{"id":841,"date":"2021-12-26T08:01:00","date_gmt":"2021-12-26T00:01:00","guid":{"rendered":"http:\/\/www.langmanezhuang.com\/index.php\/2021\/12\/26\/redis%e9%85%8d%e7%bd%ae%e6%96%87%e4%bb%b6-redis-conf\/"},"modified":"2021-12-26T08:01:00","modified_gmt":"2021-12-26T00:01:00","slug":"redis%e9%85%8d%e7%bd%ae%e6%96%87%e4%bb%b6-redis-conf","status":"publish","type":"post","link":"http:\/\/blog.langmanezhuang.com\/index.php\/2021\/12\/26\/redis%e9%85%8d%e7%bd%ae%e6%96%87%e4%bb%b6-redis-conf\/","title":{"rendered":"redis\u914d\u7f6e\u6587\u4ef6 redis.conf"},"content":{"rendered":"<div class=\"cnblogs_Highlighter\">\n<pre class=\"brush:bash;gutter:true;\"># Redis configuration file example.\n#\n# Note that in order to read the configuration file, Redis must be\n# started with the file path as first argument:\n#\n# .\/redis-server \/path\/to\/redis.conf\n\n# Note on units: when memory size is needed, it is possible to specify\n# it in the usual form of 1k 5GB 4M and so forth:\n#\n# 1k =&gt; 1000 bytes\n# 1kb =&gt; 1024 bytes\n# 1m =&gt; 1000000 bytes\n# 1mb =&gt; 1024*1024 bytes\n# 1g =&gt; 1000000000 bytes\n# 1gb =&gt; 1024*1024*1024 bytes\n#\n# units are case insensitive so 1GB 1Gb 1gB are all the same.\n\n################################## INCLUDES ###################################\n\n# Include one or more other config files here.  This is useful if you\n# have a standard template that goes to all Redis servers but also need\n# to customize a few per-server settings.  Include files can include\n# other files, so use this wisely.\n#\n# Notice option \"include\" won't be rewritten by command \"CONFIG REWRITE\"\n# from admin or Redis Sentinel. Since Redis always uses the last processed\n# line as value of a configuration directive, you'd better put includes\n# at the beginning of this file to avoid overwriting config change at runtime.\n#\n# If instead you are interested in using includes to override configuration\n# options, it is better to use include as the last line.\n#\n# include \/path\/to\/local.conf\n# include \/path\/to\/other.conf\n\n################################## MODULES #####################################\n\n# Load modules at startup. If the server is not able to load modules\n# it will abort. It is possible to use multiple loadmodule directives.\n#\n# loadmodule \/path\/to\/my_module.so\n# loadmodule \/path\/to\/other_module.so\n\n################################## NETWORK #####################################\n\n# By default, if no \"bind\" configuration directive is specified, Redis listens\n# for connections from all the network interfaces available on the server.\n# It is possible to listen to just one or multiple selected interfaces using\n# the \"bind\" configuration directive, followed by one or more IP addresses.\n#\n# Examples:\n#\n# bind 192.168.1.100 10.0.0.1\nbind 127.0.0.1 ::1\n#\n# ~~~ WARNING ~~~ If the computer running Redis is directly exposed to the\n# internet, binding to all the interfaces is dangerous and will expose the\n# instance to everybody on the internet. So by default we uncomment the\n# following bind directive, that will force Redis to listen only into\n# the IPv4 loopback interface address (this means Redis will be able to\n# accept connections only from clients running into the same computer it\n# is running).\n#\n# IF YOU ARE SURE YOU WANT YOUR INSTANCE TO LISTEN TO ALL THE INTERFACES\n# JUST COMMENT THE FOLLOWING LINE.\n# ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~\nbind 127.0.0.1\n\n# Protected mode is a layer of security protection, in order to avoid that\n# Redis instances left open on the internet are accessed and exploited.\n#\n# When protected mode is on and if:\n#\n# 1) The server is not binding explicitly to a set of addresses using the\n#    \"bind\" directive.\n# 2) No password is configured.\n#\n# The server only accepts connections from clients connecting from the\n# IPv4 and IPv6 loopback addresses 127.0.0.1 and ::1, and from Unix domain\n# sockets.\n#\n# By default protected mode is enabled. You should disable it only if\n# you are sure you want clients from other hosts to connect to Redis\n# even if no authentication is configured, nor a specific set of interfaces\n# are explicitly listed using the \"bind\" directive.\nprotected-mode yes\n\n# Accept connections on the specified port, default is 6379 (IANA #815344).\n# If port 0 is specified Redis will not listen on a TCP socket.\nport 6379\n\n# TCP listen() backlog.\n#\n# In high requests-per-second environments you need an high backlog in order\n# to avoid slow clients connections issues. Note that the Linux kernel\n# will silently truncate it to the value of \/proc\/sys\/net\/core\/somaxconn so\n# make sure to raise both the value of somaxconn and tcp_max_syn_backlog\n# in order to get the desired effect.\ntcp-backlog 511\n\n# Unix socket.\n#\n# Specify the path for the Unix socket that will be used to listen for\n# incoming connections. There is no default, so Redis will not listen\n# on a unix socket when not specified.\n#\n# unixsocket \/tmp\/redis.sock\n# unixsocketperm 700\n\n# Close the connection after a client is idle for N seconds (0 to disable)\ntimeout 0\n\n# TCP keepalive.\n#\n# If non-zero, use SO_KEEPALIVE to send TCP ACKs to clients in absence\n# of communication. This is useful for two reasons:\n#\n# 1) Detect dead peers.\n# 2) Take the connection alive from the point of view of network\n#    equipment in the middle.\n#\n# On Linux, the specified value (in seconds) is the period used to send ACKs.\n# Note that to close the connection the double of the time is needed.\n# On other kernels the period depends on the kernel configuration.\n#\n# A reasonable value for this option is 300 seconds, which is the new\n# Redis default starting with Redis 3.2.1.\ntcp-keepalive 300\n\n################################# GENERAL #####################################\n\n# By default Redis does not run as a daemon. Use 'yes' if you need it.\n# Note that Redis will write a pid file in \/var\/run\/redis.pid when daemonized.\ndaemonize yes\n\n# If you run Redis from upstart or systemd, Redis can interact with your\n# supervision tree. Options:\n#   supervised no      - no supervision interaction\n#   supervised upstart - signal upstart by putting Redis into SIGSTOP mode\n#   supervised systemd - signal systemd by writing READY=1 to $NOTIFY_SOCKET\n#   supervised auto    - detect upstart or systemd method based on\n#                        UPSTART_JOB or NOTIFY_SOCKET environment variables\n# Note: these supervision methods only signal \"process is ready.\"\n#       They do not enable continuous liveness pings back to your supervisor.\nsupervised no\n\n# If a pid file is specified, Redis writes it where specified at startup\n# and removes it at exit.\n#\n# When the server runs non daemonized, no pid file is created if none is\n# specified in the configuration. When the server is daemonized, the pid file\n# is used even if not specified, defaulting to \"\/var\/run\/redis.pid\".\n#\n# Creating a pid file is best effort: if Redis is not able to create it\n# nothing bad happens, the server will start and run normally.\npidfile \/var\/run\/redis_6379.pid\n\n# Specify the server verbosity level.\n# This can be one of:\n# debug (a lot of information, useful for development\/testing)\n# verbose (many rarely useful info, but not a mess like the debug level)\n# notice (moderately verbose, what you want in production probably)\n# warning (only very important \/ critical messages are logged)\nloglevel notice\n\n# Specify the log file name. Also the empty string can be used to force\n# Redis to log on the standard output. Note that if you use standard\n# output for logging but daemonize, logs will be sent to \/dev\/null\nlogfile \/usr\/local\/redis\/redis.log\n\n# To enable logging to the system logger, just set 'syslog-enabled' to yes,\n# and optionally update the other syslog parameters to suit your needs.\n# syslog-enabled no\n\n# Specify the syslog identity.\n# syslog-ident redis\n\n# Specify the syslog facility. Must be USER or between LOCAL0-LOCAL7.