# Redis 配置文件 1. 单位格式 ```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. ``` 大小写不敏感 2. 导入其他配置文件 ```conf # 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. # # Note that 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. # # Included paths may contain wildcards. All files matching the wildcards will # be included in alphabetical order. # Note that if an include path contains a wildcards but no files match it when # the server is started, the include statement will be ignored and no error will # be emitted. It is safe, therefore, to include wildcard files from empty # directories. # # include /path/to/local.conf # include /path/to/other.conf # include /path/to/fragments/*.conf ``` 3. 网络配置 ```conf bind 127.0.0.1 -::1 # 绑定主机地址 protected-mode yes # 保护模式 port 6379 # 端口号 ``` * 每个地址都可以加上“-”前缀，表示没有地址时redis不会启动失败 * 当保护模式打开且默认用户没有密码时，服务器只接受来自 IPv4 地址（127.0.0.1）、IPv6 地址的本地连接(::1) 或 Unix 域套接字。 4. 一般设置 ```conf daemonize no # 是否以守护进程形式运行 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 logfile "" databases 16 # 数据库数量 always-show-logo no # 是否总是显示logo ``` 5. 快照 ```conf # Unless specified otherwise, by default Redis will save the DB: # * After 3600 seconds (an hour) if at least 1 change was performed # * After 300 seconds (5 minutes) if at least 100 changes were performed # * After 60 seconds if at least 10000 changes were performed # # You can set these explicitly by uncommenting the following line. # # save 3600 1 300 100 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. stop-writes-on-bgsave-error yes # Compress string objects using LZF when dump .rdb databases? # By default compression is enabled 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 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 ./ ``` 6. 备份 ```conf # 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 # 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 ``` 7. 安全 ```conf # IMPORTANT NOTE: starting with Redis 6 "requirepass" is just a compatibility # layer on top of the new ACL system. The option effect will be just setting # the password for the default user. Clients will still authenticate using # AUTH as usually, or more explicitly with AUTH default # if they follow the new protocol: both will work. # # The requirepass is not compatible with aclfile option and the ACL LOAD # command, these will cause requirepass to be ignored. # # requirepass foobared ``` 8. 客户端 ```conf # 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'. # # IMPORTANT: When Redis Cluster is used, the max number of connections is also # shared with the cluster bus: every node in the cluster will use two # connections, one incoming and another outgoing. It is important to size the # limit accordingly in case of very large clusters. # # maxclients 10000 ``` 9. 内存管理 ```conf # 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 # MAXMEMORY POLICY: how Redis will select what to remove when maxmemory # is reached. You can select one from the following behaviors: # # volatile-lru -> Evict using approximated LRU, only keys with an expire set. # allkeys-lru -> Evict any key using approximated LRU. # volatile-lfu -> Evict using approximated LFU, only keys with an expire set. # allkeys-lfu -> Evict any key using approximated LFU. # volatile-random -> Remove a random key having 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, when there are no suitable keys for # eviction, Redis will return an error on write operations that require # more memory. These are usually commands that create new keys, add data or # modify existing keys. A few examples are: SET, INCR, HSET, LPUSH, SUNIONSTORE, # SORT (due to the STORE argument), and EXEC (if the transaction includes any # command that requires memory). # # The default is: # # maxmemory-policy noeviction ``` **Redis 的八种内存淘汰策略：** * volatile-lru -> Evict using approximated LRU, only keys with an expire set. * allkeys-lru -> Evict any key using approximated LRU. * volatile-lfu -> Evict using approximated LFU, only keys with an expire set. * allkeys-lfu -> Evict any key using approximated LFU. * volatile-random -> Remove a random key having 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. 10. 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