xref: /redis-3.2.3/redis.conf (revision 0a45fbc3)
1e16c0c19Santirez# Redis configuration file example.
2e16c0c19Santirez#
3e16c0c19Santirez# Note that in order to read the configuration file, Redis must be
4e16c0c19Santirez# started with the file path as first argument:
5e16c0c19Santirez#
6e16c0c19Santirez# ./redis-server /path/to/redis.conf
7ed9b544eSantirez
857c0cf8bSKashif Rasul# Note on units: when memory size is needed, it is possible to specify
972324005Santirez# it in the usual form of 1k 5GB 4M and so forth:
1072324005Santirez#
1172324005Santirez# 1k => 1000 bytes
1272324005Santirez# 1kb => 1024 bytes
1372324005Santirez# 1m => 1000000 bytes
1472324005Santirez# 1mb => 1024*1024 bytes
1572324005Santirez# 1g => 1000000000 bytes
1672324005Santirez# 1gb => 1024*1024*1024 bytes
1772324005Santirez#
1872324005Santirez# units are case insensitive so 1GB 1Gb 1gB are all the same.
1972324005Santirez
207da423f7SYubao Liu################################## INCLUDES ###################################
217da423f7SYubao Liu
227da423f7SYubao Liu# Include one or more other config files here.  This is useful if you
23f62f00e0SBen# have a standard template that goes to all Redis servers but also need
247da423f7SYubao Liu# to customize a few per-server settings.  Include files can include
257da423f7SYubao Liu# other files, so use this wisely.
267da423f7SYubao Liu#
277da423f7SYubao Liu# Notice option "include" won't be rewritten by command "CONFIG REWRITE"
28305d7f29Santirez# from admin or Redis Sentinel. Since Redis always uses the last processed
29305d7f29Santirez# line as value of a configuration directive, you'd better put includes
30305d7f29Santirez# at the beginning of this file to avoid overwriting config change at runtime.
31305d7f29Santirez#
32305d7f29Santirez# If instead you are interested in using includes to override configuration
33305d7f29Santirez# options, it is better to use include as the last line.
347da423f7SYubao Liu#
357da423f7SYubao Liu# include /path/to/local.conf
367da423f7SYubao Liu# include /path/to/other.conf
377da423f7SYubao Liu
3810246642Santirez################################## NETWORK #####################################
397da423f7SYubao Liu
4010246642Santirez# By default, if no "bind" configuration directive is specified, Redis listens
4110246642Santirez# for connections from all the network interfaces available on the server.
4210246642Santirez# It is possible to listen to just one or multiple selected interfaces using
4310246642Santirez# the "bind" configuration directive, followed by one or more IP addresses.
4410246642Santirez#
4510246642Santirez# Examples:
4610246642Santirez#
4710246642Santirez# bind 192.168.1.100 10.0.0.1
4810246642Santirez# bind 127.0.0.1 ::1
4910246642Santirez#
5010246642Santirez# ~~~ WARNING ~~~ If the computer running Redis is directly exposed to the
5110246642Santirez# internet, binding to all the interfaces is dangerous and will expose the
5210246642Santirez# instance to everybody on the internet. So by default we uncomment the
5310246642Santirez# following bind directive, that will force Redis to listen only into
5410246642Santirez# the IPv4 lookback interface address (this means Redis will be able to
5510246642Santirez# accept connections only from clients running into the same computer it
5610246642Santirez# is running).
570aa5acc8Santirez#
580aa5acc8Santirez# IF YOU ARE SURE YOU WANT YOUR INSTANCE TO LISTEN TO ALL THE INTERFACES
59a8a25573Santirez# JUST COMMENT THE FOLLOWING LINE.
6010246642Santirez# ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
6110246642Santirezbind 127.0.0.1
62ed329fcfSLuc Heinrich
63273c49e7Santirez# Protected mode is a layer of security protection, in order to avoid that
64273c49e7Santirez# Redis instances left open on the internet are accessed and exploited.
65273c49e7Santirez#
66273c49e7Santirez# When protected mode is on and if:
67273c49e7Santirez#
68273c49e7Santirez# 1) The server is not binding explicitly to a set of addresses using the
69273c49e7Santirez#    "bind" directive.
70273c49e7Santirez# 2) No password is configured.
71273c49e7Santirez#
72273c49e7Santirez# The server only accepts connections from clients connecting from the
73273c49e7Santirez# IPv4 and IPv6 loopback addresses 127.0.0.1 and ::1, and from Unix domain
74273c49e7Santirez# sockets.
75273c49e7Santirez#
76273c49e7Santirez# By default protected mode is enabled. You should disable it only if
77273c49e7Santirez# you are sure you want clients from other hosts to connect to Redis
78273c49e7Santirez# even if no authentication is configured, nor a specific set of interfaces
79273c49e7Santirez# are explicitly listed using the "bind" directive.
80273c49e7Santirezprotected-mode yes
81273c49e7Santirez
82066d7a29SItamar Haber# Accept connections on the specified port, default is 6379 (IANA #815344).
8368d6345dSantirez# If port 0 is specified Redis will not listen on a TCP socket.
84ed9b544eSantirezport 6379
85ed9b544eSantirez
86e40d3e28Santirez# TCP listen() backlog.
87e40d3e28Santirez#
88e40d3e28Santirez# In high requests-per-second environments you need an high backlog in order
89e40d3e28Santirez# to avoid slow clients connections issues. Note that the Linux kernel
90e40d3e28Santirez# will silently truncate it to the value of /proc/sys/net/core/somaxconn so
91e40d3e28Santirez# make sure to raise both the value of somaxconn and tcp_max_syn_backlog
92e40d3e28Santirez# in order to get the desired effect.
937be946fdSantireztcp-backlog 511
94d76aa96dSNenad Merdanovic
9510246642Santirez# Unix socket.
96ed9b544eSantirez#
9774da4a57Santirez# Specify the path for the Unix socket that will be used to listen for
985d10923fSPieter Noordhuis# incoming connections. There is no default, so Redis will not listen
995d10923fSPieter Noordhuis# on a unix socket when not specified.
100a5639e7dSPieter Noordhuis#
1015d10923fSPieter Noordhuis# unixsocket /tmp/redis.sock
10267c4fbedSEdgars Irmejs# unixsocketperm 700
103a5639e7dSPieter Noordhuis
1040150db36SAman Gupta# Close the connection after a client is idle for N seconds (0 to disable)
105aba4adb7Santireztimeout 0
106ed9b544eSantirez
10798b1a852Santirez# TCP keepalive.
10898b1a852Santirez#
10993ae95deSantirez# If non-zero, use SO_KEEPALIVE to send TCP ACKs to clients in absence
11093ae95deSantirez# of communication. This is useful for two reasons:
11198b1a852Santirez#
11293ae95deSantirez# 1) Detect dead peers.
11393ae95deSantirez# 2) Take the connection alive from the point of view of network
11493ae95deSantirez#    equipment in the middle.
11593ae95deSantirez#
11693ae95deSantirez# On Linux, the specified value (in seconds) is the period used to send ACKs.
11793ae95deSantirez# Note that to close the connection the double of the time is needed.
11893ae95deSantirez# On other kernels the period depends on the kernel configuration.
11993ae95deSantirez#
12040cfe131Santirez# A reasonable value for this option is 300 seconds, which is the new
12140cfe131Santirez# Redis default starting with Redis 3.2.1.
12240cfe131Santireztcp-keepalive 300
12398b1a852Santirez
12410246642Santirez################################# GENERAL #####################################
12510246642Santirez
12610246642Santirez# By default Redis does not run as a daemon. Use 'yes' if you need it.
12710246642Santirez# Note that Redis will write a pid file in /var/run/redis.pid when daemonized.
12810246642Santirezdaemonize no
12910246642Santirez
13010246642Santirez# If you run Redis from upstart or systemd, Redis can interact with your
13110246642Santirez# supervision tree. Options:
13210246642Santirez#   supervised no      - no supervision interaction
13310246642Santirez#   supervised upstart - signal upstart by putting Redis into SIGSTOP mode
13410246642Santirez#   supervised systemd - signal systemd by writing READY=1 to $NOTIFY_SOCKET
13510246642Santirez#   supervised auto    - detect upstart or systemd method based on
13610246642Santirez#                        UPSTART_JOB or NOTIFY_SOCKET environment variables
13710246642Santirez# Note: these supervision methods only signal "process is ready."