\n# syslog-facility local0\n\n# Set the number of databases. The default database is DB 0, you can select\n# a different one on a per-connection basis using SELECT &lt;dbid&gt; where\n# dbid is a number between 0 and 'databases'-1\ndatabases 16\n\n# By default Redis shows an ASCII art logo only when started to log to the\n# standard output and if the standard output is a TTY. Basically this means\n# that normally a logo is displayed only in interactive sessions.\n#\n# However it is possible to force the pre-4.0 behavior and always show a\n# ASCII art logo in startup logs by setting the following option to yes.\nalways-show-logo yes\n\n################################ SNAPSHOTTING  ################################\n#\n# Save the DB on disk:\n#\n#   save &lt;seconds&gt; &lt;changes&gt;\n#\n#   Will save the DB if both the given number of seconds and the given\n#   number of write operations against the DB occurred.\n#\n#   In the example below the behaviour will be to save:\n#   after 900 sec (15 min) if at least 1 key changed\n#   after 300 sec (5 min) if at least 10 keys changed\n#   after 60 sec if at least 10000 keys changed\n#\n#   Note: you can disable saving completely by commenting out all \"save\" lines.\n#\n#   It is also possible to remove all the previously configured save\n#   points by adding a save directive with a single empty string argument\n#   like in the following example:\n#\n#   save \"\"\n\nsave 900 1\nsave 300 10\nsave 60 10000\n\n# By default Redis will stop accepting writes if RDB snapshots are enabled\n# (at least one save point) and the latest background save failed.\n# This will make the user aware (in a hard way) that data is not persisting\n# on disk properly, otherwise chances are that no one will notice and some\n# disaster will happen.\n#\n# If the background saving process will start working again Redis will\n# automatically allow writes again.\n#\n# However if you have setup your proper monitoring of the Redis server\n# and persistence, you may want to disable this feature so that Redis will\n# continue to work as usual even if there are problems with disk,\n# permissions, and so forth.\nstop-writes-on-bgsave-error yes\n\n# Compress string objects using LZF when dump .rdb databases?\n# For default that's set to 'yes' as it's almost always a win.\n# If you want to save some CPU in the saving child set it to 'no' but\n# the dataset will likely be bigger if you have compressible values or keys.\nrdbcompression yes\n\n# Since version 5 of RDB a CRC64 checksum is placed at the end of the file.\n# This makes the format more resistant to corruption but there is a performance\n# hit to pay (around 10%) when saving and loading RDB files, so you can disable it\n# for maximum performances.\n#\n# RDB files created with checksum disabled have a checksum of zero that will\n# tell the loading code to skip the check.\nrdbchecksum yes\n\n# The filename where to dump the DB\ndbfilename dump.rdb\n\n# The working directory.\n#\n# The DB will be written inside this directory, with the filename specified\n# above using the 'dbfilename' configuration directive.\n#\n# The Append Only File will also be created inside this directory.\n#\n# Note that you must specify a directory here, not a file name.\ndir \/usr\/local\/redis\/var\n\n################################# REPLICATION #################################\n\n# Master-Replica replication. Use replicaof to make a Redis instance a copy of\n# another Redis server. A few things to understand ASAP about Redis replication.\n#\n#   +------------------+      +---------------+\n#   |      Master      | ---&gt; |    Replica    |\n#   | (receive writes) |      |  (exact copy) |\n#   +------------------+      +---------------+\n#\n# 1) Redis replication is asynchronous, but you can configure a master to\n#    stop accepting writes if it appears to be not connected with at least\n#    a given number of replicas.\n# 2) Redis replicas are able to perform a partial resynchronization with the\n#    master if the replication link is lost for a relatively small amount of\n#    time. You may want to configure the replication backlog size (see the next\n#    sections of this file) with a sensible value depending on your needs.\n# 3) Replication is automatic and does not need user intervention. After a\n#    network partition replicas automatically try to reconnect to masters\n#    and resynchronize with them.\n#\n# replicaof &lt;masterip&gt; &lt;masterport&gt;\n\n# If the master is password protected (using the \"requirepass\" configuration\n# directive below) it is possible to tell the replica to authenticate before\n# starting the replication synchronization process, otherwise the master will\n# refuse the replica request.\n#\n# masterauth &lt;master-password&gt;\n\n# When a replica loses its connection with the master, or when the replication\n# is still in progress, the replica can act in two different ways:\n#\n# 1) if replica-serve-stale-data is set to 'yes' (the default) the replica will\n#    still reply to client requests, possibly with out of date data, or the\n#    data set may just be empty if this is the first synchronization.\n#\n# 2) if replica-serve-stale-data is set to 'no' the replica will reply with\n#    an error \"SYNC with master in progress\" to all the kind of commands\n#    but to INFO, replicaOF, AUTH, PING, SHUTDOWN, REPLCONF, ROLE, CONFIG,\n#    SUBSCRIBE, UNSUBSCRIBE, PSUBSCRIBE, PUNSUBSCRIBE, PUBLISH, PUBSUB,\n#    COMMAND, POST, HOST: and LATENCY.\n#\nreplica-serve-stale-data yes\n\n# You can configure a replica instance to accept writes or not. Writing against\n# a replica instance may be useful to store some ephemeral data (because data\n# written on a replica will be easily deleted after resync with the master) but\n# may also cause problems if clients are writing to it because of a\n# misconfiguration.\n#\n# Since Redis 2.6 by default replicas are read-only.\n#\n# Note: read only replicas are not designed to be exposed to untrusted clients\n# on the internet. It's just a protection layer against misuse of the instance.\n# Still a read only replica exports by default all the administrative commands\n# such as CONFIG, DEBUG, and so forth. To a limited extent you can improve\n# security of read only replicas using 'rename-command' to shadow all the\n# administrative \/ dangerous commands.\nreplica-read-only yes\n\n# Replication SYNC strategy: disk or socket.\n#\n# -------------------------------------------------------\n# WARNING: DISKLESS REPLICATION IS EXPERIMENTAL CURRENTLY\n# -------------------------------------------------------\n#\n# New replicas and reconnecting replicas that are not able to continue the replication\n# process just receiving differences, need to do what is called a \"full\n# synchronization\". An RDB file is transmitted from the master to the replicas.\n# The transmission can happen in two different ways:\n#\n# 1) Disk-backed: The Redis master creates a new process that writes the RDB\n#                 file on disk. Later the file is transferred by the parent\n#                 process to the replicas incrementally.\n# 2) Diskless: The Redis master creates a new process that directly writes the\n#              RDB file to replica sockets, without touching the disk at all.\n#\n# With disk-backed replication, while the RDB file is generated, more replicas\n# can be queued and served with the RDB file as soon as the current child producing\n# the RDB file finishes its work. With diskless replication instead once\n# the transfer starts, new replicas arriving will be queued and a new transfer\n# will start when the current one terminates.\n#\n# When diskless replication is used, the master waits a configurable amount of\n# time (in seconds) before starting the transfer in the hope that multiple replicas\n# will arrive and the transfer can be parallelized.\n#\n# With slow disks and fast (large bandwidth) networks, diskless replication\n# works better.\nrepl-diskless-sync no\n\n# When diskless replication is enabled, it is possible to configure the delay\n# the server waits in order to spawn the child that transfers the RDB via socket\n# to the replicas.\n#\n# This is important since once the transfer starts, it is not possible to serve\n# new replicas arriving, that will be queued for the next RDB transfer, so the server\n# waits a delay in order to let more replicas arrive.