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[数据库]Redis基本配置


# redis 配置文件示例# 当你需要为某个配置项指定内存大小的时候,必须要带上单位,# 通常的格式就是 1k 5gb 4m 等酱紫:## 1k => 1000 bytes# 1kb => 1024 bytes# 1m => 1000000 bytes# 1mb => 1024*1024 bytes# 1g => 1000000000 bytes# 1gb => 1024*1024*1024 bytes## 单位是不区分大小写的,你写 1K 5GB 4M 也行################################## INCLUDES #################################### 假如说你有一个可用于所有的 redis server 的标准配置模板,# 但针对某些 server 又需要一些个性化的设置,# 你可以使用 include 来包含一些其他的配置文件,这对你来说是非常有用的。## 但是要注意哦,include 是不能被 config rewrite 命令改写的# 由于 redis 总是以最后的加工线作为一个配置指令值,所以你最好是把 include 放在这个文件的最前面,# 以避免在运行时覆盖配置的改变,相反,你就把它放在后面(外国人真啰嗦)。## include /path/to/local.conf# include /path/to/other.conf################################ 常用 ###################################### 默认情况下 redis 不是作为守护进程运行的,如果你想让它在后台运行,你就把它改成 yes。# 当redis作为守护进程运行的时候,它会写一个 pid 到 /var/run/redis.pid 文件里面。daemonize yes# 当redis作为守护进程运行的时候,它会把 pid 默认写到 /var/run/redis.pid 文件里面,# 但是你可以在这里自己制定它的文件位置。pidfile /var/run/redis.pid# 监听端口号,默认为 6379,如果你设为 0 ,redis 将不在 socket 上监听任何客户端连接。port 6379# 客户端闲置多少秒后,断开连接 timeout 0# TCP 监听的最大容纳数量## 在高并发的环境下,你需要把这个值调高以避免客户端连接缓慢的问题。# Linux 内核会一声不响的把这个值缩小成 /proc/sys/net/core/somaxconn 对应的值,# 所以你要修改这两个值才能达到你的预期。tcp-backlog 511# 默认情况下,redis 在 server 上所有有效的网络接口上监听客户端连接。# 你如果只想让它在一个网络接口上监听,那你就绑定一个IP或者多个IP。## 示例,多个IP用空格隔开:## bind 192.168.1.100 10.0.0.1# bind 127.0.0.1# 指定 unix socket 的路径。## unixsocket /tmp/redis.sock# unixsocketperm 755# 指定在一个 client 空闲多少秒之后关闭连接(0 就是不管它)timeout 0# tcp 心跳包。## 如果设置为非零,则在与客户端缺乏通讯的时候使用 SO_KEEPALIVE 发送 tcp acks 给客户端。# 这个之所有有用,主要由两个原因:## 1) 防止死的 peers# 2) Take the connection alive from the point of view of network# equipment in the middle.## On Linux, the specified value (in seconds) is the period used to send ACKs.# Note that to close the connection the double of the time is needed.# On other kernels the period depends on the kernel configuration.## A reasonable value for this option is 60 seconds.# 推荐一个合理的值就是60秒tcp-keepalive 0# 定义日志级别。# 可以是下面的这些值:# debug (适用于开发或测试阶段)# verbose (many rarely useful info, but not a mess like the debug level)# notice (适用于生产环境)# warning (仅仅一些重要的消息被记录)loglevel notice# 指定日志文件的位置logfile ""# 要想把日志记录到系统日志,就把它改成 yes,# 也可以可选择性的更新其他的syslog 参数以达到你的要求# syslog-enabled no# 设置 syslog 的 identity。# syslog-ident redis# 设置 syslog 的 facility,必须是 USER 或者是 LOCAL0-LOCAL7 之间的值。# syslog-facility local0# 设置数据库的数目。# 默认数据库是 DB 0,你可以在每个连接上使用 select <dbid> 命令选择一个不同的数据库,# 但是 dbid 必须是一个介于 0 到 databasees - 1 之间的值databases 16################################ 快照 ################################## 存 DB 到磁盘:## 格式:save <间隔时间(秒)> <写入次数>## 根据给定的时间间隔和写入次数将数据保存到磁盘## 下面的例子的意思是:# 900 秒后如果至少有 1 个 key 的值变化,则保存# 300 秒后如果至少有 10 个 key 的值变化,则保存# 60 秒后如果至少有 10000 个 key 的值变化,则保存## 注意:你可以注释掉所有的 save 行来停用保存功能。# 也可以直接一个空字符串来实现停用:# save ""save 900 1save 300 10save 60 10000# 默认情况下,如果 redis 最后一次的后台保存失败,redis 将停止接受写操作,# 这样以一种强硬的方式让用户知道数据不能正确的持久化到磁盘,# 否则就会没人注意到灾难的发生。## 如果后台保存进程重新启动工作了,redis 也将自动的允许写操作。## 然而你要是安装了靠谱的监控,你可能不希望 redis 这样做,那你就改成 no 好了。stop-writes-on-bgsave-error yes# 是否在 dump .rdb 数据库的时候使用 LZF 压缩字符串# 默认都设为 yes# 如果你希望保存子进程节省点 cpu ,你就设置它为 no ,# 不过这个数据集可能就会比较大rdbcompression yes# 是否校验rdb文件rdbchecksum yes# 设置 dump 的文件位置dbfilename dump.rdb# 工作目录# 例如上面的 dbfilename 只指定了文件名,# 但是它会写入到这个目录下。这个配置项一定是个目录,而不能是文件名。dir ./################################# 主从复制 ################################## 主从复制。使用 slaveof 来让一个 redis 实例成为另一个reids 实例的副本。# 注意这个只需要在 slave 上配置。## slaveof <masterip> <masterport># 如果 master 需要密码认证,就在这里设置# masterauth <master-password># 当一个 slave 与 master 失去联系,或者复制正在进行的时候,# slave 可能会有两种表现:## 1) 如果为 yes ,slave 仍然会应答客户端请求,但返回的数据可能是过时,# 或者数据可能是空的在第一次同步的时候## 2) 如果为 no ,在你执行除了 info he salveof 之外的其他命令时,# slave 都将返回一个 "SYNC with master in progress" 的错误,#slave-serve-stale-data yes# 你可以配置一个 slave 实体是否接受写入操作。# 通过写入操作来存储一些短暂的数据对于一个 slave 实例来说可能是有用的,# 因为相对从 master 重新同步数而言,据数据写入到 slave 会更容易被删除。# 但是如果客户端因为一个错误的配置写入,也可能会导致一些问题。## 从 redis 2.6 版起,默认 slaves 都是只读的。## Note: read only slaves are not designed to be exposed to untrusted clients# on the internet. It's just a protection layer against misuse of the instance.