13810246642Santirez#       They do not enable continuous liveness pings back to your supervisor.
13910246642Santirezsupervised no
14010246642Santirez
1411a93501fSantirez# If a pid file is specified, Redis writes it where specified at startup
1421a93501fSantirez# and removes it at exit.
1431a93501fSantirez#
1441a93501fSantirez# When the server runs non daemonized, no pid file is created if none is
1451a93501fSantirez# specified in the configuration. When the server is daemonized, the pid file
1461a93501fSantirez# is used even if not specified, defaulting to "/var/run/redis.pid".
1471a93501fSantirez#
1481a93501fSantirez# Creating a pid file is best effort: if Redis is not able to create it
1491a93501fSantirez# nothing bad happens, the server will start and run normally.
1506937f596Sbogdanvlvivpidfile /var/run/redis_6379.pid
15110246642Santirez
15281144645SDavid Celis# Specify the server verbosity level.
15381144645SDavid Celis# This can be one of:
154ed9b544eSantirez# debug (a lot of information, useful for development/testing)
15538aba9a1Santirez# verbose (many rarely useful info, but not a mess like the debug level)
156ed9b544eSantirez# notice (moderately verbose, what you want in production probably)
157ed9b544eSantirez# warning (only very important / critical messages are logged)
158c6f9ee88Santirezloglevel notice
159ed9b544eSantirez
16074da4a57Santirez# Specify the log file name. Also the empty string can be used to force
161029245feSantirez# Redis to log on the standard output. Note that if you use standard
162ed9b544eSantirez# output for logging but daemonize, logs will be sent to /dev/null
163310dbba0Santirezlogfile ""
164ed9b544eSantirez
165e1a586eeSJonah H. Harris# To enable logging to the system logger, just set 'syslog-enabled' to yes,
166e1a586eeSJonah H. Harris# and optionally update the other syslog parameters to suit your needs.
167e1a586eeSJonah H. Harris# syslog-enabled no
168e1a586eeSJonah H. Harris
169e1a586eeSJonah H. Harris# Specify the syslog identity.
170e1a586eeSJonah H. Harris# syslog-ident redis
171e1a586eeSJonah H. Harris
172e1a586eeSJonah H. Harris# Specify the syslog facility. Must be USER or between LOCAL0-LOCAL7.
173e1a586eeSJonah H. Harris# syslog-facility local0
174e1a586eeSJonah H. Harris
175b8b553c8Santirez# Set the number of databases. The default database is DB 0, you can select
176b8b553c8Santirez# a different one on a per-connection basis using SELECT <dbid> where
177b8b553c8Santirez# dbid is a number between 0 and 'databases'-1
178ed9b544eSantirezdatabases 16
179ed9b544eSantirez
1807da423f7SYubao Liu################################ SNAPSHOTTING  ################################
181121f70cfSantirez#
182121f70cfSantirez# Save the DB on disk:
183121f70cfSantirez#
184121f70cfSantirez#   save <seconds> <changes>
185121f70cfSantirez#
186121f70cfSantirez#   Will save the DB if both the given number of seconds and the given
187121f70cfSantirez#   number of write operations against the DB occurred.
188121f70cfSantirez#
189121f70cfSantirez#   In the example below the behaviour will be to save:
190121f70cfSantirez#   after 900 sec (15 min) if at least 1 key changed
191121f70cfSantirez#   after 300 sec (5 min) if at least 10 keys changed
192121f70cfSantirez#   after 60 sec if at least 10000 keys changed
193e7546c63Santirez#
194df484c7aSManuel Meurer#   Note: you can disable saving completely by commenting out all "save" lines.
1954aac3ff2Santirez#
1964aac3ff2Santirez#   It is also possible to remove all the previously configured save
1974aac3ff2Santirez#   points by adding a save directive with a single empty string argument
1984aac3ff2Santirez#   like in the following example:
1994aac3ff2Santirez#
2004aac3ff2Santirez#   save ""
201e7546c63Santirez
20238aba9a1Santirezsave 900 1
20338aba9a1Santirezsave 300 10
20438aba9a1Santirezsave 60 10000
205121f70cfSantirez
2064d3bbf35Santirez# By default Redis will stop accepting writes if RDB snapshots are enabled
2074d3bbf35Santirez# (at least one save point) and the latest background save failed.
20874da4a57Santirez# This will make the user aware (in a hard way) that data is not persisting
2094d3bbf35Santirez# on disk properly, otherwise chances are that no one will notice and some
21074da4a57Santirez# disaster will happen.
2114d3bbf35Santirez#
2124d3bbf35Santirez# If the background saving process will start working again Redis will
2134d3bbf35Santirez# automatically allow writes again.
2144d3bbf35Santirez#
2154d3bbf35Santirez# However if you have setup your proper monitoring of the Redis server
2164d3bbf35Santirez# and persistence, you may want to disable this feature so that Redis will
21774431b80SAnurag Ramdasan# continue to work as usual even if there are problems with disk,
2184d3bbf35Santirez# permissions, and so forth.
2194d3bbf35Santirezstop-writes-on-bgsave-error yes
2204d3bbf35Santirez
221121f70cfSantirez# Compress string objects using LZF when dump .rdb databases?
222b0553789Santirez# For default that's set to 'yes' as it's almost always a win.
223b0553789Santirez# If you want to save some CPU in the saving child set it to 'no' but
224b0553789Santirez# the dataset will likely be bigger if you have compressible values or keys.
225b0553789Santirezrdbcompression yes
226121f70cfSantirez
22781144645SDavid Celis# Since version 5 of RDB a CRC64 checksum is placed at the end of the file.
22884bcd3aaSantirez# This makes the format more resistant to corruption but there is a performance
22984bcd3aaSantirez# hit to pay (around 10%) when saving and loading RDB files, so you can disable it
23084bcd3aaSantirez# for maximum performances.
23184bcd3aaSantirez#
23284bcd3aaSantirez# RDB files created with checksum disabled have a checksum of zero that will
23384bcd3aaSantirez# tell the loading code to skip the check.
23484bcd3aaSantirezrdbchecksum yes
23584bcd3aaSantirez
236121f70cfSantirez# The filename where to dump the DB
237121f70cfSantirezdbfilename dump.rdb
238121f70cfSantirez
239029245feSantirez# The working directory.
240029245feSantirez#
241029245feSantirez# The DB will be written inside this directory, with the filename specified
242029245feSantirez# above using the 'dbfilename' configuration directive.
243029245feSantirez#
24481144645SDavid Celis# The Append Only File will also be created inside this directory.
245029245feSantirez#
246029245feSantirez# Note that you must specify a directory here, not a file name.
247121f70cfSantirezdir ./
248121f70cfSantirez
249ed9b544eSantirez################################# REPLICATION #################################
250ed9b544eSantirez
251ed9b544eSantirez# Master-Slave replication. Use slaveof to make a Redis instance a copy of
25249c817c2Santirez# another Redis server. A few things to understand ASAP about Redis replication.
25349c817c2Santirez#
25449c817c2Santirez# 1) Redis replication is asynchronous, but you can configure a master to
25549c817c2Santirez#    stop accepting writes if it appears to be not connected with at least
25649c817c2Santirez#    a given number of slaves.
25749c817c2Santirez# 2) Redis slaves are able to perform a partial resynchronization with the
25849c817c2Santirez#    master if the replication link is lost for a relatively small amount of
25949c817c2Santirez#    time. You may want to configure the replication backlog size (see the next
26049c817c2Santirez#    sections of this file) with a sensible value depending on your needs.
26149c817c2Santirez# 3) Replication is automatic and does not need user intervention. After a
26249c817c2Santirez#    network partition slaves automatically try to reconnect to masters
26349c817c2Santirez#    and resynchronize with them.
2643f477979Santirez#
265ed9b544eSantirez# slaveof <masterip> <masterport>
266ed9b544eSantirez
2673f477979Santirez# If the master is password protected (using the "requirepass" configuration
2683f477979Santirez# directive below) it is possible to tell the slave to authenticate before
2693f477979Santirez# starting the replication synchronization process, otherwise the master will
2703f477979Santirez# refuse the slave request.
2713f477979Santirez#
2723f477979Santirez# masterauth <master-password>
2733f477979Santirez
27481144645SDavid Celis# When a slave loses its connection with the master, or when the replication
2754ebfc455Santirez# is still in progress, the slave can act in two different ways:
2764ebfc455Santirez#
2774ebfc455Santirez# 1) if slave-serve-stale-data is set to 'yes' (the default) the slave will
27892a157eaSJérémy Bethmont#    still reply to client requests, possibly with out of date data, or the
2794ebfc455Santirez#    data set may just be empty if this is the first synchronization.