\n#\n# The delay is specified in seconds, and by default is 5 seconds. To disable\n# it entirely just set it to 0 seconds and the transfer will start ASAP.\nrepl-diskless-sync-delay 5\n\n# Replicas send PINGs to server in a predefined interval. It's possible to change\n# this interval with the repl_ping_replica_period option. The default value is 10\n# seconds.\n#\n# repl-ping-replica-period 10\n\n# The following option sets the replication timeout for:\n#\n# 1) Bulk transfer I\/O during SYNC, from the point of view of replica.\n# 2) Master timeout from the point of view of replicas (data, pings).\n# 3) Replica timeout from the point of view of masters (REPLCONF ACK pings).\n#\n# It is important to make sure that this value is greater than the value\n# specified for repl-ping-replica-period otherwise a timeout will be detected\n# every time there is low traffic between the master and the replica.\n#\n# repl-timeout 60\n\n# Disable TCP_NODELAY on the replica socket after SYNC?\n#\n# If you select \"yes\" Redis will use a smaller number of TCP packets and\n# less bandwidth to send data to replicas. But this can add a delay for\n# the data to appear on the replica side, up to 40 milliseconds with\n# Linux kernels using a default configuration.\n#\n# If you select \"no\" the delay for data to appear on the replica side will\n# be reduced but more bandwidth will be used for replication.\n#\n# By default we optimize for low latency, but in very high traffic conditions\n# or when the master and replicas are many hops away, turning this to \"yes\" may\n# be a good idea.\nrepl-disable-tcp-nodelay no\n\n# Set the replication backlog size. The backlog is a buffer that accumulates\n# replica data when replicas are disconnected for some time, so that when a replica\n# wants to reconnect again, often a full resync is not needed, but a partial\n# resync is enough, just passing the portion of data the replica missed while\n# disconnected.\n#\n# The bigger the replication backlog, the longer the time the replica can be\n# disconnected and later be able to perform a partial resynchronization.\n#\n# The backlog is only allocated once there is at least a replica connected.\n#\n# repl-backlog-size 1mb\n\n# After a master has no longer connected replicas for some time, the backlog\n# will be freed. The following option configures the amount of seconds that\n# need to elapse, starting from the time the last replica disconnected, for\n# the backlog buffer to be freed.\n#\n# Note that replicas never free the backlog for timeout, since they may be\n# promoted to masters later, and should be able to correctly \"partially\n# resynchronize\" with the replicas: hence they should always accumulate backlog.\n#\n# A value of 0 means to never release the backlog.\n#\n# repl-backlog-ttl 3600\n\n# The replica priority is an integer number published by Redis in the INFO output.\n# It is used by Redis Sentinel in order to select a replica to promote into a\n# master if the master is no longer working correctly.\n#\n# A replica with a low priority number is considered better for promotion, so\n# for instance if there are three replicas with priority 10, 100, 25 Sentinel will\n# pick the one with priority 10, that is the lowest.\n#\n# However a special priority of 0 marks the replica as not able to perform the\n# role of master, so a replica with priority of 0 will never be selected by\n# Redis Sentinel for promotion.\n#\n# By default the priority is 100.\nreplica-priority 100\n\n# It is possible for a master to stop accepting writes if there are less than\n# N replicas connected, having a lag less or equal than M seconds.\n#\n# The N replicas need to be in \"online\" state.\n#\n# The lag in seconds, that must be &lt;= the specified value, is calculated from\n# the last ping received from the replica, that is usually sent every second.\n#\n# This option does not GUARANTEE that N replicas will accept the write, but\n# will limit the window of exposure for lost writes in case not enough replicas\n# are available, to the specified number of seconds.\n#\n# For example to require at least 3 replicas with a lag &lt;= 10 seconds use:\n#\n# min-replicas-to-write 3\n# min-replicas-max-lag 10\n#\n# Setting one or the other to 0 disables the feature.\n#\n# By default min-replicas-to-write is set to 0 (feature disabled) and\n# min-replicas-max-lag is set to 10.\n\n# A Redis master is able to list the address and port of the attached\n# replicas in different ways. For example the \"INFO replication\" section\n# offers this information, which is used, among other tools, by\n# Redis Sentinel in order to discover replica instances.\n# Another place where this info is available is in the output of the\n# \"ROLE\" command of a master.\n#\n# The listed IP and address normally reported by a replica is obtained\n# in the following way:\n#\n#   IP: The address is auto detected by checking the peer address\n#   of the socket used by the replica to connect with the master.\n#\n#   Port: The port is communicated by the replica during the replication\n#   handshake, and is normally the port that the replica is using to\n#   listen for connections.\n#\n# However when port forwarding or Network Address Translation (NAT) is\n# used, the replica may be actually reachable via different IP and port\n# pairs. The following two options can be used by a replica in order to\n# report to its master a specific set of IP and port, so that both INFO\n# and ROLE will report those values.\n#\n# There is no need to use both the options if you need to override just\n# the port or the IP address.\n#\n# replica-announce-ip 5.5.5.5\n# replica-announce-port 1234\n\n################################## SECURITY ###################################\n\n# Require clients to issue AUTH &lt;PASSWORD&gt; before processing any other\n# commands.  This might be useful in environments in which you do not trust\n# others with access to the host running redis-server.\n#\n# This should stay commented out for backward compatibility and because most\n# people do not need auth (e.g. they run their own servers).\n#\n# Warning: since Redis is pretty fast an outside user can try up to\n# 150k passwords per second against a good box. This means that you should\n# use a very strong password otherwise it will be very easy to break.\n#\n# requirepass foobared\n\n# Command renaming.\n#\n# It is possible to change the name of dangerous commands in a shared\n# environment. For instance the CONFIG command may be renamed into something\n# hard to guess so that it will still be available for internal-use tools\n# but not available for general clients.\n#\n# Example:\n#\n# rename-command CONFIG b840fc02d524045429941cc15f59e41cb7be6c52\n#\n# It is also possible to completely kill a command by renaming it into\n# an empty string:\n#\n# rename-command CONFIG \"\"\n#\n# Please note that changing the name of commands that are logged into the\n# AOF file or transmitted to replicas may cause problems.\n\n################################### CLIENTS ####################################\n\n# Set the max number of connected clients at the same time. By default\n# this limit is set to 10000 clients, however if the Redis server is not\n# able to configure the process file limit to allow for the specified limit\n# the max number of allowed clients is set to the current file limit\n# minus 32 (as Redis reserves a few file descriptors for internal uses).\n#\n# Once the limit is reached Redis will close all the new connections sending\n# an error 'max number of clients reached'.\n#\n# maxclients 10000\n\n############################## MEMORY MANAGEMENT ################################\n\n# Set a memory usage limit to the specified amount of bytes.\n# When the memory limit is reached Redis will try to remove keys\n# according to the eviction policy selected (see maxmemory-policy).\n#\n# If Redis can't remove keys according to the policy, or if the policy is\n# set to 'noeviction', Redis will start to reply with errors to commands\n# that would use more memory, like SET, LPUSH, and so on, and will continue\n# to reply to read-only commands like GET.