# Still a read only slave exports by default all the administrative commands# such as CONFIG, DEBUG, and so forth. To a limited extent you can improve# security of read only slaves using 'rename-command' to shadow all the# administrative / dangerous commands.# 注意:只读的 slaves 没有被设计成在 internet 上暴露给不受信任的客户端。# 它仅仅是一个针对误用实例的一个保护层。slave-read-only yes# Slaves 在一个预定义的时间间隔内发送 ping 命令到 server 。# 你可以改变这个时间间隔。默认为 10 秒。## repl-ping-slave-period 10# The following option sets the replication timeout for:# 设置主从复制过期时间## 1) Bulk transfer I/O during SYNC, from the point of view of slave.# 2) Master timeout from the point of view of slaves (data, pings).# 3) Slave timeout from the point of view of masters (REPLCONF ACK pings).## It is important to make sure that this value is greater than the value# specified for repl-ping-slave-period otherwise a timeout will be detected# every time there is low traffic between the master and the slave.# 这个值一定要比 repl-ping-slave-period 大## repl-timeout 60# Disable TCP_NODELAY on the slave socket after SYNC?## If you select "yes" Redis will use a smaller number of TCP packets and# less bandwidth to send data to slaves. But this can add a delay for# the data to appear on the slave side, up to 40 milliseconds with# Linux kernels using a default configuration.## If you select "no" the delay for data to appear on the slave side will# be reduced but more bandwidth will be used for replication.## By default we optimize for low latency, but in very high traffic conditions# or when the master and slaves are many hops away, turning this to "yes" may# be a good idea.repl-disable-tcp-nodelay no# 设置主从复制容量大小。这个 backlog 是一个用来在 slaves 被断开连接时# 存放 slave 数据的 buffer,所以当一个 slave 想要重新连接,通常不希望全部重新同步,# 只是部分同步就够了,仅仅传递 slave 在断开连接时丢失的这部分数据。## The biggest the replication backlog, the longer the time the slave can be# disconnected and later be able to perform a partial resynchronization.# 这个值越大,salve 可以断开连接的时间就越长。## The backlog is only allocated once there is at least a slave connected.## repl-backlog-size 1mb# After a master has no longer connected slaves for some time, the backlog# will be freed. The following option configures the amount of seconds that# need to elapse, starting from the time the last slave disconnected, for# the backlog buffer to be freed.# 在某些时候,master 不再连接 slaves,backlog 将被释放。## A value of 0 means to never release the backlog.# 如果设置为 0 ,意味着绝不释放 backlog 。## repl-backlog-ttl 3600# 当 master 不能正常工作的时候,Redis Sentinel 会从 slaves 中选出一个新的 master,# 这个值越小,就越会被优先选中,但是如果是 0 , 那是意味着这个 slave 不可能被选中。## 默认优先级为 100。slave-priority 100# It is possible for a master to stop accepting writes if there are less than# N slaves connected, having a lag less or equal than M seconds.## The N slaves need to be in "online" state.## The lag in seconds, that must be <= the specified value, is calculated from# the last ping received from the slave, that is usually sent every second.## This option does not GUARANTEES that N replicas will accept the write, but# will limit the window of exposure for lost writes in case not enough slaves# are available, to the specified number of seconds.## For example to require at least 3 slaves with a lag <= 10 seconds use:## min-slaves-to-write 3# min-slaves-max-lag 10## Setting one or the other to 0 disables the feature.## By default min-slaves-to-write is set to 0 (feature disabled) and# min-slaves-max-lag is set to 10.################################## 安全 #################################### Require clients to issue AUTH <PASSWORD> before processing any other# commands. This might be useful in environments in which you do not trust# others with access to the host running redis-server.## This should stay commented out for backward compatibility and because most# people do not need auth (e.g. they run their own servers).# # Warning: since Redis is pretty fast an outside user can try up to# 150k passwords per second against a good box. This means that you should# use a very strong password otherwise it will be very easy to break.# # 设置认证密码# requirepass foobared# Command renaming.## It is possible to change the name of dangerous commands in a shared# environment. For instance the CONFIG command may be renamed into something# hard to guess so that it will still be available for internal-use tools# but not available for general clients.