2804ebfc455Santirez#
281d7838604SStam He# 2) if slave-serve-stale-data is set to 'no' the slave will reply with
2824ebfc455Santirez#    an error "SYNC with master in progress" to all the kind of commands
2834ebfc455Santirez#    but to INFO and SLAVEOF.
2844ebfc455Santirez#
2854ebfc455Santirezslave-serve-stale-data yes
2864ebfc455Santirez
287f3fd419fSantirez# You can configure a slave instance to accept writes or not. Writing against
288f3fd419fSantirez# a slave instance may be useful to store some ephemeral data (because data
289f3fd419fSantirez# written on a slave will be easily deleted after resync with the master) but
290ba864e09Santirez# may also cause problems if clients are writing to it because of a
291ba864e09Santirez# misconfiguration.
292f3fd419fSantirez#
293f3fd419fSantirez# Since Redis 2.6 by default slaves are read-only.
294ba864e09Santirez#
295ba864e09Santirez# Note: read only slaves are not designed to be exposed to untrusted clients
296ba864e09Santirez# on the internet. It's just a protection layer against misuse of the instance.
297ba864e09Santirez# Still a read only slave exports by default all the administrative commands
298fb6b9b14SAnurag Ramdasan# such as CONFIG, DEBUG, and so forth. To a limited extent you can improve
299ba864e09Santirez# security of read only slaves using 'rename-command' to shadow all the
300ba864e09Santirez# administrative / dangerous commands.
301f3fd419fSantirezslave-read-only yes
302f3fd419fSantirez
30318de5395Santirez# Replication SYNC strategy: disk or socket.
30418de5395Santirez#
305e07dd8b3Santirez# -------------------------------------------------------
306e07dd8b3Santirez# WARNING: DISKLESS REPLICATION IS EXPERIMENTAL CURRENTLY
307e07dd8b3Santirez# -------------------------------------------------------
308e07dd8b3Santirez#
30918de5395Santirez# New slaves and reconnecting slaves that are not able to continue the replication
31018de5395Santirez# process just receiving differences, need to do what is called a "full
31118de5395Santirez# synchronization". An RDB file is transmitted from the master to the slaves.
31218de5395Santirez# The transmission can happen in two different ways:
31318de5395Santirez#
31418de5395Santirez# 1) Disk-backed: The Redis master creates a new process that writes the RDB
31518de5395Santirez#                 file on disk. Later the file is transferred by the parent
31618de5395Santirez#                 process to the slaves incrementally.
31718de5395Santirez# 2) Diskless: The Redis master creates a new process that directly writes the
31818de5395Santirez#              RDB file to slave sockets, without touching the disk at all.
31918de5395Santirez#
32018de5395Santirez# With disk-backed replication, while the RDB file is generated, more slaves
32118de5395Santirez# can be queued and served with the RDB file as soon as the current child producing
32218de5395Santirez# the RDB file finishes its work. With diskless replication instead once
32318de5395Santirez# the transfer starts, new slaves arriving will be queued and a new transfer
32418de5395Santirez# will start when the current one terminates.
32518de5395Santirez#
32618de5395Santirez# When diskless replication is used, the master waits a configurable amount of
32718de5395Santirez# time (in seconds) before starting the transfer in the hope that multiple slaves
32818de5395Santirez# will arrive and the transfer can be parallelized.
32918de5395Santirez#
33018de5395Santirez# With slow disks and fast (large bandwidth) networks, diskless replication
33118de5395Santirez# works better.
33218de5395Santirezrepl-diskless-sync no
33318de5395Santirez
3343b9a9798Santirez# When diskless replication is enabled, it is possible to configure the delay
3356df9001dSMariano Pérez Rodríguez# the server waits in order to spawn the child that transfers the RDB via socket
3363b9a9798Santirez# to the slaves.
3373b9a9798Santirez#
3383b9a9798Santirez# This is important since once the transfer starts, it is not possible to serve
3393b9a9798Santirez# new slaves arriving, that will be queued for the next RDB transfer, so the server
3403b9a9798Santirez# waits a delay in order to let more slaves arrive.
3413b9a9798Santirez#
3423b9a9798Santirez# The delay is specified in seconds, and by default is 5 seconds. To disable
3433b9a9798Santirez# it entirely just set it to 0 seconds and the transfer will start ASAP.
3443b9a9798Santirezrepl-diskless-sync-delay 5
3453b9a9798Santirez
3468996bf77Santirez# Slaves send PINGs to server in a predefined interval. It's possible to change
3478996bf77Santirez# this interval with the repl_ping_slave_period option. The default value is 10
3488996bf77Santirez# seconds.
3498996bf77Santirez#
350f15e33a8SHerbert G. Fischer# repl-ping-slave-period 10
3518996bf77Santirez
352c9b55a29Santirez# The following option sets the replication timeout for:
353c9b55a29Santirez#
354c9b55a29Santirez# 1) Bulk transfer I/O during SYNC, from the point of view of slave.
355c9b55a29Santirez# 2) Master timeout from the point of view of slaves (data, pings).
356c9b55a29Santirez# 3) Slave timeout from the point of view of masters (REPLCONF ACK pings).
3578996bf77Santirez#
35885ccd576Santirez# It is important to make sure that this value is greater than the value
35985ccd576Santirez# specified for repl-ping-slave-period otherwise a timeout will be detected
36085ccd576Santirez# every time there is low traffic between the master and the slave.
36185ccd576Santirez#
362f15e33a8SHerbert G. Fischer# repl-timeout 60
3638996bf77Santirez
364b70b459bSantirez# Disable TCP_NODELAY on the slave socket after SYNC?
365b70b459bSantirez#
366b70b459bSantirez# If you select "yes" Redis will use a smaller number of TCP packets and
367b70b459bSantirez# less bandwidth to send data to slaves. But this can add a delay for
368b70b459bSantirez# the data to appear on the slave side, up to 40 milliseconds with
369b70b459bSantirez# Linux kernels using a default configuration.
370b70b459bSantirez#
371b70b459bSantirez# If you select "no" the delay for data to appear on the slave side will
372b70b459bSantirez# be reduced but more bandwidth will be used for replication.
373b70b459bSantirez#
374b70b459bSantirez# By default we optimize for low latency, but in very high traffic conditions
375b70b459bSantirez# or when the master and slaves are many hops away, turning this to "yes" may
376b70b459bSantirez# be a good idea.
377b70b459bSantirezrepl-disable-tcp-nodelay no
378b70b459bSantirez
37907888202Santirez# Set the replication backlog size. The backlog is a buffer that accumulates
38007888202Santirez# slave data when slaves are disconnected for some time, so that when a slave
38107888202Santirez# wants to reconnect again, often a full resync is not needed, but a partial
38207888202Santirez# resync is enough, just passing the portion of data the slave missed while
38307888202Santirez# disconnected.
38407888202Santirez#
385aa628446SJan-Erik Rediger# The bigger the replication backlog, the longer the time the slave can be
38607888202Santirez# disconnected and later be able to perform a partial resynchronization.
38707888202Santirez#
38807888202Santirez# The backlog is only allocated once there is at least a slave connected.
38907888202Santirez#
39007888202Santirez# repl-backlog-size 1mb
39107888202Santirez
39207888202Santirez# After a master has no longer connected slaves for some time, the backlog
39307888202Santirez# will be freed. The following option configures the amount of seconds that
39407888202Santirez# need to elapse, starting from the time the last slave disconnected, for
39507888202Santirez# the backlog buffer to be freed.
39607888202Santirez#
39707888202Santirez# A value of 0 means to never release the backlog.
39807888202Santirez#
39907888202Santirez# repl-backlog-ttl 3600
40007888202Santirez
401712656e8Santirez# The slave priority is an integer number published by Redis in the INFO output.
402712656e8Santirez# It is used by Redis Sentinel in order to select a slave to promote into a
403712656e8Santirez# master if the master is no longer working correctly.
404712656e8Santirez#
405712656e8Santirez# A slave with a low priority number is considered better for promotion, so
406712656e8Santirez# for instance if there are three slaves with priority 10, 100, 25 Sentinel will
40774da4a57Santirez# pick the one with priority 10, that is the lowest.
