptr]|AUXP|
+     */
     n->data[pos] = c;
     n->size++;
-    raxNode **childfield = (raxNode**)(n->data+n->size+sizeof(raxNode*)*pos);
+    src = (unsigned char*) raxNodeFirstChildPtr(n);
+    raxNode **childfield = (raxNode**)(src+sizeof(raxNode*)*pos);
     memcpy(childfield,&child,sizeof(child));
     *childptr = child;
     *parentlink = childfield;
     return n;
 }
 
-/* Return the pointer to the last child pointer in a node. For the compressed
- * nodes this is the only child pointer. */
-#define raxNodeLastChildPtr(n) ((raxNode**) ( \
-    ((char*)(n)) + \
-    raxNodeCurrentLength(n) - \
-    sizeof(raxNode*) - \
-    (((n)->iskey && !(n)->isnull) ? sizeof(void*) : 0) \
-))
-
-/* Return the pointer to the first child pointer. */
-#define raxNodeFirstChildPtr(n) ((raxNode**)((n)->data+(n)->size))
-
 /* Turn the node 'n', that must be a node without any children, into a
  * compressed node representing a set of nodes linked one after the other
  * and having exactly one child each. The node can be a key or not: this
@@ -321,7 +404,7 @@ raxNode *raxCompressNode(raxNode *n, unsigned char *s, size_t len, raxNode **chi
     if (*child == NULL) return NULL;
 
     /* Make space in the parent node. */
-    newsize = sizeof(raxNode)+len+sizeof(raxNode*);
+    newsize = sizeof(raxNode)+len+raxPadding(len)+sizeof(raxNode*);
     if (n->iskey) {
         data = raxGetData(n); /* To restore it later. */
         if (!n->isnull) newsize += sizeof(void*);
@@ -619,13 +702,14 @@ int raxGenericInsert(rax *rax, unsigned char *s, size_t len, void *data, void **
         raxNode *postfix = NULL;
 
         if (trimmedlen) {
-            nodesize = sizeof(raxNode)+trimmedlen+sizeof(raxNode*);
+            nodesize = sizeof(raxNode)+trimmedlen+raxPadding(trimmedlen)+
+                       sizeof(raxNode*);
             if (h->iskey && !h->isnull) nodesize += sizeof(void*);
             trimmed = rax_malloc(nodesize);
         }
 
         if (postfixlen) {
-            nodesize = sizeof(raxNode)+postfixlen+
+            nodesize = sizeof(raxNode)+postfixlen+raxPadding(postfixlen)+
                        sizeof(raxNode*);
             postfix = rax_malloc(nodesize);
         }
@@ -701,11 +785,12 @@ int raxGenericInsert(rax *rax, unsigned char *s, size_t len, void *data, void **
 
         /* Allocate postfix & trimmed nodes ASAP to fail for OOM gracefully. */
         size_t postfixlen = h->size - j;
-        size_t nodesize = sizeof(raxNode)+postfixlen+sizeof(raxNode*);
+        size_t nodesize = sizeof(raxNode)+postfixlen+raxPadding(postfixlen)+
+                          sizeof(raxNode*);
         if (data != NULL) nodesize += sizeof(void*);
         raxNode *postfix = rax_malloc(nodesize);
 
-        nodesize = sizeof(raxNode)+j+sizeof(raxNode*);
+        nodesize = sizeof(raxNode)+j+raxPadding(j)+sizeof(raxNode*);
         if (h->iskey && !h->isnull) nodesize += sizeof(void*);
         raxNode *trimmed = rax_malloc(nodesize);
 
@@ -875,7 +960,7 @@ raxNode *raxRemoveChild(raxNode *parent, raxNode *child) {
         return parent;
     }
 
-    /* Otherwise we need to scan for the children pointer and memmove()
+    /* Otherwise we need to scan for the child pointer and memmove()
      * accordingly.
      *
      * 1. To start we seek the first element in both the children
@@ -900,13 +985,21 @@ raxNode *raxRemoveChild(raxNode *parent, raxNode *child) {
     debugf("raxRemoveChild tail len: %d\n", taillen);
     memmove(e,e+1,taillen);
 
-    /* Since we have one data byte less, also child pointers start one byte
-     * before now. */
-    memmove(((char*)cp)-1,cp,(parent->size-taillen-1)*sizeof(raxNode**));
+    /* Compute the shift, that is the amount of bytes we should move our
+     * child pointers to the left, since the removal of one edge character
+     * and the corresponding padding change, may change the layout.
+     * We just check if in the old version of the node there was at the
+     * end just a single byte and all padding: in that case removing one char
+     * will remove a whole sizeof(void*) word. */
+    size_t shift = ((parent->size+4) % sizeof(void*)) == 1 ? sizeof(void*) : 0;
 
-    /* Move the remaining "tail" pointer at the right position as well. */
+    /* Move the children pointers before the deletion point. */
+    if (shift)
+        memmove(((char*)cp)-shift,cp,(parent->size-taillen-1)*sizeof(raxNode**));
+
+    /* Move the remaining "tail" pointers at the right position as well. */
     size_t valuelen = (parent->iskey && !parent->isnull) ? sizeof(void*) : 0;
-    memmove(((char*)c)-1,c+1,taillen*sizeof(raxNode**)+valuelen);
+    memmove(((char*)c)-shift,c+1,taillen*sizeof(raxNode**)+valuelen);
 
     /* 4. Update size. */
     parent->size--;
@@ -1072,7 +1165,7 @@ int raxRemove(rax *rax, unsigned char *s, size_t len, void **old) {
         if (nodes > 1) {
             /* If we can compress, create the new node and populate it. */
             size_t nodesize =
-                sizeof(raxNode)+comprsize+sizeof(raxNode*);
+                sizeof(raxNode)+comprsize+raxPadding(comprsize)+sizeof(raxNode*);
             raxNode *new = rax_malloc(nodesize);
             /* An out of memory here just means we cannot optimize this
              * node, but the tree is left in a consistent state. */
@@ -1793,6 +1886,7 @@ void raxShow(rax *rax) {
 
 /* Used by debugnode() macro to show info about a given node. */
 void raxDebugShowNode(const char *msg, raxNode *n) {
+    if (raxDebugMsg == 0) return;
     printf("%s: %p [%.*s] key:%d size:%d children:",
         msg, (void*)n, (int)n->size, (char*)n->data, n->iskey, n->size);
     int numcld = n->iscompr ? 1 : n->size;
@@ -1807,4 +1901,43 @@ void raxDebugShowNode(const char *msg, raxNode *n) {
     fflush(stdout);
 }
 
+/* Touch all the nodes of a tree returning a check sum. This is useful
+ * in order to make Valgrind detect if there is something wrong while
+ * reading the data structure.
+ *
+ * This function was used in order to identify Rax bugs after a big refactoring
+ * using this technique:
+ *
+ * 1. The rax-test is executed using Valgrind, adding a printf() so that for
+ *    the fuzz tester we see what iteration in the loop we are in.
+ * 2. After every modification of the radix tree made by the fuzz tester
+ *    in rax-test.c, we add a call to raxTouch().
+ * 3. Now as soon as an operation will corrupt the tree, raxTouch() will
+ *    detect it (via Valgrind) immediately. We can add more calls to narrow
+ *    the state.
+ * 4. At this point a good idea is to enable Rax debugging messages immediately
+ *    before the moment the tree is corrupted, to see what happens.
+ */
+unsigned long raxTouch(raxNode *n) {
+    debugf("Touching %p\n", (void*)n);
+    unsigned long sum = 0;
+    if (n->iskey) {
+        sum += (unsigned long)raxGetData(n);
+    }
 
+    int numchildren = n->iscompr ? 1 : n->size;
+    raxNode **cp = raxNodeFirstChildPtr(n);
+    int count = 0;
+    for (int i = 0; i < numchildren; i++) {
+        if (numchildren > 1) {
+            sum += (long)n->data[i];
+        }
+        raxNode *child;
+        memcpy(&child,cp,sizeof(child));
+        if (child == (void*)0x65d1760) count++;
+        if (count > 1) exit(1);
+        sum += raxTouch(child);
+        cp++;
+    }
+    return sum;
+}

src/rax.h

@@ -1,3 +1,33 @@
+/* Rax -- A radix tree implementation.
+ *
+ * Copyright (c) 2017-2018, Salvatore Sanfilippo <antirez at gmail dot com>
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are met:
+ *
+ *   * Redistributions of source code must retain the above copyright notice,
+ *     this list of conditions and the following disclaimer.
+ *   * Redistributions in binary form must reproduce the above copyright
+ *     notice, this list of conditions and the following disclaimer in the
+ *     documentation and/or other materials provided with the distribution.
+ *   * Neither the name of Redis nor the names of its contributors may be used
+ *     to endorse or promote products derived from this software without
+ *     specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
+ * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
+ * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
+ * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
+ * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
+ * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
+ * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
+ * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
+ * POSSIBILITY OF SUCH DAMAGE.
+ */
+
 #ifndef RAX_H
 #define RAX_H
 
@@ -77,16 +107,16 @@ typedef struct raxNode {
      * Note how the character is not stored in the children but in the
      * edge of the parents:
      *
-     * [header strlen=0][abc][a-ptr][b-ptr][c-ptr](value-ptr?)
+     * [header iscompr=0][abc][a-ptr][b-ptr][c-ptr](value-ptr?)
      *
-     * if node is compressed (strlen != 0) the node has 1 children.
+     * if node is compressed (iscompr bit is 1) the node has 1 children.
      * In that case the 'size' bytes of the string stored immediately at
      * the start of the data section, represent a sequence of successive
      * nodes linked one after the other, for which only the last one in
      * the sequence is actually represented as a node, and pointed to by
      * the current compressed node.
      *
-     * [header strlen=3][xyz][z-ptr](value-ptr?)
+     * [header iscompr=1][xyz][z-ptr](value-ptr?)
      *
      * Both compressed and not compressed nodes can represent a key
      * with associated data in the radix tree at any level (not just terminal
@@ -176,6 +206,8 @@ void raxStop(raxIterator *it);
 int raxEOF(raxIterator *it);
 void raxShow(rax *rax);
 uint64_t raxSize(rax *rax);
+unsigned long raxTouch(raxNode *n);
+void raxSetDebugMsg(int onoff);
 
 /* Internal API. May be used by the node callback in order to access rax nodes
  * in a low level way, so this function is exported as well. */

src/rdb.c

@@ -751,7 +751,7 @@ size_t rdbSaveStreamConsumers(rio *rdb, streamCG *cg) {
 
 /* Save a Redis object.
  * Returns -1 on error, number of bytes written on success. */
-ssize_t rdbSaveObject(rio *rdb, robj *o) {
+ssize_t rdbSaveObject(rio *rdb, robj *o, robj *key) {
     ssize_t n = 0, nwritten = 0;
 
     if (o->type == OBJ_STRING) {
@@ -966,7 +966,7 @@ ssize_t rdbSaveObject(rio *rdb, robj *o) {
         RedisModuleIO io;
         moduleValue *mv = o->ptr;
         moduleType *mt = mv->type;
-        moduleInitIOContext(io,mt,rdb);
+        moduleInitIOContext(io,mt,rdb,key);
 
         /* Write the "module" identifier as prefix, so that we'll be able
          * to call the right module during loading. */
@@ -996,7 +996,7 @@ ssize_t rdbSaveObject(rio *rdb, robj *o) {
  * this length with very little changes to the code. In the future
  * we could switch to a faster solution. */
 size_t rdbSavedObjectLen(robj *o) {
-    ssize_t len = rdbSaveObject(NULL,o);
+    ssize_t len = rdbSaveObject(NULL,o,NULL);
     serverAssertWithInfo(NULL,o,len != -1);
     return len;
 }
@@ -1038,7 +1038,7 @@ int rdbSaveKeyValuePair(rio *rdb, robj *key, robj *val, long long expiretime) {
     /* Save type, key, value */
     if (rdbSaveObjectType(rdb,val) == -1) return -1;
     if (rdbSaveStringObject(rdb,key) == -1) return -1;
-    if (rdbSaveObject(rdb,val) == -1) return -1;
+    if (rdbSaveObject(rdb,val,key) == -1) return -1;
     return 1;
 }
 
@@ -1380,7 +1380,7 @@ robj *rdbLoadCheckModuleValue(rio *rdb, char *modulename) {
 
 /* Load a Redis object of the specified type from the specified file.
  * On success a newly allocated object is returned, otherwise NULL. */
-robj *rdbLoadObject(int rdbtype, rio *rdb) {
+robj *rdbLoadObject(int rdbtype, rio *rdb, robj *key) {
     robj *o = NULL, *ele, *dec;
     uint64_t len;
     unsigned int i;
@@ -1645,6 +1645,9 @@ robj *rdbLoadObject(int rdbtype, rio *rdb) {
              * node: the entries inside the listpack itself are delta-encoded
              * relatively to this ID. */
             sds nodekey = rdbGenericLoadStringObject(rdb,RDB_LOAD_SDS,NULL);
+            if (nodekey == NULL) {
+                rdbExitReportCorruptRDB("Stream master ID loading failed: invalid encoding or I/O error.");
+            }
             if (sdslen(nodekey) != sizeof(streamID)) {
                 rdbExitReportCorruptRDB("Stream node key entry is not the "
                                         "size of a stream ID");
@@ -1764,7 +1767,7 @@ robj *rdbLoadObject(int rdbtype, rio *rdb) {
             exit(1);
         }
         RedisModuleIO io;
-        moduleInitIOContext(io,mt,rdb);
+        moduleInitIOContext(io,mt,rdb,key);
         io.ver = (rdbtype == RDB_TYPE_MODULE) ? 1 : 2;
         /* Call the rdb_load method of the module providing the 10 bit
          * encoding version in the lower 10 bits of the module ID. */
@@ -2003,7 +2006,7 @@ int rdbLoadRio(rio *rdb, rdbSaveInfo *rsi, int loading_aof) {
         /* Read key */
         if ((key = rdbLoadStringObject(rdb)) == NULL) goto eoferr;
         /* Read value */
-        if ((val = rdbLoadObject(type,rdb)) == NULL) goto eoferr;
+        if ((val = rdbLoadObject(type,rdb,key)) == NULL) goto eoferr;
         /* Check if the key already expired. This function is used when loading
          * an RDB file from disk, either at startup, or when an RDB was
          * received from the master. In the latter case, the master is

src/rdb.h

@@ -140,9 +140,9 @@ int rdbSaveBackground(char *filename, rdbSaveInfo *rsi);
 int rdbSaveToSlavesSockets(rdbSaveInfo *rsi);
 void rdbRemoveTempFile(pid_t childpid);
 int rdbSave(char *filename, rdbSaveInfo *rsi);
-ssize_t rdbSaveObject(rio *rdb, robj *o);
+ssize_t rdbSaveObject(rio *rdb, robj *o, robj *key);
 size_t rdbSavedObjectLen(robj *o);
-robj *rdbLoadObject(int type, rio *rdb);
+robj *rdbLoadObject(int type, rio *rdb, robj *key);
 void backgroundSaveDoneHandler(int exitcode, int bysignal);
 int rdbSaveKeyValuePair(rio *rdb, robj *key, robj *val, long long expiretime);
 robj *rdbLoadStringObject(rio *rdb);

src/redis-check-aof.c

@@ -33,11 +33,11 @@
 
 #define ERROR(...) { \
     char __buf[1024]; \
-    sprintf(__buf, __VA_ARGS__); \
-    sprintf(error, "0x%16llx: %s", (long long)epos, __buf); \
+    snprintf(__buf, sizeof(__buf), __VA_ARGS__); \
+    snprintf(error, sizeof(error), "0x%16llx: %s", (long long)epos, __buf); \
 }
 
-static char error[1024];
+static char error[1044];
 static off_t epos;
 
 int consumeNewline(char *buf) {

src/redis-check-rdb.c

@@ -285,7 +285,7 @@ int redis_check_rdb(char *rdbfilename, FILE *fp) {
         rdbstate.keys++;
         /* Read value */
         rdbstate.doing = RDB_CHECK_DOING_READ_OBJECT_VALUE;
-        if ((val = rdbLoadObject(type,&rdb)) == NULL) goto eoferr;
+        if ((val = rdbLoadObject(type,&rdb,key)) == NULL) goto eoferr;
         /* Check if the key already expired. */
         if (expiretime != -1 && expiretime < now)
             rdbstate.already_expired++;

src/redismodule.h

@@ -85,6 +85,9 @@
 #define REDISMODULE_CTX_FLAGS_OOM (1<<10)
 /* Less than 25% of memory available according to maxmemory. */
 #define REDISMODULE_CTX_FLAGS_OOM_WARNING (1<<11)
+/* The command was sent over the replication link. */
+#define REDISMODULE_CTX_FLAGS_REPLICATED (1<<12)
+
 
 #define REDISMODULE_NOTIFY_GENERIC (1<<2)     /* g */
 #define REDISMODULE_NOTIFY_STRING (1<<3)      /* $ */
@@ -117,6 +120,10 @@
 #define REDISMODULE_NODE_FAIL       (1<<4)
 #define REDISMODULE_NODE_NOFAILOVER (1<<5)
 
+#define REDISMODULE_CLUSTER_FLAG_NONE 0
+#define REDISMODULE_CLUSTER_FLAG_NO_FAILOVER (1<<1)
+#define REDISMODULE_CLUSTER_FLAG_NO_REDIRECTION (1<<2)
+
 #define REDISMODULE_NOT_USED(V) ((void) V)
 
 /* This type represents a timer handle, and is returned when a timer is
@@ -125,6 +132,11 @@
  * of timers that are going to expire, sorted by expire time. */
 typedef uint64_t RedisModuleTimerID;
 
+/* CommandFilter Flags */
+
+/* Do filter RedisModule_Call() commands initiated by module itself. */
+#define REDISMODULE_CMDFILTER_NOSELF    (1<<0)
+
 /* ------------------------- End of common defines ------------------------ */
 
 #ifndef REDISMODULE_CORE
@@ -141,6 +153,10 @@ typedef struct RedisModuleType RedisModuleType;
 typedef struct RedisModuleDigest RedisModuleDigest;
 typedef struct RedisModuleBlockedClient RedisModuleBlockedClient;
 typedef struct RedisModuleClusterInfo RedisModuleClusterInfo;
+typedef struct RedisModuleDict RedisModuleDict;
+typedef struct RedisModuleDictIter RedisModuleDictIter;
+typedef struct RedisModuleCommandFilterCtx RedisModuleCommandFilterCtx;
+typedef struct RedisModuleCommandFilter RedisModuleCommandFilter;
 
 typedef int (*RedisModuleCmdFunc)(RedisModuleCtx *ctx, RedisModuleString **argv, int argc);
 typedef void (*RedisModuleDisconnectFunc)(RedisModuleCtx *ctx, RedisModuleBlockedClient *bc);
@@ -153,6 +169,7 @@ typedef void (*RedisModuleTypeDigestFunc)(RedisModuleDigest *digest, void *value
 typedef void (*RedisModuleTypeFreeFunc)(void *value);
 typedef void (*RedisModuleClusterMessageReceiver)(RedisModuleCtx *ctx, const char *sender_id, uint8_t type, const unsigned char *payload, uint32_t len);
 typedef void (*RedisModuleTimerProc)(RedisModuleCtx *ctx, void *data);
+typedef void (*RedisModuleCommandFilterFunc) (RedisModuleCommandFilterCtx *filter);
 
 #define REDISMODULE_TYPE_METHOD_VERSION 1
 typedef struct RedisModuleTypeMethods {
@@ -269,10 +286,33 @@ int REDISMODULE_API_FUNC(RedisModule_StringAppendBuffer)(RedisModuleCtx *ctx, Re
 void REDISMODULE_API_FUNC(RedisModule_RetainString)(RedisModuleCtx *ctx, RedisModuleString *str);
 int REDISMODULE_API_FUNC(RedisModule_StringCompare)(RedisModuleString *a, RedisModuleString *b);
 RedisModuleCtx *REDISMODULE_API_FUNC(RedisModule_GetContextFromIO)(RedisModuleIO *io);
+const RedisModuleString *REDISMODULE_API_FUNC(RedisModule_GetKeyNameFromIO)(RedisModuleIO *io);
 long long REDISMODULE_API_FUNC(RedisModule_Milliseconds)(void);
 void REDISMODULE_API_FUNC(RedisModule_DigestAddStringBuffer)(RedisModuleDigest *md, unsigned char *ele, size_t len);
 void REDISMODULE_API_FUNC(RedisModule_DigestAddLongLong)(RedisModuleDigest *md, long long ele);
 void REDISMODULE_API_FUNC(RedisModule_DigestEndSequence)(RedisModuleDigest *md);
+RedisModuleDict *REDISMODULE_API_FUNC(RedisModule_CreateDict)(RedisModuleCtx *ctx);
+void REDISMODULE_API_FUNC(RedisModule_FreeDict)(RedisModuleCtx *ctx, RedisModuleDict *d);
+uint64_t REDISMODULE_API_FUNC(RedisModule_DictSize)(RedisModuleDict *d);
+int REDISMODULE_API_FUNC(RedisModule_DictSetC)(RedisModuleDict *d, void *key, size_t keylen, void *ptr);
+int REDISMODULE_API_FUNC(RedisModule_DictReplaceC)(RedisModuleDict *d, void *key, size_t keylen, void *ptr);
+int REDISMODULE_API_FUNC(RedisModule_DictSet)(RedisModuleDict *d, RedisModuleString *key, void *ptr);
+int REDISMODULE_API_FUNC(RedisModule_DictReplace)(RedisModuleDict *d, RedisModuleString *key, void *ptr);
+void *REDISMODULE_API_FUNC(RedisModule_DictGetC)(RedisModuleDict *d, void *key, size_t keylen, int *nokey);
+void *REDISMODULE_API_FUNC(RedisModule_DictGet)(RedisModuleDict *d, RedisModuleString *key, int *nokey);
+int REDISMODULE_API_FUNC(RedisModule_DictDelC)(RedisModuleDict *d, void *key, size_t keylen, void *oldval);
+int REDISMODULE_API_FUNC(RedisModule_DictDel)(RedisModuleDict *d, RedisModuleString *key, void *oldval);
+RedisModuleDictIter *REDISMODULE_API_FUNC(RedisModule_DictIteratorStartC)(RedisModuleDict *d, const char *op, void *key, size_t keylen);
+RedisModuleDictIter *REDISMODULE_API_FUNC(RedisModule_DictIteratorStart)(RedisModuleDict *d, const char *op, RedisModuleString *key);
+void REDISMODULE_API_FUNC(RedisModule_DictIteratorStop)(RedisModuleDictIter *di);
+int REDISMODULE_API_FUNC(RedisModule_DictIteratorReseekC)(RedisModuleDictIter *di, const char *op, void *key, size_t keylen);
+int REDISMODULE_API_FUNC(RedisModule_DictIteratorReseek)(RedisModuleDictIter *di, const char *op, RedisModuleString *key);
+void *REDISMODULE_API_FUNC(RedisModule_DictNextC)(RedisModuleDictIter *di, size_t *keylen, void **dataptr);
+void *REDISMODULE_API_FUNC(RedisModule_DictPrevC)(RedisModuleDictIter *di, size_t *keylen, void **dataptr);
+RedisModuleString *REDISMODULE_API_FUNC(RedisModule_DictNext)(RedisModuleCtx *ctx, RedisModuleDictIter *di, void **dataptr);
+RedisModuleString *REDISMODULE_API_FUNC(RedisModule_DictPrev)(RedisModuleCtx *ctx, RedisModuleDictIter *di, void **dataptr);
+int REDISMODULE_API_FUNC(RedisModule_DictCompareC)(RedisModuleDictIter *di, const char *op, void *key, size_t keylen);
+int REDISMODULE_API_FUNC(RedisModule_DictCompare)(RedisModuleDictIter *di, const char *op, RedisModuleString *key);
 
