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  1. # Redis configuration file example.
  2. #
  3. # Note that in order to read the configuration file, Redis must be
  4. # started with the file path as first argument:
  5. #
  6. # ./redis-server /path/to/redis.conf
  7. # Note on units: when memory size is needed, it is possible to specify
  8. # it in the usual form of 1k 5GB 4M and so forth:
  9. #
  10. # 1k => 1000 bytes
  11. # 1kb => 1024 bytes
  12. # 1m => 1000000 bytes
  13. # 1mb => 1024*1024 bytes
  14. # 1g => 1000000000 bytes
  15. # 1gb => 1024*1024*1024 bytes
  16. #
  17. # units are case insensitive so 1GB 1Gb 1gB are all the same.
  18. ################################## INCLUDES ###################################
  19. # Include one or more other config files here. This is useful if you
  20. # have a standard template that goes to all Redis servers but also need
  21. # to customize a few per-server settings. Include files can include
  22. # other files, so use this wisely.
  23. #
  24. # Notice option "include" won't be rewritten by command "CONFIG REWRITE"
  25. # from admin or Redis Sentinel. Since Redis always uses the last processed
  26. # line as value of a configuration directive, you'd better put includes
  27. # at the beginning of this file to avoid overwriting config change at runtime.
  28. #
  29. # If instead you are interested in using includes to override configuration
  30. # options, it is better to use include as the last line.
  31. #
  32. # include /path/to/local.conf
  33. # include /path/to/other.conf
  34. ################################## MODULES #####################################
  35. # Load modules at startup. If the server is not able to load modules
  36. # it will abort. It is possible to use multiple loadmodule directives.
  37. #
  38. # loadmodule /path/to/my_module.so
  39. # loadmodule /path/to/other_module.so
  40. ################################## NETWORK #####################################
  41. # By default, if no "bind" configuration directive is specified, Redis listens
  42. # for connections from all the network interfaces available on the server.
  43. # It is possible to listen to just one or multiple selected interfaces using
  44. # the "bind" configuration directive, followed by one or more IP addresses.
  45. #
  46. # Examples:
  47. #
  48. # bind 192.168.1.100 10.0.0.1
  49. # bind 127.0.0.1 ::1
  50. #
  51. # ~~~ WARNING ~~~ If the computer running Redis is directly exposed to the
  52. # internet, binding to all the interfaces is dangerous and will expose the
  53. # instance to everybody on the internet. So by default we uncomment the
  54. # following bind directive, that will force Redis to listen only into
  55. # the IPv4 loopback interface address (this means Redis will be able to
  56. # accept connections only from clients running into the same computer it
  57. # is running).
  58. #
  59. # IF YOU ARE SURE YOU WANT YOUR INSTANCE TO LISTEN TO ALL THE INTERFACES
  60. # JUST COMMENT THE FOLLOWING LINE.
  61. # ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
  62. bind 127.0.0.1
  63. # Protected mode is a layer of security protection, in order to avoid that
  64. # Redis instances left open on the internet are accessed and exploited.
  65. #
  66. # When protected mode is on and if:
  67. #
  68. # 1) The server is not binding explicitly to a set of addresses using the
  69. # "bind" directive.
  70. # 2) No password is configured.
  71. #
  72. # The server only accepts connections from clients connecting from the
  73. # IPv4 and IPv6 loopback addresses 127.0.0.1 and ::1, and from Unix domain
  74. # sockets.
  75. #
  76. # By default protected mode is enabled. You should disable it only if
  77. # you are sure you want clients from other hosts to connect to Redis
  78. # even if no authentication is configured, nor a specific set of interfaces
  79. # are explicitly listed using the "bind" directive.
  80. protected-mode yes
  81. # Accept connections on the specified port, default is 6379 (IANA #815344).
  82. # If port 0 is specified Redis will not listen on a TCP socket.
  83. port 6379
  84. # TCP listen() backlog.
  85. #
  86. # In high requests-per-second environments you need an high backlog in order
  87. # to avoid slow clients connections issues. Note that the Linux kernel
  88. # will silently truncate it to the value of /proc/sys/net/core/somaxconn so
  89. # make sure to raise both the value of somaxconn and tcp_max_syn_backlog
  90. # in order to get the desired effect.
  91. tcp-backlog 511
  92. # Unix socket.
  93. #
  94. # Specify the path for the Unix socket that will be used to listen for
  95. # incoming connections. There is no default, so Redis will not listen
  96. # on a unix socket when not specified.
  97. #
  98. unixsocket /run/redis/socket
  99. unixsocketperm 777
  100. # Close the connection after a client is idle for N seconds (0 to disable)
  101. timeout 0
  102. # TCP keepalive.
  103. #
  104. # If non-zero, use SO_KEEPALIVE to send TCP ACKs to clients in absence
  105. # of communication. This is useful for two reasons:
  106. #
  107. # 1) Detect dead peers.
  108. # 2) Take the connection alive from the point of view of network
  109. # equipment in the middle.
  110. #
  111. # On Linux, the specified value (in seconds) is the period used to send ACKs.
  112. # Note that to close the connection the double of the time is needed.
  113. # On other kernels the period depends on the kernel configuration.
  114. #
  115. # A reasonable value for this option is 300 seconds, which is the new
  116. # Redis default starting with Redis 3.2.1.
  117. tcp-keepalive 300
  118. ################################# GENERAL #####################################
  119. # By default Redis does not run as a daemon. Use 'yes' if you need it.
  120. # Note that Redis will write a pid file in /var/run/redis.pid when daemonized.
  121. daemonize no
  122. # If you run Redis from upstart or systemd, Redis can interact with your
  123. # supervision tree. Options:
  124. # supervised no - no supervision interaction
  125. # supervised upstart - signal upstart by putting Redis into SIGSTOP mode
  126. # supervised systemd - signal systemd by writing READY=1 to $NOTIFY_SOCKET
  127. # supervised auto - detect upstart or systemd method based on
  128. # UPSTART_JOB or NOTIFY_SOCKET environment variables
  129. # Note: these supervision methods only signal "process is ready."
  130. # They do not enable continuous liveness pings back to your supervisor.
  131. supervised systemd
  132. # If a pid file is specified, Redis writes it where specified at startup
  133. # and removes it at exit.
  134. #
  135. # When the server runs non daemonized, no pid file is created if none is
  136. # specified in the configuration. When the server is daemonized, the pid file
  137. # is used even if not specified, defaulting to "/var/run/redis.pid".
  138. #
  139. # Creating a pid file is best effort: if Redis is not able to create it
  140. # nothing bad happens, the server will start and run normally.
  141. pidfile /run/redis/pid
  142. # Specify the server verbosity level.
  143. # This can be one of:
  144. # debug (a lot of information, useful for development/testing)
  145. # verbose (many rarely useful info, but not a mess like the debug level)
  146. # notice (moderately verbose, what you want in production probably)
  147. # warning (only very important / critical messages are logged)
  148. loglevel notice
  149. # Specify the log file name. Also the empty string can be used to force
  150. # Redis to log on the standard output. Note that if you use standard
  151. # output for logging but daemonize, logs will be sent to /dev/null
  152. logfile ""
  153. # To enable logging to the system logger, just set 'syslog-enabled' to yes,
  154. # and optionally update the other syslog parameters to suit your needs.
  155. # syslog-enabled no
  156. # Specify the syslog identity.
  157. # syslog-ident redis
  158. # Specify the syslog facility. Must be USER or between LOCAL0-LOCAL7.
  159. # syslog-facility local0
  160. # Set the number of databases. The default database is DB 0, you can select
  161. # a different one on a per-connection basis using SELECT <dbid> where
  162. # dbid is a number between 0 and 'databases'-1
  163. databases 16
  164. # By default Redis shows an ASCII art logo only when started to log to the
  165. # standard output and if the standard output is a TTY. Basically this means
  166. # that normally a logo is displayed only in interactive sessions.