408712656e8Santirez#
409712656e8Santirez# However a special priority of 0 marks the slave as not able to perform the
410712656e8Santirez# role of master, so a slave with priority of 0 will never be selected by
411712656e8Santirez# Redis Sentinel for promotion.
412712656e8Santirez#
413712656e8Santirez# By default the priority is 100.
414712656e8Santirezslave-priority 100
415712656e8Santirez
416cbdb2153Santirez# It is possible for a master to stop accepting writes if there are less than
417cbdb2153Santirez# N slaves connected, having a lag less or equal than M seconds.
418cbdb2153Santirez#
419cbdb2153Santirez# The N slaves need to be in "online" state.
420cbdb2153Santirez#
421cbdb2153Santirez# The lag in seconds, that must be <= the specified value, is calculated from
422cbdb2153Santirez# the last ping received from the slave, that is usually sent every second.
423cbdb2153Santirez#
424f62f00e0SBen# This option does not GUARANTEE that N replicas will accept the write, but
425cbdb2153Santirez# will limit the window of exposure for lost writes in case not enough slaves
426cbdb2153Santirez# are available, to the specified number of seconds.
427cbdb2153Santirez#
428cbdb2153Santirez# For example to require at least 3 slaves with a lag <= 10 seconds use:
429cbdb2153Santirez#
430ed599d3aSantirez# min-slaves-to-write 3
431ed599d3aSantirez# min-slaves-max-lag 10
432ed599d3aSantirez#
433ed599d3aSantirez# Setting one or the other to 0 disables the feature.
434ed599d3aSantirez#
435ed599d3aSantirez# By default min-slaves-to-write is set to 0 (feature disabled) and
436ed599d3aSantirez# min-slaves-max-lag is set to 10.
437cbdb2153Santirez
438*0a45fbc3Santirez# A Redis master is able to list the address and port of the attached
439*0a45fbc3Santirez# slaves in different ways. For example the "INFO replication" section
440*0a45fbc3Santirez# offers this information, which is used, among other tools, by
441*0a45fbc3Santirez# Redis Sentinel in order to discover slave instances.
442*0a45fbc3Santirez# Another place where this info is available is in the output of the
443*0a45fbc3Santirez# "ROLE" command of a masteer.
444*0a45fbc3Santirez#
445*0a45fbc3Santirez# The listed IP and address normally reported by a slave is obtained
446*0a45fbc3Santirez# in the following way:
447*0a45fbc3Santirez#
448*0a45fbc3Santirez#   IP: The address is auto detected by checking the peer address
449*0a45fbc3Santirez#   of the socket used by the slave to connect with the master.
450*0a45fbc3Santirez#
451*0a45fbc3Santirez#   Port: The port is communicated by the slave during the replication
452*0a45fbc3Santirez#   handshake, and is normally the port that the slave is using to
453*0a45fbc3Santirez#   list for connections.
454*0a45fbc3Santirez#
455*0a45fbc3Santirez# However when port forwarding or Network Address Translation (NAT) is
456*0a45fbc3Santirez# used, the slave may be actually reachable via different IP and port
457*0a45fbc3Santirez# pairs. The following two options can be used by a slave in order to
458*0a45fbc3Santirez# report to its master a specific set of IP and port, so that both INFO
459*0a45fbc3Santirez# and ROLE will report those values.
460*0a45fbc3Santirez#
461*0a45fbc3Santirez# There is no need to use both the options if you need to override just
462*0a45fbc3Santirez# the port or the IP address.
463*0a45fbc3Santirez#
464*0a45fbc3Santirez# slave-announce-ip 5.5.5.5
465*0a45fbc3Santirez# slave-announce-port 1234
466*0a45fbc3Santirez
467f2aa84bdSantirez################################## SECURITY ###################################
468f2aa84bdSantirez
469f2aa84bdSantirez# Require clients to issue AUTH <PASSWORD> before processing any other
470f2aa84bdSantirez# commands.  This might be useful in environments in which you do not trust
471f2aa84bdSantirez# others with access to the host running redis-server.
472f2aa84bdSantirez#
473f2aa84bdSantirez# This should stay commented out for backward compatibility and because most
474f2aa84bdSantirez# people do not need auth (e.g. they run their own servers).
4753f477979Santirez#
4761b677732Santirez# Warning: since Redis is pretty fast an outside user can try up to
4771b677732Santirez# 150k passwords per second against a good box. This means that you should
4781b677732Santirez# use a very strong password otherwise it will be very easy to break.
4791b677732Santirez#
480f2aa84bdSantirez# requirepass foobared
481f2aa84bdSantirez
4828d3e063aSantirez# Command renaming.
4838d3e063aSantirez#
48457c0cf8bSKashif Rasul# It is possible to change the name of dangerous commands in a shared
4858d3e063aSantirez# environment. For instance the CONFIG command may be renamed into something
48681144645SDavid Celis# hard to guess so that it will still be available for internal-use tools
48781144645SDavid Celis# but not available for general clients.
4888d3e063aSantirez#
4898d3e063aSantirez# Example:
4908d3e063aSantirez#
4918d3e063aSantirez# rename-command CONFIG b840fc02d524045429941cc15f59e41cb7be6c52
4928d3e063aSantirez#
49381144645SDavid Celis# It is also possible to completely kill a command by renaming it into
4948d3e063aSantirez# an empty string:
4958d3e063aSantirez#
4968d3e063aSantirez# rename-command CONFIG ""
4974d629126Santirez#
4984d629126Santirez# Please note that changing the name of commands that are logged into the
4994d629126Santirez# AOF file or transmitted to slaves may cause problems.
5008d3e063aSantirez
501285add55Santirez################################### LIMITS ####################################
502285add55Santirez
50358732c23Santirez# Set the max number of connected clients at the same time. By default
50458732c23Santirez# this limit is set to 10000 clients, however if the Redis server is not
5059d09ce39Sguiquanz# able to configure the process file limit to allow for the specified limit
50658732c23Santirez# the max number of allowed clients is set to the current file limit
50758732c23Santirez# minus 32 (as Redis reserves a few file descriptors for internal uses).
50858732c23Santirez#
509285add55Santirez# Once the limit is reached Redis will close all the new connections sending
510285add55Santirez# an error 'max number of clients reached'.
5113f477979Santirez#
51258732c23Santirez# maxclients 10000
513285add55Santirez
5143fd78bcdSantirez# Don't use more memory than the specified amount of bytes.
515cebb7b92Santirez# When the memory limit is reached Redis will try to remove keys
5168534a290Santirez# according to the eviction policy selected (see maxmemory-policy).
5173fd78bcdSantirez#
518cebb7b92Santirez# If Redis can't remove keys according to the policy, or if the policy is
519cebb7b92Santirez# set to 'noeviction', Redis will start to reply with errors to commands
520cebb7b92Santirez# that would use more memory, like SET, LPUSH, and so on, and will continue
521cebb7b92Santirez# to reply to read-only commands like GET.
522144d479bSantirez#
523cebb7b92Santirez# This option is usually useful when using Redis as an LRU cache, or to set
52474da4a57Santirez# a hard memory limit for an instance (using the 'noeviction' policy).
525cebb7b92Santirez#
526cebb7b92Santirez# WARNING: If you have slaves attached to an instance with maxmemory on,
527cebb7b92Santirez# the size of the output buffers needed to feed the slaves are subtracted
528cebb7b92Santirez# from the used memory count, so that network problems / resyncs will
529cebb7b92Santirez# not trigger a loop where keys are evicted, and in turn the output
530cebb7b92Santirez# buffer of slaves is full with DELs of keys evicted triggering the deletion
531cebb7b92Santirez# of more keys, and so forth until the database is completely emptied.
5323f477979Santirez#
533f9ef912cSantirez# In short... if you have slaves attached it is suggested that you set a lower
534f9ef912cSantirez# limit for maxmemory so that there is some free RAM on the system for slave
535f9ef912cSantirez# output buffers (but this is not needed if the policy is 'noeviction').
536f9ef912cSantirez#
5373fd78bcdSantirez# maxmemory <bytes>
5383fd78bcdSantirez
539165346caSantirez# MAXMEMORY POLICY: how Redis will select what to remove when maxmemory
54081144645SDavid Celis# is reached. You can select among five behaviors:
541165346caSantirez#
542165346caSantirez# volatile-lru -> remove the key with an expire set using an LRU algorithm
543f62f00e0SBen# allkeys-lru -> remove any key according to the LRU algorithm
544165346caSantirez# volatile-random -> remove a random key with an expire set
54596e9f8d5Squiver# allkeys-random -> remove a random key, any key
546165346caSantirez# volatile-ttl -> remove the key with the nearest expire time (minor TTL)
5475402c426Santirez# noeviction -> don't expire at all, just return an error on write operations
5485402c426Santirez#
54981144645SDavid Celis# Note: with any of the above policies, Redis will return an error on write
550f62f00e0SBen#       operations, when there are no suitable keys for eviction.