## Example:## rename-command CONFIG b840fc02d524045429941cc15f59e41cb7be6c52## It is also possible to completely kill a command by renaming it into# an empty string:## rename-command CONFIG ""## Please note that changing the name of commands that are logged into the# AOF file or transmitted to slaves may cause problems.################################### 限制 ##################################### Set the max number of connected clients at the same time. By default# this limit is set to 10000 clients, however if the Redis server is not# able to configure the process file limit to allow for the specified limit# the max number of allowed clients is set to the current file limit# minus 32 (as Redis reserves a few file descriptors for internal uses).## 一旦达到最大限制,redis 将关闭所有的新连接# 并发送一个‘max number of clients reached’的错误。## maxclients 10000# 如果你设置了这个值,当缓存的数据容量达到这个值, redis 将根据你选择的# eviction 策略来移除一些 keys。## 如果 redis 不能根据策略移除 keys ,或者是策略被设置为 ‘noeviction’,# redis 将开始响应错误给命令,如 set,lpush 等等,# 并继续响应只读的命令,如 get## This option is usually useful when using Redis as an LRU cache, or to set# a hard memory limit for an instance (using the 'noeviction' policy).## WARNING: If you have slaves attached to an instance with maxmemory on,# the size of the output buffers needed to feed the slaves are subtracted# from the used memory count, so that network problems / resyncs will# not trigger a loop where keys are evicted, and in turn the output# buffer of slaves is full with DELs of keys evicted triggering the deletion# of more keys, and so forth until the database is completely emptied.## In short... if you have slaves attached it is suggested that you set a lower# limit for maxmemory so that there is some free RAM on the system for slave# output buffers (but this is not needed if the policy is 'noeviction').## 最大使用内存# maxmemory <bytes># 最大内存策略,你有 5 个选择。# # volatile-lru -> remove the key with an expire set using an LRU algorithm# volatile-lru -> 使用 LRU 算法移除包含过期设置的 key 。# allkeys-lru -> remove any key accordingly to the LRU algorithm# allkeys-lru -> 根据 LRU 算法移除所有的 key 。# volatile-random -> remove a random key with an expire set# allkeys-random -> remove a random key, any key# volatile-ttl -> remove the key with the nearest expire time (minor TTL)# noeviction -> don't expire at all, just return an error on write operations# noeviction -> 不让任何 key 过期,只是给写入操作返回一个错误# # Note: with any of the above policies, Redis will return an error on write# operations, when there are not suitable keys for eviction.## At the date of writing this commands are: set setnx setex append# incr decr rpush lpush rpushx lpushx linsert lset rpoplpush sadd# sinter sinterstore sunion sunionstore sdiff sdiffstore zadd zincrby# zunionstore zinterstore hset hsetnx hmset hincrby incrby decrby# getset mset msetnx exec sort## The default is:## maxmemory-policy noeviction# LRU and minimal TTL algorithms are not precise algorithms but approximated# algorithms (in order to save memory), so you can tune it for speed or# accuracy. For default Redis will check five keys and pick the one that was# used less recently, you can change the sample size using the following# configuration directive.## The default of 5 produces good enough results. 10 Approximates very closely# true LRU but costs a bit more CPU. 3 is very fast but not very accurate.## maxmemory-samples 5############################## APPEND ONLY MODE ################################ By default Redis asynchronously dumps the dataset on disk. This mode is# good enough in many applications, but an issue with the Redis process or# a power outage may result into a few minutes of writes lost (depending on# the configured save points).## The Append Only File is an alternative persistence mode that provides# much better durability. For instance using the default data fsync policy# (see later in the config file) Redis can lose just one second of writes in a# dramatic event like a server power outage, or a single write if something# wrong with the Redis process itself happens, but the operating system is# still running correctly.