\n#\n# This option is usually useful when using Redis as an LRU or LFU cache, or to\n# set a hard memory limit for an instance (using the 'noeviction' policy).\n#\n# WARNING: If you have replicas attached to an instance with maxmemory on,\n# the size of the output buffers needed to feed the replicas are subtracted\n# from the used memory count, so that network problems \/ resyncs will\n# not trigger a loop where keys are evicted, and in turn the output\n# buffer of replicas is full with DELs of keys evicted triggering the deletion\n# of more keys, and so forth until the database is completely emptied.\n#\n# In short... if you have replicas attached it is suggested that you set a lower\n# limit for maxmemory so that there is some free RAM on the system for replica\n# output buffers (but this is not needed if the policy is 'noeviction').\n#\n# maxmemory &lt;bytes&gt;\nmaxmemory 473000000\n\n# MAXMEMORY POLICY: how Redis will select what to remove when maxmemory\n# is reached. You can select among five behaviors:\n#\n# volatile-lru -&gt; Evict using approximated LRU among the keys with an expire set.\n# allkeys-lru -&gt; Evict any key using approximated LRU.\n# volatile-lfu -&gt; Evict using approximated LFU among the keys with an expire set.\n# allkeys-lfu -&gt; Evict any key using approximated LFU.\n# volatile-random -&gt; Remove a random key among the ones with an expire set.\n# allkeys-random -&gt; Remove a random key, any key.\n# volatile-ttl -&gt; Remove the key with the nearest expire time (minor TTL)\n# noeviction -&gt; Don't evict anything, just return an error on write operations.\n#\n# LRU means Least Recently Used\n# LFU means Least Frequently Used\n#\n# Both LRU, LFU and volatile-ttl are implemented using approximated\n# randomized algorithms.\n#\n# Note: with any of the above policies, Redis will return an error on write\n#       operations, when there are no suitable keys for eviction.\n#\n#       At the date of writing these commands are: set setnx setex append\n#       incr decr rpush lpush rpushx lpushx linsert lset rpoplpush sadd\n#       sinter sinterstore sunion sunionstore sdiff sdiffstore zadd zincrby\n#       zunionstore zinterstore hset hsetnx hmset hincrby incrby decrby\n#       getset mset msetnx exec sort\n#\n# The default is:\n#\n# maxmemory-policy noeviction\n\n# LRU, LFU and minimal TTL algorithms are not precise algorithms but approximated\n# algorithms (in order to save memory), so you can tune it for speed or\n# accuracy. For default Redis will check five keys and pick the one that was\n# used less recently, you can change the sample size using the following\n# configuration directive.\n#\n# The default of 5 produces good enough results. 10 Approximates very closely\n# true LRU but costs more CPU. 3 is faster but not very accurate.\n#\n# maxmemory-samples 5\n\n# Starting from Redis 5, by default a replica will ignore its maxmemory setting\n# (unless it is promoted to master after a failover or manually). It means\n# that the eviction of keys will be just handled by the master, sending the\n# DEL commands to the replica as keys evict in the master side.\n#\n# This behavior ensures that masters and replicas stay consistent, and is usually\n# what you want, however if your replica is writable, or you want the replica to have\n# a different memory setting, and you are sure all the writes performed to the\n# replica are idempotent, then you may change this default (but be sure to understand\n# what you are doing).\n#\n# Note that since the replica by default does not evict, it may end using more\n# memory than the one set via maxmemory (there are certain buffers that may\n# be larger on the replica, or data structures may sometimes take more memory and so\n# forth). So make sure you monitor your replicas and make sure they have enough\n# memory to never hit a real out-of-memory condition before the master hits\n# the configured maxmemory setting.\n#\n# replica-ignore-maxmemory yes\n\n############################# LAZY FREEING ####################################\n\n# Redis has two primitives to delete keys. One is called DEL and is a blocking\n# deletion of the object. It means that the server stops processing new commands\n# in order to reclaim all the memory associated with an object in a synchronous\n# way. If the key deleted is associated with a small object, the time needed\n# in order to execute the DEL command is very small and comparable to most other\n# O(1) or O(log_N) commands in Redis. However if the key is associated with an\n# aggregated value containing millions of elements, the server can block for\n# a long time (even seconds) in order to complete the operation.\n#\n# For the above reasons Redis also offers non blocking deletion primitives\n# such as UNLINK (non blocking DEL) and the ASYNC option of FLUSHALL and\n# FLUSHDB commands, in order to reclaim memory in background. Those commands\n# are executed in constant time. Another thread will incrementally free the\n# object in the background as fast as possible.\n#\n# DEL, UNLINK and ASYNC option of FLUSHALL and FLUSHDB are user-controlled.\n# It's up to the design of the application to understand when it is a good\n# idea to use one or the other. However the Redis server sometimes has to\n# delete keys or flush the whole database as a side effect of other operations.\n# Specifically Redis deletes objects independently of a user call in the\n# following scenarios:\n#\n# 1) On eviction, because of the maxmemory and maxmemory policy configurations,\n#    in order to make room for new data, without going over the specified\n#    memory limit.\n# 2) Because of expire: when a key with an associated time to live (see the\n#    EXPIRE command) must be deleted from memory.\n# 3) Because of a side effect of a command that stores data on a key that may\n#    already exist. For example the RENAME command may delete the old key\n#    content when it is replaced with another one. Similarly SUNIONSTORE\n#    or SORT with STORE option may delete existing keys. The SET command\n#    itself removes any old content of the specified key in order to replace\n#    it with the specified string.\n# 4) During replication, when a replica performs a full resynchronization with\n#    its master, the content of the whole database is removed in order to\n#    load the RDB file just transferred.\n#\n# In all the above cases the default is to delete objects in a blocking way,\n# like if DEL was called. However you can configure each case specifically\n# in order to instead release memory in a non-blocking way like if UNLINK\n# was called, using the following configuration directives:\n\nlazyfree-lazy-eviction no\nlazyfree-lazy-expire no\nlazyfree-lazy-server-del no\nreplica-lazy-flush no\n\n############################## APPEND ONLY MODE ###############################\n\n# By default Redis asynchronously dumps the dataset on disk. This mode is\n# good enough in many applications, but an issue with the Redis process or\n# a power outage may result into a few minutes of writes lost (depending on\n# the configured save points).\n#\n# The Append Only File is an alternative persistence mode that provides\n# much better durability. For instance using the default data fsync policy\n# (see later in the config file) Redis can lose just one second of writes in a\n# dramatic event like a server power outage, or a single write if something\n# wrong with the Redis process itself happens, but the operating system is\n# still running correctly.\n#\n# AOF and RDB persistence can be enabled at the same time without problems.\n# If the AOF is enabled on startup Redis will load the AOF, that is the file\n# with the better durability guarantees.\n#\n# Please check http:\/\/redis.io\/topics\/persistence for more information.\n\nappendonly no\n\n# The name of the append only file (default: \"appendonly.aof\")\n\nappendfilename \"appendonly.aof\"\n\n# The fsync() call tells the Operating System to actually write data on disk\n# instead of waiting for more data in the output buffer. Some OS will really flush\n# data on disk, some other OS will just try to do it ASAP.\n#\n# Redis supports three different modes:\n#\n# no: don't fsync, just let the OS flush the data when it wants. Faster.