5515402c426Santirez#
552be006163SMiguel Parramon#       At the date of writing these commands are: set setnx setex append
5535402c426Santirez#       incr decr rpush lpush rpushx lpushx linsert lset rpoplpush sadd
5545402c426Santirez#       sinter sinterstore sunion sunionstore sdiff sdiffstore zadd zincrby
5555402c426Santirez#       zunionstore zinterstore hset hsetnx hmset hincrby incrby decrby
5565402c426Santirez#       getset mset msetnx exec sort
5575402c426Santirez#
5585402c426Santirez# The default is:
559165346caSantirez#
5605fa3248bSantirez# maxmemory-policy noeviction
561165346caSantirez
562165346caSantirez# LRU and minimal TTL algorithms are not precise algorithms but approximated
563f4da796cSantirez# algorithms (in order to save memory), so you can tune it for speed or
564f4da796cSantirez# accuracy. For default Redis will check five keys and pick the one that was
565f4da796cSantirez# used less recently, you can change the sample size using the following
566f4da796cSantirez# configuration directive.
567165346caSantirez#
568f4da796cSantirez# The default of 5 produces good enough results. 10 Approximates very closely
569f4da796cSantirez# true LRU but costs a bit more CPU. 3 is very fast but not very accurate.
570f4da796cSantirez#
571f4da796cSantirez# maxmemory-samples 5
572165346caSantirez
57344b38ef4Santirez############################## APPEND ONLY MODE ###############################
57444b38ef4Santirez
57560e2e5b5Santirez# By default Redis asynchronously dumps the dataset on disk. This mode is
57660e2e5b5Santirez# good enough in many applications, but an issue with the Redis process or
57760e2e5b5Santirez# a power outage may result into a few minutes of writes lost (depending on
57860e2e5b5Santirez# the configured save points).
57944b38ef4Santirez#
58060e2e5b5Santirez# The Append Only File is an alternative persistence mode that provides
58160e2e5b5Santirez# much better durability. For instance using the default data fsync policy
58260e2e5b5Santirez# (see later in the config file) Redis can lose just one second of writes in a
58360e2e5b5Santirez# dramatic event like a server power outage, or a single write if something
58460e2e5b5Santirez# wrong with the Redis process itself happens, but the operating system is
58560e2e5b5Santirez# still running correctly.
5860154acdcSantirez#
58760e2e5b5Santirez# AOF and RDB persistence can be enabled at the same time without problems.
58860e2e5b5Santirez# If the AOF is enabled on startup Redis will load the AOF, that is the file
58960e2e5b5Santirez# with the better durability guarantees.
59060e2e5b5Santirez#
59160e2e5b5Santirez# Please check http://redis.io/topics/persistence for more information.
59244b38ef4Santirez
5934e141d5aSantirezappendonly no
59444b38ef4Santirez
595f3b52411SPieter Noordhuis# The name of the append only file (default: "appendonly.aof")
5966d184e02Santirez
5976d184e02Santirezappendfilename "appendonly.aof"
598f3b52411SPieter Noordhuis
5994e141d5aSantirez# The fsync() call tells the Operating System to actually write data on disk
600f62f00e0SBen# instead of waiting for more data in the output buffer. Some OS will really flush
60148f0308aSantirez# data on disk, some other OS will just try to do it ASAP.
60248f0308aSantirez#
60348f0308aSantirez# Redis supports three different modes:
60448f0308aSantirez#
60548f0308aSantirez# no: don't fsync, just let the OS flush the data when it wants. Faster.
60648f0308aSantirez# always: fsync after every write to the append only log. Slow, Safest.
60760e2e5b5Santirez# everysec: fsync only one time every second. Compromise.
60848f0308aSantirez#
60981144645SDavid Celis# The default is "everysec", as that's usually the right compromise between
6106766f45eSantirez# speed and data safety. It's up to you to understand if you can relax this to
611ce6628daSdiegok# "no" that will let the operating system flush the output buffer when
6126766f45eSantirez# it wants, for better performances (but if you can live with the idea of
6136766f45eSantirez# some data loss consider the default persistence mode that's snapshotting),
6146766f45eSantirez# or on the contrary, use "always" that's very slow but a bit safer than
6156766f45eSantirez# everysec.
6166766f45eSantirez#
61760e2e5b5Santirez# More details please check the following article:
61860e2e5b5Santirez# http://antirez.com/post/redis-persistence-demystified.html
61960e2e5b5Santirez#
6206766f45eSantirez# If unsure, use "everysec".
62148f0308aSantirez
6226766f45eSantirez# appendfsync always
6236766f45eSantirezappendfsync everysec
6244e141d5aSantirez# appendfsync no
62548f0308aSantirez
626d5d23dabSantirez# When the AOF fsync policy is set to always or everysec, and a background
627d5d23dabSantirez# saving process (a background save or AOF log background rewriting) is
628d5d23dabSantirez# performing a lot of I/O against the disk, in some Linux configurations
629d5d23dabSantirez# Redis may block too long on the fsync() call. Note that there is no fix for
630d5d23dabSantirez# this currently, as even performing fsync in a different thread will block
631d5d23dabSantirez# our synchronous write(2) call.
632d5d23dabSantirez#
633d5d23dabSantirez# In order to mitigate this problem it's possible to use the following option
634d5d23dabSantirez# that will prevent fsync() from being called in the main process while a
635d5d23dabSantirez# BGSAVE or BGREWRITEAOF is in progress.
636d5d23dabSantirez#
63781144645SDavid Celis# This means that while another child is saving, the durability of Redis is
63881144645SDavid Celis# the same as "appendfsync none". In practical terms, this means that it is
63981144645SDavid Celis# possible to lose up to 30 seconds of log in the worst scenario (with the
640d5d23dabSantirez# default Linux settings).
641d5d23dabSantirez#
642d5d23dabSantirez# If you have latency problems turn this to "yes". Otherwise leave it as
643d5d23dabSantirez# "no" that is the safest pick from the point of view of durability.
6446d184e02Santirez
645d5d23dabSantirezno-appendfsync-on-rewrite no
646d5d23dabSantirez
647b333e239Santirez# Automatic rewrite of the append only file.
648b333e239Santirez# Redis is able to automatically rewrite the log file implicitly calling
64981144645SDavid Celis# BGREWRITEAOF when the AOF log size grows by the specified percentage.
650b333e239Santirez#
651b333e239Santirez# This is how it works: Redis remembers the size of the AOF file after the
65281144645SDavid Celis# latest rewrite (if no rewrite has happened since the restart, the size of
653b333e239Santirez# the AOF at startup is used).
654b333e239Santirez#
655b333e239Santirez# This base size is compared to the current size. If the current size is
656b333e239Santirez# bigger than the specified percentage, the rewrite is triggered. Also
657b333e239Santirez# you need to specify a minimal size for the AOF file to be rewritten, this
658b333e239Santirez# is useful to avoid rewriting the AOF file even if the percentage increase
659b333e239Santirez# is reached but it is still pretty small.
660b333e239Santirez#
66157c0cf8bSKashif Rasul# Specify a percentage of zero in order to disable the automatic AOF
662b333e239Santirez# rewrite feature.
663b333e239Santirez
664b333e239Santirezauto-aof-rewrite-percentage 100
665b333e239Santirezauto-aof-rewrite-min-size 64mb
666b333e239Santirez
66731f79a46Santirez# An AOF file may be found to be truncated at the end during the Redis
66831f79a46Santirez# startup process, when the AOF data gets loaded back into memory.
66931f79a46Santirez# This may happen when the system where Redis is running
67031f79a46Santirez# crashes, especially when an ext4 filesystem is mounted without the
67131f79a46Santirez# data=ordered option (however this can't happen when Redis itself
67231f79a46Santirez# crashes or aborts but the operating system still works correctly).
67331f79a46Santirez#
67431f79a46Santirez# Redis can either exit with an error when this happens, or load as much
67531f79a46Santirez# data as possible (the default now) and start if the AOF file is found
67631f79a46Santirez# to be truncated at the end. The following option controls this behavior.