## AOF and RDB persistence can be enabled at the same time without problems.# If the AOF is enabled on startup Redis will load the AOF, that is the file# with the better durability guarantees.## Please check http://redis.io/topics/persistence for more information.appendonly no# The name of the append only file (default: "appendonly.aof")appendfilename "appendonly.aof"# The fsync() call tells the Operating System to actually write data on disk# instead to wait for more data in the output buffer. Some OS will really flush # data on disk, some other OS will just try to do it ASAP.## Redis supports three different modes:## no: don't fsync, just let the OS flush the data when it wants. Faster.# always: fsync after every write to the append only log . Slow, Safest.# everysec: fsync only one time every second. Compromise.## The default is "everysec", as that's usually the right compromise between# speed and data safety. It's up to you to understand if you can relax this to# "no" that will let the operating system flush the output buffer when# it wants, for better performances (but if you can live with the idea of# some data loss consider the default persistence mode that's snapshotting),# or on the contrary, use "always" that's very slow but a bit safer than# everysec.## More details please check the following article:# http://antirez.com/post/redis-persistence-demystified.html## If unsure, use "everysec".# appendfsync alwaysappendfsync everysec# appendfsync no# When the AOF fsync policy is set to always or everysec, and a background# saving process (a background save or AOF log background rewriting) is# performing a lot of I/O against the disk, in some Linux configurations# Redis may block too long on the fsync() call. Note that there is no fix for# this currently, as even performing fsync in a different thread will block# our synchronous write(2) call.## In order to mitigate this problem it's possible to use the following option# that will prevent fsync() from being called in the main process while a# BGSAVE or BGREWRITEAOF is in progress.## This means that while another child is saving, the durability of Redis is# the same as "appendfsync none". In practical terms, this means that it is# possible to lose up to 30 seconds of log in the worst scenario (with the# default Linux settings).# # If you have latency problems turn this to "yes". Otherwise leave it as# "no" that is the safest pick from the point of view of durability.no-appendfsync-on-rewrite no# Automatic rewrite of the append only file.# Redis is able to automatically rewrite the log file implicitly calling# BGREWRITEAOF when the AOF log size grows by the specified percentage.# # This is how it works: Redis remembers the size of the AOF file after the# latest rewrite (if no rewrite has happened since the restart, the size of# the AOF at startup is used).## This base size is compared to the current size. If the current size is# bigger than the specified percentage, the rewrite is triggered. Also# you need to specify a minimal size for the AOF file to be rewritten, this# is useful to avoid rewriting the AOF file even if the percentage increase# is reached but it is still pretty small.## Specify a percentage of zero in order to disable the automatic AOF# rewrite feature.auto-aof-rewrite-percentage 100auto-aof-rewrite-min-size 64mb################################ LUA SCRIPTING ################################ Max execution time of a Lua script in milliseconds.## If the maximum execution time is reached Redis will log that a script is# still in execution after the maximum allowed time and will start to# reply to queries with an error.## When a long running script exceed the maximum execution time only the# SCRIPT KILL and SHUTDOWN NOSAVE commands are available. The first can be# used to stop a script that did not yet called write commands. The second# is the only way to shut down the server in the case a write commands was# already issue by the script but the user don't want to wait for the natural# termination of the script.