\n# always: fsync after every write to the append only log. Slow, Safest.\n# everysec: fsync only one time every second. Compromise.\n#\n# The default is \"everysec\", as that's usually the right compromise between\n# speed and data safety. It's up to you to understand if you can relax this to\n# \"no\" that will let the operating system flush the output buffer when\n# it wants, for better performances (but if you can live with the idea of\n# some data loss consider the default persistence mode that's snapshotting),\n# or on the contrary, use \"always\" that's very slow but a bit safer than\n# everysec.\n#\n# More details please check the following article:\n# http:\/\/antirez.com\/post\/redis-persistence-demystified.html\n#\n# If unsure, use \"everysec\".\n\n# appendfsync always\nappendfsync everysec\n# appendfsync no\n\n# When the AOF fsync policy is set to always or everysec, and a background\n# saving process (a background save or AOF log background rewriting) is\n# performing a lot of I\/O against the disk, in some Linux configurations\n# Redis may block too long on the fsync() call. Note that there is no fix for\n# this currently, as even performing fsync in a different thread will block\n# our synchronous write(2) call.\n#\n# In order to mitigate this problem it's possible to use the following option\n# that will prevent fsync() from being called in the main process while a\n# BGSAVE or BGREWRITEAOF is in progress.\n#\n# This means that while another child is saving, the durability of Redis is\n# the same as \"appendfsync none\". In practical terms, this means that it is\n# possible to lose up to 30 seconds of log in the worst scenario (with the\n# default Linux settings).\n#\n# If you have latency problems turn this to \"yes\". Otherwise leave it as\n# \"no\" that is the safest pick from the point of view of durability.\n\nno-appendfsync-on-rewrite no\n\n# Automatic rewrite of the append only file.\n# Redis is able to automatically rewrite the log file implicitly calling\n# BGREWRITEAOF when the AOF log size grows by the specified percentage.\n#\n# This is how it works: Redis remembers the size of the AOF file after the\n# latest rewrite (if no rewrite has happened since the restart, the size of\n# the AOF at startup is used).\n#\n# This base size is compared to the current size. If the current size is\n# bigger than the specified percentage, the rewrite is triggered. Also\n# you need to specify a minimal size for the AOF file to be rewritten, this\n# is useful to avoid rewriting the AOF file even if the percentage increase\n# is reached but it is still pretty small.\n#\n# Specify a percentage of zero in order to disable the automatic AOF\n# rewrite feature.\n\nauto-aof-rewrite-percentage 100\nauto-aof-rewrite-min-size 64mb\n\n# An AOF file may be found to be truncated at the end during the Redis\n# startup process, when the AOF data gets loaded back into memory.\n# This may happen when the system where Redis is running\n# crashes, especially when an ext4 filesystem is mounted without the\n# data=ordered option (however this can't happen when Redis itself\n# crashes or aborts but the operating system still works correctly).\n#\n# Redis can either exit with an error when this happens, or load as much\n# data as possible (the default now) and start if the AOF file is found\n# to be truncated at the end. The following option controls this behavior.\n#\n# If aof-load-truncated is set to yes, a truncated AOF file is loaded and\n# the Redis server starts emitting a log to inform the user of the event.\n# Otherwise if the option is set to no, the server aborts with an error\n# and refuses to start. When the option is set to no, the user requires\n# to fix the AOF file using the \"redis-check-aof\" utility before to restart\n# the server.\n#\n# Note that if the AOF file will be found to be corrupted in the middle\n# the server will still exit with an error. This option only applies when\n# Redis will try to read more data from the AOF file but not enough bytes\n# will be found.\naof-load-truncated yes\n\n# When rewriting the AOF file, Redis is able to use an RDB preamble in the\n# AOF file for faster rewrites and recoveries. When this option is turned\n# on the rewritten AOF file is composed of two different stanzas:\n#\n#   [RDB file][AOF tail]\n#\n# When loading Redis recognizes that the AOF file starts with the \"REDIS\"\n# string and loads the prefixed RDB file, and continues loading the AOF\n# tail.\naof-use-rdb-preamble yes\n\n################################ LUA SCRIPTING  ###############################\n\n# Max execution time of a Lua script in milliseconds.\n#\n# If the maximum execution time is reached Redis will log that a script is\n# still in execution after the maximum allowed time and will start to\n# reply to queries with an error.\n#\n# When a long running script exceeds the maximum execution time only the\n# SCRIPT KILL and SHUTDOWN NOSAVE commands are available. The first can be\n# used to stop a script that did not yet called write commands. The second\n# is the only way to shut down the server in the case a write command was\n# already issued by the script but the user doesn't want to wait for the natural\n# termination of the script.\n#\n# Set it to 0 or a negative value for unlimited execution without warnings.\nlua-time-limit 5000\n\n################################ REDIS CLUSTER  ###############################\n\n# Normal Redis instances can't be part of a Redis Cluster; only nodes that are\n# started as cluster nodes can. In order to start a Redis instance as a\n# cluster node enable the cluster support uncommenting the following:\n#\n# cluster-enabled yes\n\n# Every cluster node has a cluster configuration file. This file is not\n# intended to be edited by hand. It is created and updated by Redis nodes.\n# Every Redis Cluster node requires a different cluster configuration file.\n# Make sure that instances running in the same system do not have\n# overlapping cluster configuration file names.\n#\n# cluster-config-file nodes-6379.conf\n\n# Cluster node timeout is the amount of milliseconds a node must be unreachable\n# for it to be considered in failure state.\n# Most other internal time limits are multiple of the node timeout.\n#\n# cluster-node-timeout 15000\n\n# A replica of a failing master will avoid to start a failover if its data\n# looks too old.\n#\n# There is no simple way for a replica to actually have an exact measure of\n# its \"data age\", so the following two checks are performed:\n#\n# 1) If there are multiple replicas able to failover, they exchange messages\n#    in order to try to give an advantage to the replica with the best\n#    replication offset (more data from the master processed).\n#    Replicas will try to get their rank by offset, and apply to the start\n#    of the failover a delay proportional to their rank.\n#\n# 2) Every single replica computes the time of the last interaction with\n#    its master. This can be the last ping or command received (if the master\n#    is still in the \"connected\" state), or the time that elapsed since the\n#    disconnection with the master (if the replication link is currently down).\n#    If the last interaction is too old, the replica will not try to failover\n#    at all.\n#\n# The point \"2\" can be tuned by user. Specifically a replica will not perform\n# the failover if, since the last interaction with the master, the time\n# elapsed is greater than:\n#\n#   (node-timeout * replica-validity-factor) + repl-ping-replica-period\n#\n# So for example if node-timeout is 30 seconds, and the replica-validity-factor\n# is 10, and assuming a default repl-ping-replica-period of 10 seconds, the\n# replica will not try to failover if it was not able to talk with the master\n# for longer than 310 seconds.\n#\n# A large replica-validity-factor may allow replicas with too old data to failover\n# a master, while a too small value may prevent the cluster from being able to\n# elect a replica at all.\n#\n# For maximum availability, it is possible to set the replica-validity-factor\n# to a value of 0, which means, that replicas will always try to failover the\n# master regardless of the last time they interacted with the master.