 /* Experimental APIs */
 #ifdef REDISMODULE_EXPERIMENTAL_API
@@ -303,6 +343,16 @@ size_t REDISMODULE_API_FUNC(RedisModule_GetClusterSize)(void);
 void REDISMODULE_API_FUNC(RedisModule_GetRandomBytes)(unsigned char *dst, size_t len);
 void REDISMODULE_API_FUNC(RedisModule_GetRandomHexChars)(char *dst, size_t len);
 void REDISMODULE_API_FUNC(RedisModule_SetDisconnectCallback)(RedisModuleBlockedClient *bc, RedisModuleDisconnectFunc callback);
+void REDISMODULE_API_FUNC(RedisModule_SetClusterFlags)(RedisModuleCtx *ctx, uint64_t flags);
+int REDISMODULE_API_FUNC(RedisModule_ExportSharedAPI)(RedisModuleCtx *ctx, const char *apiname, void *func);
+void *REDISMODULE_API_FUNC(RedisModule_GetSharedAPI)(RedisModuleCtx *ctx, const char *apiname);
+RedisModuleCommandFilter *REDISMODULE_API_FUNC(RedisModule_RegisterCommandFilter)(RedisModuleCtx *ctx, RedisModuleCommandFilterFunc cb, int flags);
+int REDISMODULE_API_FUNC(RedisModule_UnregisterCommandFilter)(RedisModuleCtx *ctx, RedisModuleCommandFilter *filter);
+int REDISMODULE_API_FUNC(RedisModule_CommandFilterArgsCount)(RedisModuleCommandFilterCtx *fctx);
+const RedisModuleString *REDISMODULE_API_FUNC(RedisModule_CommandFilterArgGet)(RedisModuleCommandFilterCtx *fctx, int pos);
+int REDISMODULE_API_FUNC(RedisModule_CommandFilterArgInsert)(RedisModuleCommandFilterCtx *fctx, int pos, RedisModuleString *arg);
+int REDISMODULE_API_FUNC(RedisModule_CommandFilterArgReplace)(RedisModuleCommandFilterCtx *fctx, int pos, RedisModuleString *arg);
+int REDISMODULE_API_FUNC(RedisModule_CommandFilterArgDelete)(RedisModuleCommandFilterCtx *fctx, int pos);
 #endif
 
 /* This is included inline inside each Redis module. */
@@ -408,10 +458,33 @@ static int RedisModule_Init(RedisModuleCtx *ctx, const char *name, int ver, int
     REDISMODULE_GET_API(RetainString);
     REDISMODULE_GET_API(StringCompare);
     REDISMODULE_GET_API(GetContextFromIO);
+    REDISMODULE_GET_API(GetKeyNameFromIO);
     REDISMODULE_GET_API(Milliseconds);
     REDISMODULE_GET_API(DigestAddStringBuffer);
     REDISMODULE_GET_API(DigestAddLongLong);
     REDISMODULE_GET_API(DigestEndSequence);
+    REDISMODULE_GET_API(CreateDict);
+    REDISMODULE_GET_API(FreeDict);
+    REDISMODULE_GET_API(DictSize);
+    REDISMODULE_GET_API(DictSetC);
+    REDISMODULE_GET_API(DictReplaceC);
+    REDISMODULE_GET_API(DictSet);
+    REDISMODULE_GET_API(DictReplace);
+    REDISMODULE_GET_API(DictGetC);
+    REDISMODULE_GET_API(DictGet);
+    REDISMODULE_GET_API(DictDelC);
+    REDISMODULE_GET_API(DictDel);
+    REDISMODULE_GET_API(DictIteratorStartC);
+    REDISMODULE_GET_API(DictIteratorStart);
+    REDISMODULE_GET_API(DictIteratorStop);
+    REDISMODULE_GET_API(DictIteratorReseekC);
+    REDISMODULE_GET_API(DictIteratorReseek);
+    REDISMODULE_GET_API(DictNextC);
+    REDISMODULE_GET_API(DictPrevC);
+    REDISMODULE_GET_API(DictNext);
+    REDISMODULE_GET_API(DictPrev);
+    REDISMODULE_GET_API(DictCompare);
+    REDISMODULE_GET_API(DictCompareC);
 
 #ifdef REDISMODULE_EXPERIMENTAL_API
     REDISMODULE_GET_API(GetThreadSafeContext);
@@ -440,6 +513,16 @@ static int RedisModule_Init(RedisModuleCtx *ctx, const char *name, int ver, int
     REDISMODULE_GET_API(GetClusterSize);
     REDISMODULE_GET_API(GetRandomBytes);
     REDISMODULE_GET_API(GetRandomHexChars);
+    REDISMODULE_GET_API(SetClusterFlags);
+    REDISMODULE_GET_API(ExportSharedAPI);
+    REDISMODULE_GET_API(GetSharedAPI);
+    REDISMODULE_GET_API(RegisterCommandFilter);
+    REDISMODULE_GET_API(UnregisterCommandFilter);
+    REDISMODULE_GET_API(CommandFilterArgsCount);
+    REDISMODULE_GET_API(CommandFilterArgGet);
+    REDISMODULE_GET_API(CommandFilterArgInsert);
+    REDISMODULE_GET_API(CommandFilterArgReplace);
+    REDISMODULE_GET_API(CommandFilterArgDelete);
 #endif
 
     if (RedisModule_IsModuleNameBusy && RedisModule_IsModuleNameBusy(name)) return REDISMODULE_ERR;

src/replication.c

@@ -30,6 +30,7 @@
 
 
 #include "server.h"
+#include "cluster.h"
 
 #include <sys/time.h>
 #include <unistd.h>
@@ -48,7 +49,7 @@ int cancelReplicationHandshake(void);
 /* Return the pointer to a string representing the slave ip:listening_port
  * pair. Mostly useful for logging, since we want to log a slave using its
  * IP address and its listening port which is more clear for the user, for
- * example: "Closing connection with slave 10.1.2.3:6380". */
+ * example: "Closing connection with replica 10.1.2.3:6380". */
 char *replicationGetSlaveName(client *c) {
     static char buf[NET_PEER_ID_LEN];
     char ip[NET_IP_STR_LEN];
@@ -64,7 +65,7 @@ char *replicationGetSlaveName(client *c) {
         if (c->slave_listening_port)
             anetFormatAddr(buf,sizeof(buf),ip,c->slave_listening_port);
         else
-            snprintf(buf,sizeof(buf),"%s:<unknown-slave-port>",ip);
+            snprintf(buf,sizeof(buf),"%s:<unknown-replica-port>",ip);
     } else {
         snprintf(buf,sizeof(buf),"client id #%llu",
             (unsigned long long) c->id);
@@ -344,7 +345,7 @@ void replicationFeedMonitors(client *c, list *monitors, int dictid, robj **argv,
 long long addReplyReplicationBacklog(client *c, long long offset) {
     long long j, skip, len;
 
-    serverLog(LL_DEBUG, "[PSYNC] Slave request offset: %lld", offset);
+    serverLog(LL_DEBUG, "[PSYNC] Replica request offset: %lld", offset);
 
     if (server.repl_backlog_histlen == 0) {
         serverLog(LL_DEBUG, "[PSYNC] Backlog history len is zero");
@@ -472,7 +473,7 @@ int masterTryPartialResynchronization(client *c) {
                 strcasecmp(master_replid, server.replid2))
             {
                 serverLog(LL_NOTICE,"Partial resynchronization not accepted: "
-                    "Replication ID mismatch (Slave asked for '%s', my "
+                    "Replication ID mismatch (Replica asked for '%s', my "
                     "replication IDs are '%s' and '%s')",
                     master_replid, server.replid, server.replid2);
             } else {
@@ -481,7 +482,7 @@ int masterTryPartialResynchronization(client *c) {
                     "up to %lld", psync_offset, server.second_replid_offset);
             }
         } else {
-            serverLog(LL_NOTICE,"Full resync requested by slave %s",
+            serverLog(LL_NOTICE,"Full resync requested by replica %s",
                 replicationGetSlaveName(c));
         }
         goto need_full_resync;
@@ -493,10 +494,10 @@ int masterTryPartialResynchronization(client *c) {
         psync_offset > (server.repl_backlog_off + server.repl_backlog_histlen))
     {
         serverLog(LL_NOTICE,
-            "Unable to partial resync with slave %s for lack of backlog (Slave request was: %lld).", replicationGetSlaveName(c), psync_offset);
+            "Unable to partial resync with replica %s for lack of backlog (Replica request was: %lld).", replicationGetSlaveName(c), psync_offset);
         if (psync_offset > server.master_repl_offset) {
             serverLog(LL_WARNING,
-                "Warning: slave %s tried to PSYNC with an offset that is greater than the master replication offset.", replicationGetSlaveName(c));
+                "Warning: replica %s tried to PSYNC with an offset that is greater than the master replication offset.", replicationGetSlaveName(c));
         }
         goto need_full_resync;
     }
@@ -567,7 +568,7 @@ int startBgsaveForReplication(int mincapa) {
     listNode *ln;
 
     serverLog(LL_NOTICE,"Starting BGSAVE for SYNC with target: %s",
-        socket_target ? "slaves sockets" : "disk");
+        socket_target ? "replicas sockets" : "disk");
 
     rdbSaveInfo rsi, *rsiptr;
     rsiptr = rdbPopulateSaveInfo(&rsi);
@@ -593,6 +594,7 @@ int startBgsaveForReplication(int mincapa) {
             client *slave = ln->value;
 
             if (slave->replstate == SLAVE_STATE_WAIT_BGSAVE_START) {
+                slave->replstate = REPL_STATE_NONE;
                 slave->flags &= ~CLIENT_SLAVE;
                 listDelNode(server.slaves,ln);
                 addReplyError(slave,
@@ -644,7 +646,7 @@ void syncCommand(client *c) {
         return;
     }
 
-    serverLog(LL_NOTICE,"Slave %s asks for synchronization",
+    serverLog(LL_NOTICE,"Replica %s asks for synchronization",
         replicationGetSlaveName(c));
 
     /* Try a partial resynchronization if this is a PSYNC command.
@@ -725,7 +727,7 @@ void syncCommand(client *c) {
         } else {
             /* No way, we need to wait for the next BGSAVE in order to
              * register differences. */
-            serverLog(LL_NOTICE,"Can't attach the slave to the current BGSAVE. Waiting for next BGSAVE for SYNC");
+            serverLog(LL_NOTICE,"Can't attach the replica to the current BGSAVE. Waiting for next BGSAVE for SYNC");
         }
 
     /* CASE 2: BGSAVE is in progress, with socket target. */
@@ -798,7 +800,7 @@ void replconfCommand(client *c) {
                 memcpy(c->slave_ip,ip,sdslen(ip)+1);
             } else {
                 addReplyErrorFormat(c,"REPLCONF ip-address provided by "
-                    "slave instance is too long: %zd bytes", sdslen(ip));
+                    "replica instance is too long: %zd bytes", sdslen(ip));
                 return;
             }
         } else if (!strcasecmp(c->argv[j]->ptr,"capa")) {
@@ -858,12 +860,12 @@ void putSlaveOnline(client *slave) {
     slave->repl_ack_time = server.unixtime; /* Prevent false timeout. */
     if (aeCreateFileEvent(server.el, slave->fd, AE_WRITABLE,
         sendReplyToClient, slave) == AE_ERR) {
-        serverLog(LL_WARNING,"Unable to register writable event for slave bulk transfer: %s", strerror(errno));
+        serverLog(LL_WARNING,"Unable to register writable event for replica bulk transfer: %s", strerror(errno));
         freeClient(slave);
         return;
     }
     refreshGoodSlavesCount();
-    serverLog(LL_NOTICE,"Synchronization with slave %s succeeded",
+    serverLog(LL_NOTICE,"Synchronization with replica %s succeeded",
         replicationGetSlaveName(slave));
 }
 
@@ -880,7 +882,7 @@ void sendBulkToSlave(aeEventLoop *el, int fd, void *privdata, int mask) {
     if (slave->replpreamble) {
         nwritten = write(fd,slave->replpreamble,sdslen(slave->replpreamble));
         if (nwritten == -1) {
-            serverLog(LL_VERBOSE,"Write error sending RDB preamble to slave: %s",
+            serverLog(LL_VERBOSE,"Write error sending RDB preamble to replica: %s",
                 strerror(errno));
             freeClient(slave);
             return;
@@ -900,14 +902,14 @@ void sendBulkToSlave(aeEventLoop *el, int fd, void *privdata, int mask) {
     lseek(slave->repldbfd,slave->repldboff,SEEK_SET);
     buflen = read(slave->repldbfd,buf,PROTO_IOBUF_LEN);
     if (buflen <= 0) {
-        serverLog(LL_WARNING,"Read error sending DB to slave: %s",
+        serverLog(LL_WARNING,"Read error sending DB to replica: %s",
             (buflen == 0) ? "premature EOF" : strerror(errno));
         freeClient(slave);
         return;
     }
     if ((nwritten = write(fd,buf,buflen)) == -1) {
         if (errno != EAGAIN) {
-            serverLog(LL_WARNING,"Write error sending DB to slave: %s",
+            serverLog(LL_WARNING,"Write error sending DB to replica: %s",
                 strerror(errno));
             freeClient(slave);
         }
@@ -961,7 +963,7 @@ void updateSlavesWaitingBgsave(int bgsaveerr, int type) {
              * the slave online. */
             if (type == RDB_CHILD_TYPE_SOCKET) {
                 serverLog(LL_NOTICE,
-                    "Streamed RDB transfer with slave %s succeeded (socket). Waiting for REPLCONF ACK from slave to enable streaming",
+                    "Streamed RDB transfer with replica %s succeeded (socket). Waiting for REPLCONF ACK from slave to enable streaming",
                         replicationGetSlaveName(slave));
                 /* Note: we wait for a REPLCONF ACK message from slave in
                  * order to really put it online (install the write handler
@@ -1089,14 +1091,23 @@ void replicationCreateMasterClient(int fd, int dbid) {
     if (dbid != -1) selectDb(server.master,dbid);
 }
 
-void restartAOF() {
-    int retry = 10;
-    while (retry-- && startAppendOnly() == C_ERR) {
-        serverLog(LL_WARNING,"Failed enabling the AOF after successful master synchronization! Trying it again in one second.");
+/* This function will try to re-enable the AOF file after the
+ * master-replica synchronization: if it fails after multiple attempts
+ * the replica cannot be considered reliable and exists with an
+ * error. */
+void restartAOFAfterSYNC() {
+    unsigned int tries, max_tries = 10;
+    for (tries = 0; tries < max_tries; ++tries) {
+        if (startAppendOnly() == C_OK) break;
+        serverLog(LL_WARNING,
+            "Failed enabling the AOF after successful master synchronization! "
+            "Trying it again in one second.");
         sleep(1);
     }
-    if (!retry) {
-        serverLog(LL_WARNING,"FATAL: this slave instance finished the synchronization with its master, but the AOF can't be turned on. Exiting now.");
+    if (tries == max_tries) {
+        serverLog(LL_WARNING,
+            "FATAL: this replica instance finished the synchronization with "
+            "its master, but the AOF can't be turned on. Exiting now.");
         exit(1);
     }
 }
@@ -1161,12 +1172,12 @@ void readSyncBulkPayload(aeEventLoop *el, int fd, void *privdata, int mask) {
              * at the next call. */
             server.repl_transfer_size = 0;
             serverLog(LL_NOTICE,
-                "MASTER <-> SLAVE sync: receiving streamed RDB from master");
+                "MASTER <-> REPLICA sync: receiving streamed RDB from master");
         } else {
             usemark = 0;
             server.repl_transfer_size = strtol(buf+1,NULL,10);
             serverLog(LL_NOTICE,
-                "MASTER <-> SLAVE sync: receiving %lld bytes from master",
+                "MASTER <-> REPLICA sync: receiving %lld bytes from master",
                 (long long) server.repl_transfer_size);
         }
         return;
@@ -1207,7 +1218,7 @@ void readSyncBulkPayload(aeEventLoop *el, int fd, void *privdata, int mask) {
 
     server.repl_transfer_lastio = server.unixtime;
     if ((nwritten = write(server.repl_transfer_fd,buf,nread)) != nread) {
-        serverLog(LL_WARNING,"Write error or short write writing to the DB dump file needed for MASTER <-> SLAVE synchronization: %s", 
+        serverLog(LL_WARNING,"Write error or short write writing to the DB dump file needed for MASTER <-> REPLICA synchronization: %s", 
             (nwritten == -1) ? strerror(errno) : "short write");
         goto error;
     }
@@ -1245,12 +1256,24 @@ void readSyncBulkPayload(aeEventLoop *el, int fd, void *privdata, int mask) {
     if (eof_reached) {
         int aof_is_enabled = server.aof_state != AOF_OFF;
 
+        /* Ensure background save doesn't overwrite synced data */
+        if (server.rdb_child_pid != -1) {
+            serverLog(LL_NOTICE,
+                "Replica is about to load the RDB file received from the "
+                "master, but there is a pending RDB child running. "
+                "Killing process %ld and removing its temp file to avoid "
+                "any race",
+                    (long) server.rdb_child_pid);
+            kill(server.rdb_child_pid,SIGUSR1);
+            rdbRemoveTempFile(server.rdb_child_pid);
+        }
+
         if (rename(server.repl_transfer_tmpfile,server.rdb_filename) == -1) {
-            serverLog(LL_WARNING,"Failed trying to rename the temp DB into dump.rdb in MASTER <-> SLAVE synchronization: %s", strerror(errno));
+            serverLog(LL_WARNING,"Failed trying to rename the temp DB into dump.rdb in MASTER <-> REPLICA synchronization: %s", strerror(errno));
             cancelReplicationHandshake();
             return;
         }
-        serverLog(LL_NOTICE, "MASTER <-> SLAVE sync: Flushing old data");
+        serverLog(LL_NOTICE, "MASTER <-> REPLICA sync: Flushing old data");
         /* We need to stop any AOFRW fork before flusing and parsing
          * RDB, otherwise we'll create a copy-on-write disaster. */
         if(aof_is_enabled) stopAppendOnly();
@@ -1264,14 +1287,14 @@ void readSyncBulkPayload(aeEventLoop *el, int fd, void *privdata, int mask) {
          * rdbLoad() will call the event loop to process events from time to
          * time for non blocking loading. */
         aeDeleteFileEvent(server.el,server.repl_transfer_s,AE_READABLE);
-        serverLog(LL_NOTICE, "MASTER <-> SLAVE sync: Loading DB in memory");
+        serverLog(LL_NOTICE, "MASTER <-> REPLICA sync: Loading DB in memory");
         rdbSaveInfo rsi = RDB_SAVE_INFO_INIT;
         if (rdbLoad(server.rdb_filename,&rsi) != C_OK) {
             serverLog(LL_WARNING,"Failed trying to load the MASTER synchronization DB from disk");
             cancelReplicationHandshake();
             /* Re-enable the AOF if we disabled it earlier, in order to restore
              * the original configuration. */
-            if (aof_is_enabled) restartAOF();
+            if (aof_is_enabled) restartAOFAfterSYNC();
             return;
         }
         /* Final setup of the connected slave <- master link */
@@ -1292,11 +1315,11 @@ void readSyncBulkPayload(aeEventLoop *el, int fd, void *privdata, int mask) {
          * masters after a failover. */
         if (server.repl_backlog == NULL) createReplicationBacklog();
 
-        serverLog(LL_NOTICE, "MASTER <-> SLAVE sync: Finished with success");
+        serverLog(LL_NOTICE, "MASTER <-> REPLICA sync: Finished with success");
         /* Restart the AOF subsystem now that we finished the sync. This
          * will trigger an AOF rewrite, and when done will start appending
          * to the new file. */
-        if (aof_is_enabled) restartAOF();
+        if (aof_is_enabled) restartAOFAfterSYNC();
     }
     return;
 
@@ -1791,7 +1814,7 @@ void syncWithMaster(aeEventLoop *el, int fd, void *privdata, int mask) {
      * uninstalling the read handler from the file descriptor. */
 
     if (psync_result == PSYNC_CONTINUE) {
-        serverLog(LL_NOTICE, "MASTER <-> SLAVE sync: Master accepted a Partial Resynchronization.");
+        serverLog(LL_NOTICE, "MASTER <-> REPLICA sync: Master accepted a Partial Resynchronization.");
         return;
     }
 
@@ -1823,7 +1846,7 @@ void syncWithMaster(aeEventLoop *el, int fd, void *privdata, int mask) {
         sleep(1);
     }
     if (dfd == -1) {
-        serverLog(LL_WARNING,"Opening the temp file needed for MASTER <-> SLAVE synchronization: %s",strerror(errno));
+        serverLog(LL_WARNING,"Opening the temp file needed for MASTER <-> REPLICA synchronization: %s",strerror(errno));
         goto error;
     }
 
@@ -1997,11 +2020,11 @@ void replicationHandleMasterDisconnection(void) {
      * the slaves only if we'll have to do a full resync with our master. */
 }
 
-void slaveofCommand(client *c) {
+void replicaofCommand(client *c) {
     /* SLAVEOF is not allowed in cluster mode as replication is automatically
      * configured using the current address of the master node. */
     if (server.cluster_enabled) {
-        addReplyError(c,"SLAVEOF not allowed in cluster mode.");
+        addReplyError(c,"REPLICAOF not allowed in cluster mode.");
         return;
     }
 
@@ -2019,13 +2042,22 @@ void slaveofCommand(client *c) {
     } else {
         long port;
 
+        if (c->flags & CLIENT_SLAVE)
+        {
+            /* If a client is already a replica they cannot run this command,
+             * because it involves flushing all replicas (including this
+             * client) */
+            addReplyError(c, "Command is not valid when client is a replica.");
+            return;
+        }
+
         if ((getLongFromObjectOrReply(c, c->argv[2], &port, NULL) != C_OK))
             return;
 
         /* Check if we are already attached to the specified slave */
         if (server.masterhost && !strcasecmp(server.masterhost,c->argv[1]->ptr)
             && server.masterport == port) {
-            serverLog(LL_NOTICE,"SLAVE OF would result into synchronization with the master we are already connected with. No operation performed.");
+            serverLog(LL_NOTICE,"REPLICAOF would result into synchronization with the master we are already connected with. No operation performed.");
             addReplySds(c,sdsnew("+OK Already connected to specified master\r\n"));
             return;
         }
@@ -2033,7 +2065,7 @@ void slaveofCommand(client *c) {
          * we can continue. */
         replicationSetMaster(c->argv[1]->ptr, port);
         sds client = catClientInfoString(sdsempty(),c);
-        serverLog(LL_NOTICE,"SLAVE OF %s:%d enabled (user request from '%s')",
+        serverLog(LL_NOTICE,"REPLICAOF %s:%d enabled (user request from '%s')",
             server.masterhost, server.masterport, client);
         sdsfree(client);
     }
@@ -2191,7 +2223,7 @@ void replicationCacheMasterUsingMyself(void) {
     unlinkClient(server.master);
     server.cached_master = server.master;
     server.master = NULL;
-    serverLog(LL_NOTICE,"Before turning into a slave, using my master parameters to synthesize a cached master: I may be able to synchronize with the new master with just a partial transfer.");
+    serverLog(LL_NOTICE,"Before turning into a replica, using my master parameters to synthesize a cached master: I may be able to synchronize with the new master with just a partial transfer.");
 }
 
 /* Free a cached master, called when there are no longer the conditions for
@@ -2407,7 +2439,7 @@ void waitCommand(client *c) {
     long long offset = c->woff;
 
     if (server.masterhost) {
-        addReplyError(c,"WAIT cannot be used with slave instances. Please also note that since Redis 4.0 if a slave is configured to be writable (which is not the default) writes to slaves are just local and are not propagated.");
+        addReplyError(c,"WAIT cannot be used with replica instances. Please also note that since Redis 4.0 if a replica is configured to be writable (which is not the default) writes to replicas are just local and are not propagated.");
         return;
     }
 