## Set it to 0 or a negative value for unlimited execution without warnings.lua-time-limit 5000################################ REDIS 集群 ################################# 启用或停用集群# cluster-enabled yes# Every cluster node has a cluster configuration file. This file is not# intended to be edited by hand. It is created and updated by Redis nodes.# Every Redis Cluster node requires a different cluster configuration file.# Make sure that instances running in the same system does not have# overlapping cluster configuration file names.## cluster-config-file nodes-6379.conf# Cluster node timeout is the amount of milliseconds a node must be unreachable # for it to be considered in failure state.# Most other internal time limits are multiple of the node timeout.## cluster-node-timeout 15000# A slave of a failing master will avoid to start a failover if its data# looks too old.## There is no simple way for a slave to actually have a exact measure of# its "data age", so the following two checks are performed:## 1) If there are multiple slaves able to failover, they exchange messages# in order to try to give an advantage to the slave with the best# replication offset (more data from the master processed).# Slaves will try to get their rank by offset, and apply to the start# of the failover a delay proportional to their rank.## 2) Every single slave computes the time of the last interaction with# its master. This can be the last ping or command received (if the master# is still in the "connected" state), or the time that elapsed since the# disconnection with the master (if the replication link is currently down).# If the last interaction is too old, the slave will not try to failover# at all.## The point "2" can be tuned by user. Specifically a slave will not perform# the failover if, since the last interaction with the master, the time# elapsed is greater than:## (node-timeout * slave-validity-factor) + repl-ping-slave-period## So for example if node-timeout is 30 seconds, and the slave-validity-factor# is 10, and assuming a default repl-ping-slave-period of 10 seconds, the# slave will not try to failover if it was not able to talk with the master# for longer than 310 seconds.## A large slave-validity-factor may allow slaves with too old data to failover# a master, while a too small value may prevent the cluster from being able to# elect a slave at all.## For maximum availability, it is possible to set the slave-validity-factor# to a value of 0, which means, that slaves will always try to failover the# master regardless of the last time they interacted with the master.# (However they'll always try to apply a delay proportional to their# offset rank).## Zero is the only value able to guarantee that when all the partitions heal# the cluster will always be able to continue.## cluster-slave-validity-factor 10# Cluster slaves are able to migrate to orphaned masters, that are masters# that are left without working slaves. This improves the cluster ability# to resist to failures as otherwise an orphaned master can't be failed over# in case of failure if it has no working slaves.## Slaves migrate to orphaned masters only if there are still at least a# given number of other working slaves for their old master. This number# is the "migration barrier". A migration barrier of 1 means that a slave# will migrate only if there is at least 1 other working slave for its master# and so forth. It usually reflects the number of slaves you want for every# master in your cluster.## Default is 1 (slaves migrate only if their masters remain with at least# one slave). To disable migration just set it to a very large value.# A value of 0 can be set but is useful only for debugging and dangerous# in production.## cluster-migration-barrier 1# In order to setup your cluster make sure to read the documentation# available at http://redis.io web site.################################## SLOW LOG #################################### The Redis Slow Log is a system to log queries that exceeded a specified# execution time. The execution time does not include the I/O operations# like talking with the client, sending the reply and so forth,# but just the time needed to actually execute the command (this is the only# stage of command execution where the thread is blocked and can not serve# other requests in the meantime).