\n# (However they'll always try to apply a delay proportional to their\n# offset rank).\n#\n# Zero is the only value able to guarantee that when all the partitions heal\n# the cluster will always be able to continue.\n#\n# cluster-replica-validity-factor 10\n\n# Cluster replicas are able to migrate to orphaned masters, that are masters\n# that are left without working replicas. This improves the cluster ability\n# to resist to failures as otherwise an orphaned master can't be failed over\n# in case of failure if it has no working replicas.\n#\n# Replicas migrate to orphaned masters only if there are still at least a\n# given number of other working replicas for their old master. This number\n# is the \"migration barrier\". A migration barrier of 1 means that a replica\n# will migrate only if there is at least 1 other working replica for its master\n# and so forth. It usually reflects the number of replicas you want for every\n# master in your cluster.\n#\n# Default is 1 (replicas migrate only if their masters remain with at least\n# one replica). To disable migration just set it to a very large value.\n# A value of 0 can be set but is useful only for debugging and dangerous\n# in production.\n#\n# cluster-migration-barrier 1\n\n# By default Redis Cluster nodes stop accepting queries if they detect there\n# is at least an hash slot uncovered (no available node is serving it).\n# This way if the cluster is partially down (for example a range of hash slots\n# are no longer covered) all the cluster becomes, eventually, unavailable.\n# It automatically returns available as soon as all the slots are covered again.\n#\n# However sometimes you want the subset of the cluster which is working,\n# to continue to accept queries for the part of the key space that is still\n# covered. In order to do so, just set the cluster-require-full-coverage\n# option to no.\n#\n# cluster-require-full-coverage yes\n\n# This option, when set to yes, prevents replicas from trying to failover its\n# master during master failures. However the master can still perform a\n# manual failover, if forced to do so.\n#\n# This is useful in different scenarios, especially in the case of multiple\n# data center operations, where we want one side to never be promoted if not\n# in the case of a total DC failure.\n#\n# cluster-replica-no-failover no\n\n# In order to setup your cluster make sure to read the documentation\n# available at http:\/\/redis.io web site.\n\n########################## CLUSTER DOCKER\/NAT support  ########################\n\n# In certain deployments, Redis Cluster nodes address discovery fails, because\n# addresses are NAT-ted or because ports are forwarded (the typical case is\n# Docker and other containers).\n#\n# In order to make Redis Cluster working in such environments, a static\n# configuration where each node knows its public address is needed. The\n# following two options are used for this scope, and are:\n#\n# * cluster-announce-ip\n# * cluster-announce-port\n# * cluster-announce-bus-port\n#\n# Each instruct the node about its address, client port, and cluster message\n# bus port. The information is then published in the header of the bus packets\n# so that other nodes will be able to correctly map the address of the node\n# publishing the information.\n#\n# If the above options are not used, the normal Redis Cluster auto-detection\n# will be used instead.\n#\n# Note that when remapped, the bus port may not be at the fixed offset of\n# clients port + 10000, so you can specify any port and bus-port depending\n# on how they get remapped. If the bus-port is not set, a fixed offset of\n# 10000 will be used as usually.\n#\n# Example:\n#\n# cluster-announce-ip 10.1.1.5\n# cluster-announce-port 6379\n# cluster-announce-bus-port 6380\n\n################################## SLOW LOG ###################################\n\n# The Redis Slow Log is a system to log queries that exceeded a specified\n# execution time. The execution time does not include the I\/O operations\n# like talking with the client, sending the reply and so forth,\n# but just the time needed to actually execute the command (this is the only\n# stage of command execution where the thread is blocked and can not serve\n# other requests in the meantime).\n#\n# You can configure the slow log with two parameters: one tells Redis\n# what is the execution time, in microseconds, to exceed in order for the\n# command to get logged, and the other parameter is the length of the\n# slow log. When a new command is logged the oldest one is removed from the\n# queue of logged commands.\n\n# The following time is expressed in microseconds, so 1000000 is equivalent\n# to one second. Note that a negative number disables the slow log, while\n# a value of zero forces the logging of every command.\nslowlog-log-slower-than 10000\n\n# There is no limit to this length. Just be aware that it will consume memory.\n# You can reclaim memory used by the slow log with SLOWLOG RESET.\nslowlog-max-len 128\n\n################################ LATENCY MONITOR ##############################\n\n# The Redis latency monitoring subsystem samples different operations\n# at runtime in order to collect data related to possible sources of\n# latency of a Redis instance.\n#\n# Via the LATENCY command this information is available to the user that can\n# print graphs and obtain reports.\n#\n# The system only logs operations that were performed in a time equal or\n# greater than the amount of milliseconds specified via the\n# latency-monitor-threshold configuration directive. When its value is set\n# to zero, the latency monitor is turned off.\n#\n# By default latency monitoring is disabled since it is mostly not needed\n# if you don't have latency issues, and collecting data has a performance\n# impact, that while very small, can be measured under big load. Latency\n# monitoring can easily be enabled at runtime using the command\n# \"CONFIG SET latency-monitor-threshold &lt;milliseconds&gt;\" if needed.\nlatency-monitor-threshold 0\n\n############################# EVENT NOTIFICATION ##############################\n\n# Redis can notify Pub\/Sub clients about events happening in the key space.\n# This feature is documented at http:\/\/redis.io\/topics\/notifications\n#\n# For instance if keyspace events notification is enabled, and a client\n# performs a DEL operation on key \"foo\" stored in the Database 0, two\n# messages will be published via Pub\/Sub:\n#\n# PUBLISH __keyspace@0__:foo del\n# PUBLISH __keyevent@0__:del foo\n#\n# It is possible to select the events that Redis will notify among a set\n# of classes. Every class is identified by a single character:\n#\n#  K     Keyspace events, published with __keyspace@&lt;db&gt;__ prefix.\n#  E     Keyevent events, published with __keyevent@&lt;db&gt;__ prefix.\n#  g     Generic commands (non-type specific) like DEL, EXPIRE, RENAME, ...\n#  $     String commands\n#  l     List commands\n#  s     Set commands\n#  h     Hash commands\n#  z     Sorted set commands\n#  x     Expired events (events generated every time a key expires)\n#  e     Evicted events (events generated when a key is evicted for maxmemory)\n#  A     Alias for g$lshzxe, so that the \"AKE\" string means all the events.\n#\n#  The \"notify-keyspace-events\" takes as argument a string that is composed\n#  of zero or multiple characters. The empty string means that notifications\n#  are disabled.\n#\n#  Example: to enable list and generic events, from the point of view of the\n#           event name, use:\n#\n#  notify-keyspace-events Elg\n#\n#  Example 2: to get the stream of the expired keys subscribing to channel\n#             name __keyevent@0__:expired use:\n#\n#  notify-keyspace-events Ex\n#\n#  By default all notifications are disabled because most users don't need\n#  this feature and the feature has some overhead. Note that if you don't\n#  specify at least one of K or E, no events will be delivered.