@@ -2539,7 +2571,7 @@ void replicationCron(void) {
         serverLog(LL_NOTICE,"Connecting to MASTER %s:%d",
             server.masterhost, server.masterport);
         if (connectWithMaster() == C_OK) {
-            serverLog(LL_NOTICE,"MASTER <-> SLAVE sync started");
+            serverLog(LL_NOTICE,"MASTER <-> REPLICA sync started");
         }
     }
 
@@ -2562,10 +2594,21 @@ void replicationCron(void) {
     if ((replication_cron_loops % server.repl_ping_slave_period) == 0 &&
         listLength(server.slaves))
     {
-        ping_argv[0] = createStringObject("PING",4);
-        replicationFeedSlaves(server.slaves, server.slaveseldb,
-            ping_argv, 1);
-        decrRefCount(ping_argv[0]);
+        /* Note that we don't send the PING if the clients are paused during
+         * a Redis Cluster manual failover: the PING we send will otherwise
+         * alter the replication offsets of master and slave, and will no longer
+         * match the one stored into 'mf_master_offset' state. */
+        int manual_failover_in_progress =
+            server.cluster_enabled &&
+            server.cluster->mf_end &&
+            clientsArePaused();
+
+        if (!manual_failover_in_progress) {
+            ping_argv[0] = createStringObject("PING",4);
+            replicationFeedSlaves(server.slaves, server.slaveseldb,
+                ping_argv, 1);
+            decrRefCount(ping_argv[0]);
+        }
     }
 
     /* Second, send a newline to all the slaves in pre-synchronization
@@ -2611,7 +2654,7 @@ void replicationCron(void) {
             if (slave->flags & CLIENT_PRE_PSYNC) continue;
             if ((server.unixtime - slave->repl_ack_time) > server.repl_timeout)
             {
-                serverLog(LL_WARNING, "Disconnecting timedout slave: %s",
+                serverLog(LL_WARNING, "Disconnecting timedout replica: %s",
                     replicationGetSlaveName(slave));
                 freeClient(slave);
             }
@@ -2641,7 +2684,7 @@ void replicationCron(void) {
              *    be the same as our repl-id.
              * 3. We, yet as master, receive some updates, that will not
              *    increment the master_repl_offset.
-             * 4. Later we are turned into a slave, connecto to the new
+             * 4. Later we are turned into a slave, connect to the new
              *    master that will accept our PSYNC request by second
              *    replication ID, but there will be data inconsistency
              *    because we received writes. */
@@ -2650,7 +2693,7 @@ void replicationCron(void) {
             freeReplicationBacklog();
             serverLog(LL_NOTICE,
                 "Replication backlog freed after %d seconds "
-                "without connected slaves.",
+                "without connected replicas.",
                 (int) server.repl_backlog_time_limit);
         }
     }

src/scripting.c

@@ -443,6 +443,11 @@ int luaRedisGenericCommand(lua_State *lua, int raise_error) {
     c->argv = argv;
     c->argc = argc;
 
+    /* Process module hooks */
+    moduleCallCommandFilters(c);
+    argv = c->argv;
+    argc = c->argc;
+
     /* Log the command if debugging is active. */
     if (ldb.active && ldb.step) {
         sds cmdlog = sdsnew("<redis>");
@@ -512,10 +517,13 @@ int luaRedisGenericCommand(lua_State *lua, int raise_error) {
      * could enlarge the memory usage are not allowed, but only if this is the
      * first write in the context of this script, otherwise we can't stop
      * in the middle. */
-    if (server.maxmemory && server.lua_write_dirty == 0 &&
+    if (server.maxmemory &&             /* Maxmemory is actually enabled. */
+        !server.loading &&              /* Don't care about mem if loading. */
+        !server.masterhost &&           /* Slave must execute the script. */
+        server.lua_write_dirty == 0 &&  /* Script had no side effects so far. */
         (cmd->flags & CMD_DENYOOM))
     {
-        if (freeMemoryIfNeeded() == C_ERR) {
+        if (getMaxmemoryState(NULL,NULL,NULL,NULL) != C_OK) {
             luaPushError(lua, shared.oomerr->ptr);
             goto cleanup;
         }
@@ -774,7 +782,7 @@ int luaRedisSetReplCommand(lua_State *lua) {
 
     flags = lua_tonumber(lua,-1);
     if ((flags & ~(PROPAGATE_AOF|PROPAGATE_REPL)) != 0) {
-        lua_pushstring(lua, "Invalid replication flags. Use REPL_AOF, REPL_SLAVE, REPL_ALL or REPL_NONE.");
+        lua_pushstring(lua, "Invalid replication flags. Use REPL_AOF, REPL_REPLICA, REPL_ALL or REPL_NONE.");
         return lua_error(lua);
     }
     server.lua_repl = flags;
@@ -914,7 +922,6 @@ void scriptingInit(int setup) {
         server.lua_client = NULL;
         server.lua_caller = NULL;
         server.lua_timedout = 0;
-        server.lua_always_replicate_commands = 0; /* Only DEBUG can change it.*/
         ldbInit();
     }
 
@@ -996,6 +1003,10 @@ void scriptingInit(int setup) {
     lua_pushnumber(lua,PROPAGATE_REPL);
     lua_settable(lua,-3);
 
+    lua_pushstring(lua,"REPL_REPLICA");
+    lua_pushnumber(lua,PROPAGATE_REPL);
+    lua_settable(lua,-3);
+
     lua_pushstring(lua,"REPL_ALL");
     lua_pushnumber(lua,PROPAGATE_AOF|PROPAGATE_REPL);
     lua_settable(lua,-3);
@@ -1215,7 +1226,7 @@ sds luaCreateFunction(client *c, lua_State *lua, robj *body) {
      * EVALSHA commands as EVAL using the original script. */
     int retval = dictAdd(server.lua_scripts,sha,body);
     serverAssertWithInfo(c ? c : server.lua_client,NULL,retval == DICT_OK);
-    server.lua_scripts_mem += sdsZmallocSize(sha) + sdsZmallocSize(body->ptr);
+    server.lua_scripts_mem += sdsZmallocSize(sha) + getStringObjectSdsUsedMemory(body);
     incrRefCount(body);
     return sha;
 }
@@ -1236,7 +1247,7 @@ void luaMaskCountHook(lua_State *lua, lua_Debug *ar) {
          * we need to mask the client executing the script from the event loop.
          * If we don't do that the client may disconnect and could no longer be
          * here when the EVAL command will return. */
-         aeDeleteFileEvent(server.el, server.lua_caller->fd, AE_READABLE);
+        protectClient(server.lua_caller);
     }
     if (server.lua_timedout) processEventsWhileBlocked();
     if (server.lua_kill) {
@@ -1250,6 +1261,7 @@ void evalGenericCommand(client *c, int evalsha) {
     lua_State *lua = server.lua;
     char funcname[43];
     long long numkeys;
+    long long initial_server_dirty = server.dirty;
     int delhook = 0, err;
 
     /* When we replicate whole scripts, we want the same PRNG sequence at
@@ -1363,14 +1375,11 @@ void evalGenericCommand(client *c, int evalsha) {
     if (delhook) lua_sethook(lua,NULL,0,0); /* Disable hook */
     if (server.lua_timedout) {
         server.lua_timedout = 0;
-        /* Restore the readable handler that was unregistered when the
-         * script timeout was detected. */
-        aeCreateFileEvent(server.el,c->fd,AE_READABLE,
-                          readQueryFromClient,c);
-        if (server.masterhost && server.master) {
-            server.master->flags |= CLIENT_UNBLOCKED;
-            listAddNodeTail(server.unblocked_clients,server.master);
-        }
+        /* Restore the client that was protected when the script timeout
+         * was detected. */
+        unprotectClient(c);
+        if (server.masterhost && server.master)
+            queueClientForReprocessing(server.master);
     }
     server.lua_caller = NULL;
 
@@ -1434,9 +1443,21 @@ void evalGenericCommand(client *c, int evalsha) {
 
             replicationScriptCacheAdd(c->argv[1]->ptr);
             serverAssertWithInfo(c,NULL,script != NULL);
-            rewriteClientCommandArgument(c,0,
-                resetRefCount(createStringObject("EVAL",4)));
-            rewriteClientCommandArgument(c,1,script);
+
+            /* If the script did not produce any changes in the dataset we want
+             * just to replicate it as SCRIPT LOAD, otherwise we risk running
+             * an aborted script on slaves (that may then produce results there)
+             * or just running a CPU costly read-only script on the slaves. */
+            if (server.dirty == initial_server_dirty) {
+                rewriteClientCommandVector(c,3,
+                    resetRefCount(createStringObject("SCRIPT",6)),
+                    resetRefCount(createStringObject("LOAD",4)),
+                    script);
+            } else {
+                rewriteClientCommandArgument(c,0,
+                    resetRefCount(createStringObject("EVAL",4)));
+                rewriteClientCommandArgument(c,1,script);
+            }
             forceCommandPropagation(c,PROPAGATE_REPL|PROPAGATE_AOF);
         }
     }
@@ -1471,7 +1492,7 @@ void scriptCommand(client *c) {
         const char *help[] = {
 "DEBUG (yes|sync|no) -- Set the debug mode for subsequent scripts executed.",
 "EXISTS <sha1> [<sha1> ...] -- Return information about the existence of the scripts in the script cache.",
-"FLUSH -- Flush the Lua scripts cache. Very dangerous on slaves.",
+"FLUSH -- Flush the Lua scripts cache. Very dangerous on replicas.",
 "KILL -- Kill the currently executing Lua script.",
 "LOAD <script> -- Load a script into the scripts cache, without executing it.",
 NULL

src/sds.c

@@ -257,8 +257,12 @@ sds sdsRemoveFreeSpace(sds s) {
     char type, oldtype = s[-1] & SDS_TYPE_MASK;
     int hdrlen, oldhdrlen = sdsHdrSize(oldtype);
     size_t len = sdslen(s);
+    size_t avail = sdsavail(s);
     sh = (char*)s-oldhdrlen;
 
+    /* Return ASAP if there is no space left. */
+    if (avail == 0) return s;
+
     /* Check what would be the minimum SDS header that is just good enough to
      * fit this string. */
     type = sdsReqType(len);
@@ -695,7 +699,7 @@ sds sdscatfmt(sds s, char const *fmt, ...) {
  * s = sdstrim(s,"Aa. :");
  * printf("%s\n", s);
  *
- * Output will be just "Hello World".
+ * Output will be just "HelloWorld".
  */
 sds sdstrim(sds s, const char *cset) {
     char *start, *end, *sp, *ep;

src/sentinel.c

@@ -452,13 +452,15 @@ struct redisCommand sentinelcmds[] = {
     {"info",sentinelInfoCommand,-1,"",0,NULL,0,0,0,0,0},
     {"role",sentinelRoleCommand,1,"l",0,NULL,0,0,0,0,0},
     {"client",clientCommand,-2,"rs",0,NULL,0,0,0,0,0},
-    {"shutdown",shutdownCommand,-1,"",0,NULL,0,0,0,0,0}
+    {"shutdown",shutdownCommand,-1,"",0,NULL,0,0,0,0,0},
+    {"auth",authCommand,2,"sltF",0,NULL,0,0,0,0,0}
 };
 
 /* This function overwrites a few normal Redis config default with Sentinel
  * specific defaults. */
 void initSentinelConfig(void) {
     server.port = REDIS_SENTINEL_PORT;
+    server.protected_mode = 0; /* Sentinel must be exposed. */
 }
 
 /* Perform the Sentinel mode initialization. */
@@ -1687,16 +1689,18 @@ char *sentinelHandleConfiguration(char **argv, int argc) {
         ri = sentinelGetMasterByName(argv[1]);
         if (!ri) return "No such master with specified name.";
         ri->leader_epoch = strtoull(argv[2],NULL,10);
-    } else if (!strcasecmp(argv[0],"known-slave") && argc == 4) {
+    } else if ((!strcasecmp(argv[0],"known-slave") ||
+                !strcasecmp(argv[0],"known-replica")) && argc == 4)
+    {
         sentinelRedisInstance *slave;
 
-        /* known-slave <name> <ip> <port> */
+        /* known-replica <name> <ip> <port> */
         ri = sentinelGetMasterByName(argv[1]);
         if (!ri) return "No such master with specified name.";
         if ((slave = createSentinelRedisInstance(NULL,SRI_SLAVE,argv[2],
                     atoi(argv[3]), ri->quorum, ri)) == NULL)
         {
-            return "Wrong hostname or port for slave.";
+            return "Wrong hostname or port for replica.";
         }
     } else if (!strcasecmp(argv[0],"known-sentinel") &&
                (argc == 4 || argc == 5)) {
@@ -1854,7 +1858,7 @@ void rewriteConfigSentinelOption(struct rewriteConfigState *state) {
             if (sentinelAddrIsEqual(slave_addr,master_addr))
                 slave_addr = master->addr;
             line = sdscatprintf(sdsempty(),
-                "sentinel known-slave %s %s %d",
+                "sentinel known-replica %s %s %d",
                 master->name, slave_addr->ip, slave_addr->port);
             rewriteConfigRewriteLine(state,"sentinel",line,1);
         }
@@ -1939,12 +1943,25 @@ werr:
 /* Send the AUTH command with the specified master password if needed.
  * Note that for slaves the password set for the master is used.
  *
+ * In case this Sentinel requires a password as well, via the "requirepass"
+ * configuration directive, we assume we should use the local password in
+ * order to authenticate when connecting with the other Sentinels as well.
+ * So basically all the Sentinels share the same password and use it to
+ * authenticate reciprocally.
+ *
  * We don't check at all if the command was successfully transmitted
  * to the instance as if it fails Sentinel will detect the instance down,
  * will disconnect and reconnect the link and so forth. */
 void sentinelSendAuthIfNeeded(sentinelRedisInstance *ri, redisAsyncContext *c) {
-    char *auth_pass = (ri->flags & SRI_MASTER) ? ri->auth_pass :
-                                                 ri->master->auth_pass;
+    char *auth_pass = NULL;
+
+    if (ri->flags & SRI_MASTER) {
+        auth_pass = ri->auth_pass;
+    } else if (ri->flags & SRI_SLAVE) {
+        auth_pass = ri->master->auth_pass;
+    } else if (ri->flags & SRI_SENTINEL) {
+        if (server.requirepass) auth_pass = server.requirepass;
+    }
 
     if (auth_pass) {
         if (redisAsyncCommand(c, sentinelDiscardReplyCallback, ri, "%s %s",
@@ -2978,8 +2995,10 @@ void sentinelCommand(client *c) {
         if ((ri = sentinelGetMasterByNameOrReplyError(c,c->argv[2]))
             == NULL) return;
         addReplySentinelRedisInstance(c,ri);
-    } else if (!strcasecmp(c->argv[1]->ptr,"slaves")) {
-        /* SENTINEL SLAVES <master-name> */
+    } else if (!strcasecmp(c->argv[1]->ptr,"slaves") ||
+               !strcasecmp(c->argv[1]->ptr,"replicas"))
+    {
+        /* SENTINEL REPLICAS <master-name> */
         sentinelRedisInstance *ri;
 
         if (c->argc != 3) goto numargserr;
@@ -3079,7 +3098,7 @@ void sentinelCommand(client *c) {
             return;
         }
         if (sentinelSelectSlave(ri) == NULL) {
-            addReplySds(c,sdsnew("-NOGOODSLAVE No suitable slave to promote\r\n"));
+            addReplySds(c,sdsnew("-NOGOODSLAVE No suitable replica to promote\r\n"));
             return;
         }
         serverLog(LL_WARNING,"Executing user requested FAILOVER of '%s'",
@@ -3261,7 +3280,7 @@ void sentinelCommand(client *c) {
                 sentinel.simfailure_flags |=
                     SENTINEL_SIMFAILURE_CRASH_AFTER_PROMOTION;
                 serverLog(LL_WARNING,"Failure simulation: this Sentinel "
-                    "will crash after promoting the selected slave to master");
+                    "will crash after promoting the selected replica to master");
             } else if (!strcasecmp(c->argv[j]->ptr,"help")) {
                 addReplyMultiBulkLen(c,2);
                 addReplyBulkCString(c,"crash-after-election");

src/server.c

@@ -200,8 +200,8 @@ struct redisCommand redisCommandTable[] = {
     {"zscan",zscanCommand,-3,"rR",0,NULL,1,1,1,0,0},
     {"zpopmin",zpopminCommand,-2,"wF",0,NULL,1,1,1,0,0},
     {"zpopmax",zpopmaxCommand,-2,"wF",0,NULL,1,1,1,0,0},
-    {"bzpopmin",bzpopminCommand,-2,"wsF",0,NULL,1,-2,1,0,0},
-    {"bzpopmax",bzpopmaxCommand,-2,"wsF",0,NULL,1,-2,1,0,0},
+    {"bzpopmin",bzpopminCommand,-3,"wsF",0,NULL,1,-2,1,0,0},
+    {"bzpopmax",bzpopmaxCommand,-3,"wsF",0,NULL,1,-2,1,0,0},
     {"hset",hsetCommand,-4,"wmF",0,NULL,1,1,1,0,0},
     {"hsetnx",hsetnxCommand,4,"wmF",0,NULL,1,1,1,0,0},
     {"hget",hgetCommand,3,"rF",0,NULL,1,1,1,0,0},
@@ -260,7 +260,8 @@ struct redisCommand redisCommandTable[] = {
     {"touch",touchCommand,-2,"rF",0,NULL,1,1,1,0,0},
     {"pttl",pttlCommand,2,"rFR",0,NULL,1,1,1,0,0},
     {"persist",persistCommand,2,"wF",0,NULL,1,1,1,0,0},
-    {"slaveof",slaveofCommand,3,"ast",0,NULL,0,0,0,0,0},
+    {"slaveof",replicaofCommand,3,"ast",0,NULL,0,0,0,0,0},
+    {"replicaof",replicaofCommand,3,"ast",0,NULL,0,0,0,0,0},
     {"role",roleCommand,1,"lst",0,NULL,0,0,0,0,0},
     {"debug",debugCommand,-2,"as",0,NULL,0,0,0,0,0},
     {"config",configCommand,-2,"last",0,NULL,0,0,0,0,0},
@@ -306,22 +307,24 @@ struct redisCommand redisCommandTable[] = {
     {"pfcount",pfcountCommand,-2,"r",0,NULL,1,-1,1,0,0},
     {"pfmerge",pfmergeCommand,-2,"wm",0,NULL,1,-1,1,0,0},
     {"pfdebug",pfdebugCommand,-3,"w",0,NULL,0,0,0,0,0},
-    {"xadd",xaddCommand,-5,"wmF",0,NULL,1,1,1,0,0},
+    {"xadd",xaddCommand,-5,"wmFR",0,NULL,1,1,1,0,0},
     {"xrange",xrangeCommand,-4,"r",0,NULL,1,1,1,0,0},
     {"xrevrange",xrevrangeCommand,-4,"r",0,NULL,1,1,1,0,0},
     {"xlen",xlenCommand,2,"rF",0,NULL,1,1,1,0,0},
     {"xread",xreadCommand,-4,"rs",0,xreadGetKeys,1,1,1,0,0},
     {"xreadgroup",xreadCommand,-7,"ws",0,xreadGetKeys,1,1,1,0,0},
     {"xgroup",xgroupCommand,-2,"wm",0,NULL,2,2,1,0,0},
+    {"xsetid",xsetidCommand,3,"wmF",0,NULL,1,1,1,0,0},
     {"xack",xackCommand,-4,"wF",0,NULL,1,1,1,0,0},
-    {"xpending",xpendingCommand,-3,"r",0,NULL,1,1,1,0,0},
-    {"xclaim",xclaimCommand,-6,"wF",0,NULL,1,1,1,0,0},
-    {"xinfo",xinfoCommand,-2,"r",0,NULL,2,2,1,0,0},
+    {"xpending",xpendingCommand,-3,"rR",0,NULL,1,1,1,0,0},
+    {"xclaim",xclaimCommand,-6,"wRF",0,NULL,1,1,1,0,0},
+    {"xinfo",xinfoCommand,-2,"rR",0,NULL,2,2,1,0,0},
     {"xdel",xdelCommand,-3,"wF",0,NULL,1,1,1,0,0},
-    {"xtrim",xtrimCommand,-2,"wF",0,NULL,1,1,1,0,0},
+    {"xtrim",xtrimCommand,-2,"wFR",0,NULL,1,1,1,0,0},
     {"post",securityWarningCommand,-1,"lt",0,NULL,0,0,0,0,0},
     {"host:",securityWarningCommand,-1,"lt",0,NULL,0,0,0,0,0},
-    {"latency",latencyCommand,-2,"aslt",0,NULL,0,0,0,0,0}
+    {"latency",latencyCommand,-2,"aslt",0,NULL,0,0,0,0,0},
+    {"lolwut",lolwutCommand,-1,"r",0,NULL,0,0,0,0,0}
 };
 
 /*============================ Utility functions ============================ */
@@ -997,10 +1000,12 @@ void clientsCron(void) {
 void databasesCron(void) {
     /* Expire keys by random sampling. Not required for slaves
      * as master will synthesize DELs for us. */
-    if (server.active_expire_enabled && server.masterhost == NULL) {
-        activeExpireCycle(ACTIVE_EXPIRE_CYCLE_SLOW);
-    } else if (server.masterhost != NULL) {
-        expireSlaveKeys();
+    if (server.active_expire_enabled) {
+        if (server.masterhost == NULL) {
+            activeExpireCycle(ACTIVE_EXPIRE_CYCLE_SLOW);
+        } else {
+            expireSlaveKeys();
+        }
     }
 
     /* Defrag keys gradually. */
@@ -1192,7 +1197,7 @@ int serverCron(struct aeEventLoop *eventLoop, long long id, void *clientData) {
     if (!server.sentinel_mode) {
         run_with_period(5000) {
             serverLog(LL_VERBOSE,
-                "%lu clients connected (%lu slaves), %zu bytes in use",
+                "%lu clients connected (%lu replicas), %zu bytes in use",
                 listLength(server.clients)-listLength(server.slaves),
                 listLength(server.slaves),
                 zmalloc_used_memory());
@@ -1320,9 +1325,7 @@ int serverCron(struct aeEventLoop *eventLoop, long long id, void *clientData) {
     }
 
     /* Run the Sentinel timer if we are in sentinel mode. */
-    run_with_period(100) {
-        if (server.sentinel_mode) sentinelTimer();
-    }
+    if (server.sentinel_mode) sentinelTimer();
 
