第一节：Redis的安装使用(Linux、docker、win) 和 目录配置详解
一. Redis安装和连接
1. 下载地址
官网：https://redis.io/
官网-中文：http://www.redis.cn/
Linux下载地址：https://download.redis.io/releases/
Windows下载地址：https://github.com/MicrosoftArchive/redis/tags
2. Linux中安装
基于Centos8 安装 Redis 5.0 详见：https://www.cnblogs.com/yaopengfei/p/13766324.html
3. docker中安装
基于docker安装Redis5.0 或者最新版本 详见：https://www.cnblogs.com/yaopengfei/p/13630267.html
4. windows中安装
直接双击：redis-server.exe 程序，就可以启动Server端。 【建议通过命令号打开 redis-server.exe，否则远程可能链接不上】
PS. 指令连接写法：
--win下的连接 redis-cli.exe -h 192.168.137.201 -p 6379 --Linux下连接（多了 ./ 表示当前目录） ./redis-cli.exe -h 192.168.137.201 -p 6379 --含密码 ./redis-cli.exe -h 192.168.137.201 -p 6379 -a 123456 --集群的连接方式(加 -c) ./redis-cli -c -h 192.168.137.201 -p 6380 -a 123456
二. 目录配置详解
1. Redis目录说明
以上为Redis5.0的安装目录下的文件。
(1). redis-benchmark：测试Redis性能的工具，可以同时模拟n个客户发送请求。
(2). redis-check-aof：aof文件校验、修复。
(3). redis-check-rdb：rdb文件校验、修复。
(4). redis-cli：redis客户端
(5). redis.conf：redis配置文件
(6). redis-sentinel：redis哨兵
(7). redis-server：redis服务端
2. 配置文件详解
以Redis5.0为例介绍配置文件，默认配置文件如下：
# Redis configuration file example. # # Note that in order to read the configuration file, Redis must be # started with the file path as first argument: # # ./redis-server /path/to/redis.conf # Note on units: when memory size is needed, it is possible to specify # it in the usual form of 1k 5GB 4M and so forth: # # 1k => 1000 bytes # 1kb => 1024 bytes # 1m => 1000000 bytes # 1mb => 1024*1024 bytes # 1g => 1000000000 bytes # 1gb => 1024*1024*1024 bytes # # units are case insensitive so 1GB 1Gb 1gB are all the same. ################################## INCLUDES ################################### # Include one or more other config files here. This is useful if you # have a standard template that goes to all Redis servers but also need # to customize a few per-server settings. Include files can include # other files, so use this wisely. # # Notice option "include" won't be rewritten by command "CONFIG REWRITE" # from admin or Redis Sentinel. Since Redis always uses the last processed # line as value of a configuration directive, you'd better put includes # at the beginning of this file to avoid overwriting config change at runtime. # # If instead you are interested in using includes to override configuration # options, it is better to use include as the last line. # # include /path/to/local.conf # include /path/to/other.conf ################################## MODULES ##################################### # Load modules at startup. If the server is not able to load modules # it will abort. It is possible to use multiple loadmodule directives. # # loadmodule /path/to/my_module.so # loadmodule /path/to/other_module.so ################################## NETWORK ##################################### # By default, if no "bind" configuration directive is specified, Redis listens # for connections from all the network interfaces available on the server. # It is possible to listen to just one or multiple selected interfaces using # the "bind" configuration directive, followed by one or more IP addresses. # # Examples: # # bind 192.168.1.100 10.0.0.1 # bind 127.0.0.1 ::1 # # ~~~ WARNING ~~~ If the computer running Redis is directly exposed to the # internet, binding to all the interfaces is dangerous and will expose the # instance to everybody on the internet. So by default we uncomment the # following bind directive, that will force Redis to listen only into # the IPv4 loopback interface address (this means Redis will be able to # accept connections only from clients running into the same computer it # is running). # # IF YOU ARE SURE YOU WANT YOUR INSTANCE TO LISTEN TO ALL THE INTERFACES # JUST COMMENT THE FOLLOWING LINE. # ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ bind 127.0.0.1 # Protected mode is a layer of security protection, in order to avoid that # Redis instances left open on the internet are accessed and exploited. # # When protected mode is on and if: # # 1) The server is not binding explicitly to a set of addresses using the # "bind" directive. # 2) No password is configured. # # The server only accepts connections from clients connecting from the # IPv4 and IPv6 loopback addresses 127.0.0.1 and ::1, and from Unix domain # sockets. # # By default protected mode is enabled. You should disable it only if # you are sure you want clients from other hosts to connect to Redis # even if no authentication is configured, nor a specific set of interfaces # are explicitly listed using the "bind" directive. protected-mode yes # Accept connections on the specified port, default is 6379 (IANA #815344). # If port 0 is specified Redis will not listen on a TCP socket. port 6379 # TCP listen() backlog. # # In high requests-per-second environments you need an high backlog in order # to avoid slow clients connections issues. Note that the Linux kernel # will silently truncate it to the value of /proc/sys/net/core/somaxconn so # make sure to raise both the value of somaxconn and tcp_max_syn_backlog # in order to get the desired effect. tcp-backlog 511 # Unix socket. # # Specify the path for the Unix socket that will be used to listen for # incoming connections. There is no default, so Redis will not listen # on a unix socket when not specified. # # unixsocket /tmp/redis.sock # unixsocketperm 700 # Close the connection after a client is idle for N seconds (0 to disable) timeout 0 # TCP keepalive. # # If non-zero, use SO_KEEPALIVE to send TCP ACKs to clients in absence # of communication. This is useful for two reasons: # # 1) Detect dead 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 300 seconds, which is the new # Redis default starting with Redis 3.2.1. tcp-keepalive 300 ################################# GENERAL ##################################### # By default Redis does not run as a daemon. Use 'yes' if you need it. # Note that Redis will write a pid file in /var/run/redis.pid when daemonized. daemonize no # If you run Redis from upstart or systemd, Redis can interact with your # supervision tree. Options: # supervised no - no supervision interaction # supervised upstart - signal upstart by putting Redis into SIGSTOP mode # supervised systemd - signal systemd by writing READY=1 to $NOTIFY_SOCKET # supervised auto - detect upstart or systemd method based on # UPSTART_JOB or NOTIFY_SOCKET environment variables # Note: these supervision methods only signal "process is ready." # They do not enable continuous liveness pings back to your supervisor. supervised no # If a pid file is specified, Redis writes it where specified at startup # and removes it at exit. # # When the server runs non daemonized, no pid file is created if none is # specified in the configuration. When the server is daemonized, the pid file # is used even if not specified, defaulting to "/var/run/redis.pid". # # Creating a pid file is best effort: if Redis is not able to create it # nothing bad happens, the server will start and run normally. pidfile /var/run/redis_6379.pid # Specify the server verbosity level. # This can be one of: # debug (a lot of information, useful for development/testing) # verbose (many rarely useful info, but not a mess like the debug level) # notice (moderately verbose, what you want in production probably) # warning (only very important / critical messages are logged) loglevel notice # Specify the log file name. Also the empty string can be used to force # Redis to log on the standard output. Note that if you use standard # output for logging but daemonize, logs will be sent to /dev/null logfile "" # To enable logging to the system logger, just set 'syslog-enabled' to yes, # and optionally update the other syslog parameters to suit your needs. # syslog-enabled no # Specify the syslog identity. # syslog-ident redis # Specify the syslog facility. Must be USER or between LOCAL0-LOCAL7. # syslog-facility local0 # Set the number of databases. The default database is DB 0, you can select # a different one on a per-connection basis using SELECT <dbid> where # dbid is a number between 0 and 'databases'-1 databases 16 # By default Redis shows an ASCII art logo only when started to log to the # standard output and if the standard output is a TTY. Basically this means # that normally a logo is displayed only in interactive sessions. # # However it is possible to force the pre-4.0 behavior and always show a # ASCII art logo in startup logs by setting the following option to yes. always-show-logo yes ################################ SNAPSHOTTING ################################ # # Save the DB on disk: # # save <seconds> <changes> # # Will save the DB if both the given number of seconds and the given # number of write operations against the DB occurred. # # In the example below the behaviour will be to save: # after 900 sec (15 min) if at least 1 key changed # after 300 sec (5 min) if at least 10 