67731f79a46Santirez#
67831f79a46Santirez# If aof-load-truncated is set to yes, a truncated AOF file is loaded and
67931f79a46Santirez# the Redis server starts emitting a log to inform the user of the event.
68031f79a46Santirez# Otherwise if the option is set to no, the server aborts with an error
68131f79a46Santirez# and refuses to start. When the option is set to no, the user requires
68231f79a46Santirez# to fix the AOF file using the "redis-check-aof" utility before to restart
68331f79a46Santirez# the server.
68431f79a46Santirez#
68531f79a46Santirez# Note that if the AOF file will be found to be corrupted in the middle
68631f79a46Santirez# the server will still exit with an error. This option only applies when
68731f79a46Santirez# Redis will try to read more data from the AOF file but not enough bytes
68831f79a46Santirez# will be found.
68931f79a46Santirezaof-load-truncated yes
69031f79a46Santirez
691eeffcf38Santirez################################ LUA SCRIPTING  ###############################
692eeffcf38Santirez
693eeffcf38Santirez# Max execution time of a Lua script in milliseconds.
694115e3ff3Santirez#
695115e3ff3Santirez# If the maximum execution time is reached Redis will log that a script is
69657c0cf8bSKashif Rasul# still in execution after the maximum allowed time and will start to
697115e3ff3Santirez# reply to queries with an error.
698115e3ff3Santirez#
699f62f00e0SBen# When a long running script exceeds the maximum execution time only the
7000b14e441Santirez# SCRIPT KILL and SHUTDOWN NOSAVE commands are available. The first can be
7010b14e441Santirez# used to stop a script that did not yet called write commands. The second
702f62f00e0SBen# is the only way to shut down the server in the case a write command was
703f62f00e0SBen# already issued by the script but the user doesn't want to wait for the natural
7040b14e441Santirez# termination of the script.
705115e3ff3Santirez#
706115e3ff3Santirez# Set it to 0 or a negative value for unlimited execution without warnings.
707115e3ff3Santirezlua-time-limit 5000
708eeffcf38Santirez
70907c152a7Santirez################################ REDIS CLUSTER  ###############################
71007c152a7Santirez#
71142357668Santirez# ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
71242357668Santirez# WARNING EXPERIMENTAL: Redis Cluster is considered to be stable code, however
71342357668Santirez# in order to mark it as "mature" we need to wait for a non trivial percentage
71442357668Santirez# of users to deploy it in production.
71542357668Santirez# ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
71642357668Santirez#
71781144645SDavid Celis# Normal Redis instances can't be part of a Redis Cluster; only nodes that are
71807c152a7Santirez# started as cluster nodes can. In order to start a Redis instance as a
71907c152a7Santirez# cluster node enable the cluster support uncommenting the following:
72007c152a7Santirez#
72107c152a7Santirez# cluster-enabled yes
72207c152a7Santirez
72307c152a7Santirez# Every cluster node has a cluster configuration file. This file is not
72407c152a7Santirez# intended to be edited by hand. It is created and updated by Redis nodes.
72507c152a7Santirez# Every Redis Cluster node requires a different cluster configuration file.
726f62f00e0SBen# Make sure that instances running in the same system do not have
72707c152a7Santirez# overlapping cluster configuration file names.
72807c152a7Santirez#
72907c152a7Santirez# cluster-config-file nodes-6379.conf
73007c152a7Santirez
731e5864c73Santirez# Cluster node timeout is the amount of milliseconds a node must be unreachable
73205fa4f40Santirez# for it to be considered in failure state.
733e5864c73Santirez# Most other internal time limits are multiple of the node timeout.
73405fa4f40Santirez#
735e5864c73Santirez# cluster-node-timeout 15000
73605fa4f40Santirez
73739603a7eSantirez# A slave of a failing master will avoid to start a failover if its data
73839603a7eSantirez# looks too old.
73939603a7eSantirez#
74039603a7eSantirez# There is no simple way for a slave to actually have a exact measure of
74139603a7eSantirez# its "data age", so the following two checks are performed:
74239603a7eSantirez#
74339603a7eSantirez# 1) If there are multiple slaves able to failover, they exchange messages
74439603a7eSantirez#    in order to try to give an advantage to the slave with the best
74539603a7eSantirez#    replication offset (more data from the master processed).
74639603a7eSantirez#    Slaves will try to get their rank by offset, and apply to the start
74739603a7eSantirez#    of the failover a delay proportional to their rank.
74839603a7eSantirez#
74939603a7eSantirez# 2) Every single slave computes the time of the last interaction with
75039603a7eSantirez#    its master. This can be the last ping or command received (if the master
75139603a7eSantirez#    is still in the "connected" state), or the time that elapsed since the
75239603a7eSantirez#    disconnection with the master (if the replication link is currently down).
75339603a7eSantirez#    If the last interaction is too old, the slave will not try to failover
75439603a7eSantirez#    at all.
75539603a7eSantirez#
75639603a7eSantirez# The point "2" can be tuned by user. Specifically a slave will not perform
75739603a7eSantirez# the failover if, since the last interaction with the master, the time
75839603a7eSantirez# elapsed is greater than:
75939603a7eSantirez#
76039603a7eSantirez#   (node-timeout * slave-validity-factor) + repl-ping-slave-period
76139603a7eSantirez#
76239603a7eSantirez# So for example if node-timeout is 30 seconds, and the slave-validity-factor
76339603a7eSantirez# is 10, and assuming a default repl-ping-slave-period of 10 seconds, the
76439603a7eSantirez# slave will not try to failover if it was not able to talk with the master
76539603a7eSantirez# for longer than 310 seconds.
76639603a7eSantirez#
76739603a7eSantirez# A large slave-validity-factor may allow slaves with too old data to failover
76839603a7eSantirez# a master, while a too small value may prevent the cluster from being able to
76939603a7eSantirez# elect a slave at all.
77039603a7eSantirez#
77139603a7eSantirez# For maximum availability, it is possible to set the slave-validity-factor
77239603a7eSantirez# to a value of 0, which means, that slaves will always try to failover the
77339603a7eSantirez# master regardless of the last time they interacted with the master.
77439603a7eSantirez# (However they'll always try to apply a delay proportional to their
77539603a7eSantirez# offset rank).
77639603a7eSantirez#
77739603a7eSantirez# Zero is the only value able to guarantee that when all the partitions heal
77839603a7eSantirez# the cluster will always be able to continue.
77939603a7eSantirez#
78039603a7eSantirez# cluster-slave-validity-factor 10
78139603a7eSantirez
782a7d30681Santirez# Cluster slaves are able to migrate to orphaned masters, that are masters
783a7d30681Santirez# that are left without working slaves. This improves the cluster ability
784a7d30681Santirez# to resist to failures as otherwise an orphaned master can't be failed over
785a7d30681Santirez# in case of failure if it has no working slaves.
786a7d30681Santirez#
787a7d30681Santirez# Slaves migrate to orphaned masters only if there are still at least a
788a7d30681Santirez# given number of other working slaves for their old master. This number
789cbfdd13bSantirez# is the "migration barrier". A migration barrier of 1 means that a slave
790a7d30681Santirez# will migrate only if there is at least 1 other working slave for its master
791a7d30681Santirez# and so forth. It usually reflects the number of slaves you want for every
792a7d30681Santirez# master in your cluster.
793a7d30681Santirez#
794a7d30681Santirez# Default is 1 (slaves migrate only if their masters remain with at least
795b8bfbf46Santirez# one slave). To disable migration just set it to a very large value.
796a7d30681Santirez# A value of 0 can be set but is useful only for debugging and dangerous
797a7d30681Santirez# in production.
798a7d30681Santirez#
799a7d30681Santirez# cluster-migration-barrier 1
800a7d30681Santirez
801c89afc8eSantirez# By default Redis Cluster nodes stop accepting queries if they detect there
802c89afc8eSantirez# is at least an hash slot uncovered (no available node is serving it).
803c89afc8eSantirez# This way if the cluster is partially down (for example a range of hash slots
804c89afc8eSantirez# are no longer covered) all the cluster becomes, eventually, unavailable.
805c89afc8eSantirez# It automatically returns available as soon as all the slots are covered again.
806c89afc8eSantirez#
807c89afc8eSantirez# However sometimes you want the subset of the cluster which is working,
808c89afc8eSantirez# to continue to accept queries for the part of the key space that is still
809c89afc8eSantirez# covered. In order to do so, just set the cluster-require-full-coverage
810c89afc8eSantirez# option to no.