\nnotify-keyspace-events \"\"\n\n############################### ADVANCED CONFIG ###############################\n\n# Hashes are encoded using a memory efficient data structure when they have a\n# small number of entries, and the biggest entry does not exceed a given\n# threshold. These thresholds can be configured using the following directives.\nhash-max-ziplist-entries 512\nhash-max-ziplist-value 64\n\n# Lists are also encoded in a special way to save a lot of space.\n# The number of entries allowed per internal list node can be specified\n# as a fixed maximum size or a maximum number of elements.\n# For a fixed maximum size, use -5 through -1, meaning:\n# -5: max size: 64 Kb  &lt;-- not recommended for normal workloads\n# -4: max size: 32 Kb  &lt;-- not recommended\n# -3: max size: 16 Kb  &lt;-- probably not recommended\n# -2: max size: 8 Kb   &lt;-- good\n# -1: max size: 4 Kb   &lt;-- good\n# Positive numbers mean store up to _exactly_ that number of elements\n# per list node.\n# The highest performing option is usually -2 (8 Kb size) or -1 (4 Kb size),\n# but if your use case is unique, adjust the settings as necessary.\nlist-max-ziplist-size -2\n\n# Lists may also be compressed.\n# Compress depth is the number of quicklist ziplist nodes from *each* side of\n# the list to *exclude* from compression.  The head and tail of the list\n# are always uncompressed for fast push\/pop operations.  Settings are:\n# 0: disable all list compression\n# 1: depth 1 means \"don't start compressing until after 1 node into the list,\n#    going from either the head or tail\"\n#    So: [head]-&gt;node-&gt;node-&gt;...-&gt;node-&gt;[tail]\n#    [head], [tail] will always be uncompressed; inner nodes will compress.\n# 2: [head]-&gt;[next]-&gt;node-&gt;node-&gt;...-&gt;node-&gt;[prev]-&gt;[tail]\n#    2 here means: don't compress head or head-&gt;next or tail-&gt;prev or tail,\n#    but compress all nodes between them.\n# 3: [head]-&gt;[next]-&gt;[next]-&gt;node-&gt;node-&gt;...-&gt;node-&gt;[prev]-&gt;[prev]-&gt;[tail]\n# etc.\nlist-compress-depth 0\n\n# Sets have a special encoding in just one case: when a set is composed\n# of just strings that happen to be integers in radix 10 in the range\n# of 64 bit signed integers.\n# The following configuration setting sets the limit in the size of the\n# set in order to use this special memory saving encoding.\nset-max-intset-entries 512\n\n# Similarly to hashes and lists, sorted sets are also specially encoded in\n# order to save a lot of space. This encoding is only used when the length and\n# elements of a sorted set are below the following limits:\nzset-max-ziplist-entries 128\nzset-max-ziplist-value 64\n\n# HyperLogLog sparse representation bytes limit. The limit includes the\n# 16 bytes header. When an HyperLogLog using the sparse representation crosses\n# this limit, it is converted into the dense representation.\n#\n# A value greater than 16000 is totally useless, since at that point the\n# dense representation is more memory efficient.\n#\n# The suggested value is ~ 3000 in order to have the benefits of\n# the space efficient encoding without slowing down too much PFADD,\n# which is O(N) with the sparse encoding. The value can be raised to\n# ~ 10000 when CPU is not a concern, but space is, and the data set is\n# composed of many HyperLogLogs with cardinality in the 0 - 15000 range.\nhll-sparse-max-bytes 3000\n\n# Streams macro node max size \/ items. The stream data structure is a radix\n# tree of big nodes that encode multiple items inside. Using this configuration\n# it is possible to configure how big a single node can be in bytes, and the\n# maximum number of items it may contain before switching to a new node when\n# appending new stream entries. If any of the following settings are set to\n# zero, the limit is ignored, so for instance it is possible to set just a\n# max entires limit by setting max-bytes to 0 and max-entries to the desired\n# value.\nstream-node-max-bytes 4096\nstream-node-max-entries 100\n\n# Active rehashing uses 1 millisecond every 100 milliseconds of CPU time in\n# order to help rehashing the main Redis hash table (the one mapping top-level\n# keys to values). The hash table implementation Redis uses (see dict.c)\n# performs a lazy rehashing: the more operation you run into a hash table\n# that is rehashing, the more rehashing \"steps\" are performed, so if the\n# server is idle the rehashing is never complete and some more memory is used\n# by the hash table.\n#\n# The default is to use this millisecond 10 times every second in order to\n# actively rehash the main dictionaries, freeing memory when possible.\n#\n# If unsure:\n# use \"activerehashing no\" if you have hard latency requirements and it is\n# not a good thing in your environment that Redis can reply from time to time\n# to queries with 2 milliseconds delay.\n#\n# use \"activerehashing yes\" if you don't have such hard requirements but\n# want to free memory asap when possible.\nactiverehashing yes\n\n# The client output buffer limits can be used to force disconnection of clients\n# that are not reading data from the server fast enough for some reason (a\n# common reason is that a Pub\/Sub client can't consume messages as fast as the\n# publisher can produce them).\n#\n# The limit can be set differently for the three different classes of clients:\n#\n# normal -&gt; normal clients including MONITOR clients\n# replica  -&gt; replica clients\n# pubsub -&gt; clients subscribed to at least one pubsub channel or pattern\n#\n# The syntax of every client-output-buffer-limit directive is the following:\n#\n# client-output-buffer-limit &lt;class&gt; &lt;hard limit&gt; &lt;soft limit&gt; &lt;soft seconds&gt;\n#\n# A client is immediately disconnected once the hard limit is reached, or if\n# the soft limit is reached and remains reached for the specified number of\n# seconds (continuously).\n# So for instance if the hard limit is 32 megabytes and the soft limit is\n# 16 megabytes \/ 10 seconds, the client will get disconnected immediately\n# if the size of the output buffers reach 32 megabytes, but will also get\n# disconnected if the client reaches 16 megabytes and continuously overcomes\n# the limit for 10 seconds.\n#\n# By default normal clients are not limited because they don't receive data\n# without asking (in a push way), but just after a request, so only\n# asynchronous clients may create a scenario where data is requested faster\n# than it can read.\n#\n# Instead there is a default limit for pubsub and replica clients, since\n# subscribers and replicas receive data in a push fashion.\n#\n# Both the hard or the soft limit can be disabled by setting them to zero.\nclient-output-buffer-limit normal 0 0 0\nclient-output-buffer-limit replica 256mb 64mb 60\nclient-output-buffer-limit pubsub 32mb 8mb 60\n\n# Client query buffers accumulate new commands. They are limited to a fixed\n# amount by default in order to avoid that a protocol desynchronization (for\n# instance due to a bug in the client) will lead to unbound memory usage in\n# the query buffer. However you can configure it here if you have very special\n# needs, such us huge multi\/exec requests or alike.\n#\n# client-query-buffer-limit 1gb\n\n# In the Redis protocol, bulk requests, that are, elements representing single\n# strings, are normally limited ot 512 mb. However you can change this limit\n# here.\n#\n# proto-max-bulk-len 512mb\n\n# Redis calls an internal function to perform many background tasks, like\n# closing connections of clients in timeout, purging expired keys that are\n# never requested, and so forth.\n#\n# Not all tasks are performed with the same frequency, but Redis checks for\n# tasks to perform according to the specified \"hz\" value.\n#\n# By default \"hz\" is set to 10. Raising the value will use more CPU when\n# Redis is idle, but at the same time will make Redis more responsive when\n# there are many keys expiring at the same time, and timeouts may be\n# handled with more precision.\n#\n# The range is between 1 and 500, however a value over 100 is usually not\n# a good idea. Most users should use the default of 10 and raise this up to\n# 100 only in environments where very low latency is required.\nhz 10\n\n# Normally it is useful to have an HZ value which is proportional to the\n# number of clients connected. This is useful in order, for instance, to\n# avoid too many clients are processed for each background task invocation\n# in order to avoid latency spikes.