# # You can configure the slow log with two parameters: one tells Redis# what is the execution time, in microseconds, to exceed in order for the# command to get logged, and the other parameter is the length of the# slow log. When a new command is logged the oldest one is removed from the# queue of logged commands.# The following time is expressed in microseconds, so 1000000 is equivalent# to one second. Note that a negative number disables the slow log, while# a value of zero forces the logging of every command.slowlog-log-slower-than 10000# There is no limit to this length. Just be aware that it will consume memory.# You can reclaim memory used by the slow log with SLOWLOG RESET.slowlog-max-len 128############################# Event notification ############################### Redis can notify Pub/Sub clients about events happening in the key space.# This feature is documented at http://redis.io/topics/keyspace-events# # For instance if keyspace events notification is enabled, and a client# performs a DEL operation on key "foo" stored in the Database 0, two# messages will be published via Pub/Sub:## PUBLISH __keyspace@0__:foo del# PUBLISH __keyevent@0__:del foo## It is possible to select the events that Redis will notify among a set# of classes. Every class is identified by a single character:## K Keyspace events, published with __keyspace@<db>__ prefix.# E Keyevent events, published with __keyevent@<db>__ prefix.# g Generic commands (non-type specific) like DEL, EXPIRE, RENAME, ...# $ String commands# l List commands# s Set commands# h Hash commands# z Sorted set commands# x Expired events (events generated every time a key expires)# e Evicted events (events generated when a key is evicted for maxmemory)# A Alias for g$lshzxe, so that the "AKE" string means all the events.## The "notify-keyspace-events" takes as argument a string that is composed# by zero or multiple characters. The empty string means that notifications# are disabled at all.## Example: to enable list and generic events, from the point of view of the# event name, use:## notify-keyspace-events Elg## Example 2: to get the stream of the expired keys subscribing to channel# name __keyevent@0__:expired use:## notify-keyspace-events Ex## By default all notifications are disabled because most users don't need# this feature and the feature has some overhead. Note that if you don't# specify at least one of K or E, no events will be delivered.notify-keyspace-events ""############################### ADVANCED CONFIG ################################ Hashes are encoded using a memory efficient data structure when they have a# small number of entries, and the biggest entry does not exceed a given# threshold. These thresholds can be configured using the following directives.hash-max-ziplist-entries 512hash-max-ziplist-value 64# Similarly to hashes, small lists are also encoded in a special way in order# to save a lot of space. The special representation is only used when# you are under the following limits:list-max-ziplist-entries 512list-max-ziplist-value 64# Sets have a special encoding in just one case: when a set is composed# of just strings that happens to be integers in radix 10 in the range# of 64 bit signed integers.# The following configuration setting sets the limit in the size of the# set in order to use this special memory saving encoding.set-max-intset-entries 512# Similarly to hashes and lists, sorted sets are also specially encoded in# order to save a lot of space. This encoding is only used when the length and# elements of a sorted set are below the following limits:zset-max-ziplist-entries 128zset-max-ziplist-value 64# HyperLogLog sparse representation bytes limit. The limit includes the# 16 bytes header. When an HyperLogLog using the sparse representation crosses# this limit, it is converted into the dense representation.## A value greater than 16000 is totally useless, since at that point the# dense representation is more memory efficient.