  167. #
  168. # However it is possible to force the pre-4.0 behavior and always show a
  169. # ASCII art logo in startup logs by setting the following option to yes.
  170. always-show-logo yes
  171. ################################ SNAPSHOTTING ################################
  172. #
  173. # Save the DB on disk:
  174. #
  175. # save <seconds> <changes>
  176. #
  177. # Will save the DB if both the given number of seconds and the given
  178. # number of write operations against the DB occurred.
  179. #
  180. # In the example below the behaviour will be to save:
  181. # after 900 sec (15 min) if at least 1 key changed
  182. # after 300 sec (5 min) if at least 10 keys changed
  183. # after 60 sec if at least 10000 keys changed
  184. #
  185. # Note: you can disable saving completely by commenting out all "save" lines.
  186. #
  187. # It is also possible to remove all the previously configured save
  188. # points by adding a save directive with a single empty string argument
  189. # like in the following example:
  190. #
  191. # save ""
  192. save 900 1
  193. save 300 10
  194. save 60 10000
  195. # By default Redis will stop accepting writes if RDB snapshots are enabled
  196. # (at least one save point) and the latest background save failed.
  197. # This will make the user aware (in a hard way) that data is not persisting
  198. # on disk properly, otherwise chances are that no one will notice and some
  199. # disaster will happen.
  200. #
  201. # If the background saving process will start working again Redis will
  202. # automatically allow writes again.
  203. #
  204. # However if you have setup your proper monitoring of the Redis server
  205. # and persistence, you may want to disable this feature so that Redis will
  206. # continue to work as usual even if there are problems with disk,
  207. # permissions, and so forth.
  208. stop-writes-on-bgsave-error yes
  209. # Compress string objects using LZF when dump .rdb databases?
  210. # For default that's set to 'yes' as it's almost always a win.
  211. # If you want to save some CPU in the saving child set it to 'no' but
  212. # the dataset will likely be bigger if you have compressible values or keys.
  213. rdbcompression yes
  214. # Since version 5 of RDB a CRC64 checksum is placed at the end of the file.
  215. # This makes the format more resistant to corruption but there is a performance
  216. # hit to pay (around 10%) when saving and loading RDB files, so you can disable it
  217. # for maximum performances.
  218. #
  219. # RDB files created with checksum disabled have a checksum of zero that will
  220. # tell the loading code to skip the check.
  221. rdbchecksum yes
  222. # The filename where to dump the DB
  223. dbfilename dump.rdb
  224. # The working directory.
  225. #
  226. # The DB will be written inside this directory, with the filename specified
  227. # above using the 'dbfilename' configuration directive.
  228. #
  229. # The Append Only File will also be created inside this directory.
  230. #
  231. # Note that you must specify a directory here, not a file name.
  232. dir /var/lib/redis
  233. ################################# REPLICATION #################################
  234. # Master-Replica replication. Use replicaof to make a Redis instance a copy of
  235. # another Redis server. A few things to understand ASAP about Redis replication.
  236. #
  237. # +------------------+ +---------------+
  238. # | Master | ---> | Replica |
  239. # | (receive writes) | | (exact copy) |
  240. # +------------------+ +---------------+
  241. #
  242. # 1) Redis replication is asynchronous, but you can configure a master to
  243. # stop accepting writes if it appears to be not connected with at least
  244. # a given number of replicas.
  245. # 2) Redis replicas are able to perform a partial resynchronization with the
  246. # master if the replication link is lost for a relatively small amount of
  247. # time. You may want to configure the replication backlog size (see the next
  248. # sections of this file) with a sensible value depending on your needs.
  249. # 3) Replication is automatic and does not need user intervention. After a
  250. # network partition replicas automatically try to reconnect to masters
  251. # and resynchronize with them.
  252. #
  253. # replicaof <masterip> <masterport>
  254. # If the master is password protected (using the "requirepass" configuration
  255. # directive below) it is possible to tell the replica to authenticate before
  256. # starting the replication synchronization process, otherwise the master will
  257. # refuse the replica request.
  258. #
  259. # masterauth <master-password>
  260. # When a replica loses its connection with the master, or when the replication
  261. # is still in progress, the replica can act in two different ways:
  262. #
  263. # 1) if replica-serve-stale-data is set to 'yes' (the default) the replica will
  264. # still reply to client requests, possibly with out of date data, or the
  265. # data set may just be empty if this is the first synchronization.
  266. #
  267. # 2) if replica-serve-stale-data is set to 'no' the replica will reply with
  268. # an error "SYNC with master in progress" to all the kind of commands
  269. # but to INFO, replicaOF, AUTH, PING, SHUTDOWN, REPLCONF, ROLE, CONFIG,
  270. # SUBSCRIBE, UNSUBSCRIBE, PSUBSCRIBE, PUNSUBSCRIBE, PUBLISH, PUBSUB,
  271. # COMMAND, POST, HOST: and LATENCY.
  272. #
  273. replica-serve-stale-data yes
  274. # You can configure a replica instance to accept writes or not. Writing against
  275. # a replica instance may be useful to store some ephemeral data (because data
  276. # written on a replica will be easily deleted after resync with the master) but
  277. # may also cause problems if clients are writing to it because of a
  278. # misconfiguration.
  279. #
  280. # Since Redis 2.6 by default replicas are read-only.
  281. #
  282. # Note: read only replicas are not designed to be exposed to untrusted clients
  283. # on the internet. It's just a protection layer against misuse of the instance.
  284. # Still a read only replica exports by default all the administrative commands
  285. # such as CONFIG, DEBUG, and so forth. To a limited extent you can improve
  286. # security of read only replicas using 'rename-command' to shadow all the
  287. # administrative / dangerous commands.
  288. replica-read-only yes
  289. # Replication SYNC strategy: disk or socket.
  290. #
  291. # -------------------------------------------------------
  292. # WARNING: DISKLESS REPLICATION IS EXPERIMENTAL CURRENTLY
  293. # -------------------------------------------------------
  294. #
  295. # New replicas and reconnecting replicas that are not able to continue the replication
  296. # process just receiving differences, need to do what is called a "full
  297. # synchronization". An RDB file is transmitted from the master to the replicas.
  298. # The transmission can happen in two different ways:
  299. #
  300. # 1) Disk-backed: The Redis master creates a new process that writes the RDB
  301. # file on disk. Later the file is transferred by the parent
  302. # process to the replicas incrementally.
  303. # 2) Diskless: The Redis master creates a new process that directly writes the
  304. # RDB file to replica sockets, without touching the disk at all.
  305. #
  306. # With disk-backed replication, while the RDB file is generated, more replicas
  307. # can be queued and served with the RDB file as soon as the current child producing
  308. # the RDB file finishes its work. With diskless replication instead once
  309. # the transfer starts, new replicas arriving will be queued and a new transfer
  310. # will start when the current one terminates.
  311. #
  312. # When diskless replication is used, the master waits a configurable amount of
  313. # time (in seconds) before starting the transfer in the hope that multiple replicas
  314. # will arrive and the transfer can be parallelized.
  315. #
  316. # With slow disks and fast (large bandwidth) networks, diskless replication
  317. # works better.
  318. repl-diskless-sync no
  319. # When diskless replication is enabled, it is possible to configure the delay
  320. # the server waits in order to spawn the child that transfers the RDB via socket
  321. # to the replicas.
  322. #
  323. # This is important since once the transfer starts, it is not possible to serve
  324. # new replicas arriving, that will be queued for the next RDB transfer, so the server
  325. # waits a delay in order to let more replicas arrive.