\n#\n# Since the default HZ value by default is conservatively set to 10, Redis\n# offers, and enables by default, the ability to use an adaptive HZ value\n# which will temporary raise when there are many connected clients.\n#\n# When dynamic HZ is enabled, the actual configured HZ will be used as\n# as a baseline, but multiples of the configured HZ value will be actually\n# used as needed once more clients are connected. In this way an idle\n# instance will use very little CPU time while a busy instance will be\n# more responsive.\ndynamic-hz yes\n\n# When a child rewrites the AOF file, if the following option is enabled\n# the file will be fsync-ed every 32 MB of data generated. This is useful\n# in order to commit the file to the disk more incrementally and avoid\n# big latency spikes.\naof-rewrite-incremental-fsync yes\n\n# When redis saves RDB file, if the following option is enabled\n# the file will be fsync-ed every 32 MB of data generated. This is useful\n# in order to commit the file to the disk more incrementally and avoid\n# big latency spikes.\nrdb-save-incremental-fsync yes\n\n# Redis LFU eviction (see maxmemory setting) can be tuned. However it is a good\n# idea to start with the default settings and only change them after investigating\n# how to improve the performances and how the keys LFU change over time, which\n# is possible to inspect via the OBJECT FREQ command.\n#\n# There are two tunable parameters in the Redis LFU implementation: the\n# counter logarithm factor and the counter decay time. It is important to\n# understand what the two parameters mean before changing them.\n#\n# The LFU counter is just 8 bits per key, it's maximum value is 255, so Redis\n# uses a probabilistic increment with logarithmic behavior. Given the value\n# of the old counter, when a key is accessed, the counter is incremented in\n# this way:\n#\n# 1. A random number R between 0 and 1 is extracted.\n# 2. A probability P is calculated as 1\/(old_value*lfu_log_factor+1).\n# 3. The counter is incremented only if R &lt; P.\n#\n# The default lfu-log-factor is 10. This is a table of how the frequency\n# counter changes with a different number of accesses with different\n# logarithmic factors:\n#\n# +--------+------------+------------+------------+------------+------------+\n# | factor | 100 hits   | 1000 hits  | 100K hits  | 1M hits    | 10M hits   |\n# +--------+------------+------------+------------+------------+------------+\n# | 0      | 104        | 255        | 255        | 255        | 255        |\n# +--------+------------+------------+------------+------------+------------+\n# | 1      | 18         | 49         | 255        | 255        | 255        |\n# +--------+------------+------------+------------+------------+------------+\n# | 10     | 10         | 18         | 142        | 255        | 255        |\n# +--------+------------+------------+------------+------------+------------+\n# | 100    | 8          | 11         | 49         | 143        | 255        |\n# +--------+------------+------------+------------+------------+------------+\n#\n# NOTE: The above table was obtained by running the following commands:\n#\n#   redis-benchmark -n 1000000 incr foo\n#   redis-cli object freq foo\n#\n# NOTE 2: The counter initial value is 5 in order to give new objects a chance\n# to accumulate hits.\n#\n# The counter decay time is the time, in minutes, that must elapse in order\n# for the key counter to be divided by two (or decremented if it has a value\n# less &lt;= 10).\n#\n# The default value for the lfu-decay-time is 1. A Special value of 0 means to\n# decay the counter every time it happens to be scanned.\n#\n# lfu-log-factor 10\n# lfu-decay-time 1\n\n########################### ACTIVE DEFRAGMENTATION #######################\n#\n# WARNING THIS FEATURE IS EXPERIMENTAL. However it was stress tested\n# even in production and manually tested by multiple engineers for some\n# time.\n#\n# What is active defragmentation?\n# -------------------------------\n#\n# Active (online) defragmentation allows a Redis server to compact the\n# spaces left between small allocations and deallocations of data in memory,\n# thus allowing to reclaim back memory.\n#\n# Fragmentation is a natural process that happens with every allocator (but\n# less so with Jemalloc, fortunately) and certain workloads. Normally a server\n# restart is needed in order to lower the fragmentation, or at least to flush\n# away all the data and create it again. However thanks to this feature\n# implemented by Oran Agra for Redis 4.0 this process can happen at runtime\n# in an \"hot\" way, while the server is running.\n#\n# Basically when the fragmentation is over a certain level (see the\n# configuration options below) Redis will start to create new copies of the\n# values in contiguous memory regions by exploiting certain specific Jemalloc\n# features (in order to understand if an allocation is causing fragmentation\n# and to allocate it in a better place), and at the same time, will release the\n# old copies of the data. This process, repeated incrementally for all the keys\n# will cause the fragmentation to drop back to normal values.\n#\n# Important things to understand:\n#\n# 1. This feature is disabled by default, and only works if you compiled Redis\n#    to use the copy of Jemalloc we ship with the source code of Redis.\n#    This is the default with Linux builds.\n#\n# 2. You never need to enable this feature if you don't have fragmentation\n#    issues.\n#\n# 3. Once you experience fragmentation, you can enable this feature when\n#    needed with the command \"CONFIG SET activedefrag yes\".\n#\n# The configuration parameters are able to fine tune the behavior of the\n# defragmentation process. If you are not sure about what they mean it is\n# a good idea to leave the defaults untouched.\n\n# Enabled active defragmentation\n# activedefrag yes\n\n# Minimum amount of fragmentation waste to start active defrag\n# active-defrag-ignore-bytes 100mb\n\n# Minimum percentage of fragmentation to start active defrag\n# active-defrag-threshold-lower 10\n\n# Maximum percentage of fragmentation at which we use maximum effort\n# active-defrag-threshold-upper 100\n\n# Minimal effort for defrag in CPU percentage\n# active-defrag-cycle-min 5\n\n# Maximal effort for defrag in CPU percentage\n# active-defrag-cycle-max 75\n\n# Maximum number of set\/hash\/zset\/list fields that will be processed from\n# the main dictionary scan\n# active-defrag-max-scan-fields 1000\n<\/pre>\n<\/div>\n<p>\u3000\u3000<\/p>\n","protected":false},"excerpt":{"rendered":"<p># Redis configuration file example. # # Note that in or &hellip; <a href=\"http:\/\/blog.langmanezhuang.com\/index.php\/2021\/12\/26\/redis%e9%85%8d%e7%bd%ae%e6%96%87%e4%bb%b6-redis-conf\/\" class=\"more-link\">\u7ee7\u7eed\u9605\u8bfb <span class=\"screen-reader-text\">redis\u914d\u7f6e\u6587\u4ef6 redis.conf<\/span> <span class=\"meta-nav\">&rarr;<\/span><\/a><\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":[],"categories":[1],"tags":[],"_links":{"self":[{"href":"http:\/\/blog.langmanezhuang.com\/index.php\/wp-json\/wp\/v2\/posts\/841"}],"collection":[{"href":"http:\/\/blog.langmanezhuang.com\/index.php\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"http:\/\/blog.langmanezhuang.com\/index.php\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"http:\/\/blog.langmanezhuang.com\/index.php\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"http:\/\/blog.langmanezhuang.com\/index.php\/wp-json\/wp\/v2\/comments?post=841"}],"version-history":[{"count":0,"href":"http:\/\/blog.langmanezhuang.com\/index.php\/wp-json\/wp\/v2\/posts\/841\/revisions"}],"wp:attachment":[{"href":"http:\/\/blog.langmanezhuang.com\/index.php\/wp-json\/wp\/v2\/media?parent=841"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"http:\/\/blog.langmanezhuang.com\/index.php\/wp-json\/wp\/v2\/categories?post=841"},{"taxonomy":"post_tag","embeddable":true,"href":"http:\/\/blog.langmanezhuang.com\/index.php\/wp-json\/wp\/v2\/tags?post=841"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}