# # The suggested value is ~ 3000 in order to have the benefits of# the space efficient encoding without slowing down too much PFADD,# which is O(N) with the sparse encoding. The value can be raised to# ~ 10000 when CPU is not a concern, but space is, and the data set is# composed of many HyperLogLogs with cardinality in the 0 - 15000 range.hll-sparse-max-bytes 3000# Active rehashing uses 1 millisecond every 100 milliseconds of CPU time in# order to help rehashing the main Redis hash table (the one mapping top-level# keys to values). The hash table implementation Redis uses (see dict.c)# performs a lazy rehashing: the more operation you run into a hash table# that is rehashing, the more rehashing "steps" are performed, so if the# server is idle the rehashing is never complete and some more memory is used# by the hash table.# # The default is to use this millisecond 10 times every second in order to# active rehashing the main dictionaries, freeing memory when possible.## If unsure:# use "activerehashing no" if you have hard latency requirements and it is# not a good thing in your environment that Redis can reply form time to time# to queries with 2 milliseconds delay.## use "activerehashing yes" if you don't have such hard requirements but# want to free memory asap when possible.activerehashing yes# The client output buffer limits can be used to force disconnection of clients# that are not reading data from the server fast enough for some reason (a# common reason is that a Pub/Sub client can't consume messages as fast as the# publisher can produce them).## The limit can be set differently for the three different classes of clients:## normal -> normal clients# slave -> slave clients and MONITOR clients# pubsub -> clients subscribed to at least one pubsub channel or pattern## The syntax of every client-output-buffer-limit directive is the following:## client-output-buffer-limit <class> <hard limit> <soft limit> <soft seconds>## A client is immediately disconnected once the hard limit is reached, or if# the soft limit is reached and remains reached for the specified number of# seconds (continuously).# So for instance if the hard limit is 32 megabytes and the soft limit is# 16 megabytes / 10 seconds, the client will get disconnected immediately# if the size of the output buffers reach 32 megabytes, but will also get# disconnected if the client reaches 16 megabytes and continuously overcomes# the limit for 10 seconds.## By default normal clients are not limited because they don't receive data# without asking (in a push way), but just after a request, so only# asynchronous clients may create a scenario where data is requested faster# than it can read.## Instead there is a default limit for pubsub and slave clients, since# subscribers and slaves receive data in a push fashion.## Both the hard or the soft limit can be disabled by setting them to zero.client-output-buffer-limit normal 0 0 0client-output-buffer-limit slave 256mb 64mb 60client-output-buffer-limit pubsub 32mb 8mb 60# Redis calls an internal function to perform many background tasks, like# closing connections of clients in timeout, purging expired keys that are# never requested, and so forth.## Not all tasks are performed with the same frequency, but Redis checks for# tasks to perform accordingly to the specified "hz" value.## By default "hz" is set to 10. Raising the value will use more CPU when# Redis is idle, but at the same time will make Redis more responsive when# there are many keys expiring at the same time, and timeouts may be# handled with more precision.## The range is between 1 and 500, however a value over 100 is usually not# a good idea. Most users should use the default of 10 and raise this up to# 100 only in environments where very low latency is required.hz 10# When a child rewrites the AOF file, if the following option is enabled# the file will be fsync-ed every 32 MB of data generated. This is useful# in order to commit the file to the disk more incrementally and avoid# big latency spikes.aof-rewrite-incremental-fsync yes