     /* Cleanup expired MIGRATE cached sockets. */
     run_with_period(1000) {
@@ -1451,11 +1454,11 @@ void createSharedObjects(void) {
     shared.slowscripterr = createObject(OBJ_STRING,sdsnew(
         "-BUSY Redis is busy running a script. You can only call SCRIPT KILL or SHUTDOWN NOSAVE.\r\n"));
     shared.masterdownerr = createObject(OBJ_STRING,sdsnew(
-        "-MASTERDOWN Link with MASTER is down and slave-serve-stale-data is set to 'no'.\r\n"));
+        "-MASTERDOWN Link with MASTER is down and replica-serve-stale-data is set to 'no'.\r\n"));
     shared.bgsaveerr = createObject(OBJ_STRING,sdsnew(
         "-MISCONF Redis is configured to save RDB snapshots, but it is currently not able to persist on disk. Commands that may modify the data set are disabled, because this instance is configured to report errors during writes if RDB snapshotting fails (stop-writes-on-bgsave-error option). Please check the Redis logs for details about the RDB error.\r\n"));
     shared.roslaveerr = createObject(OBJ_STRING,sdsnew(
-        "-READONLY You can't write against a read only slave.\r\n"));
+        "-READONLY You can't write against a read only replica.\r\n"));
     shared.noautherr = createObject(OBJ_STRING,sdsnew(
         "-NOAUTH Authentication required.\r\n"));
     shared.oomerr = createObject(OBJ_STRING,sdsnew(
@@ -1463,7 +1466,7 @@ void createSharedObjects(void) {
     shared.execaborterr = createObject(OBJ_STRING,sdsnew(
         "-EXECABORT Transaction discarded because of previous errors.\r\n"));
     shared.noreplicaserr = createObject(OBJ_STRING,sdsnew(
-        "-NOREPLICAS Not enough good slaves to write.\r\n"));
+        "-NOREPLICAS Not enough good replicas to write.\r\n"));
     shared.busykeyerr = createObject(OBJ_STRING,sdsnew(
         "-BUSYKEY Target key name already exists.\r\n"));
     shared.space = createObject(OBJ_STRING,sdsnew(" "));
@@ -1525,10 +1528,10 @@ void initServerConfig(void) {
     server.runid[CONFIG_RUN_ID_SIZE] = '\0';
     changeReplicationId();
     clearReplicationId2();
-    server.timezone = timezone; /* Initialized by tzset(). */
+    server.timezone = getTimeZone(); /* Initialized by tzset(). */
     server.configfile = NULL;
     server.executable = NULL;
-    server.config_hz = CONFIG_DEFAULT_HZ;
+    server.hz = server.config_hz = CONFIG_DEFAULT_HZ;
     server.dynamic_hz = CONFIG_DEFAULT_DYNAMIC_HZ;
     server.arch_bits = (sizeof(long) == 8) ? 64 : 32;
     server.port = CONFIG_DEFAULT_SERVER_PORT;
@@ -1621,6 +1624,7 @@ void initServerConfig(void) {
     server.cluster_announce_ip = CONFIG_DEFAULT_CLUSTER_ANNOUNCE_IP;
     server.cluster_announce_port = CONFIG_DEFAULT_CLUSTER_ANNOUNCE_PORT;
     server.cluster_announce_bus_port = CONFIG_DEFAULT_CLUSTER_ANNOUNCE_BUS_PORT;
+    server.cluster_module_flags = CLUSTER_MODULE_FLAG_NONE;
     server.migrate_cached_sockets = dictCreate(&migrateCacheDictType,NULL);
     server.next_client_id = 1; /* Client IDs, start from 1 .*/
     server.loading_process_events_interval_bytes = (1024*1024*2);
@@ -1701,6 +1705,7 @@ void initServerConfig(void) {
     server.expireCommand = lookupCommandByCString("expire");
     server.pexpireCommand = lookupCommandByCString("pexpire");
     server.xclaimCommand = lookupCommandByCString("xclaim");
+    server.xgroupCommand = lookupCommandByCString("xgroup");
 
     /* Slow log */
     server.slowlog_log_slower_than = CONFIG_DEFAULT_SLOWLOG_LOG_SLOWER_THAN;
@@ -1715,6 +1720,12 @@ void initServerConfig(void) {
     server.assert_line = 0;
     server.bug_report_start = 0;
     server.watchdog_period = 0;
+
+    /* By default we want scripts to be always replicated by effects
+     * (single commands executed by the script), and not by sending the
+     * script to the slave / AOF. This is the new way starting from
+     * Redis 5. However it is possible to revert it via redis.conf. */
+    server.lua_always_replicate_commands = 1;
 }
 
 extern char **environ;
@@ -1949,9 +1960,13 @@ int listenToPort(int port, int *fds, int *count) {
         }
         if (fds[*count] == ANET_ERR) {
             serverLog(LL_WARNING,
-                "Creating Server TCP listening socket %s:%d: %s",
+                "Could not create server TCP listening socket %s:%d: %s",
                 server.bindaddr[j] ? server.bindaddr[j] : "*",
                 port, server.neterr);
+                if (errno == ENOPROTOOPT     || errno == EPROTONOSUPPORT ||
+                    errno == ESOCKTNOSUPPORT || errno == EPFNOSUPPORT ||
+                    errno == EAFNOSUPPORT    || errno == EADDRNOTAVAIL)
+                    continue;
             return C_ERR;
         }
         anetNonBlock(NULL,fds[*count]);
@@ -2401,6 +2416,7 @@ void preventCommandReplication(client *c) {
 void call(client *c, int flags) {
     long long dirty, start, duration;
     int client_old_flags = c->flags;
+    struct redisCommand *real_cmd = c->cmd;
 
     /* Sent the command to clients in MONITOR mode, only if the commands are
      * not generated from reading an AOF. */
@@ -2449,8 +2465,11 @@ void call(client *c, int flags) {
         slowlogPushEntryIfNeeded(c,c->argv,c->argc,duration);
     }
     if (flags & CMD_CALL_STATS) {
-        c->lastcmd->microseconds += duration;
-        c->lastcmd->calls++;
+        /* use the real command that was executed (cmd and lastamc) may be
+         * different, in case of MULTI-EXEC or re-written commands such as
+         * EXPIRE, GEOADD, etc. */
+        real_cmd->microseconds += duration;
+        real_cmd->calls++;
     }
 
     /* Propagate the command into the AOF and replication link */
@@ -2524,6 +2543,8 @@ void call(client *c, int flags) {
  * other operations can be performed by the caller. Otherwise
  * if C_ERR is returned the client was destroyed (i.e. after QUIT). */
 int processCommand(client *c) {
+    moduleCallCommandFilters(c);
+
     /* The QUIT command is handled separately. Normal command procs will
      * go through checking for replication and QUIT will cause trouble
      * when FORCE_REPLICATION is enabled and would be implemented in
@@ -2591,18 +2612,22 @@ int processCommand(client *c) {
 
     /* Handle the maxmemory directive.
      *
-     * First we try to free some memory if possible (if there are volatile
-     * keys in the dataset). If there are not the only thing we can do
-     * is returning an error. */
-    if (server.maxmemory) {
-        int out_of_memory = freeMemoryIfNeeded() == C_ERR;
+     * Note that we do not want to reclaim memory if we are here re-entering
+     * the event loop since there is a busy Lua script running in timeout
+     * condition, to avoid mixing the propagation of scripts with the
+     * propagation of DELs due to eviction. */
+    if (server.maxmemory && !server.lua_timedout) {
+        int out_of_memory = freeMemoryIfNeededAndSafe() == C_ERR;
         /* freeMemoryIfNeeded may flush slave output buffers. This may result
          * into a slave, that may be the active client, to be freed. */
         if (server.current_client == NULL) return C_ERR;
 
         /* It was impossible to free enough memory, and the command the client
-         * is trying to execute is denied during OOM conditions? Error. */
-        if ((c->cmd->flags & CMD_DENYOOM) && out_of_memory) {
+         * is trying to execute is denied during OOM conditions or the client
+         * is in MULTI/EXEC context? Error. */
+        if (out_of_memory &&
+            (c->cmd->flags & CMD_DENYOOM ||
+             (c->flags & CLIENT_MULTI && c->cmd->proc != execCommand))) {
             flagTransaction(c);
             addReply(c, shared.oomerr);
             return C_OK;
@@ -3188,7 +3213,7 @@ sds genRedisInfoString(char *section) {
         bytesToHuman(peak_hmem,server.stat_peak_memory);
         bytesToHuman(total_system_hmem,total_system_mem);
         bytesToHuman(used_memory_lua_hmem,memory_lua);
-        bytesToHuman(used_memory_scripts_hmem,server.lua_scripts_mem);
+        bytesToHuman(used_memory_scripts_hmem,mh->lua_caches);
         bytesToHuman(used_memory_rss_hmem,server.cron_malloc_stats.process_rss);
         bytesToHuman(maxmemory_hmem,server.maxmemory);
 
@@ -3222,11 +3247,11 @@ sds genRedisInfoString(char *section) {
             "allocator_frag_ratio:%.2f\r\n"
             "allocator_frag_bytes:%zu\r\n"
             "allocator_rss_ratio:%.2f\r\n"
-            "allocator_rss_bytes:%zu\r\n"
+            "allocator_rss_bytes:%zd\r\n"
             "rss_overhead_ratio:%.2f\r\n"
-            "rss_overhead_bytes:%zu\r\n"
+            "rss_overhead_bytes:%zd\r\n"
             "mem_fragmentation_ratio:%.2f\r\n"
-            "mem_fragmentation_bytes:%zu\r\n"
+            "mem_fragmentation_bytes:%zd\r\n"
             "mem_not_counted_for_evict:%zu\r\n"
             "mem_replication_backlog:%zu\r\n"
             "mem_clients_slaves:%zu\r\n"
@@ -3253,7 +3278,7 @@ sds genRedisInfoString(char *section) {
             total_system_hmem,
             memory_lua,
             used_memory_lua_hmem,
-            server.lua_scripts_mem,
+            (long long) mh->lua_caches,
             used_memory_scripts_hmem,
             dictSize(server.lua_scripts),
             server.maxmemory,
@@ -3716,7 +3741,7 @@ void usage(void) {
     fprintf(stderr,"       ./redis-server (run the server with default conf)\n");
     fprintf(stderr,"       ./redis-server /etc/redis/6379.conf\n");
     fprintf(stderr,"       ./redis-server --port 7777\n");
-    fprintf(stderr,"       ./redis-server --port 7777 --slaveof 127.0.0.1 8888\n");
+    fprintf(stderr,"       ./redis-server --port 7777 --replicaof 127.0.0.1 8888\n");
     fprintf(stderr,"       ./redis-server /etc/myredis.conf --loglevel verbose\n\n");
     fprintf(stderr,"Sentinel mode:\n");
     fprintf(stderr,"       ./redis-server /etc/sentinel.conf --sentinel\n");
@@ -3782,6 +3807,7 @@ static void sigShutdownHandler(int sig) {
         rdbRemoveTempFile(getpid());
         exit(1); /* Exit with an error since this was not a clean shutdown. */
     } else if (server.loading) {
+        serverLogFromHandler(LL_WARNING, "Received shutdown signal during loading, exiting now.");
         exit(0);
     }
 
@@ -3838,7 +3864,7 @@ void loadDataFromDisk(void) {
                 (float)(ustime()-start)/1000000);
 
             /* Restore the replication ID / offset from the RDB file. */
-            if (server.masterhost &&
+            if ((server.masterhost || (server.cluster_enabled && nodeIsSlave(server.cluster->myself)))&&
                 rsi.repl_id_is_set &&
                 rsi.repl_offset != -1 &&
                 /* Note that older implementations may save a repl_stream_db
@@ -3997,12 +4023,12 @@ int main(int argc, char **argv) {
             return sha1Test(argc, argv);
         } else if (!strcasecmp(argv[2], "util")) {
             return utilTest(argc, argv);
-        } else if (!strcasecmp(argv[2], "sds")) {
-            return sdsTest(argc, argv);
         } else if (!strcasecmp(argv[2], "endianconv")) {
             return endianconvTest(argc, argv);
         } else if (!strcasecmp(argv[2], "crc64")) {
             return crc64Test(argc, argv);
+        } else if (!strcasecmp(argv[2], "zmalloc")) {
+            return zmalloc_test(argc, argv);
         }
 
         return -1; /* test not found */

src/server.h

@@ -256,6 +256,7 @@ typedef long long mstime_t; /* millisecond time type. */
 #define CLIENT_LUA_DEBUG (1<<25)  /* Run EVAL in debug mode. */
 #define CLIENT_LUA_DEBUG_SYNC (1<<26)  /* EVAL debugging without fork() */
 #define CLIENT_MODULE (1<<27) /* Non connected client used by some module. */
+#define CLIENT_PROTECTED (1<<28) /* Client should not be freed for now. */
 
 /* Client block type (btype field in client structure)
  * if CLIENT_BLOCKED flag is set. */
@@ -550,16 +551,18 @@ typedef struct RedisModuleIO {
     int ver;            /* Module serialization version: 1 (old),
                          * 2 (current version with opcodes annotation). */
     struct RedisModuleCtx *ctx; /* Optional context, see RM_GetContextFromIO()*/
+    struct redisObject *key;    /* Optional name of key processed */
 } RedisModuleIO;
 
 /* Macro to initialize an IO context. Note that the 'ver' field is populated
  * inside rdb.c according to the version of the value to load. */
-#define moduleInitIOContext(iovar,mtype,rioptr) do { \
+#define moduleInitIOContext(iovar,mtype,rioptr,keyptr) do { \
     iovar.rio = rioptr; \
     iovar.type = mtype; \
     iovar.bytes = 0; \
     iovar.error = 0; \
     iovar.ver = 0; \
+    iovar.key = keyptr; \
     iovar.ctx = NULL; \
 } while(0);
 
@@ -653,6 +656,9 @@ typedef struct multiCmd {
 typedef struct multiState {
     multiCmd *commands;     /* Array of MULTI commands */
     int count;              /* Total number of MULTI commands */
+    int cmd_flags;          /* The accumulated command flags OR-ed together.
+                               So if at least a command has a given flag, it
+                               will be set in this field. */
     int minreplicas;        /* MINREPLICAS for synchronous replication */
     time_t minreplicas_timeout; /* MINREPLICAS timeout as unixtime. */
 } multiState;
@@ -863,11 +869,11 @@ struct redisMemOverhead {
     float dataset_perc;
     float peak_perc;
     float total_frag;
-    size_t total_frag_bytes;
+    ssize_t total_frag_bytes;
     float allocator_frag;
-    size_t allocator_frag_bytes;
+    ssize_t allocator_frag_bytes;
     float allocator_rss;
-    size_t allocator_rss_bytes;
+    ssize_t allocator_rss_bytes;
     float rss_extra;
     size_t rss_extra_bytes;
     size_t num_dbs;
@@ -950,7 +956,9 @@ struct redisServer {
     size_t initial_memory_usage; /* Bytes used after initialization. */
     int always_show_logo;       /* Show logo even for non-stdout logging. */
     /* Modules */
-    dict *moduleapi;            /* Exported APIs dictionary for modules. */
+    dict *moduleapi;            /* Exported core APIs dictionary for modules. */
+    dict *sharedapi;            /* Like moduleapi but containing the APIs that
+                                   modules share with each other. */
     list *loadmodule_queue;     /* List of modules to load at startup. */
     int module_blocked_pipe[2]; /* Pipe used to awake the event loop if a
                                    client blocked on a module command needs
@@ -989,7 +997,8 @@ struct redisServer {
     struct redisCommand *delCommand, *multiCommand, *lpushCommand,
                         *lpopCommand, *rpopCommand, *zpopminCommand,
                         *zpopmaxCommand, *sremCommand, *execCommand,
-                        *expireCommand, *pexpireCommand, *xclaimCommand;
+                        *expireCommand, *pexpireCommand, *xclaimCommand,
+                        *xgroupCommand;
     /* Fields used only for stats */
     time_t stat_starttime;          /* Server start time */
     long long stat_numcommands;     /* Number of processed commands */
@@ -1056,6 +1065,7 @@ struct redisServer {
     off_t aof_rewrite_min_size;     /* the AOF file is at least N bytes. */
     off_t aof_rewrite_base_size;    /* AOF size on latest startup or rewrite. */
     off_t aof_current_size;         /* AOF current size. */
+    off_t aof_fsync_offset;         /* AOF offset which is already synced to disk. */
     int aof_rewrite_scheduled;      /* Rewrite once BGSAVE terminates. */
     pid_t aof_child_pid;            /* PID if rewriting process */
     list *aof_rewrite_buf_blocks;   /* Hold changes during an AOF rewrite. */
@@ -1232,6 +1242,10 @@ struct redisServer {
     char *cluster_announce_ip;  /* IP address to announce on cluster bus. */
     int cluster_announce_port;     /* base port to announce on cluster bus. */
     int cluster_announce_bus_port; /* bus port to announce on cluster bus. */
+    int cluster_module_flags;      /* Set of flags that Redis modules are able
+                                      to set in order to suppress certain
+                                      native Redis Cluster features. Check the
+                                      REDISMODULE_CLUSTER_FLAG_*. */
     /* Scripting */
     lua_State *lua; /* The Lua interpreter. We use just one for all clients */
     client *lua_client;   /* The "fake client" to query Redis from Lua */
@@ -1396,7 +1410,7 @@ size_t moduleCount(void);
 void moduleAcquireGIL(void);
 void moduleReleaseGIL(void);
 void moduleNotifyKeyspaceEvent(int type, const char *event, robj *key, int dbid);
-
+void moduleCallCommandFilters(client *c);
 
 /* Utils */
 long long ustime(void);
@@ -1418,11 +1432,13 @@ void sendReplyToClient(aeEventLoop *el, int fd, void *privdata, int mask);
 void *addDeferredMultiBulkLength(client *c);
 void setDeferredMultiBulkLength(client *c, void *node, long length);
 void processInputBuffer(client *c);
+void processInputBufferAndReplicate(client *c);
 void acceptHandler(aeEventLoop *el, int fd, void *privdata, int mask);
 void acceptTcpHandler(aeEventLoop *el, int fd, void *privdata, int mask);
 void acceptUnixHandler(aeEventLoop *el, int fd, void *privdata, int mask);
 void readQueryFromClient(aeEventLoop *el, int fd, void *privdata, int mask);
 void addReplyString(client *c, const char *s, size_t len);
+void AddReplyFromClient(client *c, client *src);
 void addReplyBulk(client *c, robj *obj);
 void addReplyBulkCString(client *c, const char *s);
 void addReplyBulkCBuffer(client *c, const void *p, size_t len);
@@ -1468,6 +1484,8 @@ int clientHasPendingReplies(client *c);
 void unlinkClient(client *c);
 int writeToClient(int fd, client *c, int handler_installed);
 void linkClient(client *c);
+void protectClient(client *c);
+void unprotectClient(client *c);
 
 #ifdef __GNUC__
 void addReplyErrorFormat(client *c, const char *fmt, ...)
@@ -1552,6 +1570,7 @@ int compareStringObjects(robj *a, robj *b);
 int collateStringObjects(robj *a, robj *b);
 int equalStringObjects(robj *a, robj *b);
 unsigned long long estimateObjectIdleTime(robj *o);
+void trimStringObjectIfNeeded(robj *o);
 #define sdsEncodedObject(objptr) (objptr->encoding == OBJ_ENCODING_RAW || objptr->encoding == OBJ_ENCODING_EMBSTR)
 
 /* Synchronous I/O with timeout */
@@ -1690,6 +1709,7 @@ int zslLexValueLteMax(sds value, zlexrangespec *spec);
 int getMaxmemoryState(size_t *total, size_t *logical, size_t *tofree, float *level);
 size_t freeMemoryGetNotCountedMemory();
 int freeMemoryIfNeeded(void);
+int freeMemoryIfNeededAndSafe(void);
 int processCommand(client *c);
 void setupSignalHandlers(void);
 struct redisCommand *lookupCommand(sds name);
@@ -1883,6 +1903,7 @@ sds luaCreateFunction(client *c, lua_State *lua, robj *body);
 void processUnblockedClients(void);
 void blockClient(client *c, int btype);
 void unblockClient(client *c);
+void queueClientForReprocessing(client *c);
 void replyToBlockedClientTimedOut(client *c);
 int getTimeoutFromObjectOrReply(client *c, robj *object, mstime_t *timeout, int unit);
 void disconnectAllBlockedClients(void);
@@ -1996,7 +2017,7 @@ void ttlCommand(client *c);
 void touchCommand(client *c);
 void pttlCommand(client *c);
 void persistCommand(client *c);
-void slaveofCommand(client *c);
+void replicaofCommand(client *c);
 void roleCommand(client *c);
 void debugCommand(client *c);
 void msetCommand(client *c);
@@ -2101,12 +2122,14 @@ void xrevrangeCommand(client *c);
 void xlenCommand(client *c);
 void xreadCommand(client *c);
 void xgroupCommand(client *c);
+void xsetidCommand(client *c);
 void xackCommand(client *c);
 void xpendingCommand(client *c);
 void xclaimCommand(client *c);
 void xinfoCommand(client *c);
 void xdelCommand(client *c);
 void xtrimCommand(client *c);
+void lolwutCommand(client *c);
 
 #if defined(__GNUC__)
 void *calloc(size_t count, size_t size) __attribute__ ((deprecated));

src/setproctitle.c

@@ -39,7 +39,7 @@
 #include <errno.h>	/* errno program_invocation_name program_invocation_short_name */
 
 #if !defined(HAVE_SETPROCTITLE)
-#if (defined __NetBSD__ || defined __FreeBSD__ || defined __OpenBSD__)
+#if (defined __NetBSD__ || defined __FreeBSD__ || defined __OpenBSD__ || defined __DragonFly__)
 #define HAVE_SETPROCTITLE 1
 #else
 #define HAVE_SETPROCTITLE 0

src/t_hash.c

@@ -615,6 +615,10 @@ void hincrbyfloatCommand(client *c) {
     }
 
     value += incr;
+    if (isnan(value) || isinf(value)) {
+        addReplyError(c,"increment would produce NaN or Infinity");
+        return;
+    }
 
     char buf[MAX_LONG_DOUBLE_CHARS];
     int len = ld2string(buf,sizeof(buf),value,1);

src/t_list.c

@@ -520,7 +520,7 @@ void lremCommand(client *c) {
 
     if (removed) {
         signalModifiedKey(c->db,c->argv[1]);
-        notifyKeyspaceEvent(NOTIFY_GENERIC,"lrem",c->argv[1],c->db->id);
+        notifyKeyspaceEvent(NOTIFY_LIST,"lrem",c->argv[1],c->db->id);
     }
 
     if (listTypeLength(subject) == 0) {
@@ -596,7 +596,7 @@ void rpoplpushCommand(client *c) {
         signalModifiedKey(c->db,touchedkey);
         decrRefCount(touchedkey);
         server.dirty++;
-        if (c->lastcmd->proc == brpoplpushCommand) {
+        if (c->cmd->proc == brpoplpushCommand) {
             rewriteClientCommandVector(c,3,shared.rpoplpush,c->argv[1],c->argv[2]);
         }
     }
@@ -617,7 +617,7 @@ void rpoplpushCommand(client *c) {
  *    the AOF and replication channel.
  *
  * The argument 'where' is LIST_TAIL or LIST_HEAD, and indicates if the
- * 'value' element was popped fron the head (BLPOP) or tail (BRPOP) so that
+ * 'value' element was popped from the head (BLPOP) or tail (BRPOP) so that
  * we can propagate the command properly.
  *
  * The function returns C_OK if we are able to serve the client, otherwise

src/t_stream.c

@@ -349,7 +349,8 @@ int streamAppendItem(stream *s, robj **argv, int64_t numfields, streamID *added_
     lp = lpAppendInteger(lp,lp_count);
 
     /* Insert back into the tree in order to update the listpack pointer. */
-    raxInsert(s->rax,(unsigned char*)&rax_key,sizeof(rax_key),lp,NULL);
+    if (ri.data != lp)
+        raxInsert(s->rax,(unsigned char*)&rax_key,sizeof(rax_key),lp,NULL);
     s->length++;
     s->last_id = id;
     if (added_id) *added_id = id;
@@ -491,14 +492,14 @@ void streamIteratorStart(streamIterator *si, stream *s, streamID *start, streamI
         streamEncodeID(si->start_key,start);
     } else {
         si->start_key[0] = 0;
-        si->start_key[0] = 0;
+        si->start_key[1] = 0;
     }
 
     if (end) {
         streamEncodeID(si->end_key,end);
     } else {
         si->end_key[0] = UINT64_MAX;
-        si->end_key[0] = UINT64_MAX;
+        si->end_key[1] = UINT64_MAX;
     }
 