  326. #
  327. # The delay is specified in seconds, and by default is 5 seconds. To disable
  328. # it entirely just set it to 0 seconds and the transfer will start ASAP.
  329. repl-diskless-sync-delay 5
  330. # Replicas send PINGs to server in a predefined interval. It's possible to change
  331. # this interval with the repl_ping_replica_period option. The default value is 10
  332. # seconds.
  333. #
  334. # repl-ping-replica-period 10
  335. # The following option sets the replication timeout for:
  336. #
  337. # 1) Bulk transfer I/O during SYNC, from the point of view of replica.
  338. # 2) Master timeout from the point of view of replicas (data, pings).
  339. # 3) Replica timeout from the point of view of masters (REPLCONF ACK pings).
  340. #
  341. # It is important to make sure that this value is greater than the value
  342. # specified for repl-ping-replica-period otherwise a timeout will be detected
  343. # every time there is low traffic between the master and the replica.
  344. #
  345. # repl-timeout 60
  346. # Disable TCP_NODELAY on the replica socket after SYNC?
  347. #
  348. # If you select "yes" Redis will use a smaller number of TCP packets and
  349. # less bandwidth to send data to replicas. But this can add a delay for
  350. # the data to appear on the replica side, up to 40 milliseconds with
  351. # Linux kernels using a default configuration.
  352. #
  353. # If you select "no" the delay for data to appear on the replica side will
  354. # be reduced but more bandwidth will be used for replication.
  355. #
  356. # By default we optimize for low latency, but in very high traffic conditions
  357. # or when the master and replicas are many hops away, turning this to "yes" may
  358. # be a good idea.
  359. repl-disable-tcp-nodelay no
  360. # Set the replication backlog size. The backlog is a buffer that accumulates
  361. # replica data when replicas are disconnected for some time, so that when a replica
  362. # wants to reconnect again, often a full resync is not needed, but a partial
  363. # resync is enough, just passing the portion of data the replica missed while
  364. # disconnected.
  365. #
  366. # The bigger the replication backlog, the longer the time the replica can be
  367. # disconnected and later be able to perform a partial resynchronization.
  368. #
  369. # The backlog is only allocated once there is at least a replica connected.
  370. #
  371. # repl-backlog-size 1mb
  372. # After a master has no longer connected replicas for some time, the backlog
  373. # will be freed. The following option configures the amount of seconds that
  374. # need to elapse, starting from the time the last replica disconnected, for
  375. # the backlog buffer to be freed.
  376. #
  377. # Note that replicas never free the backlog for timeout, since they may be
  378. # promoted to masters later, and should be able to correctly "partially
  379. # resynchronize" with the replicas: hence they should always accumulate backlog.
  380. #
  381. # A value of 0 means to never release the backlog.
  382. #
  383. # repl-backlog-ttl 3600
  384. # The replica priority is an integer number published by Redis in the INFO output.
  385. # It is used by Redis Sentinel in order to select a replica to promote into a
  386. # master if the master is no longer working correctly.
  387. #
  388. # A replica with a low priority number is considered better for promotion, so
  389. # for instance if there are three replicas with priority 10, 100, 25 Sentinel will
  390. # pick the one with priority 10, that is the lowest.
  391. #
  392. # However a special priority of 0 marks the replica as not able to perform the
  393. # role of master, so a replica with priority of 0 will never be selected by
  394. # Redis Sentinel for promotion.
  395. #
  396. # By default the priority is 100.
  397. replica-priority 100
  398. # It is possible for a master to stop accepting writes if there are less than
  399. # N replicas connected, having a lag less or equal than M seconds.
  400. #
  401. # The N replicas need to be in "online" state.
  402. #
  403. # The lag in seconds, that must be <= the specified value, is calculated from
  404. # the last ping received from the replica, that is usually sent every second.
  405. #
  406. # This option does not GUARANTEE that N replicas will accept the write, but
  407. # will limit the window of exposure for lost writes in case not enough replicas
  408. # are available, to the specified number of seconds.
  409. #
  410. # For example to require at least 3 replicas with a lag <= 10 seconds use:
  411. #
  412. # min-replicas-to-write 3
  413. # min-replicas-max-lag 10
  414. #
  415. # Setting one or the other to 0 disables the feature.
  416. #
  417. # By default min-replicas-to-write is set to 0 (feature disabled) and
  418. # min-replicas-max-lag is set to 10.
  419. # A Redis master is able to list the address and port of the attached
  420. # replicas in different ways. For example the "INFO replication" section
  421. # offers this information, which is used, among other tools, by
  422. # Redis Sentinel in order to discover replica instances.
  423. # Another place where this info is available is in the output of the
  424. # "ROLE" command of a master.
  425. #
  426. # The listed IP and address normally reported by a replica is obtained
  427. # in the following way:
  428. #
  429. # IP: The address is auto detected by checking the peer address
  430. # of the socket used by the replica to connect with the master.
  431. #
  432. # Port: The port is communicated by the replica during the replication
  433. # handshake, and is normally the port that the replica is using to
  434. # listen for connections.
  435. #
  436. # However when port forwarding or Network Address Translation (NAT) is
  437. # used, the replica may be actually reachable via different IP and port
  438. # pairs. The following two options can be used by a replica in order to
  439. # report to its master a specific set of IP and port, so that both INFO
  440. # and ROLE will report those values.
  441. #
  442. # There is no need to use both the options if you need to override just
  443. # the port or the IP address.
  444. #
  445. # replica-announce-ip 5.5.5.5
  446. # replica-announce-port 1234
  447. ################################## SECURITY ###################################
  448. # Require clients to issue AUTH <PASSWORD> before processing any other
  449. # commands. This might be useful in environments in which you do not trust
  450. # others with access to the host running redis-server.
  451. #
  452. # This should stay commented out for backward compatibility and because most
  453. # people do not need auth (e.g. they run their own servers).
  454. #
  455. # Warning: since Redis is pretty fast an outside user can try up to
  456. # 150k passwords per second against a good box. This means that you should
  457. # use a very strong password otherwise it will be very easy to break.
  458. #
  459. # requirepass foobared
  460. # Command renaming.
  461. #
  462. # It is possible to change the name of dangerous commands in a shared
  463. # environment. For instance the CONFIG command may be renamed into something
  464. # hard to guess so that it will still be available for internal-use tools
  465. # but not available for general clients.
  466. #
  467. # Example:
  468. #
  469. # rename-command CONFIG b840fc02d524045429941cc15f59e41cb7be6c52
  470. #
  471. # It is also possible to completely kill a command by renaming it into
  472. # an empty string:
  473. #
  474. # rename-command CONFIG ""
  475. #
  476. # Please note that changing the name of commands that are logged into the
  477. # AOF file or transmitted to replicas may cause problems.
  478. ################################### CLIENTS ####################################
  479. # Set the max number of connected clients at the same time. By default
  480. # this limit is set to 10000 clients, however if the Redis server is not
  481. # able to configure the process file limit to allow for the specified limit
  482. # the max number of allowed clients is set to the current file limit
  483. # minus 32 (as Redis reserves a few file descriptors for internal uses).
  484. #
  485. # Once the limit is reached Redis will close all the new connections sending
  486. # an error 'max number of clients reached'.
  487. #
  488. # maxclients 10000
  489. ############################## MEMORY MANAGEMENT ################################
  490. # Set a memory usage limit to the specified amount of bytes.
  491. # When the memory limit is reached Redis will try to remove keys
  492. # according to the eviction policy selected (see maxmemory-policy).
  493. #
  494. # If Redis can't remove keys according to the policy, or if the policy is
  495. # set to 'noeviction', Redis will start to reply with errors to commands
  496. # that would use more memory, like SET, LPUSH, and so on, and will continue
  497. # to reply to read-only commands like GET.