keys changed # after 60 sec if at least 10000 keys changed # # Note: you can disable saving completely by commenting out all "save" lines. # # It is also possible to remove all the previously configured save # points by adding a save directive with a single empty string argument # like in the following example: # # save "" save 900 1 save 300 10 save 60 10000 # By default Redis will stop accepting writes if RDB snapshots are enabled # (at least one save point) and the latest background save failed. # This will make the user aware (in a hard way) that data is not persisting # on disk properly, otherwise chances are that no one will notice and some # disaster will happen. # # If the background saving process will start working again Redis will # automatically allow writes again. # # However if you have setup your proper monitoring of the Redis server # and persistence, you may want to disable this feature so that Redis will # continue to work as usual even if there are problems with disk, # permissions, and so forth. stop-writes-on-bgsave-error yes # Compress string objects using LZF when dump .rdb databases? # For default that's set to 'yes' as it's almost always a win. # If you want to save some CPU in the saving child set it to 'no' but # the dataset will likely be bigger if you have compressible values or keys. rdbcompression yes # Since version 5 of RDB a CRC64 checksum is placed at the end of the file. # This makes the format more resistant to corruption but there is a performance # hit to pay (around 10%) when saving and loading RDB files, so you can disable it # for maximum performances. # # RDB files created with checksum disabled have a checksum of zero that will # tell the loading code to skip the check. rdbchecksum yes # The filename where to dump the DB dbfilename dump.rdb # The working directory. # # The DB will be written inside this directory, with the filename specified # above using the 'dbfilename' configuration directive. # # The Append Only File will also be created inside this directory. # # Note that you must specify a directory here, not a file name. dir ./ ################################# REPLICATION ################################# # Master-Replica replication. Use replicaof to make a Redis instance a copy of # another Redis server. A few things to understand ASAP about Redis replication. # # +------------------+ +---------------+ # | Master | ---> | Replica | # | (receive writes) | | (exact copy) | # +------------------+ +---------------+ # # 1) Redis replication is asynchronous, but you can configure a master to # stop accepting writes if it appears to be not connected with at least # a given number of replicas. # 2) Redis replicas are able to perform a partial resynchronization with the # master if the replication link is lost for a relatively small amount of # time. You may want to configure the replication backlog size (see the next # sections of this file) with a sensible value depending on your needs. # 3) Replication is automatic and does not need user intervention. After a # network partition replicas automatically try to reconnect to masters # and resynchronize with them. # # replicaof <masterip> <masterport> # If the master is password protected (using the "requirepass" configuration # directive below) it is possible to tell the replica to authenticate before # starting the replication synchronization process, otherwise the master will # refuse the replica request. # # masterauth <master-password> # When a replica loses its connection with the master, or when the replication # is still in progress, the replica can act in two different ways: # # 1) if replica-serve-stale-data is set to 'yes' (the default) the replica will # still reply to client requests, possibly with out of date data, or the # data set may just be empty if this is the first synchronization. # # 2) if replica-serve-stale-data is set to 'no' the replica will reply with # an error "SYNC with master in progress" to all the kind of commands # but to INFO, replicaOF, AUTH, PING, SHUTDOWN, REPLCONF, ROLE, CONFIG, # SUBSCRIBE, UNSUBSCRIBE, PSUBSCRIBE, PUNSUBSCRIBE, PUBLISH, PUBSUB, # COMMAND, POST, HOST: and LATENCY. # replica-serve-stale-data yes # You can configure a replica instance to accept writes or not. Writing against # a replica instance may be useful to store some ephemeral data (because data # written on a replica will be easily deleted after resync with the master) but # may also cause problems if clients are writing to it because of a # misconfiguration. # # Since Redis 2.6 by default replicas are read-only. # # Note: read only replicas are not designed to be exposed to untrusted clients # on the internet. It's just a protection layer against misuse of the instance. # Still a read only replica exports by default all the administrative commands # such as CONFIG, DEBUG, and so forth. To a limited extent you can improve # security of read only replicas using 'rename-command' to shadow all the # administrative / dangerous commands. replica-read-only yes # Replication SYNC strategy: disk or socket. # # ------------------------------------------------------- # WARNING: DISKLESS REPLICATION IS EXPERIMENTAL CURRENTLY # ------------------------------------------------------- # # New replicas and reconnecting replicas that are not able to continue the replication # process just receiving differences, need to do what is called a "full # synchronization". An RDB file is transmitted from the master to the replicas. # The transmission can happen in two different ways: # # 1) Disk-backed: The Redis master creates a new process that writes the RDB # file on disk. Later the file is transferred by the parent # process to the replicas incrementally. # 2) Diskless: The Redis master creates a new process that directly writes the # RDB file to replica sockets, without touching the disk at all. # # With disk-backed replication, while the RDB file is generated, more replicas # can be queued and served with the RDB file as soon as the current child producing # the RDB file finishes its work. With diskless replication instead once # the transfer starts, new replicas arriving will be queued and a new transfer # will start when the current one terminates. # # When diskless replication is used, the master waits a configurable amount of # time (in seconds) before starting the transfer in the hope that multiple replicas # will arrive and the transfer can be parallelized. # # With slow disks and fast (large bandwidth) networks, diskless replication # works better. repl-diskless-sync no # When diskless replication is enabled, it is possible to configure the delay # the server waits in order to spawn the child that transfers the RDB via socket # to the replicas. # # This is important since once the transfer starts, it is not possible to serve # new replicas arriving, that will be queued for the next RDB transfer, so the server # waits a delay in order to let more replicas arrive. # # The delay is specified in seconds, and by default is 5 seconds. To disable # it entirely just set it to 0 seconds and the transfer will start ASAP. repl-diskless-sync-delay 5 # Replicas send PINGs to server in a predefined interval. It's possible to change # this interval with the repl_ping_replica_period option. The default value is 10 # seconds. # # repl-ping-replica-period 10 # The following option sets the replication timeout for: # # 1) Bulk transfer I/O during SYNC, from the point of view of replica. # 2) Master timeout from the point of view of replicas (data, pings). # 3) Replica timeout from the point of view of masters (REPLCONF ACK pings). # # It is important to make sure that this value is greater than the value # specified for repl-ping-replica-period otherwise a timeout will be detected # every time there is low traffic between the master and the replica. # # repl-timeout 60 # Disable TCP_NODELAY on the replica socket after SYNC? # # If you select "yes" Redis will use a smaller number of TCP packets and # less bandwidth to send data to replicas. But this can add a delay for # the data to appear on the replica side, up to 40 milliseconds with # Linux kernels using a default configuration. # # If you select "no" the delay for data to appear on the replica side will # be reduced but more bandwidth will be used for replication. # # By default we optimize for low latency, but in very high traffic conditions # or when the master and replicas are many hops away, turning this to "yes" may # be a good idea. repl-disable-tcp-nodelay no # Set the replication backlog size. The backlog is a buffer that accumulates # replica data when replicas are disconnected for some time, so that when a replica # wants to reconnect again, often a full resync is not needed, but a partial # resync is enough, just passing the portion of data the replica missed while # disconnected. # # The bigger the replication backlog, the longer the time the replica can be # disconnected and later be able to perform a partial resynchronization. # # The backlog is only allocated once there is at least a replica connected. # # repl-backlog-size 1mb # After a master has no longer connected replicas for some time, the backlog # will be freed. The following option configures the amount of seconds that # need to elapse, starting from the time the last replica disconnected, for # the backlog buffer to be freed. # # Note that replicas never free the backlog for timeout, since they may be # promoted to masters later, and should be able to correctly "partially # resynchronize" with the replicas: hence they should always accumulate backlog. # # A value of 0 means to never release the backlog. # # repl-backlog-ttl 3600 # The replica priority is an integer number published by Redis in the INFO output. # It is used by Redis Sentinel in order to select a replica to promote into a # master if the master is no longer working correctly. # # A replica with a low priority number is considered better for promotion, so # for instance if there are three replicas with priority 10, 100, 25 Sentinel will # pick the one with priority 10, that is the lowest. # # However a special priority of 0 marks the replica as not able to perform the # role of master, so a replica with priority of 0 will never be selected by # Redis Sentinel for promotion. # # By default the priority is 100. replica-priority 100 # It is possible for a master to stop accepting writes if there are less than # N replicas connected, having a lag less or equal than M seconds. # # The N replicas need to be in "online" state. # # The lag in seconds, that must be <= the specified value, is calculated from # the last ping received from the replica, that is usually sent every second. # # This option does not GUARANTEE that N replicas will accept the write, but # will limit the window of exposure for lost writes in case not enough replicas # are available, to the specified number of seconds. # # For example to require at least 3 replicas with a lag <= 10 seconds use: # # min-replicas-to-write 3 # min-replicas-max-lag 10 # # Setting one or the other to 0 disables the feature. # # By default min-replicas-to-write is set to 0 (feature disabled) and # min-replicas-max-lag is set to 10. # A Redis master is able to list the address and port of the attached # replicas in different ways. For example the "INFO replication" section # offers this information, which is used, among other tools, by # Redis Sentinel in order to discover replica instances. # Another place where this info is available is in the output of the # "ROLE" command of a master. # # The listed IP and address normally reported by a replica is obtained # in the following way: # # IP: The address is auto detected by checking the peer address # of the socket used by the replica to connect with the master. # # Port: The port is communicated by the replica during the replication # handshake, and is normally the port that the replica is using to # listen for connections. # # However when port forwarding or Network Address Translation (NAT) is # used, the replica may be actually reachable via different IP and port # pairs. The following two options can be used by a replica in order to # report to its master a specific set of IP and port, so that both INFO # and ROLE will report those values. # # There is no need to use both the options if you need to override just # the port or the IP address. # # replica-announce-ip 5.5.5.5 # replica-announce-port 1234 ################################## SECURITY ################################### # 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. # # 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 replicas may cause problems. ################################### CLIENTS #################################### # 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). # # Once the limit is reached Redis will close all the new connections sending # an error 'max number of clients reached'. # # maxclients 10000 ############################## MEMORY MANAGEMENT ################################ # Set a memory usage limit to the specified amount of bytes. # When the memory limit is reached Redis will try to remove keys # according to the eviction policy selected (see maxmemory-policy). # # If Redis can't remove keys according to the policy, or if the policy is # set to 'noeviction', Redis will start to reply with errors to commands # that would use more memory, like SET, LPUSH, and so on, and will continue # to reply to read-only commands like GET. # # This option is usually useful when using Redis as an LRU or LFU cache, or to # set a hard memory limit for an instance (using the 'noeviction' policy). # # WARNING: If you have replicas attached to an instance with maxmemory on, # the size of the output buffers needed to feed the replicas are subtracted # from the used memory count, so that network problems / resyncs will # not trigger a loop where keys are evicted, and in turn the output # buffer of replicas is full with DELs of keys evicted triggering the deletion # of more keys, and so forth until the database is completely emptied. # # In short... if you have replicas attached it is suggested that you set a lower # limit for maxmemory so that there is some free RAM on the system for replica # output buffers (but this is not needed if the policy is 'noeviction'). # # maxmemory <bytes> # MAXMEMORY POLICY: how Redis will select what to remove when maxmemory # is reached. You can select among five behaviors: # # volatile-lru -> Evict using approximated LRU among the keys with an expire set. # allkeys-lru -> Evict any key using approximated LRU. # volatile-lfu -> Evict using approximated LFU among the keys with an expire set. # allkeys-lfu -> Evict any key using approximated LFU. # volatile-random -> Remove a random key among the ones 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 evict anything, just return an error on write operations. # # LRU means Least Recently Used # LFU means Least Frequently Used # # Both LRU, LFU and volatile-ttl are implemented using approximated # randomized algorithms. # # Note: with any of the above policies, Redis will return an error on write # operations, when there are no suitable keys for eviction. # # At the date of writing these 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, LFU 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 more CPU. 3 is faster but not very accurate. # # maxmemory-samples 5 # Starting from Redis 5, by default a replica will ignore its maxmemory setting # (unless it is promoted to master after a failover or manually). It means # that the eviction of keys will be just handled by the master, sending the # DEL commands to the replica as keys evict in the master side. # # This behavior ensures that masters and replicas stay consistent, and is usually # what you want, however if your replica is writable, or you want the replica to have # a different memory setting, and you are sure all the writes performed to the # replica are idempotent, then you may change this default (but be sure to understand # what you are doing). # # Note that since the replica by default does not evict, it may end using more # memory than the one set via maxmemory (there are certain buffers that may # be larger on the replica, or data structures may sometimes take more memory and so # forth). So make sure you monitor your replicas and make sure they have enough # memory to never hit a real out-of-memory condition before the master hits # the configured maxmemory setting. # # replica-ignore-maxmemory yes ############################# LAZY FREEING #################################### # Redis has two primitives to delete keys. One is called DEL and is a blocking # deletion of the object. It means that the server stops processing new commands # in order to reclaim all the memory associated with an object in a synchronous # way. If the key deleted is associated with a small object, the time needed # in order to execute the DEL command is very small and comparable to most other # O(1) or O(log_N) commands in Redis. However if the key is associated with an # aggregated value containing millions of elements, the server can block for # a long time (even seconds) in order to complete the operation. # # For the above reasons Redis also offers non blocking deletion primitives # such as UNLINK (non blocking DEL) and the ASYNC option of FLUSHALL and # FLUSHDB commands, in order to reclaim memory in background. Those commands # are executed in constant time. Another thread will incrementally free the # object in the background as fast as possible. # # DEL, UNLINK and ASYNC option of FLUSHALL and FLUSHDB are user-controlled. # It's up to