     /* Seek the correct node in the radix tree. */
@@ -724,6 +725,10 @@ void streamIteratorRemoveEntry(streamIterator *si, streamID *current) {
         p = lpNext(lp,p); /* Seek deleted field. */
         aux = lpGetInteger(p);
         lp = lpReplaceInteger(lp,&p,aux+1);
+
+        /* Update the listpack with the new pointer. */
+        if (si->lp != lp)
+            raxInsert(si->stream->rax,si->ri.key,si->ri.key_len,lp,NULL);
     }
 
     /* Update the number of entries counter. */
@@ -772,8 +777,8 @@ int streamDeleteItem(stream *s, streamID *id) {
  * in the standard <ms>-<seq> format, using the simple string protocol
  * of REPL. */
 void addReplyStreamID(client *c, streamID *id) {
-    sds replyid = sdscatfmt(sdsempty(),"+%U-%U\r\n",id->ms,id->seq);
-    addReplySds(c,replyid);
+    sds replyid = sdscatfmt(sdsempty(),"%U-%U",id->ms,id->seq);
+    addReplyBulkSds(c,replyid);
 }
 
 /* Similar to the above function, but just creates an object, usually useful
@@ -786,18 +791,18 @@ robj *createObjectFromStreamID(streamID *id) {
 /* As a result of an explicit XCLAIM or XREADGROUP command, new entries
  * are created in the pending list of the stream and consumers. We need
  * to propagate this changes in the form of XCLAIM commands. */
-void streamPropagateXCLAIM(client *c, robj *key, robj *group, robj *id, streamNACK *nack) {
+void streamPropagateXCLAIM(client *c, robj *key, streamCG *group, robj *groupname, robj *id, streamNACK *nack) {
     /* We need to generate an XCLAIM that will work in a idempotent fashion:
      *
      * XCLAIM <key> <group> <consumer> 0 <id> TIME <milliseconds-unix-time>
-     *        RETRYCOUNT <count> FORCE JUSTID.
+     *        RETRYCOUNT <count> FORCE JUSTID LASTID <id>.
      *
      * Note that JUSTID is useful in order to avoid that XCLAIM will do
      * useless work in the slave side, trying to fetch the stream item. */
-    robj *argv[12];
+    robj *argv[14];
     argv[0] = createStringObject("XCLAIM",6);
     argv[1] = key;
-    argv[2] = group;
+    argv[2] = groupname;
     argv[3] = createStringObject(nack->consumer->name,sdslen(nack->consumer->name));
     argv[4] = createStringObjectFromLongLong(0);
     argv[5] = id;
@@ -807,7 +812,9 @@ void streamPropagateXCLAIM(client *c, robj *key, robj *group, robj *id, streamNA
     argv[9] = createStringObjectFromLongLong(nack->delivery_count);
     argv[10] = createStringObject("FORCE",5);
     argv[11] = createStringObject("JUSTID",6);
-    propagate(server.xclaimCommand,c->db->id,argv,12,PROPAGATE_AOF|PROPAGATE_REPL);
+    argv[12] = createStringObject("LASTID",6);
+    argv[13] = createObjectFromStreamID(&group->last_id);
+    propagate(server.xclaimCommand,c->db->id,argv,14,PROPAGATE_AOF|PROPAGATE_REPL);
     decrRefCount(argv[0]);
     decrRefCount(argv[3]);
     decrRefCount(argv[4]);
@@ -817,13 +824,38 @@ void streamPropagateXCLAIM(client *c, robj *key, robj *group, robj *id, streamNA
     decrRefCount(argv[9]);
     decrRefCount(argv[10]);
     decrRefCount(argv[11]);
+    decrRefCount(argv[12]);
+    decrRefCount(argv[13]);
 }
 
-/* Send the specified range to the client 'c'. The range the client will
- * receive is between start and end inclusive, if 'count' is non zero, no more
- * than 'count' elemnets are sent. The 'end' pointer can be NULL to mean that
- * we want all the elements from 'start' till the end of the stream. If 'rev'
- * is non zero, elements are produced in reversed order from end to start.
+/* We need this when we want to propoagate the new last-id of a consumer group
+ * that was consumed by XREADGROUP with the NOACK option: in that case we can't
+ * propagate the last ID just using the XCLAIM LASTID option, so we emit
+ *
+ *  XGROUP SETID <key> <groupname> <id>
+ */
+void streamPropagateGroupID(client *c, robj *key, streamCG *group, robj *groupname) {
+    robj *argv[5];
+    argv[0] = createStringObject("XGROUP",6);
+    argv[1] = createStringObject("SETID",5);
+    argv[2] = key;
+    argv[3] = groupname;
+    argv[4] = createObjectFromStreamID(&group->last_id);
+    propagate(server.xgroupCommand,c->db->id,argv,5,PROPAGATE_AOF|PROPAGATE_REPL);
+    decrRefCount(argv[0]);
+    decrRefCount(argv[1]);
+    decrRefCount(argv[4]);
+}
+
+/* Send the stream items in the specified range to the client 'c'. The range
+ * the client will receive is between start and end inclusive, if 'count' is
+ * non zero, no more than 'count' elements are sent.
+ *
+ * The 'end' pointer can be NULL to mean that we want all the elements from
+ * 'start' till the end of the stream. If 'rev' is non zero, elements are
+ * produced in reversed order from end to start.
+ *
+ * The function returns the number of entries emitted.
  *
  * If group and consumer are not NULL, the function performs additional work:
  * 1. It updates the last delivered ID in the group in case we are
@@ -862,22 +894,21 @@ void streamPropagateXCLAIM(client *c, robj *key, robj *group, robj *id, streamNA
 #define STREAM_RWR_NOACK (1<<0)         /* Do not create entries in the PEL. */
 #define STREAM_RWR_RAWENTRIES (1<<1)    /* Do not emit protocol for array
                                            boundaries, just the entries. */
+#define STREAM_RWR_HISTORY (1<<2)       /* Only serve consumer local PEL. */
 size_t streamReplyWithRange(client *c, stream *s, streamID *start, streamID *end, size_t count, int rev, streamCG *group, streamConsumer *consumer, int flags, streamPropInfo *spi) {
     void *arraylen_ptr = NULL;
     size_t arraylen = 0;
     streamIterator si;
     int64_t numfields;
     streamID id;
+    int propagate_last_id = 0;
 
-    /* If a group was passed, we check if the request is about messages
-     * never delivered so far (normally this happens when ">" ID is passed).
-     *
-     * If instead the client is asking for some history, we serve it
-     * using a different function, so that we return entries *solely*
-     * from its own PEL. This ensures each consumer will always and only
-     * see the history of messages delivered to it and not yet confirmed
+    /* If the client is asking for some history, we serve it using a
+     * different function, so that we return entries *solely* from its
+     * own PEL. This ensures each consumer will always and only see
+     * the history of messages delivered to it and not yet confirmed
      * as delivered. */
-    if (group && streamCompareID(start,&group->last_id) <= 0) {
+    if (group && (flags & STREAM_RWR_HISTORY)) {
         return streamReplyWithRangeFromConsumerPEL(c,s,start,end,count,
                                                    consumer);
     }
@@ -887,8 +918,10 @@ size_t streamReplyWithRange(client *c, stream *s, streamID *start, streamID *end
     streamIteratorStart(&si,s,start,end,rev);
     while(streamIteratorGetID(&si,&id,&numfields)) {
         /* Update the group last_id if needed. */
-        if (group && streamCompareID(&id,&group->last_id) > 0)
+        if (group && streamCompareID(&id,&group->last_id) > 0) {
             group->last_id = id;
+            propagate_last_id = 1;
+        }
 
         /* Emit a two elements array for each item. The first is
          * the ID, the second is an array of field-value pairs. */
@@ -948,9 +981,12 @@ size_t streamReplyWithRange(client *c, stream *s, streamID *start, streamID *end
             /* Propagate as XCLAIM. */
             if (spi) {
                 robj *idarg = createObjectFromStreamID(&id);
-                streamPropagateXCLAIM(c,spi->keyname,spi->groupname,idarg,nack);
+                streamPropagateXCLAIM(c,spi->keyname,group,spi->groupname,idarg,nack);
                 decrRefCount(idarg);
             }
+        } else {
+            if (propagate_last_id)
+                streamPropagateGroupID(c,spi->keyname,group,spi->groupname);
         }
 
         arraylen++;
@@ -989,7 +1025,7 @@ size_t streamReplyWithRangeFromConsumerPEL(client *c, stream *s, streamID *start
         if (end && memcmp(ri.key,end,ri.key_len) > 0) break;
         streamID thisid;
         streamDecodeID(ri.key,&thisid);
-        if (streamReplyWithRange(c,s,&thisid,NULL,1,0,NULL,NULL,
+        if (streamReplyWithRange(c,s,&thisid,&thisid,1,0,NULL,NULL,
                                  STREAM_RWR_RAWENTRIES,NULL) == 0)
         {
             /* Note that we may have a not acknowledged entry in the PEL
@@ -1114,8 +1150,20 @@ int streamParseStrictIDOrReply(client *c, robj *o, streamID *id, uint64_t missin
     return streamGenericParseIDOrReply(c,o,id,missing_seq,1);
 }
 
+/* We propagate MAXLEN ~ <count> as MAXLEN = <resulting-len-of-stream>
+ * otherwise trimming is no longer determinsitic on replicas / AOF. */
+void streamRewriteApproxMaxlen(client *c, stream *s, int maxlen_arg_idx) {
+    robj *maxlen_obj = createStringObjectFromLongLong(s->length);
+    robj *equal_obj = createStringObject("=",1);
 
-/* XADD key [MAXLEN <count>] <ID or *> [field value] [field value] ... */
+    rewriteClientCommandArgument(c,maxlen_arg_idx,maxlen_obj);
+    rewriteClientCommandArgument(c,maxlen_arg_idx-1,equal_obj);
+
+    decrRefCount(equal_obj);
+    decrRefCount(maxlen_obj);
+}
+
+/* XADD key [MAXLEN [~|=] <count>] <ID or *> [field value] [field value] ... */
 void xaddCommand(client *c) {
     streamID id;
     int id_given = 0; /* Was an ID different than "*" specified? */
@@ -1135,11 +1183,14 @@ void xaddCommand(client *c) {
              * creation. */
             break;
         } else if (!strcasecmp(opt,"maxlen") && moreargs) {
+            approx_maxlen = 0;
             char *next = c->argv[i+1]->ptr;
             /* Check for the form MAXLEN ~ <count>. */
             if (moreargs >= 2 && next[0] == '~' && next[1] == '\0') {
                 approx_maxlen = 1;
                 i++;
+            } else if (moreargs >= 2 && next[0] == '=' && next[1] == '\0') {
+                i++;
             }
             if (getLongLongFromObjectOrReply(c,c->argv[i+1],&maxlen,NULL)
                 != C_OK) return;
@@ -1186,18 +1237,12 @@ void xaddCommand(client *c) {
     notifyKeyspaceEvent(NOTIFY_STREAM,"xadd",c->argv[1],c->db->id);
     server.dirty++;
 
-    /* Remove older elements if MAXLEN was specified. */
     if (maxlen >= 0) {
-        if (!streamTrimByLength(s,maxlen,approx_maxlen)) {
-            /* If no trimming was performed, for instance because approximated
-             * trimming length was specified, rewrite the MAXLEN argument
-             * as zero, so that the command is propagated without trimming. */
-            robj *zeroobj = createStringObjectFromLongLong(0);
-            rewriteClientCommandArgument(c,maxlen_arg_idx,zeroobj);
-            decrRefCount(zeroobj);
-        } else {
+        /* Notify xtrim event if needed. */
+        if (streamTrimByLength(s,maxlen,approx_maxlen)) {
             notifyKeyspaceEvent(NOTIFY_STREAM,"xtrim",c->argv[1],c->db->id);
         }
+        if (approx_maxlen) streamRewriteApproxMaxlen(c,s,maxlen_arg_idx);
     }
 
     /* Let's rewrite the ID argument with the one actually generated for
@@ -1217,7 +1262,7 @@ void xrangeGenericCommand(client *c, int rev) {
     robj *o;
     stream *s;
     streamID startid, endid;
-    long long count = 0;
+    long long count = -1;
     robj *startarg = rev ? c->argv[3] : c->argv[2];
     robj *endarg = rev ? c->argv[2] : c->argv[3];
 
@@ -1244,7 +1289,13 @@ void xrangeGenericCommand(client *c, int rev) {
     if ((o = lookupKeyReadOrReply(c,c->argv[1],shared.emptymultibulk)) == NULL
         || checkType(c,o,OBJ_STREAM)) return;
     s = o->ptr;
-    streamReplyWithRange(c,s,&startid,&endid,count,rev,NULL,NULL,0,NULL);
+
+    if (count == 0) {
+        addReply(c,shared.nullmultibulk);
+    } else {
+        if (count == -1) count = 0;
+        streamReplyWithRange(c,s,&startid,&endid,count,rev,NULL,NULL,0,NULL);
+    }
 }
 
 /* XRANGE key start end [COUNT <n>] */
@@ -1421,8 +1472,10 @@ void xreadCommand(client *c) {
         stream *s = o->ptr;
         streamID *gt = ids+i; /* ID must be greater than this. */
         int serve_synchronously = 0;
+        int serve_history = 0; /* True for XREADGROUP with ID != ">". */
 
-        /* Check if there are the conditions to serve the client synchronously. */
+        /* Check if there are the conditions to serve the client
+         * synchronously. */
         if (groups) {
             /* If the consumer is blocked on a group, we always serve it
              * synchronously (serving its local history) if the ID specified
@@ -1431,12 +1484,13 @@ void xreadCommand(client *c) {
                 gt->seq != UINT64_MAX)
             {
                 serve_synchronously = 1;
+                serve_history = 1;
             } else {
                 /* We also want to serve a consumer in a consumer group
                  * synchronously in case the group top item delivered is smaller
                  * than what the stream has inside. */
                 streamID *last = &groups[i]->last_id;
-                if (streamCompareID(&s->last_id, last) > 0) {
+                if (s->length && (streamCompareID(&s->last_id, last) > 0)) {
                     serve_synchronously = 1;
                     *gt = *last;
                 }
@@ -1444,7 +1498,7 @@ void xreadCommand(client *c) {
         } else {
             /* For consumers without a group, we serve synchronously if we can
              * actually provide at least one item from the stream. */
-            if (streamCompareID(&s->last_id, gt) > 0) {
+            if (s->length && (streamCompareID(&s->last_id, gt) > 0)) {
                 serve_synchronously = 1;
             }
         }
@@ -1466,9 +1520,12 @@ void xreadCommand(client *c) {
             if (groups) consumer = streamLookupConsumer(groups[i],
                                                         consumername->ptr,1);
             streamPropInfo spi = {c->argv[i+streams_arg],groupname};
+            int flags = 0;
+            if (noack) flags |= STREAM_RWR_NOACK;
+            if (serve_history) flags |= STREAM_RWR_HISTORY;
             streamReplyWithRange(c,s,&start,NULL,count,0,
                                  groups ? groups[i] : NULL,
-                                 consumer, noack, &spi);
+                                 consumer, flags, &spi);
             if (groups) server.dirty++;
         }
     }
@@ -1640,13 +1697,14 @@ uint64_t streamDelConsumer(streamCG *cg, sds name) {
  * Consumer groups commands
  * ----------------------------------------------------------------------- */
 
-/* XGROUP CREATE <key> <groupname> <id or $>
- * XGROUP SETID <key> <id or $>
+/* XGROUP CREATE <key> <groupname> <id or $> [MKSTREAM]
+ * XGROUP SETID <key> <groupname> <id or $>
  * XGROUP DESTROY <key> <groupname>
  * XGROUP DELCONSUMER <key> <groupname> <consumername> */
 void xgroupCommand(client *c) {
     const char *help[] = {
-"CREATE      <key> <groupname> <id or $>  -- Create a new consumer group.",
+"CREATE      <key> <groupname> <id or $> [opt] -- Create a new consumer group.",
+"            option MKSTREAM: create the empty stream if it does not exist.",
 "SETID       <key> <groupname> <id or $>  -- Set the current group ID.",
 "DESTROY     <key> <groupname>            -- Remove the specified group.",
 "DELCONSUMER <key> <groupname> <consumer> -- Remove the specified consumer.",
@@ -1657,13 +1715,40 @@ NULL
     sds grpname = NULL;
     streamCG *cg = NULL;
     char *opt = c->argv[1]->ptr; /* Subcommand name. */
+    int mkstream = 0;
+    robj *o;
 
-    /* Lookup the key now, this is common for all the subcommands but HELP. */
-    if (c->argc >= 4) {
-        robj *o = lookupKeyWriteOrReply(c,c->argv[2],shared.nokeyerr);
-        if (o == NULL || checkType(c,o,OBJ_STREAM)) return;
-        s = o->ptr;
+    /* CREATE has an MKSTREAM option that creates the stream if it
+     * does not exist. */
+    if (c->argc == 6 && !strcasecmp(opt,"CREATE")) {
+        if (strcasecmp(c->argv[5]->ptr,"MKSTREAM")) {
+            addReplySubcommandSyntaxError(c);
+            return;
+        }
+        mkstream = 1;
         grpname = c->argv[3]->ptr;
+    }
+
+    /* Everything but the "HELP" option requires a key and group name. */
+    if (c->argc >= 4) {
+        o = lookupKeyWrite(c->db,c->argv[2]);
+        if (o) {
+            if (checkType(c,o,OBJ_STREAM)) return;
+            s = o->ptr;
+        }
+        grpname = c->argv[3]->ptr;
+    }
+
+    /* Check for missing key/group. */
+    if (c->argc >= 4 && !mkstream) {
+        /* At this point key must exist, or there is an error. */
+        if (s == NULL) {
+            addReplyError(c,
+                "The XGROUP subcommand requires the key to exist. "
+                "Note that for CREATE you may want to use the MKSTREAM "
+                "option to create an empty stream automatically.");
+            return;
+        }
 
         /* Certain subcommands require the group to exist. */
         if ((cg = streamLookupCG(s,grpname)) == NULL &&
@@ -1678,13 +1763,27 @@ NULL
     }
 
     /* Dispatch the different subcommands. */
-    if (!strcasecmp(opt,"CREATE") && c->argc == 5) {
+    if (!strcasecmp(opt,"CREATE") && (c->argc == 5 || c->argc == 6)) {
         streamID id;
         if (!strcmp(c->argv[4]->ptr,"$")) {
-            id = s->last_id;
+            if (s) {
+                id = s->last_id;
+            } else {
+                id.ms = 0;
+                id.seq = 0;
+            }
         } else if (streamParseStrictIDOrReply(c,c->argv[4],&id,0) != C_OK) {
             return;
         }
+
+        /* Handle the MKSTREAM option now that the command can no longer fail. */
+        if (s == NULL) {
+            serverAssert(mkstream);
+            o = createStreamObject();
+            dbAdd(c->db,c->argv[2],o);
+            s = o->ptr;
+        }
+
         streamCG *cg = streamCreateCG(s,grpname,sdslen(grpname),&id);
         if (cg) {
             addReply(c,shared.ok);
@@ -1732,6 +1831,40 @@ NULL
     }
 }
 
+/* XSETID <stream> <groupname> <id>
+ *
+ * Set the internal "last ID" of a stream. */
+void xsetidCommand(client *c) {
+    robj *o = lookupKeyWriteOrReply(c,c->argv[1],shared.nokeyerr);
+    if (o == NULL || checkType(c,o,OBJ_STREAM)) return;
+
+    stream *s = o->ptr;
+    streamID id;
+    if (streamParseStrictIDOrReply(c,c->argv[2],&id,0) != C_OK) return;
+
+    /* If the stream has at least one item, we want to check that the user
+     * is setting a last ID that is equal or greater than the current top
+     * item, otherwise the fundamental ID monotonicity assumption is violated. */
+    if (s->length > 0) {
+        streamID maxid;
+        streamIterator si;
+        streamIteratorStart(&si,s,NULL,NULL,1);
+        int64_t numfields;
+        streamIteratorGetID(&si,&maxid,&numfields);
+        streamIteratorStop(&si);
+
+        if (streamCompareID(&id,&maxid) < 0) {
+            addReplyError(c,"The ID specified in XSETID is smaller than the "
+                            "target stream top item");
+            return;
+        }
+    }
+    s->last_id = id;
+    addReply(c,shared.ok);
+    server.dirty++;
+    notifyKeyspaceEvent(NOTIFY_STREAM,"xsetid",c->argv[1],c->db->id);
+}
+
 /* XACK <key> <group> <id> <id> ... <id>
  *
  * Acknowledge a message as processed. In practical terms we just check the
@@ -1777,7 +1910,7 @@ void xackCommand(client *c) {
     addReplyLongLong(c,acknowledged);
 }
 
-/* XPENDING <key> <group> [<start> <stop> <count>] [<consumer>]
+/* XPENDING <key> <group> [<start> <stop> <count> [<consumer>]]
  *
  * If start and stop are omitted, the command just outputs information about
  * the amount of pending messages for the key/group pair, together with
@@ -1806,6 +1939,7 @@ void xpendingCommand(client *c) {
     if (c->argc >= 6) {
         if (getLongLongFromObjectOrReply(c,c->argv[5],&count,NULL) == C_ERR)
             return;
+        if (count < 0) count = 0;
         if (streamParseIDOrReply(c,c->argv[3],&startid,0) == C_ERR)
             return;
         if (streamParseIDOrReply(c,c->argv[4],&endid,UINT64_MAX) == C_ERR)
@@ -1979,6 +2113,14 @@ void xpendingCommand(client *c) {
  *      Return just an array of IDs of messages successfully claimed,
  *      without returning the actual message.
  *
+ * 6. LASTID <id>:
+ *      Update the consumer group last ID with the specified ID if the
+ *      current last ID is smaller than the provided one.
+ *      This is used for replication / AOF, so that when we read from a
+ *      consumer group, the XCLAIM that gets propagated to give ownership
+ *      to the consumer, is also used in order to update the group current
+ *      ID.
+ *
  * The command returns an array of messages that the user
  * successfully claimed, so that the caller is able to understand
  * what messages it is now in charge of. */
@@ -2023,7 +2165,9 @@ void xclaimCommand(client *c) {
 
     /* If we stopped because some IDs cannot be parsed, perhaps they
      * are trailing options. */
-    time_t now = mstime();
+    mstime_t now = mstime();
+    streamID last_id = {0,0};
+    int propagate_last_id = 0;
     for (; j < c->argc; j++) {
         int moreargs = (c->argc-1) - j; /* Number of additional arguments. */
         char *opt = c->argv[j]->ptr;
@@ -2047,20 +2191,28 @@ void xclaimCommand(client *c) {
             if (getLongLongFromObjectOrReply(c,c->argv[j],&retrycount,
                 "Invalid RETRYCOUNT option argument for XCLAIM")
                 != C_OK) return;
+        } else if (!strcasecmp(opt,"LASTID") && moreargs) {
+            j++;
+            if (streamParseStrictIDOrReply(c,c->argv[j],&last_id,0) != C_OK) return;
         } else {
             addReplyErrorFormat(c,"Unrecognized XCLAIM option '%s'",opt);
             return;
         }
     }
 
+    if (streamCompareID(&last_id,&group->last_id) > 0) {
+        group->last_id = last_id;
+        propagate_last_id = 1;
+    }
+
     if (deliverytime != -1) {
         /* If a delivery time was passed, either with IDLE or TIME, we
          * do some sanity check on it, and set the deliverytime to now
          * (which is a sane choice usually) if the value is bogus.
          * To raise an error here is not wise because clients may compute
-         * the idle time doing some math startin from their local time,
+         * the idle time doing some math starting from their local time,
          * and this is not a good excuse to fail in case, for instance,
-         * the computed time is a bit in the future from our POV. */
+         * the computer time is a bit in the future from our POV. */
         if (deliverytime < 0 || deliverytime > now) deliverytime = now;
     } else {
         /* If no IDLE/TIME option was passed, we want the last delivery
@@ -2076,7 +2228,8 @@ void xclaimCommand(client *c) {
     for (int j = 5; j <= last_id_arg; j++) {
         streamID id;
         unsigned char buf[sizeof(streamID)];
-        if (streamParseStrictIDOrReply(c,c->argv[j],&id,0) != C_OK) return;
+        if (streamParseStrictIDOrReply(c,c->argv[j],&id,0) != C_OK)
+            serverPanic("StreamID invalid after check. Should not be possible.");
         streamEncodeID(buf,&id);
 