  498. #
  499. # This option is usually useful when using Redis as an LRU or LFU cache, or to
  500. # set a hard memory limit for an instance (using the 'noeviction' policy).
  501. #
  502. # WARNING: If you have replicas attached to an instance with maxmemory on,
  503. # the size of the output buffers needed to feed the replicas are subtracted
  504. # from the used memory count, so that network problems / resyncs will
  505. # not trigger a loop where keys are evicted, and in turn the output
  506. # buffer of replicas is full with DELs of keys evicted triggering the deletion
  507. # of more keys, and so forth until the database is completely emptied.
  508. #
  509. # In short... if you have replicas attached it is suggested that you set a lower
  510. # limit for maxmemory so that there is some free RAM on the system for replica
  511. # output buffers (but this is not needed if the policy is 'noeviction').
  512. #
  513. maxmemory 4GB
  514. # MAXMEMORY POLICY: how Redis will select what to remove when maxmemory
  515. # is reached. You can select among five behaviors:
  516. #
  517. # volatile-lru -> Evict using approximated LRU among the keys with an expire set.
  518. # allkeys-lru -> Evict any key using approximated LRU.
  519. # volatile-lfu -> Evict using approximated LFU among the keys with an expire set.
  520. # allkeys-lfu -> Evict any key using approximated LFU.
  521. # volatile-random -> Remove a random key among the ones with an expire set.
  522. # allkeys-random -> Remove a random key, any key.
  523. # volatile-ttl -> Remove the key with the nearest expire time (minor TTL)
  524. # noeviction -> Don't evict anything, just return an error on write operations.
  525. #
  526. # LRU means Least Recently Used
  527. # LFU means Least Frequently Used
  528. #
  529. # Both LRU, LFU and volatile-ttl are implemented using approximated
  530. # randomized algorithms.
  531. #
  532. # Note: with any of the above policies, Redis will return an error on write
  533. # operations, when there are no suitable keys for eviction.
  534. #
  535. # At the date of writing these commands are: set setnx setex append
  536. # incr decr rpush lpush rpushx lpushx linsert lset rpoplpush sadd
  537. # sinter sinterstore sunion sunionstore sdiff sdiffstore zadd zincrby
  538. # zunionstore zinterstore hset hsetnx hmset hincrby incrby decrby
  539. # getset mset msetnx exec sort
  540. #
  541. # The default is:
  542. #
  543. maxmemory-policy allkeys-lfu
  544. # LRU, LFU and minimal TTL algorithms are not precise algorithms but approximated
  545. # algorithms (in order to save memory), so you can tune it for speed or
  546. # accuracy. For default Redis will check five keys and pick the one that was
  547. # used less recently, you can change the sample size using the following
  548. # configuration directive.
  549. #
  550. # The default of 5 produces good enough results. 10 Approximates very closely
  551. # true LRU but costs more CPU. 3 is faster but not very accurate.
  552. #
  553. maxmemory-samples 5
  554. # Starting from Redis 5, by default a replica will ignore its maxmemory setting
  555. # (unless it is promoted to master after a failover or manually). It means
  556. # that the eviction of keys will be just handled by the master, sending the
  557. # DEL commands to the replica as keys evict in the master side.
  558. #
  559. # This behavior ensures that masters and replicas stay consistent, and is usually
  560. # what you want, however if your replica is writable, or you want the replica to have
  561. # a different memory setting, and you are sure all the writes performed to the
  562. # replica are idempotent, then you may change this default (but be sure to understand
  563. # what you are doing).
  564. #
  565. # Note that since the replica by default does not evict, it may end using more
  566. # memory than the one set via maxmemory (there are certain buffers that may
  567. # be larger on the replica, or data structures may sometimes take more memory and so
  568. # forth). So make sure you monitor your replicas and make sure they have enough
  569. # memory to never hit a real out-of-memory condition before the master hits
  570. # the configured maxmemory setting.
  571. #
  572. # replica-ignore-maxmemory yes
  573. ############################# LAZY FREEING ####################################
  574. # Redis has two primitives to delete keys. One is called DEL and is a blocking
  575. # deletion of the object. It means that the server stops processing new commands
  576. # in order to reclaim all the memory associated with an object in a synchronous
  577. # way. If the key deleted is associated with a small object, the time needed
  578. # in order to execute the DEL command is very small and comparable to most other
  579. # O(1) or O(log_N) commands in Redis. However if the key is associated with an
  580. # aggregated value containing millions of elements, the server can block for
  581. # a long time (even seconds) in order to complete the operation.
  582. #
  583. # For the above reasons Redis also offers non blocking deletion primitives
  584. # such as UNLINK (non blocking DEL) and the ASYNC option of FLUSHALL and
  585. # FLUSHDB commands, in order to reclaim memory in background. Those commands
  586. # are executed in constant time. Another thread will incrementally free the
  587. # object in the background as fast as possible.
  588. #
  589. # DEL, UNLINK and ASYNC option of FLUSHALL and FLUSHDB are user-controlled.
  590. # It's up to the design of the application to understand when it is a good
  591. # idea to use one or the other. However the Redis server sometimes has to
  592. # delete keys or flush the whole database as a side effect of other operations.
  593. # Specifically Redis deletes objects independently of a user call in the
  594. # following scenarios:
  595. #
  596. # 1) On eviction, because of the maxmemory and maxmemory policy configurations,
  597. # in order to make room for new data, without going over the specified
  598. # memory limit.
  599. # 2) Because of expire: when a key with an associated time to live (see the
  600. # EXPIRE command) must be deleted from memory.
  601. # 3) Because of a side effect of a command that stores data on a key that may
  602. # already exist. For example the RENAME command may delete the old key
  603. # content when it is replaced with another one. Similarly SUNIONSTORE
  604. # or SORT with STORE option may delete existing keys. The SET command
  605. # itself removes any old content of the specified key in order to replace
  606. # it with the specified string.
  607. # 4) During replication, when a replica performs a full resynchronization with
  608. # its master, the content of the whole database is removed in order to
  609. # load the RDB file just transferred.
  610. #
  611. # In all the above cases the default is to delete objects in a blocking way,
  612. # like if DEL was called. However you can configure each case specifically
  613. # in order to instead release memory in a non-blocking way like if UNLINK
  614. # was called, using the following configuration directives:
  615. lazyfree-lazy-eviction no
  616. lazyfree-lazy-expire no
  617. lazyfree-lazy-server-del no
  618. replica-lazy-flush no
  619. ############################## APPEND ONLY MODE ###############################
  620. # By default Redis asynchronously dumps the dataset on disk. This mode is
  621. # good enough in many applications, but an issue with the Redis process or
  622. # a power outage may result into a few minutes of writes lost (depending on
  623. # the configured save points).
  624. #
  625. # The Append Only File is an alternative persistence mode that provides
  626. # much better durability. For instance using the default data fsync policy
  627. # (see later in the config file) Redis can lose just one second of writes in a
  628. # dramatic event like a server power outage, or a single write if something
  629. # wrong with the Redis process itself happens, but the operating system is
  630. # still running correctly.
  631. #
  632. # AOF and RDB persistence can be enabled at the same time without problems.
  633. # If the AOF is enabled on startup Redis will load the AOF, that is the file
  634. # with the better durability guarantees.
  635. #
  636. # Please check http://redis.io/topics/persistence for more information.
  637. appendonly no
  638. # The name of the append only file (default: "appendonly.aof")
  639. appendfilename "appendonly.aof"
  640. # The fsync() call tells the Operating System to actually write data on disk
  641. # instead of waiting for more data in the output buffer. Some OS will really flush
  642. # data on disk, some other OS will just try to do it ASAP.