the design of the application to understand when it is a good # idea to use one or the other. However the Redis server sometimes has to # delete keys or flush the whole database as a side effect of other operations. # Specifically Redis deletes objects independently of a user call in the # following scenarios: # # 1) On eviction, because of the maxmemory and maxmemory policy configurations, # in order to make room for new data, without going over the specified # memory limit. # 2) Because of expire: when a key with an associated time to live (see the # EXPIRE command) must be deleted from memory. # 3) Because of a side effect of a command that stores data on a key that may # already exist. For example the RENAME command may delete the old key # content when it is replaced with another one. Similarly SUNIONSTORE # or SORT with STORE option may delete existing keys. The SET command # itself removes any old content of the specified key in order to replace # it with the specified string. # 4) During replication, when a replica performs a full resynchronization with # its master, the content of the whole database is removed in order to # load the RDB file just transferred. # # In all the above cases the default is to delete objects in a blocking way, # like if DEL was called. However you can configure each case specifically # in order to instead release memory in a non-blocking way like if UNLINK # was called, using the following configuration directives: lazyfree-lazy-eviction no lazyfree-lazy-expire no lazyfree-lazy-server-del no replica-lazy-flush no ############################## 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 of waiting 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 always appendfsync 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 100 auto-aof-rewrite-min-size 64mb # An AOF file may be found to be truncated at the end during the Redis # startup process, when the AOF data gets loaded back into memory. # This may happen when the system where Redis is running # crashes, especially when an ext4 filesystem is mounted without the # data=ordered option (however this can't happen when Redis itself # crashes or aborts but the operating system still works correctly). # # Redis can either exit with an error when this happens, or load as much # data as possible (the default now) and start if the AOF file is found # to be truncated at the end. The following option controls this behavior. # # If aof-load-truncated is set to yes, a truncated AOF file is loaded and # the Redis server starts emitting a log to inform the user of the event. # Otherwise if the option is set to no, the server aborts with an error # and refuses to start. When the option is set to no, the user requires # to fix the AOF file using the "redis-check-aof" utility before to restart # the server. # # Note that if the AOF file will be found to be corrupted in the middle # the server will still exit with an error. This option only applies when # Redis will try to read more data from the AOF file but not enough bytes # will be found. aof-load-truncated yes # When rewriting the AOF file, Redis is able to use an RDB preamble in the # AOF file for faster rewrites and recoveries. When this option is turned # on the rewritten AOF file is composed of two different stanzas: # # [RDB file][AOF tail] # # When loading Redis recognizes that the AOF file starts with the "REDIS" # string and loads the prefixed RDB file, and continues loading the AOF # tail. aof-use-rdb-preamble yes ################################ 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 exceeds 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 command was # already issued by the script but the user doesn'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 CLUSTER ############################### # # ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ # WARNING EXPERIMENTAL: Redis Cluster is considered to be stable code, however # in order to mark it as "mature" we need to wait for a non trivial percentage # of users to deploy it in production. # ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ # # Normal Redis instances can't be part of a Redis Cluster; only nodes that are # started as cluster nodes can. In order to start a Redis instance as a # cluster node enable the cluster support uncommenting the following: # # 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 do 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 replica of a failing master will avoid to start a failover if its data # looks too old. # # There is no simple way for a replica to actually have an exact measure of # its "data age", so the following two checks are performed: # # 1) If there are multiple replicas able to failover, they exchange messages # in order to try to give an advantage to the replica with the best # replication offset (more data from the master processed). # Replicas will try to get their rank by offset, and apply to the start # of the failover a delay proportional to their rank. # # 2) Every single replica computes the time of the last interaction with # its master. This can be the last ping or command received (if the master # is still in the "connected" state), or the time that elapsed since the # disconnection with the master (if the replication link is currently down). # If the last interaction is too old, the replica will not try to failover # at all. # # The point "2" can be tuned by user. Specifically a replica will not perform # the failover if, since the last interaction with the master, the time # elapsed is greater than: # # (node-timeout * replica-validity-factor) + repl-ping-replica-period # # So for example if node-timeout is 30 seconds, and the replica-validity-factor # is 10, and assuming a default repl-ping-replica-period of 10 seconds, the # replica will not try to failover if it was not able to talk with the master # for longer than 310 seconds. # # A large replica-validity-factor may allow replicas with too old data to failover # a master, while a too small value may prevent the cluster from being able to # elect a replica at all. # # For maximum availability, it is possible to set the replica-validity-factor # to a value of 0, which means, that replicas will always try to failover the # master regardless of the last time they interacted with the master. # (However they'll always try to apply a delay proportional to their # offset rank). # # Zero is the only value able to guarantee that when all the partitions heal # the cluster will always be able to continue. # # cluster-replica-validity-factor 10 # Cluster replicas are able to migrate to orphaned masters, that are masters # that are left without working replicas. This improves the cluster ability # to resist to failures as otherwise an orphaned master can't be failed over # in case of failure if it has no working replicas. # # Replicas migrate to orphaned masters only if there are still at least a # given number of other working replicas for their old master. This number # is the "migration barrier". A migration barrier of 1 means that a replica # will migrate only if there is at least 1 other working replica for its master # and so forth. It usually reflects the number of replicas you want for every # master in your cluster. # # Default is 1 (replicas migrate only if their masters remain with at least # one replica). To disable migration just set it to a very large value. # A value of 0 can be set but is useful only for debugging and dangerous # in production. # # cluster-migration-barrier 1 # By default Redis Cluster nodes stop accepting queries if they detect there # is at least an hash slot uncovered (no available node is serving it). # This way if the cluster is partially down (for example a range of hash slots # are no longer covered) all the cluster becomes, eventually, unavailable. # It automatically returns available as soon as all the slots are covered again. # # However sometimes you want the subset of the cluster which is working, # to continue to accept queries for the part of the key space that is still # covered. In order to do so, just set the cluster-require-full-coverage # option to no. # # cluster-require-full-coverage yes # This option, when set to yes, prevents replicas from trying to failover its # master during master failures. However the master can still perform a # manual failover, if forced to do so. # # This is useful in different scenarios, especially in the case of multiple # data center operations, where we want one side to never be promoted if not # in the case of a total DC failure. # # cluster-replica-no-failover no # In order to setup your cluster make sure to read the documentation # available at http://redis.io web site. ########################## CLUSTER DOCKER/NAT support ######################## # In certain deployments, Redis Cluster