811c89afc8eSantirez#
812c89afc8eSantirez# cluster-require-full-coverage yes
813c89afc8eSantirez
81407c152a7Santirez# In order to setup your cluster make sure to read the documentation
81507c152a7Santirez# available at http://redis.io web site.
81607c152a7Santirez
81735a60441Santirez################################## SLOW LOG ###################################
81835a60441Santirez
81935a60441Santirez# The Redis Slow Log is a system to log queries that exceeded a specified
82035a60441Santirez# execution time. The execution time does not include the I/O operations
82135a60441Santirez# like talking with the client, sending the reply and so forth,
82235a60441Santirez# but just the time needed to actually execute the command (this is the only
82335a60441Santirez# stage of command execution where the thread is blocked and can not serve
82435a60441Santirez# other requests in the meantime).
82535a60441Santirez#
82635a60441Santirez# You can configure the slow log with two parameters: one tells Redis
82735a60441Santirez# what is the execution time, in microseconds, to exceed in order for the
82835a60441Santirez# command to get logged, and the other parameter is the length of the
82935a60441Santirez# slow log. When a new command is logged the oldest one is removed from the
83035a60441Santirez# queue of logged commands.
83135a60441Santirez
832de32c37cSantirez# The following time is expressed in microseconds, so 1000000 is equivalent
833de32c37cSantirez# to one second. Note that a negative number disables the slow log, while
834de32c37cSantirez# a value of zero forces the logging of every command.
83535a60441Santirezslowlog-log-slower-than 10000
836de32c37cSantirez
837de32c37cSantirez# There is no limit to this length. Just be aware that it will consume memory.
838de32c37cSantirez# You can reclaim memory used by the slow log with SLOWLOG RESET.
839d3701d27Santirezslowlog-max-len 128
84035a60441Santirez
841e173f7a0Santirez################################ LATENCY MONITOR ##############################
842e173f7a0Santirez
843e173f7a0Santirez# The Redis latency monitoring subsystem samples different operations
844e173f7a0Santirez# at runtime in order to collect data related to possible sources of
845e173f7a0Santirez# latency of a Redis instance.
846e173f7a0Santirez#
847e173f7a0Santirez# Via the LATENCY command this information is available to the user that can
848e173f7a0Santirez# print graphs and obtain reports.
849e173f7a0Santirez#
850e173f7a0Santirez# The system only logs operations that were performed in a time equal or
851e173f7a0Santirez# greater than the amount of milliseconds specified via the
852e173f7a0Santirez# latency-monitor-threshold configuration directive. When its value is set
853e173f7a0Santirez# to zero, the latency monitor is turned off.
854e173f7a0Santirez#
855e173f7a0Santirez# By default latency monitoring is disabled since it is mostly not needed
856e173f7a0Santirez# if you don't have latency issues, and collecting data has a performance
857e173f7a0Santirez# impact, that while very small, can be measured under big load. Latency
8586df9001dSMariano Pérez Rodríguez# monitoring can easily be enabled at runtime using the command
859e173f7a0Santirez# "CONFIG SET latency-monitor-threshold <milliseconds>" if needed.
860e173f7a0Santirezlatency-monitor-threshold 0
861e173f7a0Santirez
8622b3eba05SMasahiko Sawada############################# EVENT NOTIFICATION ##############################
8634cdbce34Santirez
8644cdbce34Santirez# Redis can notify Pub/Sub clients about events happening in the key space.
865c90af7cdSvps# This feature is documented at http://redis.io/topics/notifications
8664cdbce34Santirez#
8674cdbce34Santirez# For instance if keyspace events notification is enabled, and a client
8684cdbce34Santirez# performs a DEL operation on key "foo" stored in the Database 0, two
8694cdbce34Santirez# messages will be published via Pub/Sub:
8704cdbce34Santirez#
8714cdbce34Santirez# PUBLISH __keyspace@0__:foo del
8724cdbce34Santirez# PUBLISH __keyevent@0__:del foo
8734cdbce34Santirez#
874fce016d3Santirez# It is possible to select the events that Redis will notify among a set
875fce016d3Santirez# of classes. Every class is identified by a single character:
876fce016d3Santirez#
877fce016d3Santirez#  K     Keyspace events, published with __keyspace@<db>__ prefix.
878fce016d3Santirez#  E     Keyevent events, published with __keyevent@<db>__ prefix.
879fce016d3Santirez#  g     Generic commands (non-type specific) like DEL, EXPIRE, RENAME, ...
880fce016d3Santirez#  $     String commands
881fce016d3Santirez#  l     List commands
882fce016d3Santirez#  s     Set commands
883fce016d3Santirez#  h     Hash commands
884fce016d3Santirez#  z     Sorted set commands
885fce016d3Santirez#  x     Expired events (events generated every time a key expires)
886fce016d3Santirez#  e     Evicted events (events generated when a key is evicted for maxmemory)
887fce016d3Santirez#  A     Alias for g$lshzxe, so that the "AKE" string means all the events.
888fce016d3Santirez#
889fce016d3Santirez#  The "notify-keyspace-events" takes as argument a string that is composed
890f62f00e0SBen#  of zero or multiple characters. The empty string means that notifications
891f62f00e0SBen#  are disabled.
892fce016d3Santirez#
893fce016d3Santirez#  Example: to enable list and generic events, from the point of view of the
894fce016d3Santirez#           event name, use:
895fce016d3Santirez#
896fce016d3Santirez#  notify-keyspace-events Elg
897fce016d3Santirez#
898fce016d3Santirez#  Example 2: to get the stream of the expired keys subscribing to channel
899fce016d3Santirez#             name __keyevent@0__:expired use:
900fce016d3Santirez#
901fce016d3Santirez#  notify-keyspace-events Ex
902fce016d3Santirez#
903fce016d3Santirez#  By default all notifications are disabled because most users don't need
904fce016d3Santirez#  this feature and the feature has some overhead. Note that if you don't
905fce016d3Santirez#  specify at least one of K or E, no events will be delivered.
906fce016d3Santireznotify-keyspace-events ""
9074cdbce34Santirez
908ed9b544eSantirez############################### ADVANCED CONFIG ###############################
909ed9b544eSantirez
910d3ea4c86SPieter Noordhuis# Hashes are encoded using a memory efficient data structure when they have a
911d3ea4c86SPieter Noordhuis# small number of entries, and the biggest entry does not exceed a given
912d3ea4c86SPieter Noordhuis# threshold. These thresholds can be configured using the following directives.
913d3ea4c86SPieter Noordhuishash-max-ziplist-entries 512
914d3ea4c86SPieter Noordhuishash-max-ziplist-value 64
915b3f83f12SJeremy Zawodny
91602bb515aSMatt Stancliff# Lists are also encoded in a special way to save a lot of space.
91702bb515aSMatt Stancliff# The number of entries allowed per internal list node can be specified
91802bb515aSMatt Stancliff# as a fixed maximum size or a maximum number of elements.
91902bb515aSMatt Stancliff# For a fixed maximum size, use -5 through -1, meaning:
92002bb515aSMatt Stancliff# -5: max size: 64 Kb  <-- not recommended for normal workloads
92102bb515aSMatt Stancliff# -4: max size: 32 Kb  <-- not recommended
92202bb515aSMatt Stancliff# -3: max size: 16 Kb  <-- probably not recommended
92302bb515aSMatt Stancliff# -2: max size: 8 Kb   <-- good
92402bb515aSMatt Stancliff# -1: max size: 4 Kb   <-- good
92502bb515aSMatt Stancliff# Positive numbers mean store up to _exactly_ that number of elements
92602bb515aSMatt Stancliff# per list node.
92702bb515aSMatt Stancliff# The highest performing option is usually -2 (8 Kb size) or -1 (4 Kb size),
92802bb515aSMatt Stancliff# but if your use case is unique, adjust the settings as necessary.
92902bb515aSMatt Stanclifflist-max-ziplist-size -2
93002bb515aSMatt Stancliff
93102bb515aSMatt Stancliff# Lists may also be compressed.