  643. #
  644. # Redis supports three different modes:
  645. #
  646. # no: don't fsync, just let the OS flush the data when it wants. Faster.
  647. # always: fsync after every write to the append only log. Slow, Safest.
  648. # everysec: fsync only one time every second. Compromise.
  649. #
  650. # The default is "everysec", as that's usually the right compromise between
  651. # speed and data safety. It's up to you to understand if you can relax this to
  652. # "no" that will let the operating system flush the output buffer when
  653. # it wants, for better performances (but if you can live with the idea of
  654. # some data loss consider the default persistence mode that's snapshotting),
  655. # or on the contrary, use "always" that's very slow but a bit safer than
  656. # everysec.
  657. #
  658. # More details please check the following article:
  659. # http://antirez.com/post/redis-persistence-demystified.html
  660. #
  661. # If unsure, use "everysec".
  662. # appendfsync always
  663. appendfsync everysec
  664. # appendfsync no
  665. # When the AOF fsync policy is set to always or everysec, and a background
  666. # saving process (a background save or AOF log background rewriting) is
  667. # performing a lot of I/O against the disk, in some Linux configurations
  668. # Redis may block too long on the fsync() call. Note that there is no fix for
  669. # this currently, as even performing fsync in a different thread will block
  670. # our synchronous write(2) call.
  671. #
  672. # In order to mitigate this problem it's possible to use the following option
  673. # that will prevent fsync() from being called in the main process while a
  674. # BGSAVE or BGREWRITEAOF is in progress.
  675. #
  676. # This means that while another child is saving, the durability of Redis is
  677. # the same as "appendfsync none". In practical terms, this means that it is
  678. # possible to lose up to 30 seconds of log in the worst scenario (with the
  679. # default Linux settings).
  680. #
  681. # If you have latency problems turn this to "yes". Otherwise leave it as
  682. # "no" that is the safest pick from the point of view of durability.
  683. no-appendfsync-on-rewrite no
  684. # Automatic rewrite of the append only file.
  685. # Redis is able to automatically rewrite the log file implicitly calling
  686. # BGREWRITEAOF when the AOF log size grows by the specified percentage.
  687. #
  688. # This is how it works: Redis remembers the size of the AOF file after the
  689. # latest rewrite (if no rewrite has happened since the restart, the size of
  690. # the AOF at startup is used).
  691. #
  692. # This base size is compared to the current size. If the current size is
  693. # bigger than the specified percentage, the rewrite is triggered. Also
  694. # you need to specify a minimal size for the AOF file to be rewritten, this
  695. # is useful to avoid rewriting the AOF file even if the percentage increase
  696. # is reached but it is still pretty small.
  697. #
  698. # Specify a percentage of zero in order to disable the automatic AOF
  699. # rewrite feature.
  700. auto-aof-rewrite-percentage 100
  701. auto-aof-rewrite-min-size 64mb
  702. # An AOF file may be found to be truncated at the end during the Redis
  703. # startup process, when the AOF data gets loaded back into memory.
  704. # This may happen when the system where Redis is running
  705. # crashes, especially when an ext4 filesystem is mounted without the
  706. # data=ordered option (however this can't happen when Redis itself
  707. # crashes or aborts but the operating system still works correctly).
  708. #
  709. # Redis can either exit with an error when this happens, or load as much
  710. # data as possible (the default now) and start if the AOF file is found
  711. # to be truncated at the end. The following option controls this behavior.
  712. #
  713. # If aof-load-truncated is set to yes, a truncated AOF file is loaded and
  714. # the Redis server starts emitting a log to inform the user of the event.
  715. # Otherwise if the option is set to no, the server aborts with an error
  716. # and refuses to start. When the option is set to no, the user requires
  717. # to fix the AOF file using the "redis-check-aof" utility before to restart
  718. # the server.
  719. #
  720. # Note that if the AOF file will be found to be corrupted in the middle
  721. # the server will still exit with an error. This option only applies when
  722. # Redis will try to read more data from the AOF file but not enough bytes
  723. # will be found.
  724. aof-load-truncated yes
  725. # When rewriting the AOF file, Redis is able to use an RDB preamble in the
  726. # AOF file for faster rewrites and recoveries. When this option is turned
  727. # on the rewritten AOF file is composed of two different stanzas:
  728. #
  729. # [RDB file][AOF tail]
  730. #
  731. # When loading Redis recognizes that the AOF file starts with the "REDIS"
  732. # string and loads the prefixed RDB file, and continues loading the AOF
  733. # tail.
  734. aof-use-rdb-preamble yes
  735. ################################ LUA SCRIPTING ###############################
  736. # Max execution time of a Lua script in milliseconds.
  737. #
  738. # If the maximum execution time is reached Redis will log that a script is
  739. # still in execution after the maximum allowed time and will start to
  740. # reply to queries with an error.
  741. #
  742. # When a long running script exceeds the maximum execution time only the
  743. # SCRIPT KILL and SHUTDOWN NOSAVE commands are available. The first can be
  744. # used to stop a script that did not yet called write commands. The second
  745. # is the only way to shut down the server in the case a write command was
  746. # already issued by the script but the user doesn't want to wait for the natural
  747. # termination of the script.
  748. #
  749. # Set it to 0 or a negative value for unlimited execution without warnings.
  750. lua-time-limit 5000
  751. ################################ REDIS CLUSTER ###############################
  752. # Normal Redis instances can't be part of a Redis Cluster; only nodes that are
  753. # started as cluster nodes can. In order to start a Redis instance as a
  754. # cluster node enable the cluster support uncommenting the following:
  755. #
  756. # cluster-enabled yes
  757. # Every cluster node has a cluster configuration file. This file is not
  758. # intended to be edited by hand. It is created and updated by Redis nodes.
  759. # Every Redis Cluster node requires a different cluster configuration file.
  760. # Make sure that instances running in the same system do not have
  761. # overlapping cluster configuration file names.
  762. #
  763. # cluster-config-file nodes-6379.conf
  764. # Cluster node timeout is the amount of milliseconds a node must be unreachable
  765. # for it to be considered in failure state.
  766. # Most other internal time limits are multiple of the node timeout.
  767. #
  768. # cluster-node-timeout 15000
  769. # A replica of a failing master will avoid to start a failover if its data
  770. # looks too old.
  771. #
  772. # There is no simple way for a replica to actually have an exact measure of
  773. # its "data age", so the following two checks are performed:
  774. #
  775. # 1) If there are multiple replicas able to failover, they exchange messages
  776. # in order to try to give an advantage to the replica with the best
  777. # replication offset (more data from the master processed).
  778. # Replicas will try to get their rank by offset, and apply to the start
  779. # of the failover a delay proportional to their rank.
  780. #
  781. # 2) Every single replica computes the time of the last interaction with
  782. # its master. This can be the last ping or command received (if the master
  783. # is still in the "connected" state), or the time that elapsed since the
  784. # disconnection with the master (if the replication link is currently down).
  785. # If the last interaction is too old, the replica will not try to failover
  786. # at all.
  787. #
  788. # The point "2" can be tuned by user. Specifically a replica will not perform
  789. # the failover if, since the last interaction with the master, the time
  790. # elapsed is greater than:
  791. #
  792. # (node-timeout * replica-validity-factor) + repl-ping-replica-period
  793. #
  794. # So for example if node-timeout is 30 seconds, and the replica-validity-factor
  795. # is 10, and assuming a default repl-ping-replica-period of 10 seconds, the
  796. # replica will not try to failover if it was not able to talk with the master
  797. # for longer than 310 seconds.