nodes address discovery fails, because # addresses are NAT-ted or because ports are forwarded (the typical case is # Docker and other containers). # # In order to make Redis Cluster working in such environments, a static # configuration where each node knows its public address is needed. The # following two options are used for this scope, and are: # # * cluster-announce-ip # * cluster-announce-port # * cluster-announce-bus-port # # Each instruct the node about its address, client port, and cluster message # bus port. The information is then published in the header of the bus packets # so that other nodes will be able to correctly map the address of the node # publishing the information. # # If the above options are not used, the normal Redis Cluster auto-detection # will be used instead. # # Note that when remapped, the bus port may not be at the fixed offset of # clients port + 10000, so you can specify any port and bus-port depending # on how they get remapped. If the bus-port is not set, a fixed offset of # 10000 will be used as usually. # # Example: # # cluster-announce-ip 10.1.1.5 # cluster-announce-port 6379 # cluster-announce-bus-port 6380 ################################## 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 ################################ LATENCY MONITOR ############################## # The Redis latency monitoring subsystem samples different operations # at runtime in order to collect data related to possible sources of # latency of a Redis instance. # # Via the LATENCY command this information is available to the user that can # print graphs and obtain reports. # # The system only logs operations that were performed in a time equal or # greater than the amount of milliseconds specified via the # latency-monitor-threshold configuration directive. When its value is set # to zero, the latency monitor is turned off. # # By default latency monitoring is disabled since it is mostly not needed # if you don't have latency issues, and collecting data has a performance # impact, that while very small, can be measured under big load. Latency # monitoring can easily be enabled at runtime using the command # "CONFIG SET latency-monitor-threshold <milliseconds>" if needed. latency-monitor-threshold 0 ############################# EVENT NOTIFICATION ############################## # Redis can notify Pub/Sub clients about events happening in the key space. # This feature is documented at http://redis.io/topics/notifications # # 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 # of zero or multiple characters. The empty string means that notifications # are disabled. # # 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 512 hash-max-ziplist-value 64 # Lists are also encoded in a special way to save a lot of space. # The number of entries allowed per internal list node can be specified # as a fixed maximum size or a maximum number of elements. # For a fixed maximum size, use -5 through -1, meaning: # -5: max size: 64 Kb <-- not recommended for normal workloads # -4: max size: 32 Kb <-- not recommended # -3: max size: 16 Kb <-- probably not recommended # -2: max size: 8 Kb <-- good # -1: max size: 4 Kb <-- good # Positive numbers mean store up to _exactly_ that number of elements # per list node. # The highest performing option is usually -2 (8 Kb size) or -1 (4 Kb size), # but if your use case is unique, adjust the settings as necessary. list-max-ziplist-size -2 # Lists may also be compressed. # Compress depth is the number of quicklist ziplist nodes from *each* side of # the list to *exclude* from compression. The head and tail of the list # are always uncompressed for fast push/pop operations. Settings are: # 0: disable all list compression # 1: depth 1 means "don't start compressing until after 1 node into the list, # going from either the head or tail" # So: [head]->node->node->...->node->[tail] # [head], [tail] will always be uncompressed; inner nodes will compress. # 2: [head]->[next]->node->node->...->node->[prev]->[tail] # 2 here means: don't compress head or head->next or tail->prev or tail, # but compress all nodes between them. # 3: [head]->[next]->[next]->node->node->...->node->[prev]->[prev]->[tail] # etc. list-compress-depth 0 # Sets have a special encoding in just one case: when a set is composed # of just strings that happen 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 128 zset-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 # Streams macro node max size / items. The stream data structure is a radix # tree of big nodes that encode multiple items inside. Using this configuration # it is possible to configure how big a single node can be in bytes, and the # maximum number of items it may contain before switching to a new node when # appending new stream entries. If any of the following settings are set to # zero, the limit is ignored, so for instance it is possible to set just a # max entires limit by setting max-bytes to 0 and max-entries to the desired # value. stream-node-max-bytes 4096 stream-node-max-entries 100 # 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 # actively rehash 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 from 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 including MONITOR clients # replica -> replica clients # pubsub -> clients subscribed to at least one pubsub channel or pattern # # The syntax of every client-output-buffer-limit directive is the following: # # 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 replica clients, since # subscribers and replicas receive data in a push fashion. # # Both the hard or the soft limit can be disabled by setting them to zero. client-output-buffer-limit normal 0 0 0 client-output-buffer-limit replica 256mb 64mb 60 client-output-buffer-limit pubsub 32mb 8mb 60 # Client query buffers accumulate new commands. They are limited to a fixed # amount by default in order to avoid that a protocol desynchronization (for # instance due to a bug in the client) will lead to unbound memory usage in # the query buffer. However you can configure it here if you have very special # needs, such us huge multi/exec requests or alike. # # client-query-buffer-limit 1gb # In the Redis protocol, bulk requests, that are, elements representing single # strings, are normally limited ot 512 mb. However you can change this limit # here. # # proto-max-bulk-len 512mb # 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 according 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 # Normally it is useful to have an HZ value which is proportional to the # number of clients connected. This is useful in order, for instance, to # avoid too many clients are processed for each background task invocation # in order to avoid latency spikes. # # Since the default HZ value by default is conservatively set to 10, Redis # offers, and enables by default, the ability to use an adaptive HZ value # which will temporary raise when there are many connected clients. # # When dynamic HZ is enabled, the actual configured HZ will be used as # as a baseline, but multiples of the configured HZ value will be actually # used as needed once more clients are connected. In this way an idle # instance will use very little CPU time while a busy instance will be # more responsive. dynamic-hz yes # 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 # When redis saves RDB 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. rdb-save-incremental-fsync yes # Redis LFU eviction (see maxmemory setting) can be tuned. However it is a good # idea to start with the default settings and only change them after investigating # how to improve the performances and how the keys LFU change over time, which # is possible to inspect via the OBJECT FREQ command. # # There are two tunable parameters in the Redis LFU implementation: the # counter logarithm factor and the counter decay time. It is important to # understand what the two parameters mean before changing them. # # The LFU counter is just 8 bits per key, it's maximum value is 255, so Redis # uses a probabilistic increment with logarithmic behavior. Given the value # of the old counter, when a key is accessed, the counter is incremented in # this way: # # 1. A random number R between 0 and 1 is extracted. # 2. A probability P is calculated as 1/(old_value*lfu_log_factor+1). # 3. The counter is incremented only if R < P. # # The default lfu-log-factor is 10. This is a table of how the frequency # counter changes with a different number of accesses with different # logarithmic factors: # # +--------+------------+------------+------------+------------+------------+ # | factor | 100 hits | 1000 hits | 100K hits | 1M hits | 10M hits | # +--------+------------+------------+------------+------------+------------+ # | 0 | 104 | 255 | 255 | 255 | 255 | # +--------+------------+------------+------------+------------+------------+ # | 1 | 18 | 49 | 255 | 255 | 255 | # +--------+------------+------------+------------+------------+------------+ # | 10 | 10 | 18 | 142 | 255 | 255 | # +--------+------------+------------+------------+------------+------------+ # | 100 | 8 | 11 | 49 | 143 | 255 | # +--------+------------+------------+------------+------------+------------+ # # NOTE: The above table was obtained by running the following commands: # # redis-benchmark -n 1000000 incr foo # redis-cli object freq foo # # NOTE 2: The counter initial value is 5 in order to give new objects a chance # to accumulate hits. # # The counter decay time is the time, in minutes, that must elapse in order # for the key counter to be divided by two (or decremented if it has a value # less <= 10). # # The default value for the lfu-decay-time is 1. A Special value of 0 means to # decay the counter every time it happens to be scanned. # # lfu-log-factor 10 # lfu-decay-time 1 ########################### ACTIVE DEFRAGMENTATION ####################### # # WARNING THIS FEATURE IS EXPERIMENTAL. However it was stress tested # even in production and manually tested by multiple engineers for some # time. # # What is active defragmentation? # ------------------------------- # # Active (online) defragmentation allows a Redis server to compact the # spaces left between small allocations and deallocations of data in memory, # thus allowing to reclaim back memory. # # Fragmentation is a natural process that happens with every allocator (but # less so with Jemalloc, fortunately) and certain workloads. Normally a server # restart is needed in order to lower the fragmentation, or at least to flush # away all the data and create it again. However thanks to this feature # implemented by Oran Agra for Redis 4.0 this process can happen at runtime # in an "hot" way, while the server is running. # # Basically when the fragmentation is over a certain level (see the # configuration options below) Redis will start to create new copies of the # values in contiguous memory regions by exploiting certain specific Jemalloc # features (in order to understand if an allocation is causing fragmentation # and to allocate it in a better place), and at the same time, will release the # old copies of the data. This process, repeated incrementally for all the keys # will cause the fragmentation to drop back to normal values. # # Important things to understand: # # 1. This feature is disabled by default, and only works if you compiled Redis # to use the copy of Jemalloc we ship with the source code of Redis. # This is the default with Linux builds. # # 2. You never need to enable this feature if you don't have fragmentation # issues. # # 3. Once you experience fragmentation, you can enable this feature when # needed with the command "CONFIG SET activedefrag yes". # # The configuration parameters are able to fine tune the behavior of the # defragmentation process. If you are not sure about what they mean it is # a good idea to leave the defaults untouched. # Enabled active defragmentation # activedefrag yes # Minimum amount of fragmentation waste to start active defrag # active-defrag-ignore-bytes 100mb # Minimum percentage of fragmentation to start active defrag # active-defrag-threshold-lower 10 # Maximum percentage of fragmentation at which we use maximum effort # active-defrag-threshold-upper 100 # Minimal effort for defrag in CPU percentage # active-defrag-cycle-min 5 # Maximal effort for defrag in CPU percentage # active-defrag-cycle-max 75 # Maximum number of set/hash/zset/list fields that will be processed from # the main dictionary scan # active-defrag-max-scan-fields 1000
(1). 允许远程访问
#1. 注释掉下面代码，或者改为 bind 0.0.0.0
#bind 127.0.0.1
#2. 关闭保护模式
protected-mode no
#3. 开启密码(开启密码后，上面的保护模式可以不用关闭，远程也可以连接)
requirepass 123456
PS：还需保证端口开放或者防火墙关闭。
(2). redis cluster配置
# 一. 允许远程访问
#1. 注释掉下面代码，或者改为 bind 0.0.0.0
#bind 127.0.0.1
#2. 关闭保护模式
protected-mode no
#二. 通用配置
#1. 开启守护进程
daemonize yes
#2. 配置密码（必须设置相同的密码，不设masterauth的话宕机了不能自动恢复）
requirepass 123456
masterauth 123456
#三.集群配置
port 6384 #配置端口
cluster-enabled yes #开启集群
cluster-config-file nodes-6384.conf #集群节点配置文件
pidfile /var/run/redis_6384.pid
cluster-node-timeout 5000 #集群节点超时时间
(3). 数据持久化
#一. RDB存储 # 下面配置为默认配置，默认就是开启的，在一定的间隔时间中，检测key的变化情况，然后持久化数据 save 900 1 #900s后至少1个key发生变化则进行存储 save 300 10 #300s后至少10个key发生变化则进行存储 save 60 10000 #60s后至少10000个key发生变化则进行存储 #二. AOP存储 #默认是关闭的，日志记录的方式，可以记录每一条命令的操作。可以每一次命令操作后，持久化数据，启用的话通常使用每隔一秒持久化一次的策略 appendonly no（默认no） --> appendonly yes （开启aof） # appendfsync always #每一次操作都进行持久化 appendfsync everysec #每隔一秒进行一次持久化 # appendfsync no # 不进行持久化
(4). 缓存淘汰策略
# - volatile-lru: 针对到期的键值，采取 LRU 策略； # - volatile-lfu: 针对到期的键值，采取 LFU 策略； # - volatile-random: 针对到期的键值，采取随机策略； # - allkeys-lru: 针对所有键值，采取 LRU 策略； # - allkeys-lfu: 针对所有键值，采取 LFU 策略； # - allkeys-random: 针对所有键值，采取随机策略； # - volatile-ttl: 删除最近到期的key（次要TTL） # - noeviction: 不清除任何内容，只是在写入操作时报错。 # # LRU表示最近最少使用 # LFU意味着最少使用 # # LRU，LFU和volatile-ttl都是使用近似随机算法实现的。 # # 默认值是：noeviction # # maxmemory-policy noeviction
(5). 常用配置汇总
#修改daemonize为yes，即默认以后台程序方式运行 daemonize yes #修改默认监听端口(一般用默认的) port 6379 #修改生成默认日志文件位置，默认为"" logfile "" #默认rdb存储方式的名称 dbfilename dump.rdb #rdb文件存放位置,默认为当前目录 dir ./ #开启aof存储，默认为no appendonly no #aof存储持久化文件的名称 appendfilename "appendonly.aof" #PID文件 pidfile /home/apps/redis/redis.pid #保护模式 protected-mode no #支持集群 cluster-enabled yes #密码 requirepass 123456 #集群相关密码 masterauth 123456 #缓存淘汰策略（默认不清除） maxmemory-policy noeviction
(6). 全部文件翻译（来源于网络）
# 请注意，为了读取配置文件，必须以文件路径作为第一个参数启动Redis： # ./redis-server /path/to/redis.conf # 内存大小单位 # # 1k => 1000 bytes # 1kb => 1024 bytes # 1m => 1000000 bytes # 1mb => 1024*1024 bytes # 1g => 1000000000 bytes # 1gb => 1024*1024*1024 bytes # # 单位不区分大小写，因此 1GB 1Gb 1gB 是一样的. ################################## INCLUDES ################################### # 在此处包含一个或多个其他配置文件。如果您有一个标准模板可用于所有Redis服务器，但还需要自定义一些服务器设置。 # # “include”不会被来自admin或Redis Sentinel的命令“CONFIG REWRITE”重写。 # 由于Redis始终使用最后处理的行为作为配置指令的值，因此最好将include放在此文件的开头，以避免在运行时覆盖配置更改。 # # 如果你要使用includes来覆盖配置选项，最好将include作为最后一行。 # # include /path/to/local.conf # include /path/to/other.conf ################################## MODULES ##################################### # 启动时加载指定模块，如果服务器无法加载模块，它将中止。 这里可以使用多个loadmodule指令。 # # loadmodule /path/to/my_module.so # loadmodule /path/to/other_module.so ################################## NETWORK ##################################### # 默认情况下，如果未指定“bind”配置指令，则Redis将监听来自服务器上可用的所有端口的连接。 # 可以使用“bind”配置指令仅监听一个或多个指定的IP地址。 # # Examples: # # bind 192.168.1.100 10.0.0.1 # bind 127.0.0.1 ::1 # # ~~~ WARNING ~~~ 如果运行Redis的计算机直接暴露于Internet，则绑定到所有接口是危险的，并且会将实例暴露给Internet上的每个人。 # 因此，默认情况下，我们不会注释以下绑定指令，这意味着Redis只能接受来自指定ip的客户端的连接 # # IF YOU ARE SURE YOU WANT YOUR INSTANCE TO LISTEN TO ALL THE INTERFACES # JUST COMMENT THE FOLLOWING LINE. # ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ bind 127.0.0.1 # 保护模式是一层安全保护，以避免在Internet上打开的Redis实例被访问和利用。 # # 当保护模式打开的情况下,如果： # # 1) 服务器未使用“bind”指令显式绑定到一组地址。 # 2) 没有配置密码。 # # 服务器仅接受来自IPv4和IPv6环回地址127.0.0.1和:: 1以及Unix域套接字的客户端的连接。 # # 默认情况下保护模式是开启的。 只有在希望其他主机的客户端即使未配置任何身份验证，仍要连接到Redis时，应该禁用此选项并且不使用“bind”指令明确列出一组特定的接口。 protected-mode yes # 接受指定端口上的连接，默认为6379 # 如果指定了端口0，则Redis不会侦听TCP套接字。 port 6379 # TCP连接最大积压数 # # 在大量客户端连接的情况下，应该提高该值，以免客户端连接慢。 # 但该值受系统内核参数的限制，包括 somaxconn 和 tcp_max_syn_backlog。 tcp-backlog 511 # Unix socket. # # 指定将用于监听传入连接的Unix套接字的路径。 没有默认值，因此Redis在未指定时不会侦听unix套接字。 # # unixsocket /tmp/redis.sock # unixsocketperm 700 # 当连接的客户端连续空闲指定时间后，就断开该连接。指定值为0时禁用超时机制。 timeout 0 # TCP keepalive. # 周期性检测客户端是否可用 # 如果非零，则在没有通信的情况下使用SO_KEEPALIVE向客户端发送TCP ACK。 # 此选项的合理值为300秒 tcp-keepalive 300 ################################# GENERAL ##################################### # 设定是否以守护进程启动服务（默认是no），守护进程会生成 PID 文件 /var/run/redis_6379.pid。 daemonize no # If you run Redis from upstart or systemd, Redis can interact with your # supervision tree. Options: # supervised no - no supervision interaction # supervised upstart - signal upstart by putting Redis into SIGSTOP mode # supervised systemd - signal systemd by writing READY=1 to $NOTIFY_SOCKET # supervised auto - detect upstart or systemd method based on # UPSTART_JOB or NOTIFY_SOCKET environment variables # Note: these supervision methods only signal "process is ready." # They do not enable continuous liveness pings back to your supervisor. supervised no # 启用守护进程模式时，会生成该文件。 pidfile /var/run/redis_6379.pid # 指定日志级别 # 日志级别有以下选项: # debug (适用于开发/测试) # verbose (很少但很有用的信息) # notice (信息适中，推荐选项) # warning (只记录非常重要/关键的消息) loglevel notice # 指定保存日志的文件。请注意，如果您使用标准输出进行日志记录，守护进程情况下，日志将发送到/dev/null logfile "" # 要启用日志记录到系统记录器，只需将“syslog-enabled”设置为yes，并可选择更新其他syslog参数以满足您的需要。 # syslog-enabled no # 指定syslog标识。 # syslog-ident redis # 指定syslog工具。 必须是USER或LOCAL0-LOCAL7之间。 # syslog-facility local0 # 设置数据库数量，默认为16. 默认数据库是 DB 0, 你可以使用 SELECT <dbid> 选择使用的数据库。 # 数据库编号在 0 到 'databases'-1 databases 16 # 启动日志中是否显示redis logo，默认是开启的 always-show-logo yes ################################ SNAPSHOTTING ################################ # # 数据持久化: # # save <seconds> <changes> # # 指定时间间隔后，如果数据变化达到指定次数，则导出生成快照文件 # # 示例如下： # # 900 秒(15 分钟)内至少有1个key被修改 # 300 秒(5分钟)内至少有10个key被修改 # 60 秒(1分钟)内至少有10000个key被修改 # # # 如果指定 save ""，则相当于清除前面指定的所有 save 设置 # # save "" save 900 1 save 300 10 save 60 10000 # 在启用快照的情况下(指定了有效的 save)，如果遇到某次快照生成失败(比如目录无权限)， # 之后的数据修改就会被禁止。这有利于用户及早发现快照保存失败，以免更多的数据不能持久化而丢失的风险。 # 当快照恢复正常后，数据的修改会自动开启。 # 如果你有其他的持久化监控，你可以关闭本机制。 stop-writes-on-bgsave-error yes # 快照中字符串值是否压缩 rdbcompression yes # 如果开启，校验和会被放在文件尾部。这将使快照数据更可靠，但会在快照生成与加载时降低大约 10% 的性能，追求高性能时可关闭该功能。 rdbchecksum yes # 指定保存快照文件的名称 dbfilename dump.rdb # 指定保存快照文件的目录，AOF(Append Only File) 文件也会生成到该目录 dir ./ ################################# REPLICATION ################################# # 主从复制。 使用 replicaof 使Redis实例成为另一台Redis服务器的副本。 # # +------------------+ +---------------+ # | Master | ---> | Replica | # | (receive writes) | | (exact copy) | # +------------------+ +---------------+ # # 1) Redis复制是异步的，但是如果master与一定数量的副本无法连接，则可以将主服务器配置为停止接受写入。 # 2) 如果再较短时间内与副本失去了连接，当Redis副本与master重新连接时可以执行部分重新同步。因此就要求配置一个合理的 backlog 值。 # 3) 当副本节点重新连接到master时，重新同步复制时自动的，不需要用户干预。 # # replicaof <masterip> <masterport> # 如果主服务器受密码保护（使用下面的“requirepass”配置指令），则可以在启动复制同步过程之前告知副本服务器进行身份验证，否则主服务器将拒绝副本服务器请求。 # # masterauth <master-password> # 当从库与主库连接中断，或者主从同步正在进行时，如果有客户端向从库读取数据： # - yes: 从库答复现有数据，可能是旧数据(初始从未修改的值则为空值) # - no: 从库报错“正在从主库同步” replica-serve-stale-data yes # 从库只允许读取 replica-read-only yes # 无盘同步 # # ------------------------------------------------------- # WARNING: DISKLESS REPLICATION IS EXPERIMENTAL CURRENTLY # ------------------------------------------------------- # 新连接(包括连接中断后重连)的从库不可采用增量同步，只能采用全量同步(RDB文件由主库传给从库)，有两种传递方式： # - 磁盘形式：主库创建子进程，子进程写入磁盘 RDB 文件，再由父进程立即传给从库； # - 无磁盘形式：主库创建子进程，子进程把 RDB 文件直接写入从库的 SOCKET 连接。 repl-diskless-sync no # 无盘同步传输间隔（秒） repl-diskless-sync-delay 5 # 从库向主库PING的间隔（秒） # # repl-ping-replica-period 10 # 以下选项设置复制超时： # # 1) 从副本的角度来看，在SYNC期间批量传输I / O. # 2) 从副本（data，ping）的角度来看master超时。 # 3) 从主服务器的角度来看副本超时（REPLCONF ACK ping）。 # # 确保此值大于为repl-ping-replica-period指定的值非常重要，否则每次主服务器和副本服务器之间的流量较低时都会检测到超时。 # # repl-timeout 60 # 在SYNC之后禁用副本套接字上的TCP_NODELAY？ # # 如果选择“yes”，Redis将使用较少数量的TCP数据包和较少的带宽将数据发送到副本。 但这可能会增加数据在副本端出现的延迟，使用默认配置的Linux内核最多可达40毫秒。 # # 如果选择“no”，则副本上显示的数据延迟将减少，但将使用更多带宽进行复制。 # # 默认情况下，我们针对低延迟进行优化，但是在非常高的流量条件下，或者当主节点和副本很多时，将其设置为 yes 或许是较好的选择 repl-disable-tcp-nodelay no # 设置复制积压大小（backlog）。 积压是一个缓冲区，当副本断开连接一段时间后会累积副本数据，因此当副本想要再次重新连接时，通常不需要完全重新同步，只需要部分重新同步就足够了 # # 复制backlog越大，副本可以断开连接的时间越长。 # # repl-backlog-size 1mb # 当master与副本节点断开时间超过指定时间后，将释放复制积压缓冲区（backlog） # # 如果设置为0，表示一直不释放复制积压缓冲区 # # repl-backlog-ttl 3600 # 副本优先级，哨兵模式下，如果主服务器不再正常工作，Redis Sentinel 将优先使用它来选择要升级为主服务器的副本。 # # 值越低，优先级越高 # # 优先级为0会将副本标记为无法担任master的角色，因此Redis Sentinel永远不会选择优先级为0的副本进行升级。 # # 默认情况下，优先级为100。 replica-priority 100 # 如果可用连接的副本数少于N个，并且延迟小于或等于M秒，则master停止接受写入。 # # 以秒为单位的延迟（必须<=指定值）是根据从副本接收的最后一次ping计算的，通常每秒发送一次。 # # 例如，要求至少3个在线且滞后时间<= 10秒的副本： # # min-replicas-to-write 3 # min-replicas-max-lag 10 # # 以上两个属性，任意一个设置为0，都会禁用该功能。 # # 默认情况下，min-replicas-to-write设置为0（功能已禁用），min-replicas-max-lag设置为10。 # 当使用端口转发或网络地址转换（NAT）时，实际上可以通过不同的IP和端口对副本进行访问。 # 副本可以使用以下两个选项，向其主服务器报告一组特定的IP和端口。 # # 如果只需要覆盖端口或IP地址，则无需使用这两个选项。 # # replica-announce-ip 5.5.5.5 # replica-announce-port 1234 ################################## SECURITY ################################### # 设置redis访问密码 # # requirepass foobared # 命令重命名. # 对于一些敏感的命令，不希望任意客户端都可以执行，可以改掉默认的名字，新名字只告知特定的客户端来执行。 # 可以命令改名：rename-command CONFIG b840fc02d524045429941cc15f59e41cb7be6c52 # 可以禁用命令：rename-command CONFIG ""，即新名称为空串。 # 需要注意的是，命令改名保存至 AOF 文件或传输至从库，可能导致问题。 # rename-command CONFIG "" ################################### CLIENTS #################################### # 同一时刻最多可以接纳的客户端数目(Redis 服务要占用其中的大约 32 个文件描述符)。 # 如果客户端连接数达到该上限，新来客户端将被告知“已达到最大客户端连接数”。 # # maxclients 10000 ############################## MEMORY MANAGEMENT ################################ # 内存使用上限 # # 当内存达到上限时，Redis 将使用指定的策略清除其他键值。 # 如果 Redis 无法清除(或者策略不允许清除键值)，将对占用内存的命令报错，但对只读的命令正常服务。 # # maxmemory <bytes> # - volatile-lru: 针对到期的键值，采取 LRU 策略； # - volatile-lfu: 针对到期的键值，采取 LFU 策略； # - volatile-random: 针对到期的键值，采取随机策略； # - allkeys-lru: 针对所有键值，采取 LRU 策略； # - allkeys-lfu: 针对所有键值，采取 LFU 策略； # - allkeys-random: 针对所有键值，采取随机策略； # - volatile-ttl: 删除最近到期的key（次要TTL） # - noeviction: 不清除任何内容，只是在写入操作时报错。 # # LRU表示最近最少使用 # LFU意味着最少使用 # # LRU，LFU和volatile-ttl都是使用近似随机算法实现的。 # # 默认值是：noeviction # # maxmemory-policy noeviction # 清除键值时取样数量 # LRU，LFU和最小TTL算法不是精确的算法，而是近似算法（为了节省内存），因此您可以调整它以获得速度或精度。 # 默认情况下，Redis将检查五个键并选择最近使用的键，您可以使用以下配置指令更改样本大小。 # 默认值为5会产生足够好的结果。 10:近似非常接近真实的LRU但成本更高的CPU。 3:更快但不是很准确。 # # maxmemory-samples 5 # 从Redis 5开始，默认情况下，副本将忽略其maxmemory设置（除非在故障转移后或手动将其提升为主设备）。 # 这意味着key的清除将由主服务器处理，当主服务器中的key清除时，将DEL命令发送到副本。 # # 此行为可确保主服务器和副本服务器保持一致，但是如果您的副本服务器是可写的，或者您希望副本服务器具有不同的内存设置， # 并且您确定对副本服务器执行的所有写操作都是幂等的， 然后你可以改变这个默认值（但一定要明白你在做什么）。 # # replica-ignore-maxmemory yes ############################# LAZY FREEING #################################### # lazy free 为惰性删除或延迟释放； # 当删除键的时候,redis提供异步延时释放key内存的功能， # 把key释放操作放在bio(Background I/O)单独的子线程处理中， # 减少删除big key对redis主线程的阻塞。有效地避免删除big key带来的性能和可用性问题。 # lazy free的使用分为2类：第一类是与DEL命令对应的主动删除，第二类是过期key删除。 # 针对redis内存使用达到maxmeory，并设置有淘汰策略时；在被动淘汰键时，是否采用lazy free机制； lazyfree-lazy-eviction no # 针对设置有TTL的键，达到过期后，被redis清理删除时是否采用lazy free机制； lazyfree-lazy-expire no # 针对有些指令在处理已存在的键时，会带有一个隐式的DEL键的操作。如rename命令，当目标键已存在,redis会先删除目标键，如果这些目标键是一个big key,那就会引入阻塞删除的性能问题 lazyfree-lazy-server-del no # 针对slave进行全量数据同步，slave在加载master的RDB文件前，会运行flushall来清理自己的数据场景， replica-lazy-flush no ############################## APPEND ONLY MODE ############################### # 可以同时启用AOF和RDB持久性而不会出现问题。 如果在启动时检查到启用了AOF，Redis将优先加载AOF。 # AOF 持久化机制默认是关闭的 # appendonly no # AOF持久化文件名称默认为 appendonly.aof appendfilename "appendonly.aof" # fsync() 调用会告诉操作系统将缓冲区的数据同步到磁盘，可取三种值：always、everysec和no。 # always：实时会极大消弱Redis的性能，因为这种模式下每次write后都会调用fsync。 # no：write后不会有fsync调用，由操作系统自动调度刷磁盘，性能是最好的。 # everysec：每秒调用一次fsync（默认） # appendfsync always appendfsync everysec # appendfsync no # 在AOF文件 rewrite期间,是否对aof新记录的append暂缓使用文件同步策略,主要考虑磁盘IO开支和请求阻塞时间。默认为no,表示"不暂缓",新的aof记录仍然会被立即同步 no-appendfsync-on-rewrite no # 当AOF增长超过指定比例时，重写AOF文件，设置为0表示不自动重写AOF文件，重写是为了使aof体积保持最小，而确保保存最完整的数据。 # 这里表示增长一倍 auto-aof-rewrite-percentage 100 #触发aof rewrite的最小文件大小，这里表示，文件大小最小64mb才会触发重写机制 auto-aof-rewrite-min-size 64mb # AOF文件可能在尾部是不完整的。那redis重启时load进内存的时候就有问题了。 # # 如果选择的是yes，当截断的aof文件被导入的时候，会自动发布一个log给客户端然后load。如果是no，用户必须手动redis-check-aof修复AOF文件才可以。默认值为 yes。 aof-load-truncated yes # 开启混合持久化 # redis保证RDB转储跟AOF重写不会同时进行。 # 当redis启动时，即便RDB和AOF持久化同时启用且AOF，RDB文件都存在，则redis总是会先加载AOF文件，这是因为AOF文件被认为能够更好的保证数据一致性， # 当加载AOF文件时，如果启用了混合持久化，那么redis将首先检查AOF文件的前缀，如果前缀字符是REDIS，那么该AOF文件就是混合格式的，redis服务器会先加载RDB部分，然后再加载AOF部分。 aof-use-rdb-preamble yes ################################ LUA SCRIPTING ############################### # Lua脚本执行超时时间 # # 设置成0或者负值表示不限时 lua-time-limit 5000 ################################ REDIS CLUSTER ############################### # # 开启集群功能，此redis实例作为集群的一个节点 # # cluster-enabled yes # 集群配置文件 # 此配置文件不能人工编辑，它是集群节点自动维护的文件，主要用于记录集群中有哪些节点、他们的状态以及一些持久化参数等，方便在重启时恢复这些状态。通常是在收到请求之后这个文件就会被更新 # cluster-config-file nodes-6379.conf # 集群中的节点能够失联的最大时间，超过这个时间，该节点就会被认为故障。如果主节点超过这个时间还是不可达，则用它的从节点将启动故障迁移，升级成主节点 # # cluster-node-timeout 15000 # 如果设置成０，则无论从节点与主节点失联多久，从节点都会尝试升级成主节点。 # 如果设置成正数，则cluster-node-timeout*cluster-slave-validity-factor得到的时间，是从节点与主节点失联后， # 此从节点数据有效的最长时间，超过这个时间，从节点不会启动故障迁移。 # 假设cluster-node-timeout=5，cluster-slave-validity-factor=10，则如果从节点跟主节点失联超过50秒，此从节点不能成为主节点。 # 注意，如果此参数配置为非0，将可能出现由于某主节点失联却没有从节点能顶上的情况，从而导致集群不能正常工作， # 在这种情况下，只有等到原来的主节点重新回归到集群，集群才恢复运作。 # # cluster-replica-validity-factor 10 # 主节点需要的最小从节点数，只有达到这个数，主节点失败时，从节点才会进行迁移。 # # cluster-migration-barrier 1 # 在部分key所在的节点不可用时，如果此参数设置为"yes"(默认值), 则整个集群停止接受操作； # 如果此参数设置为”no”，则集群依然为可达节点上的key提供读操作。 # # cluster-require-full-coverage yes # 在主节点失效期间,从节点不允许对master失效转移 # cluster-replica-no-failover no ########################## CLUSTER DOCKER/NAT support ######################## #默认情况下，Redis会自动检测自己的IP和从配置中获取绑定的PORT，告诉客户端或者是其他节点。 #而在Docker环境中，如果使用的不是host网络模式，在容器内部的IP和PORT都是隔离的，那么客户端和其他节点无法通过节点公布的IP和PORT建立连接。 #如果开启以下配置，Redis节点会将配置中的这些IP和PORT告知客户端或其他节点。而这些IP和PORT是通过Docker转发到容器内的临时IP和PORT的。 # # Example: # # cluster-announce-ip 10.1.1.5 # cluster-announce-port 6379 # cluster-announce-bus-port 6380 ################################## SLOW LOG ################################### # 执行时间大于slowlog-log-slower-than的才会定义成慢查询，才会被slow-log记录 # 这里的单位是微秒，默认是 10ms slowlog-log-slower-than 10000 # 慢查询最大的条数，当slowlog超过设定的最大值后，会将最早的slowlog删除，是个FIFO队列 slowlog-max-len 128 ################################ LATENCY MONITOR ############################## # Redis延迟监视子系统在运行时对不同的操作进行采样，以便收集可能导致延时的数据根源。 # # 通过LATENCY命令，可以打印图表并获取报告。 # # 系统仅记录在等于或大于 latency-monitor-threshold 指定的毫秒数的时间内执行的操作。 当其值设置为0时，将关闭延迟监视器。 # # 默认情况下，延迟监视被禁用，因为如果您没有延迟问题，则通常不需要延迟监视，并且收集数据会对性能产生影响，虽然非常小。 # 如果需要，可以使用命令“CONFIG SET latency-monitor-threshold <milliseconds>”在运行时轻松启用延迟监视。 latency-monitor-threshold 0 ############################# EVENT NOTIFICATION ############################## # Redis可以向Pub / Sub客户端通知键空间发生的事件。 # # 例如，如果启用了键空间事件通知，并且客户端对存储在数据库0中的键 foo 执行DEL操作，则将通过Pub / Sub发布两条消息: # # PUBLISH __keyspace@0__:foo del # PUBLISH __keyevent@0__:del foo # 以 keyspace 为前缀的频道被称为键空间通知（key-space notification）， 而以 keyevent 为前缀的频道则被称为键事件通知（key-event notification）。 # 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 键空间通知，所有通知以 __keyspace@<db>__ 为前缀. # E 键事件通知，所有通知以 __keyevent@<db>__ 为前缀 # g DEL 、 EXPIRE 、 RENAME 等类型无关的通用命令的通知 # $ 字符串命令的通知 # l 列表命令的通知 # s 集合命令的通知 # h 哈希命令的通知 # z 有序集合命令的通知 # x 过期事件：每当有过期键被删除时发送 # e 驱逐(evict)事件：每当有键因为 maxmemory 策略而被删除时发送 # A 参数 g$lshzxe 的别名 # # 输入的参数中至少要有一个 K 或者 E ， 否则的话， 不管其余的参数是什么， 都不会有任何通知被分发。 # 如果只想订阅键空间中和列表相关的通知， 那么参数就应该设为 Kl。将参数设为字符串 "AKE" 表示发送所有类型的通知。 notify-keyspace-events "" ############################### ADVANCED CONFIG ############################### # hash类型的数据结构在编码上可以使用ziplist和hashtable。 # ziplist的特点就是文件存储(以及内存存储)所需的空间较小,在内容较小时,性能和hashtable几乎一样。 # 因此redis对hash类型默认采取ziplist。如果hash中条目个数或者value长度达到阀值,内部编码将使用hashtable。 # 这个参数指的是ziplist中允许存储的最大条目个数，默认为512，建议为128 hash-max-ziplist-entries 512 # ziplist中允许条目value值最大字节数，默认为64，建议为1024 hash-max-ziplist-value 64 # 当取正值的时候，表示按照数据项个数来限定每个quicklist节点上的ziplist长度。比如，当这个参数配置成5的时候，表示每个quicklist节点的ziplist最多包含5个数据项。 # 当取负值的时候，表示按照占用字节数来限定每个quicklist节点上的ziplist长度。这时，它只能取-1到-5这五个值 # -5: max size: 64 Kb <-- not recommended for normal workloads # -4: max size: 32 Kb <-- not recommended # -3: max size: 16 Kb <-- probably not recommended # -2: max size: 8 Kb <-- good # -1: max size: 4 Kb <-- good # 性能最高的选项通常为-2（8 Kb大小）或-1（4 Kb大小）。 list-max-ziplist-size -2 # 一个quicklist两端不被压缩的节点个数 # 参数list-compress-depth的取值含义如下： # 0: 表示都不压缩。这是Redis的默认值 # 1: 表示quicklist两端各有1个节点不压缩，中间的节点压缩。 # So: [head]->node->node->...->node->[tail] # [head], [tail] 不压缩; 内部节点将被压缩. # 2: [head]->[next]->node->node->...->node->[prev]->[tail] # 2：表示quicklist两端各有2个节点不压缩，中间的节点压缩 # 3: [head]->[next]->[next]->node->node->...->node->[prev]->[prev]->[tail] # 3: 表示quicklist两端各有3个节点不压缩，中间的节点压缩。 # etc. list-compress-depth 0 # 数据量小于等于512用intset，大于512用set set-max-intset-entries 512 # 数据量小于等于zset-max-ziplist-entries用ziplist，大于zset-max-ziplist-entries用zset zset-max-ziplist-entries 128 zset-max-ziplist-value 64 # value大小小于等于hll-sparse-max-bytes使用稀疏数据结构（sparse） # 大于hll-sparse-max-bytes使用稠密的数据结构（dense），一个比16000大的value是几乎没用的， # 建议的value大概为3000。如果对CPU要求不高，对空间要求较高的，建议设置到10000左右 hll-sparse-max-bytes 3000 #Streams宏节点最大大小。流数据结构是基数编码内部多个项目的大节点树。使用此配置 #可以配置单个节点的字节数，以及切换到新节点之前可能包含的最大项目数 #追加新的流条目。如果以下任何设置设置为0，忽略限制，因此例如可以设置一个 #大入口限制将max-bytes设置为0，将max-entries设置为所需的值 stream-node-max-bytes 4096 stream-node-max-entries 100 # 主动重新散列每100毫秒CPU时间使用1毫秒，以帮助重新散列主Redis散列表（将顶级键映射到值）。 # Redis使用的散列表实现（请参阅dict.c）执行延迟重新散列：您在重新散列的散列表中运行的操作越多，执行的重复“步骤”就越多， # 因此如果服务器处于空闲状态，则重新散列将永远不会完成 哈希表使用了一些内存。 activerehashing yes # 对客户端输出缓冲进行限制可以强迫那些不从服务器读取数据的客户端断开连接，用来强制关闭传输缓慢的客户端。 # 对于normal client，第一个0表示取消hard limit，第二个0和第三个0表示取消soft limit，normal client默认取消限制 client-output-buffer-limit normal 0 0 0 # 对于slave client和MONITER client，如果client-output-buffer一旦超过256mb，又或者超过64mb持续60秒，那么服务器就会立即断开客户端连接。 client-output-buffer-limit replica 256mb 64mb 60 # 对于pubsub client，如果client-output-buffer一旦超过32mb，又或者超过8mb持续60秒，那么服务器就会立即断开客户端连接。 client-output-buffer-limit pubsub 32mb 8mb 60 # 客户端查询缓冲区累积新命令。 默认情况下，它被限制为固定数量，以避免协议失步（例如由于客户端中的错误）将导致查询缓冲区中的未绑定内存使用。 # 但是，如果您有非常特殊的需求，可以在此配置它，例如我们巨大执行请求。 # # client-query-buffer-limit 1gb # 在Redis协议中，批量请求（即表示单个字符串的元素）通常限制为512 MB。 但是，您可以在此更改此限制。 # # proto-max-bulk-len 512mb # Redis调用内部函数来执行许多后台任务，例如在超时时关闭客户端的连接，清除从未请求过期的过期密钥等等。 # # 并非所有任务都以相同的频率执行，但Redis会根据指定的“hz”值检查要执行的任务。 # # 默认情况下，hz设置为10.提高值时，在Redis处于空闲状态下，将使用更多CPU # 但同时，当有很多键同时到期时，Redis会响应更快，并且可以更精确地处理超时。 # # 范围介于1到500之间，但超过100的值通常不是一个好主意。 大多数用户应使用默认值10，除非仅在需要非常低延迟的环境中将此值提高到100。 hz 10 # 通常，推荐使HZ的值与连接的客户端数量成比例。这有助于避免为每个后台任务调用处理太多客户端，以避免延迟峰值。 # # 默认情况下默认的HZ值为10。Redis 提供并启用自适应HZ值的功能，当有很多连接的客户端时，该值会临时增加。 # # 启用动态HZ时，实际配置的HZ将用作基线，但是一旦连接了更多客户端，将根据实际需要使用配置的HZ值的倍数。 # 通过这种方式，空闲实例将使用非常少的CPU时间，而繁忙的实例将更具响应性。 dynamic-hz yes # 当一个子进程重写AOF文件时，如果启用下面的选项，则文件每生成32M数据会被同步。 aof-rewrite-incremental-fsync yes # 当redis保存RDB文件时，如果启用了以下选项，则每生成32 MB数据将对文件进行fsync。 这对于以递增方式将文件提交到磁盘并避免大延迟峰值非常有用。 rdb-save-incremental-fsync yes # 可以调整Redis LFU（参见maxmemory设置）。 但是，最好使用默认设置，仅在调查如何改进性能以及LFU如何随时间变化后更改它们，这可以通过OBJECT FREQ命令进行检查。 # # Redis LFU实现中有两个可调参数：计数器对数因子和计数器衰减时间。 在更改它们之前，了解这两个参数的含义非常重要。 # # LFU计数器每个键只有8位，它的最大值是255，因此Redis使用具有对数行为的概率增量。 给定旧计数器的值，当访问密钥时，计数器以这种方式递增： # # 1. A random number R between 0 and 1 is extracted. # 2. A probability P is calculated as 1/(old_value*lfu_log_factor+1). # 3. The counter is incremented only if R < P. # # The default lfu-log-factor is 10. This is a table of how the frequency # counter changes with a different number of accesses with different # logarithmic factors: # # +--------+------------+------------+------------+------------+------------+ # | factor | 100 hits | 1000 hits | 100K hits | 1M hits | 10M hits | # +--------+------------+------------+------------+------------+------------+ # | 0 | 104 | 255 | 255 | 255 | 255 | # +--------+------------+------------+------------+------------+------------+ # | 1 | 18 | 49 | 255 | 255 | 255 | # +--------+------------+------------+------------+------------+------------+ # | 10 | 10 | 18 | 142 | 255 | 255 | # +--------+------------+------------+------------+------------+------------+ # | 100 | 8 | 11 | 49 | 143 | 255 | # +--------+------------+------------+------------+------------+------------+ # # NOTE: The above table was obtained by running the following commands: # # redis-benchmark -n 1000000 incr foo # redis-cli object freq foo # # NOTE 2: The counter initial value is 5 in order to give new objects a chance # to accumulate hits. # # The counter decay time is the time, in minutes, that must elapse in order # for the key counter to be divided by two (or decremented if it has a value # less <= 10). # # The default value for the lfu-decay-time is 1. A Special value of 0 means to # decay the counter every time it happens to be scanned. # # lfu-log-factor 10 # lfu-decay-time 1 ########################### ACTIVE DEFRAGMENTATION ####################### # # WARNING THIS FEATURE IS EXPERIMENTAL. However it was stress tested # even in production and manually tested by multiple engineers for some # time. # # What is active defragmentation? # ------------------------------- # # Active (online) defragmentation allows a Redis server to compact the # spaces left between small allocations and deallocations of data in memory, # thus allowing to reclaim back memory. # # Fragmentation is a natural process that happens with every allocator (but # less so with Jemalloc, fortunately) and certain workloads. Normally a server # restart is needed in order to lower the fragmentation, or at least to flush # away all the data and create it again. However thanks to this feature # implemented by Oran Agra for Redis 4.0 this process can happen at runtime # in an "hot" way, while the server is running. # # Basically when the fragmentation is over a certain level (see the # configuration options below) Redis will start to create new copies of the # values in contiguous memory regions by exploiting certain specific Jemalloc # features (in order to understand if an allocation is causing fragmentation # and to allocate it in a better place), and at the same time, will release the # old copies of the data. This process, repeated incrementally for all the keys # will cause the fragmentation to drop back to normal values. # # Important things to understand: # # 1. This feature is disabled by default, and only works if you compiled Redis # to use the copy of Jemalloc we ship with the source code of Redis. # This is the default with Linux builds. # # 2. You never need to enable this feature if you don't have fragmentation # issues. # # 3. Once you experience fragmentation, you can enable this feature when # needed with the command "CONFIG SET activedefrag yes". # # The configuration parameters are able to fine tune the behavior of the # defragmentation process. If you are not sure about what they mean it is # a good idea to leave the defaults untouched. # 启用主动碎片整理 # activedefrag yes # 启动活动碎片整理的最小碎片浪费量 # active-defrag-ignore-bytes 100mb # 启动碎片整理的最小碎片百分比 # active-defrag-threshold-lower 10 # 使用最大消耗时的最大碎片百分比 # active-defrag-threshold-upper 100 # 在CPU百分比中进行碎片整理的最小消耗 # active-defrag-cycle-min 5 # 在CPU百分比达到最大值时，进行碎片整理 # active-defrag-cycle-max 75 # 从set / hash / zset / list 扫描的最大字段数 # active-defrag-max-scan-fields 1000
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- 作 者 : Yaopengfei(姚鹏飞)
- 博客地址 : http://www.cnblogs.com/yaopengfei/
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