         /* Lookup the ID in the group PEL. */
@@ -2106,8 +2259,12 @@ void xclaimCommand(client *c) {
 
         if (nack != raxNotFound) {
             /* We need to check if the minimum idle time requested
-             * by the caller is satisfied by this entry. */
-            if (minidle) {
+             * by the caller is satisfied by this entry.
+             *
+             * Note that the nack could be created by FORCE, in this
+             * case there was no pre-existing entry and minidle should
+             * be ignored, but in that case nick->consumer is NULL. */
+            if (nack->consumer && minidle) {
                 mstime_t this_idle = now - nack->delivery_time;
                 if (this_idle < minidle) continue;
             }
@@ -2119,24 +2276,35 @@ void xclaimCommand(client *c) {
             /* Update the consumer and idle time. */
             nack->consumer = consumer;
             nack->delivery_time = deliverytime;
-            /* Set the delivery attempts counter if given. */
-            if (retrycount >= 0) nack->delivery_count = retrycount;
+            /* Set the delivery attempts counter if given, otherwise 
+             * autoincrement unless JUSTID option provided */
+            if (retrycount >= 0) {
+                nack->delivery_count = retrycount;
+            } else if (!justid) {
+                nack->delivery_count++;
+            }
             /* Add the entry in the new consumer local PEL. */
             raxInsert(consumer->pel,buf,sizeof(buf),nack,NULL);
             /* Send the reply for this entry. */
             if (justid) {
                 addReplyStreamID(c,&id);
             } else {
-                streamReplyWithRange(c,o->ptr,&id,NULL,1,0,NULL,NULL,
-                                     STREAM_RWR_RAWENTRIES,NULL);
+                size_t emitted = streamReplyWithRange(c,o->ptr,&id,&id,1,0,
+                                    NULL,NULL,STREAM_RWR_RAWENTRIES,NULL);
+                if (!emitted) addReply(c,shared.nullbulk);
             }
             arraylen++;
 
             /* Propagate this change. */
-            streamPropagateXCLAIM(c,c->argv[1],c->argv[3],c->argv[j],nack);
+            streamPropagateXCLAIM(c,c->argv[1],group,c->argv[2],c->argv[j],nack);
+            propagate_last_id = 0; /* Will be propagated by XCLAIM itself. */
             server.dirty++;
         }
     }
+    if (propagate_last_id) {
+        streamPropagateGroupID(c,c->argv[1],group,c->argv[2]);
+        server.dirty++;
+    }
     setDeferredMultiBulkLength(c,arraylenptr,arraylen);
     preventCommandPropagation(c);
 }
@@ -2182,7 +2350,7 @@ void xdelCommand(client *c) {
  *
  * List of options:
  *
- * MAXLEN [~] <count>       -- Trim so that the stream will be capped at
+ * MAXLEN [~|=] <count>     -- Trim so that the stream will be capped at
  *                             the specified length. Use ~ before the
  *                             count in order to demand approximated trimming
  *                             (like XADD MAXLEN option).
@@ -2201,9 +2369,10 @@ void xtrimCommand(client *c) {
 
     /* Argument parsing. */
     int trim_strategy = TRIM_STRATEGY_NONE;
-    long long maxlen = 0;   /* 0 means no maximum length. */
+    long long maxlen = -1;  /* If left to -1 no trimming is performed. */
     int approx_maxlen = 0;  /* If 1 only delete whole radix tree nodes, so
                                the maxium length is not applied verbatim. */
+    int maxlen_arg_idx = 0; /* Index of the count in MAXLEN, for rewriting. */
 
     /* Parse options. */
     int i = 2; /* Start of options. */
@@ -2211,16 +2380,25 @@ void xtrimCommand(client *c) {
         int moreargs = (c->argc-1) - i; /* Number of additional arguments. */
         char *opt = c->argv[i]->ptr;
         if (!strcasecmp(opt,"maxlen") && moreargs) {
+            approx_maxlen = 0;
             trim_strategy = TRIM_STRATEGY_MAXLEN;
             char *next = c->argv[i+1]->ptr;
             /* Check for the form MAXLEN ~ <count>. */
             if (moreargs >= 2 && next[0] == '~' && next[1] == '\0') {
                 approx_maxlen = 1;
                 i++;
+            } else if (moreargs >= 2 && next[0] == '=' && next[1] == '\0') {
+                i++;
             }
             if (getLongLongFromObjectOrReply(c,c->argv[i+1],&maxlen,NULL)
                 != C_OK) return;
+
+            if (maxlen < 0) {
+                addReplyError(c,"The MAXLEN argument must be >= 0.");
+                return;
+            }
             i++;
+            maxlen_arg_idx = i;
         } else {
             addReply(c,shared.syntaxerr);
             return;
@@ -2241,11 +2419,12 @@ void xtrimCommand(client *c) {
         signalModifiedKey(c->db,c->argv[1]);
         notifyKeyspaceEvent(NOTIFY_STREAM,"xtrim",c->argv[1],c->db->id);
         server.dirty += deleted;
+        if (approx_maxlen) streamRewriteApproxMaxlen(c,s,maxlen_arg_idx);
     }
     addReplyLongLong(c,deleted);
 }
 
-/* XINFO CONSUMERS key group
+/* XINFO CONSUMERS <key> <group>
  * XINFO GROUPS <key>
  * XINFO STREAM <key>
  * XINFO HELP. */
@@ -2302,11 +2481,11 @@ NULL
             if (idle < 0) idle = 0;
 
             addReplyMultiBulkLen(c,6);
-            addReplyStatus(c,"name");
+            addReplyBulkCString(c,"name");
             addReplyBulkCBuffer(c,consumer->name,sdslen(consumer->name));
-            addReplyStatus(c,"pending");
+            addReplyBulkCString(c,"pending");
             addReplyLongLong(c,raxSize(consumer->pel));
-            addReplyStatus(c,"idle");
+            addReplyBulkCString(c,"idle");
             addReplyLongLong(c,idle);
         }
         raxStop(&ri);
@@ -2324,28 +2503,28 @@ NULL
         while(raxNext(&ri)) {
             streamCG *cg = ri.data;
             addReplyMultiBulkLen(c,8);
-            addReplyStatus(c,"name");
+            addReplyBulkCString(c,"name");
             addReplyBulkCBuffer(c,ri.key,ri.key_len);
-            addReplyStatus(c,"consumers");
+            addReplyBulkCString(c,"consumers");
             addReplyLongLong(c,raxSize(cg->consumers));
-            addReplyStatus(c,"pending");
+            addReplyBulkCString(c,"pending");
             addReplyLongLong(c,raxSize(cg->pel));
-            addReplyStatus(c,"last-delivered-id");
+            addReplyBulkCString(c,"last-delivered-id");
             addReplyStreamID(c,&cg->last_id);
         }
         raxStop(&ri);
     } else if (!strcasecmp(opt,"STREAM") && c->argc == 3) {
         /* XINFO STREAM <key> (or the alias XINFO <key>). */
         addReplyMultiBulkLen(c,14);
-        addReplyStatus(c,"length");
+        addReplyBulkCString(c,"length");
         addReplyLongLong(c,s->length);
-        addReplyStatus(c,"radix-tree-keys");
+        addReplyBulkCString(c,"radix-tree-keys");
         addReplyLongLong(c,raxSize(s->rax));
-        addReplyStatus(c,"radix-tree-nodes");
+        addReplyBulkCString(c,"radix-tree-nodes");
         addReplyLongLong(c,s->rax->numnodes);
-        addReplyStatus(c,"groups");
+        addReplyBulkCString(c,"groups");
         addReplyLongLong(c,s->cgroups ? raxSize(s->cgroups) : 0);
-        addReplyStatus(c,"last-generated-id");
+        addReplyBulkCString(c,"last-generated-id");
         addReplyStreamID(c,&s->last_id);
 
         /* To emit the first/last entry we us the streamReplyWithRange()
@@ -2354,11 +2533,11 @@ NULL
         streamID start, end;
         start.ms = start.seq = 0;
         end.ms = end.seq = UINT64_MAX;
-        addReplyStatus(c,"first-entry");
+        addReplyBulkCString(c,"first-entry");
         count = streamReplyWithRange(c,s,&start,&end,1,0,NULL,NULL,
                                      STREAM_RWR_RAWENTRIES,NULL);
         if (!count) addReply(c,shared.nullbulk);
-        addReplyStatus(c,"last-entry");
+        addReplyBulkCString(c,"last-entry");
         count = streamReplyWithRange(c,s,&start,&end,1,1,NULL,NULL,
                                      STREAM_RWR_RAWENTRIES,NULL);
         if (!count) addReply(c,shared.nullbulk);

src/t_string.c

@@ -301,24 +301,22 @@ void mgetCommand(client *c) {
 }
 
 void msetGenericCommand(client *c, int nx) {
-    int j, busykeys = 0;
+    int j;
 
     if ((c->argc % 2) == 0) {
         addReplyError(c,"wrong number of arguments for MSET");
         return;
     }
+
     /* Handle the NX flag. The MSETNX semantic is to return zero and don't
-     * set nothing at all if at least one already key exists. */
+     * set anything if at least one key alerady exists. */
     if (nx) {
         for (j = 1; j < c->argc; j += 2) {
             if (lookupKeyWrite(c->db,c->argv[j]) != NULL) {
-                busykeys++;
+                addReply(c, shared.czero);
+                return;
             }
         }
-        if (busykeys) {
-            addReply(c, shared.czero);
-            return;
-        }
     }
 
     for (j = 1; j < c->argc; j += 2) {

src/t_zset.c

@@ -574,12 +574,12 @@ int zslParseLexRangeItem(robj *item, sds *dest, int *ex) {
     switch(c[0]) {
     case '+':
         if (c[1] != '\0') return C_ERR;
-        *ex = 0;
+        *ex = 1;
         *dest = shared.maxstring;
         return C_OK;
     case '-':
         if (c[1] != '\0') return C_ERR;
-        *ex = 0;
+        *ex = 1;
         *dest = shared.minstring;
         return C_OK;
     case '(':
@@ -652,9 +652,8 @@ int zslIsInLexRange(zskiplist *zsl, zlexrangespec *range) {
     zskiplistNode *x;
 
     /* Test for ranges that will always be empty. */
-    if (sdscmplex(range->min,range->max) > 1 ||
-            (sdscmp(range->min,range->max) == 0 &&
-            (range->minex || range->maxex)))
+    int cmp = sdscmplex(range->min,range->max);
+    if (cmp > 0 || (cmp == 0 && (range->minex || range->maxex)))
         return 0;
     x = zsl->tail;
     if (x == NULL || !zslLexValueGteMin(x->ele,range))
@@ -927,9 +926,8 @@ int zzlIsInLexRange(unsigned char *zl, zlexrangespec *range) {
     unsigned char *p;
 
     /* Test for ranges that will always be empty. */
-    if (sdscmplex(range->min,range->max) > 1 ||
-            (sdscmp(range->min,range->max) == 0 &&
-            (range->minex || range->maxex)))
+    int cmp = sdscmplex(range->min,range->max);
+    if (cmp > 0 || (cmp == 0 && (range->minex || range->maxex)))
         return 0;
 
     p = ziplistIndex(zl,-2); /* Last element. */
@@ -2909,7 +2907,10 @@ void genericZrangebylexCommand(client *c, int reverse) {
         while (remaining) {
             if (remaining >= 3 && !strcasecmp(c->argv[pos]->ptr,"limit")) {
                 if ((getLongFromObjectOrReply(c, c->argv[pos+1], &offset, NULL) != C_OK) ||
-                    (getLongFromObjectOrReply(c, c->argv[pos+2], &limit, NULL) != C_OK)) return;
+                    (getLongFromObjectOrReply(c, c->argv[pos+2], &limit, NULL) != C_OK)) {
+                    zslFreeLexRange(&range);
+                    return;
+                }
                 pos += 3; remaining -= 3;
             } else {
                 zslFreeLexRange(&range);
@@ -3143,7 +3144,10 @@ void genericZpopCommand(client *c, robj **keyv, int keyc, int where, int emitkey
     if (countarg) {
         if (getLongFromObjectOrReply(c,countarg,&count,NULL) != C_OK)
             return;
-        if (count < 0) count = 1;
+        if (count <= 0) {
+            addReply(c,shared.emptymultibulk);
+            return;
+        }
     }
 
     /* Check type and break on the first error, otherwise identify candidate. */

src/util.c

@@ -39,6 +39,7 @@
 #include <float.h>
 #include <stdint.h>
 #include <errno.h>
+#include <time.h>
 
 #include "util.h"
 #include "sha1.h"
@@ -47,7 +48,7 @@
 int stringmatchlen(const char *pattern, int patternLen,
         const char *string, int stringLen, int nocase)
 {
-    while(patternLen) {
+    while(patternLen && stringLen) {
         switch(pattern[0]) {
         case '*':
             while (pattern[1] == '*') {
@@ -170,6 +171,22 @@ int stringmatch(const char *pattern, const char *string, int nocase) {
     return stringmatchlen(pattern,strlen(pattern),string,strlen(string),nocase);
 }
 
+/* Fuzz stringmatchlen() trying to crash it with bad input. */
+int stringmatchlen_fuzz_test(void) {
+    char str[32];
+    char pat[32];
+    int cycles = 10000000;
+    int total_matches = 0;
+    while(cycles--) {
+        int strlen = rand() % sizeof(str);
+        int patlen = rand() % sizeof(pat);
+        for (int j = 0; j < strlen; j++) str[j] = rand() % 128;
+        for (int j = 0; j < patlen; j++) pat[j] = rand() % 128;
+        total_matches += stringmatchlen(pat, patlen, str, strlen, 0);
+    }
+    return total_matches;
+}
+
 /* Convert a string representing an amount of memory into the number of
  * bytes, so for instance memtoll("1Gb") will return 1073741824 that is
  * (1024*1024*1024).
@@ -430,7 +447,7 @@ int string2l(const char *s, size_t slen, long *lval) {
  * a double: no spaces or other characters before or after the string
  * representing the number are accepted. */
 int string2ld(const char *s, size_t slen, long double *dp) {
-    char buf[256];
+    char buf[MAX_LONG_DOUBLE_CHARS];
     long double value;
     char *eptr;
 
@@ -605,7 +622,7 @@ void getRandomHexChars(char *p, size_t len) {
  * already, this will be detected and handled correctly.
  *
  * The function does not try to normalize everything, but only the obvious
- * case of one or more "../" appearning at the start of "filename"
+ * case of one or more "../" appearing at the start of "filename"
  * relative path. */
 sds getAbsolutePath(char *filename) {
     char cwd[1024];
@@ -652,6 +669,24 @@ sds getAbsolutePath(char *filename) {
     return abspath;
 }
 
+/*
+ * Gets the proper timezone in a more portable fashion
+ * i.e timezone variables are linux specific.
+ */
+
+unsigned long getTimeZone(void) {
+#ifdef __linux__
+    return timezone;
+#else
+    struct timeval tv;
+    struct timezone tz;
+
+    gettimeofday(&tv, &tz);
+
+    return tz.tz_minuteswest * 60UL;
+#endif
+}
+
 /* Return true if the specified path is just a file basename without any
  * relative or absolute path. This function just checks that no / or \
  * character exists inside the specified path, that's enough in the

src/util.h

@@ -40,6 +40,7 @@
 
 int stringmatchlen(const char *p, int plen, const char *s, int slen, int nocase);
 int stringmatch(const char *p, const char *s, int nocase);
+int stringmatchlen_fuzz_test(void);
 long long memtoll(const char *p, int *err);
 uint32_t digits10(uint64_t v);
 uint32_t sdigits10(int64_t v);
@@ -50,6 +51,7 @@ int string2ld(const char *s, size_t slen, long double *dp);
 int d2string(char *buf, size_t len, double value);
 int ld2string(char *buf, size_t len, long double value, int humanfriendly);
 sds getAbsolutePath(char *filename);
+unsigned long getTimeZone(void);
 int pathIsBaseName(char *path);
 
 #ifdef REDIS_TEST

src/version.h

@@ -1 +1 @@
-#define REDIS_VERSION "999.999.999"
+#define REDIS_VERSION "5.0.5"

src/ziplist.c

@@ -576,7 +576,7 @@ void zipEntry(unsigned char *p, zlentry *e) {
 
 /* Create a new empty ziplist. */
 unsigned char *ziplistNew(void) {
-    unsigned int bytes = ZIPLIST_HEADER_SIZE+1;
+    unsigned int bytes = ZIPLIST_HEADER_SIZE+ZIPLIST_END_SIZE;
     unsigned char *zl = zmalloc(bytes);
     ZIPLIST_BYTES(zl) = intrev32ifbe(bytes);
     ZIPLIST_TAIL_OFFSET(zl) = intrev32ifbe(ZIPLIST_HEADER_SIZE);

src/zmalloc.c

@@ -164,7 +164,7 @@ void *zrealloc(void *ptr, size_t size) {
     if (!newptr) zmalloc_oom_handler(size);
 
     *((size_t*)newptr) = size;
-    update_zmalloc_stat_free(oldsize);
+    update_zmalloc_stat_free(oldsize+PREFIX_SIZE);
     update_zmalloc_stat_alloc(size+PREFIX_SIZE);
     return (char*)newptr+PREFIX_SIZE;
 #endif
@@ -438,4 +438,20 @@ size_t zmalloc_get_memory_size(void) {
 #endif
 }
 
+#ifdef REDIS_TEST
+#define UNUSED(x) ((void)(x))
+int zmalloc_test(int argc, char **argv) {
+    void *ptr;
 
+    UNUSED(argc);
+    UNUSED(argv);
+    printf("Initial used memory: %zu\n", zmalloc_used_memory());
+    ptr = zmalloc(123);
+    printf("Allocated 123 bytes; used: %zu\n", zmalloc_used_memory());
+    ptr = zrealloc(ptr, 456);
+    printf("Reallocated to 456 bytes; used: %zu\n", zmalloc_used_memory());
+    zfree(ptr);
+    printf("Freed pointer; used: %zu\n", zmalloc_used_memory());
+    return 0;
+}
+#endif

src/zmalloc.h

@@ -103,4 +103,8 @@ size_t zmalloc_usable(void *ptr);
 #define zmalloc_usable(p) zmalloc_size(p)
 #endif
 
+#ifdef REDIS_TEST
+int zmalloc_test(int argc, char **argv);
+#endif
+
 #endif /* __ZMALLOC_H */

tests/integration/block-repl.tcl

@@ -49,7 +49,7 @@ start_server {tags {"repl"}} {
                 set fd [open /tmp/repldump2.txt w]
                 puts -nonewline $fd $csv2
                 close $fd
-                puts "Master - Slave inconsistency"
+                puts "Master - Replica inconsistency"
                 puts "Run diff -u against /tmp/repldump*.txt for more info"
             }
             assert_equal [r debug digest] [r -1 debug digest]

tests/integration/psync2-reg.tcl

@@ -29,7 +29,7 @@ start_server {} {
         wait_for_condition 50 1000 {
             [$R(1) dbsize] == 1 && [$R(2) dbsize] == 1
         } else {
-            fail "Slaves not replicating from master"
+            fail "Replicas not replicating from master"
         }
         $R(0) config set repl-backlog-size 10mb
         $R(1) config set repl-backlog-size 10mb
@@ -41,12 +41,12 @@ start_server {} {
         set elapsed [expr {[clock milliseconds]-$cycle_start_time}]
         if {$elapsed > $duration*1000} break
         if {rand() < .05} {
-            test "PSYNC2 #3899 regression: kill first slave" {
+            test "PSYNC2 #3899 regression: kill first replica" {
                 $R(1) client kill type master
             }
         }
         if {rand() < .05} {
-            test "PSYNC2 #3899 regression: kill chained slave" {
+            test "PSYNC2 #3899 regression: kill chained replica" {
                 $R(2) client kill type master
             }
         }

tests/integration/psync2.tcl

@@ -95,7 +95,7 @@ start_server {} {
                     if {$disconnect} {
                         $R($slave_id) client kill type master
                         if {$debug_msg} {
-                            puts "+++ Breaking link for slave #$slave_id"
+                            puts "+++ Breaking link for replica #$slave_id"
                         }
                     }
                 }
@@ -158,7 +158,7 @@ start_server {} {
         wait_for_condition 50 1000 {
             [status $R($master_id) connected_slaves] == 4
         } else {
-            fail "Slave not reconnecting"
+            fail "Replica not reconnecting"
         }
     }
 
@@ -166,20 +166,23 @@ start_server {} {
         # Pick a random slave
         set slave_id [expr {($master_id+1)%5}]
         set sync_count [status $R($master_id) sync_full]
+        set sync_partial [status $R($master_id) sync_partial_ok]
         catch {
             $R($slave_id) config rewrite
             $R($slave_id) debug restart
         }
+        # note: just waiting for connected_slaves==4 has a race condition since
+        # we might do the check before the master realized that the slave disconnected
         wait_for_condition 50 1000 {
-            [status $R($master_id) connected_slaves] == 4
+            [status $R($master_id) sync_partial_ok] == $sync_partial + 1
         } else {
-            fail "Slave not reconnecting"
+            fail "Replica not reconnecting"
         }
         set new_sync_count [status $R($master_id) sync_full]
         assert {$sync_count == $new_sync_count}
     }
 
-    test "PSYNC2: Slave RDB restart with EVALSHA in backlog issue #4483" {
+    test "PSYNC2: Replica RDB restart with EVALSHA in backlog issue #4483" {
         # Pick a random slave
         set slave_id [expr {($master_id+1)%5}]
         set sync_count [status $R($master_id) sync_full]
@@ -194,7 +197,7 @@ start_server {} {
         wait_for_condition 50 1000 {
             [$R($master_id) debug digest] == [$R($slave_id) debug digest]
         } else {
-            fail "Slave not reconnecting"
+            fail "Replica not reconnecting"
         }
 
         # Prevent the slave from receiving master updates, and at
@@ -228,7 +231,7 @@ start_server {} {
         wait_for_condition 50 1000 {
             [status $R($master_id) connected_slaves] == 4
         } else {
-            fail "Slave not reconnecting"
+            fail "Replica not reconnecting"
         }
         set new_sync_count [status $R($master_id) sync_full]
         assert {$sync_count == $new_sync_count}
@@ -238,7 +241,7 @@ start_server {} {
         wait_for_condition 50 1000 {
             [$R($master_id) debug digest] == [$R($slave_id) debug digest]
         } else {
-            fail "Debug digest mismatch between master and slave in post-restart handshake"
+            fail "Debug digest mismatch between master and replica in post-restart handshake"
         }
     }
 

tests/integration/replication-2.tcl

@@ -16,7 +16,7 @@ start_server {tags {"repl"}} {
             wait_for_condition 50 100 {
                 [r -1 get foo] eq {12345}
             } else {
-                fail "Write did not reached slave"
+                fail "Write did not reached replica"
             }
         }
 
@@ -34,7 +34,7 @@ start_server {tags {"repl"}} {
             wait_for_condition 50 100 {
                 [r -1 get foo] eq {12345}
             } else {
-                fail "Write did not reached slave"
+                fail "Write did not reached replica"
             }
         }
 
@@ -60,7 +60,7 @@ start_server {tags {"repl"}} {
             wait_for_condition 50 100 {
                 [r -1 get foo] eq {aaabbb}
             } else {
-                fail "Write did not reached slave"
+                fail "Write did not reached replica"
             }
         }
 