  798. #
  799. # A large replica-validity-factor may allow replicas with too old data to failover
  800. # a master, while a too small value may prevent the cluster from being able to
  801. # elect a replica at all.
  802. #
  803. # For maximum availability, it is possible to set the replica-validity-factor
  804. # to a value of 0, which means, that replicas will always try to failover the
  805. # master regardless of the last time they interacted with the master.
  806. # (However they'll always try to apply a delay proportional to their
  807. # offset rank).
  808. #
  809. # Zero is the only value able to guarantee that when all the partitions heal
  810. # the cluster will always be able to continue.
  811. #
  812. # cluster-replica-validity-factor 10
  813. # Cluster replicas are able to migrate to orphaned masters, that are masters
  814. # that are left without working replicas. This improves the cluster ability
  815. # to resist to failures as otherwise an orphaned master can't be failed over
  816. # in case of failure if it has no working replicas.
  817. #
  818. # Replicas migrate to orphaned masters only if there are still at least a
  819. # given number of other working replicas for their old master. This number
  820. # is the "migration barrier". A migration barrier of 1 means that a replica
  821. # will migrate only if there is at least 1 other working replica for its master
  822. # and so forth. It usually reflects the number of replicas you want for every
  823. # master in your cluster.
  824. #
  825. # Default is 1 (replicas migrate only if their masters remain with at least
  826. # one replica). To disable migration just set it to a very large value.
  827. # A value of 0 can be set but is useful only for debugging and dangerous
  828. # in production.
  829. #
  830. # cluster-migration-barrier 1
  831. # By default Redis Cluster nodes stop accepting queries if they detect there
  832. # is at least an hash slot uncovered (no available node is serving it).
  833. # This way if the cluster is partially down (for example a range of hash slots
  834. # are no longer covered) all the cluster becomes, eventually, unavailable.
  835. # It automatically returns available as soon as all the slots are covered again.
  836. #
  837. # However sometimes you want the subset of the cluster which is working,
  838. # to continue to accept queries for the part of the key space that is still
  839. # covered. In order to do so, just set the cluster-require-full-coverage
  840. # option to no.
  841. #
  842. # cluster-require-full-coverage yes
  843. # This option, when set to yes, prevents replicas from trying to failover its
  844. # master during master failures. However the master can still perform a
  845. # manual failover, if forced to do so.
  846. #
  847. # This is useful in different scenarios, especially in the case of multiple
  848. # data center operations, where we want one side to never be promoted if not
  849. # in the case of a total DC failure.
  850. #
  851. # cluster-replica-no-failover no
  852. # In order to setup your cluster make sure to read the documentation
  853. # available at http://redis.io web site.
  854. ########################## CLUSTER DOCKER/NAT support ########################
  855. # In certain deployments, Redis Cluster nodes address discovery fails, because
  856. # addresses are NAT-ted or because ports are forwarded (the typical case is
  857. # Docker and other containers).
  858. #
  859. # In order to make Redis Cluster working in such environments, a static
  860. # configuration where each node knows its public address is needed. The
  861. # following two options are used for this scope, and are:
  862. #
  863. # * cluster-announce-ip
  864. # * cluster-announce-port
  865. # * cluster-announce-bus-port
  866. #
  867. # Each instruct the node about its address, client port, and cluster message
  868. # bus port. The information is then published in the header of the bus packets
  869. # so that other nodes will be able to correctly map the address of the node
  870. # publishing the information.
  871. #
  872. # If the above options are not used, the normal Redis Cluster auto-detection
  873. # will be used instead.
  874. #
  875. # Note that when remapped, the bus port may not be at the fixed offset of
  876. # clients port + 10000, so you can specify any port and bus-port depending
  877. # on how they get remapped. If the bus-port is not set, a fixed offset of
  878. # 10000 will be used as usually.
  879. #
  880. # Example:
  881. #
  882. # cluster-announce-ip 10.1.1.5
  883. # cluster-announce-port 6379
  884. # cluster-announce-bus-port 6380
  885. ################################## SLOW LOG ###################################
  886. # The Redis Slow Log is a system to log queries that exceeded a specified
  887. # execution time. The execution time does not include the I/O operations
  888. # like talking with the client, sending the reply and so forth,
  889. # but just the time needed to actually execute the command (this is the only
  890. # stage of command execution where the thread is blocked and can not serve
  891. # other requests in the meantime).
  892. #
  893. # You can configure the slow log with two parameters: one tells Redis
  894. # what is the execution time, in microseconds, to exceed in order for the
  895. # command to get logged, and the other parameter is the length of the
  896. # slow log. When a new command is logged the oldest one is removed from the
  897. # queue of logged commands.
  898. # The following time is expressed in microseconds, so 1000000 is equivalent
  899. # to one second. Note that a negative number disables the slow log, while
  900. # a value of zero forces the logging of every command.
  901. slowlog-log-slower-than 10000
  902. # There is no limit to this length. Just be aware that it will consume memory.
  903. # You can reclaim memory used by the slow log with SLOWLOG RESET.
  904. slowlog-max-len 128
  905. ################################ LATENCY MONITOR ##############################
  906. # The Redis latency monitoring subsystem samples different operations
  907. # at runtime in order to collect data related to possible sources of
  908. # latency of a Redis instance.
  909. #
  910. # Via the LATENCY command this information is available to the user that can
  911. # print graphs and obtain reports.
  912. #
  913. # The system only logs operations that were performed in a time equal or
  914. # greater than the amount of milliseconds specified via the
  915. # latency-monitor-threshold configuration directive. When its value is set
  916. # to zero, the latency monitor is turned off.
  917. #
  918. # By default latency monitoring is disabled since it is mostly not needed
  919. # if you don't have latency issues, and collecting data has a performance
  920. # impact, that while very small, can be measured under big load. Latency
  921. # monitoring can easily be enabled at runtime using the command
  922. # "CONFIG SET latency-monitor-threshold <milliseconds>" if needed.
  923. latency-monitor-threshold 0
  924. ############################# EVENT NOTIFICATION ##############################
  925. # Redis can notify Pub/Sub clients about events happening in the key space.
  926. # This feature is documented at http://redis.io/topics/notifications
  927. #
  928. # For instance if keyspace events notification is enabled, and a client
  929. # performs a DEL operation on key "foo" stored in the Database 0, two
  930. # messages will be published via Pub/Sub:
  931. #
  932. # PUBLISH __keyspace@0__:foo del
  933. # PUBLISH __keyevent@0__:del foo
  934. #
  935. # It is possible to select the events that Redis will notify among a set
  936. # of classes. Every class is identified by a single character:
  937. #
  938. # K Keyspace events, published with __keyspace@<db>__ prefix.
  939. # E Keyevent events, published with __keyevent@<db>__ prefix.
  940. # g Generic commands (non-type specific) like DEL, EXPIRE, RENAME, ...
  941. # $ String commands
  942. # l List commands
  943. # s Set commands
  944. # h Hash commands
  945. # z Sorted set commands
  946. # x Expired events (events generated every time a key expires)
  947. # e Evicted events (events generated when a key is evicted for maxmemory)
  948. # A Alias for g$lshzxe, so that the "AKE" string means all the events.
  949. #
  950. # The "notify-keyspace-events" takes as argument a string that is composed
  951. # of zero or multiple characters. The empty string means that notifications
  952. # are disabled.
  953. #
  954. # Example: to enable list and generic events, from the point of view of the
  955. # event name, use:
  956. #
  957. # notify-keyspace-events Elg
  958. #
  959. # Example 2: to get the stream of the expired keys subscribing to channel
  960. # name __keyevent@0__:expired use:
  961. #
  962. # notify-keyspace-events Ex
  963. #
  964. # By default all notifications are disabled because most users don't need
  965. # this feature and the feature has some overhead. Note that if you don't
  966. # specify at least one of K or E, no events will be delivered.