93202bb515aSMatt Stancliff# Compress depth is the number of quicklist ziplist nodes from *each* side of
93302bb515aSMatt Stancliff# the list to *exclude* from compression.  The head and tail of the list
93402bb515aSMatt Stancliff# are always uncompressed for fast push/pop operations.  Settings are:
93502bb515aSMatt Stancliff# 0: disable all list compression
93602bb515aSMatt Stancliff# 1: depth 1 means "don't start compressing until after 1 node into the list,
93702bb515aSMatt Stancliff#    going from either the head or tail"
93802bb515aSMatt Stancliff#    So: [head]->node->node->...->node->[tail]
93902bb515aSMatt Stancliff#    [head], [tail] will always be uncompressed; inner nodes will compress.
94002bb515aSMatt Stancliff# 2: [head]->[next]->node->node->...->node->[prev]->[tail]
94102bb515aSMatt Stancliff#    2 here means: don't compress head or head->next or tail->prev or tail,
94202bb515aSMatt Stancliff#    but compress all nodes between them.
94302bb515aSMatt Stancliff# 3: [head]->[next]->[next]->node->node->...->node->[prev]->[prev]->[tail]
94402bb515aSMatt Stancliff# etc.
94502bb515aSMatt Stanclifflist-compress-depth 0
9466a246b1eSantirez
9476a246b1eSantirez# Sets have a special encoding in just one case: when a set is composed
948f62f00e0SBen# of just strings that happen to be integers in radix 10 in the range
9496a246b1eSantirez# of 64 bit signed integers.
9506a246b1eSantirez# The following configuration setting sets the limit in the size of the
9516a246b1eSantirez# set in order to use this special memory saving encoding.
9526a246b1eSantirezset-max-intset-entries 512
9536a246b1eSantirez
9543ea204e1SPieter Noordhuis# Similarly to hashes and lists, sorted sets are also specially encoded in
9553ea204e1SPieter Noordhuis# order to save a lot of space. This encoding is only used when the length and
9563ea204e1SPieter Noordhuis# elements of a sorted set are below the following limits:
9573ea204e1SPieter Noordhuiszset-max-ziplist-entries 128
9583ea204e1SPieter Noordhuiszset-max-ziplist-value 64
9593ea204e1SPieter Noordhuis
960402110f9Santirez# HyperLogLog sparse representation bytes limit. The limit includes the
961402110f9Santirez# 16 bytes header. When an HyperLogLog using the sparse representation crosses
96212e435d2SKevin Menard# this limit, it is converted into the dense representation.
963402110f9Santirez#
964402110f9Santirez# A value greater than 16000 is totally useless, since at that point the
965402110f9Santirez# dense representation is more memory efficient.
966402110f9Santirez#
967402110f9Santirez# The suggested value is ~ 3000 in order to have the benefits of
968402110f9Santirez# the space efficient encoding without slowing down too much PFADD,
96912e435d2SKevin Menard# which is O(N) with the sparse encoding. The value can be raised to
970402110f9Santirez# ~ 10000 when CPU is not a concern, but space is, and the data set is
971402110f9Santirez# composed of many HyperLogLogs with cardinality in the 0 - 15000 range.
972402110f9Santirezhll-sparse-max-bytes 3000
973402110f9Santirez
9748ca3e9d1Santirez# Active rehashing uses 1 millisecond every 100 milliseconds of CPU time in
9758ca3e9d1Santirez# order to help rehashing the main Redis hash table (the one mapping top-level
97657c0cf8bSKashif Rasul# keys to values). The hash table implementation Redis uses (see dict.c)
97774da4a57Santirez# performs a lazy rehashing: the more operation you run into a hash table
97857c0cf8bSKashif Rasul# that is rehashing, the more rehashing "steps" are performed, so if the
9798ca3e9d1Santirez# server is idle the rehashing is never complete and some more memory is used
9808ca3e9d1Santirez# by the hash table.
9818ca3e9d1Santirez#
9828ca3e9d1Santirez# The default is to use this millisecond 10 times every second in order to
983f62f00e0SBen# actively rehash the main dictionaries, freeing memory when possible.
9848ca3e9d1Santirez#
9858ca3e9d1Santirez# If unsure:
9868ca3e9d1Santirez# use "activerehashing no" if you have hard latency requirements and it is
987f62f00e0SBen# not a good thing in your environment that Redis can reply from time to time
9888ca3e9d1Santirez# to queries with 2 milliseconds delay.
9898ca3e9d1Santirez#
9908ca3e9d1Santirez# use "activerehashing yes" if you don't have such hard requirements but
9918ca3e9d1Santirez# want to free memory asap when possible.
9928ca3e9d1Santirezactiverehashing yes
9938ca3e9d1Santirez
994c8a607f2Santirez# The client output buffer limits can be used to force disconnection of clients
995c8a607f2Santirez# that are not reading data from the server fast enough for some reason (a
996c8a607f2Santirez# common reason is that a Pub/Sub client can't consume messages as fast as the
997c8a607f2Santirez# publisher can produce them).
998c8a607f2Santirez#
999c8a607f2Santirez# The limit can be set differently for the three different classes of clients:
1000c8a607f2Santirez#
100156d26c23Santirez# normal -> normal clients including MONITOR clients
100256d26c23Santirez# slave  -> slave clients
10036d5fa2e0SYubao Liu# pubsub -> clients subscribed to at least one pubsub channel or pattern
1004c8a607f2Santirez#
1005c8a607f2Santirez# The syntax of every client-output-buffer-limit directive is the following:
1006c8a607f2Santirez#
10073cbce4f4Santirez# client-output-buffer-limit <class> <hard limit> <soft limit> <soft seconds>
1008c8a607f2Santirez#
1009c8a607f2Santirez# A client is immediately disconnected once the hard limit is reached, or if
1010c8a607f2Santirez# the soft limit is reached and remains reached for the specified number of
1011c8a607f2Santirez# seconds (continuously).
1012c8a607f2Santirez# So for instance if the hard limit is 32 megabytes and the soft limit is
1013c8a607f2Santirez# 16 megabytes / 10 seconds, the client will get disconnected immediately
1014c8a607f2Santirez# if the size of the output buffers reach 32 megabytes, but will also get
1015c8a607f2Santirez# disconnected if the client reaches 16 megabytes and continuously overcomes
1016c8a607f2Santirez# the limit for 10 seconds.
1017c8a607f2Santirez#
1018c8a607f2Santirez# By default normal clients are not limited because they don't receive data
1019c8a607f2Santirez# without asking (in a push way), but just after a request, so only
1020c8a607f2Santirez# asynchronous clients may create a scenario where data is requested faster
1021c8a607f2Santirez# than it can read.
1022c8a607f2Santirez#
1023c8a607f2Santirez# Instead there is a default limit for pubsub and slave clients, since
1024c8a607f2Santirez# subscribers and slaves receive data in a push fashion.
1025c8a607f2Santirez#
102681144645SDavid Celis# Both the hard or the soft limit can be disabled by setting them to zero.
1027c8a607f2Santirezclient-output-buffer-limit normal 0 0 0
1028c8a607f2Santirezclient-output-buffer-limit slave 256mb 64mb 60
1029c8a607f2Santirezclient-output-buffer-limit pubsub 32mb 8mb 60
1030c8a607f2Santirez
1031f1481d4aSantirez# Redis calls an internal function to perform many background tasks, like
103274da4a57Santirez# closing connections of clients in timeout, purging expired keys that are
1033f1481d4aSantirez# never requested, and so forth.
1034f1481d4aSantirez#
103581144645SDavid Celis# Not all tasks are performed with the same frequency, but Redis checks for
1036f62f00e0SBen# tasks to perform according to the specified "hz" value.
1037f1481d4aSantirez#
1038f1481d4aSantirez# By default "hz" is set to 10. Raising the value will use more CPU when
1039f1481d4aSantirez# Redis is idle, but at the same time will make Redis more responsive when
1040f1481d4aSantirez# there are many keys expiring at the same time, and timeouts may be
1041f1481d4aSantirez# handled with more precision.
1042f1481d4aSantirez#
1043f1481d4aSantirez# The range is between 1 and 500, however a value over 100 is usually not
1044f1481d4aSantirez# a good idea. Most users should use the default of 10 and raise this up to
1045f1481d4aSantirez# 100 only in environments where very low latency is required.
1046f1481d4aSantirezhz 10
1047f1481d4aSantirez
1048d264122fSantirez# When a child rewrites the AOF file, if the following option is enabled
1049d264122fSantirez# the file will be fsync-ed every 32 MB of data generated. This is useful
1050d264122fSantirez# in order to commit the file to the disk more incrementally and avoid
1051d264122fSantirez# big latency spikes.
1052d264122fSantirezaof-rewrite-incremental-fsync yes
1053