@@ -81,7 +81,7 @@ start_server {tags {"repl"}} {
                 set fd [open /tmp/repldump2.txt w]
                 puts -nonewline $fd $csv2
                 close $fd
-                puts "Master - Slave inconsistency"
+                puts "Master - Replica inconsistency"
                 puts "Run diff -u against /tmp/repldump*.txt for more info"
             }
             assert_equal [r debug digest] [r -1 debug digest]

tests/integration/replication-3.tcl

@@ -25,7 +25,7 @@ start_server {tags {"repl"}} {
                 set fd [open /tmp/repldump2.txt w]
                 puts -nonewline $fd $csv2
                 close $fd
-                puts "Master - Slave inconsistency"
+                puts "Master - Replica inconsistency"
                 puts "Run diff -u against /tmp/repldump*.txt for more info"
             }
             assert_equal [r debug digest] [r -1 debug digest]
@@ -98,7 +98,7 @@ start_server {tags {"repl"}} {
                 set fd [open /tmp/repldump2.txt w]
                 puts -nonewline $fd $csv2
                 close $fd
-                puts "Master - Slave inconsistency"
+                puts "Master - Replica inconsistency"
                 puts "Run diff -u against /tmp/repldump*.txt for more info"
             }
 

tests/integration/replication-4.tcl

@@ -47,7 +47,7 @@ start_server {tags {"repl"}} {
                 set fd [open /tmp/repldump2.txt w]
                 puts -nonewline $fd $csv2
                 close $fd
-                puts "Master - Slave inconsistency"
+                puts "Master - Replica inconsistency"
                 puts "Run diff -u against /tmp/repldump*.txt for more info"
             }
             assert_equal [r debug digest] [r -1 debug digest]

tests/integration/replication-psync.tcl

@@ -60,7 +60,7 @@ proc test_psync {descr duration backlog_size backlog_ttl delay cond diskless rec
                 if ($reconnect) {
                     for {set j 0} {$j < $duration*10} {incr j} {
                         after 100
-                        # catch {puts "MASTER [$master dbsize] keys, SLAVE [$slave dbsize] keys"}
+                        # catch {puts "MASTER [$master dbsize] keys, REPLICA [$slave dbsize] keys"}
 
                         if {($j % 20) == 0} {
                             catch {
@@ -79,6 +79,32 @@ proc test_psync {descr duration backlog_size backlog_ttl delay cond diskless rec
                 stop_bg_complex_data $load_handle0
                 stop_bg_complex_data $load_handle1
                 stop_bg_complex_data $load_handle2
+
+                # Wait for the slave to reach the "online"
+                # state from the POV of the master.
+                set retry 5000
+                while {$retry} {
+                    set info [$master info]
+                    if {[string match {*slave0:*state=online*} $info]} {
+                        break
+                    } else {
+                        incr retry -1
+                        after 100
+                    }
+                }
+                if {$retry == 0} {
+                    error "assertion:Slave not correctly synchronized"
+                }
+
+                # Wait that slave acknowledge it is online so
+                # we are sure that DBSIZE and DEBUG DIGEST will not
+                # fail because of timing issues. (-LOADING error)
+                wait_for_condition 5000 100 {
+                    [lindex [$slave role] 3] eq {connected}
+                } else {
+                    fail "Slave still not connected after some time"
+                }  
+
                 set retry 10
                 while {$retry && ([$master debug digest] ne [$slave debug digest])}\
                 {
@@ -96,7 +122,7 @@ proc test_psync {descr duration backlog_size backlog_ttl delay cond diskless rec
                     set fd [open /tmp/repldump2.txt w]
                     puts -nonewline $fd $csv2
                     close $fd
-                    puts "Master - Slave inconsistency"
+                    puts "Master - Replica inconsistency"
                     puts "Run diff -u against /tmp/repldump*.txt for more info"
                 }
                 assert_equal [r debug digest] [r -1 debug digest]

tests/integration/replication.tcl

@@ -32,7 +32,7 @@ start_server {tags {"repl"}} {
             wait_for_condition 50 1000 {
                 [string match *handshake* [$slave role]]
             } else {
-                fail "Slave does not enter handshake state"
+                fail "Replica does not enter handshake state"
             }
         }
 
@@ -45,7 +45,7 @@ start_server {tags {"repl"}} {
             wait_for_condition 50 1000 {
                 [log_file_matches $slave_log "*Timeout connecting to the MASTER*"]
             } else {
-                fail "Slave is not able to detect timeout"
+                fail "Replica is not able to detect timeout"
             }
         }
     }
@@ -66,7 +66,7 @@ start_server {tags {"repl"}} {
                 [lindex [$A role] 0] eq {slave} &&
                 [string match {*master_link_status:up*} [$A info replication]]
             } else {
-                fail "Can't turn the instance into a slave"
+                fail "Can't turn the instance into a replica"
             }
         }
 
@@ -77,7 +77,7 @@ start_server {tags {"repl"}} {
             wait_for_condition 50 100 {
                 [$A debug digest] eq [$B debug digest]
             } else {
-                fail "Master and slave have different digest: [$A debug digest] VS [$B debug digest]"
+                fail "Master and replica have different digest: [$A debug digest] VS [$B debug digest]"
             }
         }
 
@@ -102,10 +102,10 @@ start_server {tags {"repl"}} {
                 [lindex [$B role] 0] eq {slave} &&
                 [string match {*master_link_status:up*} [$B info replication]]
             } else {
-                fail "Can't turn the instance into a slave"
+                fail "Can't turn the instance into a replica"
             }
 
-            # Push elements into the "foo" list of the new slave.
+            # Push elements into the "foo" list of the new replica.
             # If the client is still attached to the instance, we'll get
             # a desync between the two instances.
             $A rpush foo a b c
@@ -116,7 +116,7 @@ start_server {tags {"repl"}} {
                 [$A lrange foo 0 -1] eq {a b c} &&
                 [$B lrange foo 0 -1] eq {a b c}
             } else {
-                fail "Master and slave have different digest: [$A debug digest] VS [$B debug digest]"
+                fail "Master and replica have different digest: [$A debug digest] VS [$B debug digest]"
             }
         }
     }
@@ -135,7 +135,7 @@ start_server {tags {"repl"}} {
             s master_link_status
         } {down}
 
-        test {The role should immediately be changed to "slave"} {
+        test {The role should immediately be changed to "replica"} {
             s role
         } {slave}
 
@@ -154,7 +154,7 @@ start_server {tags {"repl"}} {
             wait_for_condition 500 100 {
                 [r  0 get mykey] eq {bar}
             } else {
-                fail "SET on master did not propagated on slave"
+                fail "SET on master did not propagated on replica"
             }
         }
 
@@ -201,7 +201,7 @@ foreach dl {no yes} {
                 lappend slaves [srv 0 client]
                 start_server {} {
                     lappend slaves [srv 0 client]
-                    test "Connect multiple slaves at the same time (issue #141), diskless=$dl" {
+                    test "Connect multiple replicas at the same time (issue #141), diskless=$dl" {
                         # Send SLAVEOF commands to slaves
                         [lindex $slaves 0] slaveof $master_host $master_port
                         [lindex $slaves 1] slaveof $master_host $master_port
@@ -220,7 +220,7 @@ foreach dl {no yes} {
                             }
                         }
                         if {$retry == 0} {
-                            error "assertion:Slaves not correctly synchronized"
+                            error "assertion:Replicas not correctly synchronized"
                         }
 
                         # Wait that slaves acknowledge they are online so
@@ -231,7 +231,7 @@ foreach dl {no yes} {
                             [lindex [[lindex $slaves 1] role] 3] eq {connected} &&
                             [lindex [[lindex $slaves 2] role] 3] eq {connected}
                         } else {
-                            fail "Slaves still not connected after some time"
+                            fail "Replicas still not connected after some time"
                         }
 
                         # Stop the write load
@@ -248,7 +248,7 @@ foreach dl {no yes} {
                             [$master dbsize] == [[lindex $slaves 1] dbsize] &&
                             [$master dbsize] == [[lindex $slaves 2] dbsize]
                         } else {
-                            fail "Different number of keys between masted and slave after too long time."
+                            fail "Different number of keys between masted and replica after too long time."
                         }
 
                         # Check digests
@@ -273,9 +273,8 @@ start_server {tags {"repl"}} {
     set master_port [srv 0 port]
     set load_handle0 [start_write_load $master_host $master_port 3]
     start_server {} {
-        test "Master stream is correctly processed while the slave has a script in -BUSY state" {
+        test "Master stream is correctly processed while the replica has a script in -BUSY state" {
             set slave [srv 0 client]
-            puts [srv 0 port]
             $slave config set lua-time-limit 500
             $slave slaveof $master_host $master_port
 
@@ -283,7 +282,7 @@ start_server {tags {"repl"}} {
             wait_for_condition 500 100 {
                 [lindex [$slave role] 3] eq {connected}
             } else {
-                fail "Slave still not connected after some time"
+                fail "Replica still not connected after some time"
             }
 
             # Wait some time to make sure the master is sending data
@@ -305,7 +304,7 @@ start_server {tags {"repl"}} {
             wait_for_condition 500 100 {
                 [$master debug digest] eq [$slave debug digest]
             } else {
-                fail "Different datasets between slave and master"
+                fail "Different datasets between replica and master"
             }
         }
     }

tests/modules/Makefile

@@ -0,0 +1,24 @@
+
+# find the OS
+uname_S := $(shell sh -c 'uname -s 2>/dev/null || echo not')
+
+# Compile flags for linux / osx
+ifeq ($(uname_S),Linux)
+	SHOBJ_CFLAGS ?= -W -Wall -fno-common -g -ggdb -std=c99 -O2
+	SHOBJ_LDFLAGS ?= -shared
+else
+	SHOBJ_CFLAGS ?= -W -Wall -dynamic -fno-common -g -ggdb -std=c99 -O2
+	SHOBJ_LDFLAGS ?= -bundle -undefined dynamic_lookup
+endif
+
+.SUFFIXES: .c .so .xo .o
+
+all: commandfilter.so
+
+.c.xo:
+	$(CC) -I../../src $(CFLAGS) $(SHOBJ_CFLAGS) -fPIC -c $< -o $@
+
+commandfilter.xo: ../../src/redismodule.h
+
+commandfilter.so: commandfilter.xo
+	$(LD) -o $@ $< $(SHOBJ_LDFLAGS) $(LIBS) -lc

tests/modules/commandfilter.c

@@ -0,0 +1,149 @@
+#define REDISMODULE_EXPERIMENTAL_API
+#include "redismodule.h"
+
+#include <string.h>
+
+static RedisModuleString *log_key_name;
+
+static const char log_command_name[] = "commandfilter.log";
+static const char ping_command_name[] = "commandfilter.ping";
+static const char unregister_command_name[] = "commandfilter.unregister";
+static int in_log_command = 0;
+
+static RedisModuleCommandFilter *filter = NULL;
+
+int CommandFilter_UnregisterCommand(RedisModuleCtx *ctx, RedisModuleString **argv, int argc)
+{
+    (void) argc;
+    (void) argv;
+
+    RedisModule_ReplyWithLongLong(ctx,
+            RedisModule_UnregisterCommandFilter(ctx, filter));
+
+    return REDISMODULE_OK;
+}
+
+int CommandFilter_PingCommand(RedisModuleCtx *ctx, RedisModuleString **argv, int argc)
+{
+    (void) argc;
+    (void) argv;
+
+    RedisModuleCallReply *reply = RedisModule_Call(ctx, "ping", "c", "@log");
+    if (reply) {
+        RedisModule_ReplyWithCallReply(ctx, reply);
+        RedisModule_FreeCallReply(reply);
+    } else {
+        RedisModule_ReplyWithSimpleString(ctx, "Unknown command or invalid arguments");
+    }
+
+    return REDISMODULE_OK;
+}
+
+int CommandFilter_LogCommand(RedisModuleCtx *ctx, RedisModuleString **argv, int argc)
+{
+    RedisModuleString *s = RedisModule_CreateString(ctx, "", 0);
+
+    int i;
+    for (i = 1; i < argc; i++) {
+        size_t arglen;
+        const char *arg = RedisModule_StringPtrLen(argv[i], &arglen);
+
+        if (i > 1) RedisModule_StringAppendBuffer(ctx, s, " ", 1);
+        RedisModule_StringAppendBuffer(ctx, s, arg, arglen);
+    }
+
+    RedisModuleKey *log = RedisModule_OpenKey(ctx, log_key_name, REDISMODULE_WRITE|REDISMODULE_READ);
+    RedisModule_ListPush(log, REDISMODULE_LIST_HEAD, s);
+    RedisModule_CloseKey(log);
+    RedisModule_FreeString(ctx, s);
+
+    in_log_command = 1;
+
+    size_t cmdlen;
+    const char *cmdname = RedisModule_StringPtrLen(argv[1], &cmdlen);
+    RedisModuleCallReply *reply = RedisModule_Call(ctx, cmdname, "v", &argv[2], argc - 2);
+    if (reply) {
+        RedisModule_ReplyWithCallReply(ctx, reply);
+        RedisModule_FreeCallReply(reply);
+    } else {
+        RedisModule_ReplyWithSimpleString(ctx, "Unknown command or invalid arguments");
+    }
+
+    in_log_command = 0;
+
+    return REDISMODULE_OK;
+}
+
+void CommandFilter_CommandFilter(RedisModuleCommandFilterCtx *filter)
+{
+    if (in_log_command) return;  /* don't process our own RM_Call() from CommandFilter_LogCommand() */
+
+    /* Fun manipulations:
+     * - Remove @delme
+     * - Replace @replaceme
+     * - Append @insertbefore or @insertafter
+     * - Prefix with Log command if @log encounterd
+     */
+    int log = 0;
+    int pos = 0;
+    while (pos < RedisModule_CommandFilterArgsCount(filter)) {
+        const RedisModuleString *arg = RedisModule_CommandFilterArgGet(filter, pos);
+        size_t arg_len;
+        const char *arg_str = RedisModule_StringPtrLen(arg, &arg_len);
+
+        if (arg_len == 6 && !memcmp(arg_str, "@delme", 6)) {
+            RedisModule_CommandFilterArgDelete(filter, pos);
+            continue;
+        } 
+        if (arg_len == 10 && !memcmp(arg_str, "@replaceme", 10)) {
+            RedisModule_CommandFilterArgReplace(filter, pos,
+                    RedisModule_CreateString(NULL, "--replaced--", 12));
+        } else if (arg_len == 13 && !memcmp(arg_str, "@insertbefore", 13)) {
+            RedisModule_CommandFilterArgInsert(filter, pos,
+                    RedisModule_CreateString(NULL, "--inserted-before--", 19));
+            pos++;
+        } else if (arg_len == 12 && !memcmp(arg_str, "@insertafter", 12)) {
+            RedisModule_CommandFilterArgInsert(filter, pos + 1,
+                    RedisModule_CreateString(NULL, "--inserted-after--", 18));
+            pos++;
+        } else if (arg_len == 4 && !memcmp(arg_str, "@log", 4)) {
+            log = 1;
+        }
+        pos++;
+    }
+
+    if (log) RedisModule_CommandFilterArgInsert(filter, 0,
+            RedisModule_CreateString(NULL, log_command_name, sizeof(log_command_name)-1));
+}
+
+int RedisModule_OnLoad(RedisModuleCtx *ctx, RedisModuleString **argv, int argc) {
+    if (RedisModule_Init(ctx,"commandfilter",1,REDISMODULE_APIVER_1)
+            == REDISMODULE_ERR) return REDISMODULE_ERR;
+
+    if (argc != 2) {
+        RedisModule_Log(ctx, "warning", "Log key name not specified");
+        return REDISMODULE_ERR;
+    }
+
+    long long noself = 0;
+    log_key_name = RedisModule_CreateStringFromString(ctx, argv[0]);
+    RedisModule_StringToLongLong(argv[1], &noself);
+
+    if (RedisModule_CreateCommand(ctx,log_command_name,
+                CommandFilter_LogCommand,"write deny-oom",1,1,1) == REDISMODULE_ERR)
+            return REDISMODULE_ERR;
+
+    if (RedisModule_CreateCommand(ctx,ping_command_name,
+                CommandFilter_PingCommand,"deny-oom",1,1,1) == REDISMODULE_ERR)
+            return REDISMODULE_ERR;
+
+    if (RedisModule_CreateCommand(ctx,unregister_command_name,
+                CommandFilter_UnregisterCommand,"write deny-oom",1,1,1) == REDISMODULE_ERR)
+            return REDISMODULE_ERR;
+
+    if ((filter = RedisModule_RegisterCommandFilter(ctx, CommandFilter_CommandFilter, 
+                    noself ? REDISMODULE_CMDFILTER_NOSELF : 0))
+            == NULL) return REDISMODULE_ERR;
+
+    return REDISMODULE_OK;
+}

tests/support/util.tcl

@@ -91,6 +91,14 @@ proc wait_for_sync r {
     }
 }
 
+proc wait_for_ofs_sync {r1 r2} {
+    wait_for_condition 50 100 {
+        [status $r1 master_repl_offset] eq [status $r2 master_repl_offset]
+    } else {
+        fail "replica didn't sync in time"
+    }
+}
+
 # Random integer between 0 and max (excluded).
 proc randomInt {max} {
     expr {int(rand()*$max)}

tests/test_helper.tcl

@@ -502,7 +502,7 @@ for {set j 0} {$j < [llength $argv]} {incr j} {
     } elseif {$opt eq {--only}} {
         lappend ::only_tests $arg
         incr j
-    } elseif {$opt eq {--skiptill}} {
+    } elseif {$opt eq {--skip-till}} {
         set ::skip_till $arg
         incr j
     } elseif {$opt eq {--list-tests}} {

tests/unit/dump.tcl

@@ -33,7 +33,7 @@ start_server {tags {"dump"}} {
         set now [clock milliseconds]
         r restore foo [expr $now+3000] $encoded absttl
         set ttl [r pttl foo]
-        assert {$ttl >= 2990 && $ttl <= 3000}
+        assert {$ttl >= 2900 && $ttl <= 3100}
         r get foo
     } {bar}
     

tests/unit/hyperloglog.tcl

@@ -115,6 +115,34 @@ start_server {tags {"hll"}} {
         set e
     } {*WRONGTYPE*}
 
+    test {Fuzzing dense/sparse encoding: Redis should always detect errors} {
+        for {set j 0} {$j < 1000} {incr j} {
+            r del hll
+            set items {}
+            set numitems [randomInt 3000]
+            for {set i 0} {$i < $numitems} {incr i} {
+                lappend items [expr {rand()}]
+            }
+            r pfadd hll {*}$items
+
+            # Corrupt it in some random way.
+            for {set i 0} {$i < 5} {incr i} {
+                set len [r strlen hll]
+                set pos [randomInt $len]
+                set byte [randstring 1 1 binary]
+                r setrange hll $pos $byte
+                # Don't modify more bytes 50% of times
+                if {rand() < 0.5} break
+            }
+
+            # Use the hyperloglog to check if it crashes
+            # Redis in some way.
+            catch {
+                r pfcount hll
+            }
+        }
+    }
+
     test {PFADD, PFCOUNT, PFMERGE type checking works} {
         r set foo bar
         catch {r pfadd foo 1} e

tests/unit/introspection-2.tcl

@@ -1,3 +1,9 @@
+proc cmdstat {cmd} {
+    if {[regexp "\r\ncmdstat_$cmd:(.*?)\r\n" [r info commandstats] _ value]} {
+        set _ $value
+    }
+}
+
 start_server {tags {"introspection"}} {
     test {TTL and TYPYE do not alter the last access time of a key} {
         r set foo bar
@@ -20,4 +26,55 @@ start_server {tags {"introspection"}} {
         r set key2 2
         r touch key0 key1 key2 key3
     } 2
+
+    test {command stats for GEOADD} {
+        r config resetstat
+        r GEOADD foo 0 0 bar
+        assert_match {*calls=1,*} [cmdstat geoadd]
+        assert_match {} [cmdstat zadd]
+    }
+
+    test {command stats for EXPIRE} {
+        r config resetstat
+        r SET foo bar
+        r EXPIRE foo 0
+        assert_match {*calls=1,*} [cmdstat expire]
+        assert_match {} [cmdstat del]
+    }
+
+    test {command stats for BRPOP} {
+        r config resetstat
+        r LPUSH list foo
+        r BRPOP list 0
+        assert_match {*calls=1,*} [cmdstat brpop]
+        assert_match {} [cmdstat rpop]
+    }
+
+    test {command stats for MULTI} {
+        r config resetstat
+        r MULTI
+        r set foo bar
+        r GEOADD foo2 0 0 bar
+        r EXPIRE foo2 0
+        r EXEC
+        assert_match {*calls=1,*} [cmdstat multi]
+        assert_match {*calls=1,*} [cmdstat exec]
+        assert_match {*calls=1,*} [cmdstat set]
+        assert_match {*calls=1,*} [cmdstat expire]
+        assert_match {*calls=1,*} [cmdstat geoadd]
+    }
+
+    test {command stats for scripts} {
+        r config resetstat
+        r set mykey myval
+        r eval {
+            redis.call('set', KEYS[1], 0)
+            redis.call('expire', KEYS[1], 0)
+            redis.call('geoadd', KEYS[1], 0, 0, "bar")
+        } 1 mykey
+        assert_match {*calls=1,*} [cmdstat eval]
+        assert_match {*calls=2,*} [cmdstat set]
+        assert_match {*calls=1,*} [cmdstat expire]
+        assert_match {*calls=1,*} [cmdstat geoadd]
+    }
 }

tests/unit/maxmemory.tcl

@@ -161,9 +161,9 @@ proc test_slave_buffers {test_name cmd_count payload_len limit_memory pipeline}
             }
 
             # make sure master doesn't disconnect slave because of timeout
-            $master config set repl-timeout 300 ;# 5 minutes
+            $master config set repl-timeout 1200 ;# 20 minutes (for valgrind and slow machines)
             $master config set maxmemory-policy allkeys-random
-            $master config set client-output-buffer-limit "slave 100000000 100000000 300"
+            $master config set client-output-buffer-limit "replica 100000000 100000000 300"
             $master config set repl-backlog-size [expr {10*1024}]
 
             $slave slaveof $master_host $master_port
@@ -212,7 +212,8 @@ proc test_slave_buffers {test_name cmd_count payload_len limit_memory pipeline}
 
             assert {[$master dbsize] == 100}
             assert {$slave_buf > 2*1024*1024} ;# some of the data may have been pushed to the OS buffers
-            assert {$delta < 50*1024 && $delta > -50*1024} ;# 1 byte unaccounted for, with 1M commands will consume some 1MB
+            set delta_max [expr {$cmd_count / 2}] ;# 1 byte unaccounted for, with 1M commands will consume some 1MB
+            assert {$delta < $delta_max && $delta > -$delta_max}
 
             $master client kill type slave
             set killed_used [s -1 used_memory]
@@ -221,7 +222,7 @@ proc test_slave_buffers {test_name cmd_count payload_len limit_memory pipeline}
             set killed_used_no_repl [expr {$killed_used - $killed_mem_not_counted_for_evict}]
             set delta_no_repl [expr {$killed_used_no_repl - $used_no_repl}]
             assert {$killed_slave_buf == 0}
-            assert {$delta_no_repl > -50*1024 && $delta_no_repl < 50*1024} ;# 1 byte unaccounted for, with 1M commands will consume some 1MB
+            assert {$delta_no_repl > -$delta_max && $delta_no_repl < $delta_max}
 
         }
         # unfreeze slave process (after the 'test' succeeded or failed, but before we attempt to terminate the server
@@ -238,5 +239,5 @@ test_slave_buffers {slave buffer are counted correctly} 1000000 10 0 1
 