  967. notify-keyspace-events ""
  968. ############################### ADVANCED CONFIG ###############################
  969. # Hashes are encoded using a memory efficient data structure when they have a
  970. # small number of entries, and the biggest entry does not exceed a given
  971. # threshold. These thresholds can be configured using the following directives.
  972. hash-max-ziplist-entries 512
  973. hash-max-ziplist-value 64
  974. # Lists are also encoded in a special way to save a lot of space.
  975. # The number of entries allowed per internal list node can be specified
  976. # as a fixed maximum size or a maximum number of elements.
  977. # For a fixed maximum size, use -5 through -1, meaning:
  978. # -5: max size: 64 Kb <-- not recommended for normal workloads
  979. # -4: max size: 32 Kb <-- not recommended
  980. # -3: max size: 16 Kb <-- probably not recommended
  981. # -2: max size: 8 Kb <-- good
  982. # -1: max size: 4 Kb <-- good
  983. # Positive numbers mean store up to _exactly_ that number of elements
  984. # per list node.
  985. # The highest performing option is usually -2 (8 Kb size) or -1 (4 Kb size),
  986. # but if your use case is unique, adjust the settings as necessary.
  987. list-max-ziplist-size -2
  988. # Lists may also be compressed.
  989. # Compress depth is the number of quicklist ziplist nodes from *each* side of
  990. # the list to *exclude* from compression. The head and tail of the list
  991. # are always uncompressed for fast push/pop operations. Settings are:
  992. # 0: disable all list compression
  993. # 1: depth 1 means "don't start compressing until after 1 node into the list,
  994. # going from either the head or tail"
  995. # So: [head]->node->node->...->node->[tail]
  996. # [head], [tail] will always be uncompressed; inner nodes will compress.
  997. # 2: [head]->[next]->node->node->...->node->[prev]->[tail]
  998. # 2 here means: don't compress head or head->next or tail->prev or tail,
  999. # but compress all nodes between them.
  1000. # 3: [head]->[next]->[next]->node->node->...->node->[prev]->[prev]->[tail]
  1001. # etc.
  1002. list-compress-depth 0
  1003. # Sets have a special encoding in just one case: when a set is composed
  1004. # of just strings that happen to be integers in radix 10 in the range
  1005. # of 64 bit signed integers.
  1006. # The following configuration setting sets the limit in the size of the
  1007. # set in order to use this special memory saving encoding.
  1008. set-max-intset-entries 512
  1009. # Similarly to hashes and lists, sorted sets are also specially encoded in
  1010. # order to save a lot of space. This encoding is only used when the length and
  1011. # elements of a sorted set are below the following limits:
  1012. zset-max-ziplist-entries 128
  1013. zset-max-ziplist-value 64
  1014. # HyperLogLog sparse representation bytes limit. The limit includes the
  1015. # 16 bytes header. When an HyperLogLog using the sparse representation crosses
  1016. # this limit, it is converted into the dense representation.
  1017. #
  1018. # A value greater than 16000 is totally useless, since at that point the
  1019. # dense representation is more memory efficient.
  1020. #
  1021. # The suggested value is ~ 3000 in order to have the benefits of
  1022. # the space efficient encoding without slowing down too much PFADD,
  1023. # which is O(N) with the sparse encoding. The value can be raised to
  1024. # ~ 10000 when CPU is not a concern, but space is, and the data set is
  1025. # composed of many HyperLogLogs with cardinality in the 0 - 15000 range.
  1026. hll-sparse-max-bytes 3000
  1027. # Streams macro node max size / items. The stream data structure is a radix
  1028. # tree of big nodes that encode multiple items inside. Using this configuration
  1029. # it is possible to configure how big a single node can be in bytes, and the
  1030. # maximum number of items it may contain before switching to a new node when
  1031. # appending new stream entries. If any of the following settings are set to
  1032. # zero, the limit is ignored, so for instance it is possible to set just a
  1033. # max entires limit by setting max-bytes to 0 and max-entries to the desired
  1034. # value.
  1035. stream-node-max-bytes 4096
  1036. stream-node-max-entries 100
  1037. # Active rehashing uses 1 millisecond every 100 milliseconds of CPU time in
  1038. # order to help rehashing the main Redis hash table (the one mapping top-level
  1039. # keys to values). The hash table implementation Redis uses (see dict.c)
  1040. # performs a lazy rehashing: the more operation you run into a hash table
  1041. # that is rehashing, the more rehashing "steps" are performed, so if the
  1042. # server is idle the rehashing is never complete and some more memory is used
  1043. # by the hash table.
  1044. #
  1045. # The default is to use this millisecond 10 times every second in order to
  1046. # actively rehash the main dictionaries, freeing memory when possible.
  1047. #
  1048. # If unsure:
  1049. # use "activerehashing no" if you have hard latency requirements and it is
  1050. # not a good thing in your environment that Redis can reply from time to time
  1051. # to queries with 2 milliseconds delay.
  1052. #
  1053. # use "activerehashing yes" if you don't have such hard requirements but
  1054. # want to free memory asap when possible.
  1055. activerehashing yes
  1056. # The client output buffer limits can be used to force disconnection of clients
  1057. # that are not reading data from the server fast enough for some reason (a
  1058. # common reason is that a Pub/Sub client can't consume messages as fast as the
  1059. # publisher can produce them).
  1060. #
  1061. # The limit can be set differently for the three different classes of clients:
  1062. #
  1063. # normal -> normal clients including MONITOR clients
  1064. # replica -> replica clients
  1065. # pubsub -> clients subscribed to at least one pubsub channel or pattern
  1066. #
  1067. # The syntax of every client-output-buffer-limit directive is the following:
  1068. #
  1069. # client-output-buffer-limit <class> <hard limit> <soft limit> <soft seconds>
  1070. #
  1071. # A client is immediately disconnected once the hard limit is reached, or if
  1072. # the soft limit is reached and remains reached for the specified number of
  1073. # seconds (continuously).
  1074. # So for instance if the hard limit is 32 megabytes and the soft limit is
  1075. # 16 megabytes / 10 seconds, the client will get disconnected immediately
  1076. # if the size of the output buffers reach 32 megabytes, but will also get
  1077. # disconnected if the client reaches 16 megabytes and continuously overcomes
  1078. # the limit for 10 seconds.
  1079. #
  1080. # By default normal clients are not limited because they don't receive data
  1081. # without asking (in a push way), but just after a request, so only
  1082. # asynchronous clients may create a scenario where data is requested faster
  1083. # than it can read.
  1084. #
  1085. # Instead there is a default limit for pubsub and replica clients, since
  1086. # subscribers and replicas receive data in a push fashion.
  1087. #
  1088. # Both the hard or the soft limit can be disabled by setting them to zero.
  1089. client-output-buffer-limit normal 0 0 0
  1090. client-output-buffer-limit replica 256mb 64mb 60
  1091. client-output-buffer-limit pubsub 32mb 8mb 60
  1092. # Client query buffers accumulate new commands. They are limited to a fixed
  1093. # amount by default in order to avoid that a protocol desynchronization (for
  1094. # instance due to a bug in the client) will lead to unbound memory usage in
  1095. # the query buffer. However you can configure it here if you have very special
  1096. # needs, such us huge multi/exec requests or alike.
  1097. #
  1098. # client-query-buffer-limit 1gb
  1099. # In the Redis protocol, bulk requests, that are, elements representing single
  1100. # strings, are normally limited ot 512 mb. However you can change this limit
  1101. # here.
  1102. #
  1103. # proto-max-bulk-len 512mb
  1104. # Redis calls an internal function to perform many background tasks, like
  1105. # closing connections of clients in timeout, purging expired keys that are
  1106. # never requested, and so forth.
  1107. #
  1108. # Not all tasks are performed with the same frequency, but Redis checks for
  1109. # tasks to perform according to the specified "hz" value.
  1110. #
  1111. # By default "hz" is set to 10. Raising the value will use more CPU when
  1112. # Redis is idle, but at the same time will make Redis more responsive when
  1113. # there are many keys expiring at the same time, and timeouts may be
  1114. # handled with more precision.
  1115. #
  1116. # The range is between 1 and 500, however a value over 100 is usually not
  1117. # a good idea. Most users should use the default of 10 and raise this up to
  1118. # 100 only in environments where very low latency is required.
  1119. hz 10
  1120. # Normally it is useful to have an HZ value which is proportional to the
  1121. # number of clients connected. This is useful in order, for instance, to
  1122. # avoid too many clients are processed for each background task invocation
  1123. # in order to avoid latency spikes.
  1124. #
  1125. # Since the default HZ value by default is conservatively set to 10, Redis
  1126. # offers, and enables by default, the ability to use an adaptive HZ value
  1127. # which will temporary raise when there are many connected clients.
  1128. #
  1129. # When dynamic HZ is enabled, the actual configured HZ will be used as
  1130. # as a baseline, but multiples of the configured HZ value will be actually
  1131. # used as needed once more clients are connected. In this way an idle
  1132. # instance will use very little CPU time while a busy instance will be
  1133. # more responsive.
  1134. dynamic-hz yes
  1135. # When a child rewrites the AOF file, if the following option is enabled
  1136. # the file will be fsync-ed every 32 MB of data generated. This is useful
  1137. # in order to commit the file to the disk more incrementally and avoid
  1138. # big latency spikes.
  1139. aof-rewrite-incremental-fsync yes
  1140. # When redis saves RDB file, if the following option is enabled
  1141. # the file will be fsync-ed every 32 MB of data generated. This is useful
  1142. # in order to commit the file to the disk more incrementally and avoid
  1143. # big latency spikes.
  1144. rdb-save-incremental-fsync yes
  1145. # Redis LFU eviction (see maxmemory setting) can be tuned. However it is a good
  1146. # idea to start with the default settings and only change them after investigating
  1147. # how to improve the performances and how the keys LFU change over time, which
  1148. # is possible to inspect via the OBJECT FREQ command.
  1149. #
  1150. # There are two tunable parameters in the Redis LFU implementation: the
  1151. # counter logarithm factor and the counter decay time. It is important to
  1152. # understand what the two parameters mean before changing them.
  1153. #
  1154. # The LFU counter is just 8 bits per key, it's maximum value is 255, so Redis
  1155. # uses a probabilistic increment with logarithmic behavior. Given the value
  1156. # of the old counter, when a key is accessed, the counter is incremented in
  1157. # this way:
  1158. #
  1159. # 1. A random number R between 0 and 1 is extracted.
  1160. # 2. A probability P is calculated as 1/(old_value*lfu_log_factor+1).
  1161. # 3. The counter is incremented only if R < P.
  1162. #
  1163. # The default lfu-log-factor is 10. This is a table of how the frequency
  1164. # counter changes with a different number of accesses with different
  1165. # logarithmic factors:
  1166. #
  1167. # +--------+------------+------------+------------+------------+------------+
  1168. # | factor | 100 hits | 1000 hits | 100K hits | 1M hits | 10M hits |
  1169. # +--------+------------+------------+------------+------------+------------+
  1170. # | 0 | 104 | 255 | 255 | 255 | 255 |
  1171. # +--------+------------+------------+------------+------------+------------+
  1172. # | 1 | 18 | 49 | 255 | 255 | 255 |
  1173. # +--------+------------+------------+------------+------------+------------+
  1174. # | 10 | 10 | 18 | 142 | 255 | 255 |
  1175. # +--------+------------+------------+------------+------------+------------+
  1176. # | 100 | 8 | 11 | 49 | 143 | 255 |
  1177. # +--------+------------+------------+------------+------------+------------+
  1178. #
  1179. # NOTE: The above table was obtained by running the following commands:
  1180. #
  1181. # redis-benchmark -n 1000000 incr foo
  1182. # redis-cli object freq foo
  1183. #
  1184. # NOTE 2: The counter initial value is 5 in order to give new objects a chance
  1185. # to accumulate hits.
  1186. #
  1187. # The counter decay time is the time, in minutes, that must elapse in order
  1188. # for the key counter to be divided by two (or decremented if it has a value
  1189. # less <= 10).
  1190. #
  1191. # The default value for the lfu-decay-time is 1. A Special value of 0 means to
  1192. # decay the counter every time it happens to be scanned.
  1193. #
  1194. # lfu-log-factor 10
  1195. # lfu-decay-time 1
  1196. ########################### ACTIVE DEFRAGMENTATION #######################
  1197. #
  1198. # WARNING THIS FEATURE IS EXPERIMENTAL. However it was stress tested
  1199. # even in production and manually tested by multiple engineers for some
  1200. # time.
  1201. #
  1202. # What is active defragmentation?
  1203. # -------------------------------
  1204. #
  1205. # Active (online) defragmentation allows a Redis server to compact the
  1206. # spaces left between small allocations and deallocations of data in memory,
  1207. # thus allowing to reclaim back memory.
  1208. #
  1209. # Fragmentation is a natural process that happens with every allocator (but
  1210. # less so with Jemalloc, fortunately) and certain workloads. Normally a server
  1211. # restart is needed in order to lower the fragmentation, or at least to flush
  1212. # away all the data and create it again. However thanks to this feature
  1213. # implemented by Oran Agra for Redis 4.0 this process can happen at runtime
  1214. # in an "hot" way, while the server is running.
  1215. #
  1216. # Basically when the fragmentation is over a certain level (see the
  1217. # configuration options below) Redis will start to create new copies of the
  1218. # values in contiguous memory regions by exploiting certain specific Jemalloc
  1219. # features (in order to understand if an allocation is causing fragmentation
  1220. # and to allocate it in a better place), and at the same time, will release the
  1221. # old copies of the data. This process, repeated incrementally for all the keys
  1222. # will cause the fragmentation to drop back to normal values.
  1223. #
  1224. # Important things to understand:
  1225. #
  1226. # 1. This feature is disabled by default, and only works if you compiled Redis
  1227. # to use the copy of Jemalloc we ship with the source code of Redis.
  1228. # This is the default with Linux builds.
  1229. #
  1230. # 2. You never need to enable this feature if you don't have fragmentation
  1231. # issues.
  1232. #
  1233. # 3. Once you experience fragmentation, you can enable this feature when
  1234. # needed with the command "CONFIG SET activedefrag yes".
  1235. #
  1236. # The configuration parameters are able to fine tune the behavior of the
  1237. # defragmentation process. If you are not sure about what they mean it is
  1238. # a good idea to leave the defaults untouched.
  1239. # Enabled active defragmentation
  1240. # activedefrag yes
  1241. # Minimum amount of fragmentation waste to start active defrag
  1242. # active-defrag-ignore-bytes 100mb
  1243. # Minimum percentage of fragmentation to start active defrag
  1244. # active-defrag-threshold-lower 10
  1245. # Maximum percentage of fragmentation at which we use maximum effort
  1246. # active-defrag-threshold-upper 100
  1247. # Minimal effort for defrag in CPU percentage
  1248. # active-defrag-cycle-min 5
  1249. # Maximal effort for defrag in CPU percentage
  1250. # active-defrag-cycle-max 75
  1251. # Maximum number of set/hash/zset/list fields that will be processed from
  1252. # the main dictionary scan
  1253. # active-defrag-max-scan-fields 1000