 # test that slave buffer don't induce eviction
 # test again with fewer (and bigger) commands without pipeline, but with eviction
-test_slave_buffers "slave buffer don't induce eviction" 100000 100 1 0
+test_slave_buffers "replica buffer don't induce eviction" 100000 100 1 0
 

tests/unit/memefficiency.tcl

@@ -90,6 +90,7 @@ start_server {tags {"defrag"}} {
         test "Active defrag big keys" {
             r flushdb
             r config resetstat
+            r config set save "" ;# prevent bgsave from interfereing with save below
             r config set activedefrag no
             r config set active-defrag-max-scan-fields 1000
             r config set active-defrag-threshold-lower 5

tests/unit/moduleapi/commandfilter.tcl

@@ -0,0 +1,84 @@
+set testmodule [file normalize tests/modules/commandfilter.so]
+
+start_server {tags {"modules"}} {
+    r module load $testmodule log-key 0
+
+    test {Command Filter handles redirected commands} {
+        r set mykey @log
+        r lrange log-key 0 -1
+    } "{set mykey @log}"
+
+    test {Command Filter can call RedisModule_CommandFilterArgDelete} {
+        r rpush mylist elem1 @delme elem2
+        r lrange mylist 0 -1
+    } {elem1 elem2}
+
+    test {Command Filter can call RedisModule_CommandFilterArgInsert} {
+        r del mylist
+        r rpush mylist elem1 @insertbefore elem2 @insertafter elem3
+        r lrange mylist 0 -1
+    } {elem1 --inserted-before-- @insertbefore elem2 @insertafter --inserted-after-- elem3}
+
+    test {Command Filter can call RedisModule_CommandFilterArgReplace} {
+        r del mylist
+        r rpush mylist elem1 @replaceme elem2
+        r lrange mylist 0 -1
+    } {elem1 --replaced-- elem2}
+
+    test {Command Filter applies on RM_Call() commands} {
+        r del log-key
+        r commandfilter.ping
+        r lrange log-key 0 -1
+    } "{ping @log}"
+
+    test {Command Filter applies on Lua redis.call()} {
+        r del log-key
+        r eval "redis.call('ping', '@log')" 0
+        r lrange log-key 0 -1
+    } "{ping @log}"
+
+    test {Command Filter applies on Lua redis.call() that calls a module} {
+        r del log-key
+        r eval "redis.call('commandfilter.ping')" 0
+        r lrange log-key 0 -1
+    } "{ping @log}"
+
+    test {Command Filter is unregistered implicitly on module unload} {
+        r del log-key
+        r module unload commandfilter
+        r set mykey @log
+        r lrange log-key 0 -1
+    } {}
+
+    r module load $testmodule log-key 0
+
+    test {Command Filter unregister works as expected} {
+        # Validate reloading succeeded
+        r del log-key
+        r set mykey @log
+        assert_equal "{set mykey @log}" [r lrange log-key 0 -1]
+
+        # Unregister
+        r commandfilter.unregister
+        r del log-key
+
+        r set mykey @log
+        r lrange log-key 0 -1
+    } {}
+
+    r module unload commandfilter
+    r module load $testmodule log-key 1
+
+    test {Command Filter REDISMODULE_CMDFILTER_NOSELF works as expected} {
+        r set mykey @log
+        assert_equal "{set mykey @log}" [r lrange log-key 0 -1]
+
+        r del log-key
+        r commandfilter.ping
+        assert_equal {} [r lrange log-key 0 -1]
+
+        r eval "redis.call('commandfilter.ping')" 0
+        assert_equal {} [r lrange log-key 0 -1]
+    }
+
+} 

tests/unit/pendingquerybuf.tcl

@@ -29,7 +29,7 @@ start_server {} {
         set m_usedmemory [info_memory $master used_memory]
         set s_usedmemory [info_memory $slave used_memory]
         if { $s_usedmemory > $m_usedmemory + 10*1024*1024 } {
-            fail "the used_memory of slave is too larger than master.Master:$m_usedmemory Slave:$s_usedmemory"
+            fail "the used_memory of replica is much larger than master. Master:$m_usedmemory Replica:$s_usedmemory"
         }
     }  
 }}

tests/unit/scripting.tcl

@@ -148,9 +148,11 @@ start_server {tags {"scripting"}} {
 
     test {EVAL - Scripts can't run certain commands} {
         set e {}
+        r debug lua-always-replicate-commands 0
         catch {
             r eval "redis.pcall('randomkey'); return redis.pcall('set','x','ciao')" 0
         } e
+        r debug lua-always-replicate-commands 1
         set e
     } {*not allowed after*}
 
@@ -299,9 +301,12 @@ start_server {tags {"scripting"}} {
     } {b534286061d4b9e4026607613b95c06c06015ae8 loaded}
 
     test "In the context of Lua the output of random commands gets ordered" {
+        r debug lua-always-replicate-commands 0
         r del myset
         r sadd myset a b c d e f g h i l m n o p q r s t u v z aa aaa azz
-        r eval {return redis.call('smembers',KEYS[1])} 1 myset
+        set res [r eval {return redis.call('smembers',KEYS[1])} 1 myset]
+        r debug lua-always-replicate-commands 1
+        set res
     } {a aa aaa azz b c d e f g h i l m n o p q r s t u v z}
 
     test "SORT is normally not alpha re-ordered for the scripting engine" {
@@ -537,7 +542,7 @@ foreach cmdrepl {0 1} {
                 r debug lua-always-replicate-commands 1
             }
 
-            test "Before the slave connects we issue two EVAL commands $rt" {
+            test "Before the replica connects we issue two EVAL commands $rt" {
                 # One with an error, but still executing a command.
                 # SHA is: 67164fc43fa971f76fd1aaeeaf60c1c178d25876
                 catch {
@@ -548,13 +553,13 @@ foreach cmdrepl {0 1} {
                 r eval {return redis.call('incr',KEYS[1])} 1 x
             } {2}
 
-            test "Connect a slave to the master instance $rt" {
+            test "Connect a replica to the master instance $rt" {
                 r -1 slaveof [srv 0 host] [srv 0 port]
                 wait_for_condition 50 100 {
                     [s -1 role] eq {slave} &&
                     [string match {*master_link_status:up*} [r -1 info replication]]
                 } else {
-                    fail "Can't turn the instance into a slave"
+                    fail "Can't turn the instance into a replica"
                 }
             }
 
@@ -587,7 +592,7 @@ foreach cmdrepl {0 1} {
                 wait_for_condition 50 100 {
                     [r -1 lrange a 0 -1] eq [r lrange a 0 -1]
                 } else {
-                    fail "Expected list 'a' in slave and master to be the same, but they are respectively '[r -1 lrange a 0 -1]' and '[r lrange a 0 -1]'"
+                    fail "Expected list 'a' in replica and master to be the same, but they are respectively '[r -1 lrange a 0 -1]' and '[r lrange a 0 -1]'"
                 }
                 set res
             } {a 1}
@@ -622,7 +627,7 @@ foreach cmdrepl {0 1} {
                 wait_for_condition 50 100 {
                     [r -1 debug digest] eq [r debug digest]
                 } else {
-                    fail "Master-Slave desync after Lua script using SELECT."
+                    fail "Master-Replica desync after Lua script using SELECT."
                 }
             }
         }
@@ -631,13 +636,13 @@ foreach cmdrepl {0 1} {
 
 start_server {tags {"scripting repl"}} {
     start_server {overrides {appendonly yes aof-use-rdb-preamble no}} {
-        test "Connect a slave to the master instance" {
+        test "Connect a replica to the master instance" {
             r -1 slaveof [srv 0 host] [srv 0 port]
             wait_for_condition 50 100 {
                 [s -1 role] eq {slave} &&
                 [string match {*master_link_status:up*} [r -1 info replication]]
             } else {
-                fail "Can't turn the instance into a slave"
+                fail "Can't turn the instance into a replica"
             }
         }
 
@@ -655,11 +660,13 @@ start_server {tags {"scripting repl"}} {
         } {1}
 
         test "Redis.set_repl() must be issued after replicate_commands()" {
+            r debug lua-always-replicate-commands 0
             catch {
                 r eval {
                     redis.set_repl(redis.REPL_ALL);
                 } 0
             } e
+            r debug lua-always-replicate-commands 1
             set e
         } {*only after turning on*}
 
@@ -689,7 +696,7 @@ start_server {tags {"scripting repl"}} {
             wait_for_condition 50 100 {
                 [r -1 mget a b c d] eq {1 {} {} 4}
             } else {
-                fail "Only a and c should be replicated to slave"
+                fail "Only a and c should be replicated to replica"
             }
 
             # Master should have everything right now
@@ -728,7 +735,7 @@ start_server {tags {"scripting repl"}} {
             wait_for_condition 50 100 {
                 [r get time] eq [r -1 get time]
             } else {
-                fail "Time key does not match between master and slave"
+                fail "Time key does not match between master and replica"
             }
         }
     }

tests/unit/slowlog.tcl

@@ -80,9 +80,11 @@ start_server {tags {"slowlog"} overrides {slowlog-log-slower-than 1000000}} {
     }
 
     test {SLOWLOG - can be disabled} {
+        r config set slowlog-max-len 1
         r config set slowlog-log-slower-than 1
         r slowlog reset
-        assert_equal [r slowlog len] 1 
+        r debug sleep 0.2
+        assert_equal [r slowlog len] 1
         r config set slowlog-log-slower-than -1
         r slowlog reset
         r debug sleep 0.2

tests/unit/type/stream-cgroups.tcl

@@ -9,6 +9,17 @@ start_server {
         set err
     } {BUSYGROUP*}
 
+    test {XGROUP CREATE: automatic stream creation fails without MKSTREAM} {
+        r DEL mystream
+        catch {r XGROUP CREATE mystream mygroup $} err
+        set err
+    } {ERR*}
+
+    test {XGROUP CREATE: automatic stream creation works with MKSTREAM} {
+        r DEL mystream
+        r XGROUP CREATE mystream mygroup $ MKSTREAM
+    } {OK}
+
     test {XREADGROUP will return only new elements} {
         r XADD mystream * a 1
         r XADD mystream * b 2
@@ -96,4 +107,185 @@ start_server {
         set c [llength [lindex [r xreadgroup group g1 c2 streams events >] 0 1]]
         assert {$c == 5}
     }
+
+    test {XREADGROUP will not report data on empty history. Bug #5577} {
+        r del events
+        r xadd events * a 1
+        r xadd events * b 2
+        r xadd events * c 3
+        r xgroup create events mygroup 0
+
+        # Current local PEL should be empty
+        set res [r xpending events mygroup - + 10]
+        assert {[llength $res] == 0}
+
+        # So XREADGROUP should read an empty history as well
+        set res [r xreadgroup group mygroup myconsumer count 3 streams events 0]
+        assert {[llength [lindex $res 0 1]] == 0}
+
+        # We should fetch all the elements in the stream asking for >
+        set res [r xreadgroup group mygroup myconsumer count 3 streams events >]
+        assert {[llength [lindex $res 0 1]] == 3}
+
+        # Now the history is populated with three not acked entries
+        set res [r xreadgroup group mygroup myconsumer count 3 streams events 0]
+        assert {[llength [lindex $res 0 1]] == 3}
+    }
+
+    test {XREADGROUP history reporting of deleted entries. Bug #5570} {
+        r del mystream
+        r XGROUP CREATE mystream mygroup $ MKSTREAM
+        r XADD mystream 1 field1 A
+        r XREADGROUP GROUP mygroup myconsumer STREAMS mystream >
+        r XADD mystream MAXLEN 1 2 field1 B
+        r XREADGROUP GROUP mygroup myconsumer STREAMS mystream >
+
+        # Now we have two pending entries, however one should be deleted
+        # and one should be ok (we should only see "B")
+        set res [r XREADGROUP GROUP mygroup myconsumer STREAMS mystream 0-1]
+        assert {[lindex $res 0 1 0] == {1-0 {}}}
+        assert {[lindex $res 0 1 1] == {2-0 {field1 B}}}
+    }
+
+    test {XCLAIM can claim PEL items from another consumer} {
+        # Add 3 items into the stream, and create a consumer group
+        r del mystream
+        set id1 [r XADD mystream * a 1]
+        set id2 [r XADD mystream * b 2]
+        set id3 [r XADD mystream * c 3]
+        r XGROUP CREATE mystream mygroup 0
+
+        # Client 1 reads item 1 from the stream without acknowledgements.
+        # Client 2 then claims pending item 1 from the PEL of client 1
+        set reply [
+            r XREADGROUP GROUP mygroup client1 count 1 STREAMS mystream >
+        ]
+        assert {[llength [lindex $reply 0 1 0 1]] == 2}
+        assert {[lindex $reply 0 1 0 1] eq {a 1}}
+        r debug sleep 0.2
+        set reply [
+            r XCLAIM mystream mygroup client2 10 $id1
+        ]
+        assert {[llength [lindex $reply 0 1]] == 2}
+        assert {[lindex $reply 0 1] eq {a 1}}
+
+        # Client 1 reads another 2 items from stream
+        r XREADGROUP GROUP mygroup client1 count 2 STREAMS mystream >
+        r debug sleep 0.2
+
+        # Delete item 2 from the stream. Now client 1 has PEL that contains
+        # only item 3. Try to use client 2 to claim the deleted item 2
+        # from the PEL of client 1, this should return nil
+        r XDEL mystream $id2
+        set reply [
+            r XCLAIM mystream mygroup client2 10 $id2
+        ]
+        assert {[llength $reply] == 1}
+        assert_equal "" [lindex $reply 0]
+
+        # Delete item 3 from the stream. Now client 1 has PEL that is empty.
+        # Try to use client 2 to claim the deleted item 3 from the PEL
+        # of client 1, this should return nil
+        r debug sleep 0.2
+        r XDEL mystream $id3
+        set reply [
+            r XCLAIM mystream mygroup client2 10 $id3
+        ]
+        assert {[llength $reply] == 1}
+        assert_equal "" [lindex $reply 0]
+    }
+
+    test {XCLAIM without JUSTID increments delivery count} {
+        # Add 3 items into the stream, and create a consumer group
+        r del mystream
+        set id1 [r XADD mystream * a 1]
+        set id2 [r XADD mystream * b 2]
+        set id3 [r XADD mystream * c 3]
+        r XGROUP CREATE mystream mygroup 0
+
+        # Client 1 reads item 1 from the stream without acknowledgements.
+        # Client 2 then claims pending item 1 from the PEL of client 1
+        set reply [
+            r XREADGROUP GROUP mygroup client1 count 1 STREAMS mystream >
+        ]
+        assert {[llength [lindex $reply 0 1 0 1]] == 2}
+        assert {[lindex $reply 0 1 0 1] eq {a 1}}
+        r debug sleep 0.2
+        set reply [
+            r XCLAIM mystream mygroup client2 10 $id1
+        ]
+        assert {[llength [lindex $reply 0 1]] == 2}
+        assert {[lindex $reply 0 1] eq {a 1}}
+
+        set reply [
+            r XPENDING mystream mygroup - + 10
+        ]
+        assert {[llength [lindex $reply 0]] == 4}
+        assert {[lindex $reply 0 3] == 2}
+
+        # Client 3 then claims pending item 1 from the PEL of client 2 using JUSTID
+        r debug sleep 0.2
+        set reply [
+            r XCLAIM mystream mygroup client3 10 $id1 JUSTID
+        ]
+        assert {[llength $reply] == 1}
+        assert {[lindex $reply 0] eq $id1}
+
+        set reply [
+            r XPENDING mystream mygroup - + 10
+        ]
+        assert {[llength [lindex $reply 0]] == 4}
+        assert {[lindex $reply 0 3] == 2}
+    }
+
+    start_server {} {
+        set master [srv -1 client]
+        set master_host [srv -1 host]
+        set master_port [srv -1 port]
+        set slave [srv 0 client]
+
+        foreach noack {0 1} {
+            test "Consumer group last ID propagation to slave (NOACK=$noack)" {
+                $slave slaveof $master_host $master_port
+                wait_for_condition 50 100 {
+                    [s 0 master_link_status] eq {up}
+                } else {
+                    fail "Replication not started."
+                }
+
+                $master del stream
+                $master xadd stream * a 1
+                $master xadd stream * a 2
+                $master xadd stream * a 3
+                $master xgroup create stream mygroup 0
+
+                # Consume the first two items on the master
+                for {set j 0} {$j < 2} {incr j} {
+                    if {$noack} {
+                        set item [$master xreadgroup group mygroup \
+                                  myconsumer COUNT 1 NOACK STREAMS stream >]
+                    } else {
+                        set item [$master xreadgroup group mygroup \
+                                  myconsumer COUNT 1 STREAMS stream >]
+                    }
+                    set id [lindex $item 0 1 0 0]
+                    if {$noack == 0} {
+                        assert {[$master xack stream mygroup $id] eq "1"}
+                    }
+                }
+
+                wait_for_ofs_sync $master $slave
+
+                # Turn slave into master
+                $slave slaveof no one
+
+                set item [$slave xreadgroup group mygroup myconsumer \
+                          COUNT 1 STREAMS stream >]
+
+                # The consumed enty should be the third
+                set myentry [lindex $item 0 1 0 1]
+                assert {$myentry eq {a 3}}
+            }
+        }
+    }
 }

tests/unit/type/stream.tcl

@@ -317,3 +317,97 @@ start_server {
         assert_equal [r xrevrange teststream2 1234567891245 -] {{1234567891240-0 {key1 value2}} {1234567891230-0 {key1 value1}}}
     }
 }
+
+start_server {tags {"stream"} overrides {appendonly yes}} {
+    test {XADD with MAXLEN > xlen can propagate correctly} {
+        for {set j 0} {$j < 100} {incr j} {
+            r XADD mystream * xitem v
+        }
+        r XADD mystream MAXLEN 200 * xitem v
+        incr j
+        assert {[r xlen mystream] == $j}
+        r debug loadaof
+        r XADD mystream * xitem v
+        incr j
+        assert {[r xlen mystream] == $j}
+    }
+}
+
+start_server {tags {"stream"} overrides {appendonly yes}} {
+    test {XADD with ~ MAXLEN can propagate correctly} {
+        for {set j 0} {$j < 100} {incr j} {
+            r XADD mystream * xitem v
+        }
+        r XADD mystream MAXLEN ~ $j * xitem v
+        incr j
+        assert {[r xlen mystream] == $j}
+        r config set stream-node-max-entries 1
+        r debug loadaof
+        r XADD mystream * xitem v
+        incr j
+        assert {[r xlen mystream] == $j}
+    }
+}
+
+start_server {tags {"stream"} overrides {appendonly yes stream-node-max-entries 10}} {
+    test {XTRIM with ~ MAXLEN can propagate correctly} {
+        for {set j 0} {$j < 100} {incr j} {
+            r XADD mystream * xitem v
+        }
+        r XTRIM mystream MAXLEN ~ 85
+        assert {[r xlen mystream] == 89}
+        r config set stream-node-max-entries 1
+        r debug loadaof
+        r XADD mystream * xitem v
+        incr j
+        assert {[r xlen mystream] == 90}
+    }
+}
+
+start_server {tags {"xsetid"}} {
+    test {XADD can CREATE an empty stream} {
+        r XADD mystream MAXLEN 0 * a b
+        assert {[dict get [r xinfo stream mystream] length] == 0}
+    }
+
+    test {XSETID can set a specific ID} {
+        r XSETID mystream "200-0"
+        assert {[dict get [r xinfo stream mystream] last-generated-id] == "200-0"}
+    }
+
+    test {XSETID cannot SETID with smaller ID} {
+        r XADD mystream * a b
+        catch {r XSETID mystream "1-1"} err
+        r XADD mystream MAXLEN 0 * a b
+        set err
+    } {ERR*smaller*}
+
+    test {XSETID cannot SETID on non-existent key} {
+        catch {r XSETID stream 1-1} err
+        set _ $err
+    } {ERR no such key}
+}
+
+start_server {tags {"stream"} overrides {appendonly yes aof-use-rdb-preamble no}} {
+    test {Empty stream can be rewrite into AOF correctly} {
+        r XADD mystream MAXLEN 0 * a b
+        assert {[dict get [r xinfo stream mystream] length] == 0}
+        r bgrewriteaof
+        waitForBgrewriteaof r
+        r debug loadaof
+        assert {[dict get [r xinfo stream mystream] length] == 0}
+    }
+
+    test {Stream can be rewrite into AOF correctly after XDEL lastid} {
+        r XSETID mystream 0-0
+        r XADD mystream 1-1 a b
+        r XADD mystream 2-2 a b
+        assert {[dict get [r xinfo stream mystream] length] == 2}
+        r XDEL mystream 2-2
+        r bgrewriteaof
+        waitForBgrewriteaof r
+        r debug loadaof
+        assert {[dict get [r xinfo stream mystream] length] == 1}
+        assert {[dict get [r xinfo stream mystream] last-generated-id] == "2-2"}
+    }
+}

tests/unit/type/zset.tcl

@@ -388,7 +388,7 @@ start_server {tags {"zset"}} {
                               0 omega}
         }
 
-        test "ZRANGEBYLEX/ZREVRANGEBYLEX/ZCOUNT basics" {
+        test "ZRANGEBYLEX/ZREVRANGEBYLEX/ZLEXCOUNT basics" {
             create_default_lex_zset
 
             # inclusive range
@@ -416,6 +416,22 @@ start_server {tags {"zset"}} {
             assert_equal {} [r zrevrangebylex zset \[elez \[elex]
             assert_equal {} [r zrevrangebylex zset (hill (omega]
         }
+        
+        test "ZLEXCOUNT advanced" {
+            create_default_lex_zset
+    
+            assert_equal 9 [r zlexcount zset - +]
+            assert_equal 0 [r zlexcount zset + -]
+            assert_equal 0 [r zlexcount zset + \[c]
+            assert_equal 0 [r zlexcount zset \[c -]
+            assert_equal 8 [r zlexcount zset \[bar +]
+            assert_equal 5 [r zlexcount zset \[bar \[foo]
+            assert_equal 4 [r zlexcount zset \[bar (foo]
+            assert_equal 4 [r zlexcount zset (bar \[foo]
+            assert_equal 3 [r zlexcount zset (bar (foo]
+            assert_equal 5 [r zlexcount zset - (foo]
+            assert_equal 1 [r zlexcount zset (maxstring +]
+        }
 
         test "ZRANGEBYSLEX with LIMIT" {
             create_default_lex_zset

utils/corrupt_rdb.c

@@ -21,8 +21,9 @@ int main(int argc, char **argv) {
     }
 
     srand(time(NULL));
+    char *filename = argv[1];
     cycles = atoi(argv[2]);
-    fd = open("dump.rdb",O_RDWR);
+    fd = open(filename,O_RDWR);
     if (fd == -1) {
         perror("open");
         exit(1);

utils/releasetools/changelog.tcl

@@ -1,12 +1,17 @@
 #!/usr/bin/env tclsh
 
-if {[llength $::argv] != 2} {
-    puts "Usage: $::argv0 <branch> <version>"
+if {[llength $::argv] != 2 && [llength $::argv] != 3} {
+    puts "Usage: $::argv0 <branch> <version> \[<num-commits>\]"
     exit 1
 }
 
 set branch [lindex $::argv 0]
 set ver [lindex $::argv 1]
+if {[llength $::argv] == 3} {
+    set count [lindex ::$argv 2]
+} else {
+    set count 100
+}
 
 set template {
 ================================================================================
@@ -21,7 +26,7 @@ append template "\n\n"
 set date [clock format [clock seconds]]
 set template [string map [list %ver% $ver %date% $date] $template]
 
-append template [exec git log $branch~100..$branch "--format=format:%an in commit %h:%n %s" --shortstat]
+append template [exec git log $branch~$count..$branch "--format=format:%an in commit %h:%n %s" --shortstat]
 
 #Older, more verbose version.
 #