02 Redis6-配置文件

深藏阁楼爱情的钟 2022-09-12 05:44 149阅读 0赞

### Units单位 ###

# 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包含 ###

################################## 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.
    #
    # 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.
    #
    # include /path/to/local.conf
    # include /path/to/other.conf

### NETWORK网络 ###

# IF YOU ARE SURE YOU WANT YOUR INSTANCE TO LISTEN TO ALL THE INTERFACES
    # JUST COMMENT OUT THE FOLLOWING LINE.
    # ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
    bind 127.0.0.1 ::1
    ....
    # TCP listen() backlog.
    #
    # In high requests-per-second environments you need a high backlog in order
    # to avoid slow clients connection 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
    ...
    # 空闲多少时间自动关闭，0就一直连接
    # 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) Force network equipment in the middle to consider the connection to be
    #    alive.
    #
    # 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

Tcp-backlog，设置tcp的backlog，backlog其实就是一个连接队列，backlog队列总和=未完成三次握手队列+已经完成三次握手队列。在高并发环境下你需要一个高的backlog值来避免慢客户端连接问题。

### general通用配置 ###

################################# 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 /usr/local/var/run/redis.pid when daemonized.
    # When Redis is supervised by upstart or systemd, this parameter has no impact.
    # daemonize no
    # 修改为yes
    daemonize yes
    
    # 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
    #                        requires "expect stop" in your upstart job config
    #   supervised systemd - signal systemd by writing READY=1 to $NOTIFY_SOCKET
    #                        on startup, and updating Redis status on a regular
    #                        basis.
    #   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 pings back to your supervisor.
    #
    # The default is "no". To run under upstart/systemd, you can simply uncomment
    # the line below:
    #
    # supervised auto
    
    # 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 "/usr/local/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.
    #
    # Note that on modern Linux systems "/run/redis.pid" is more conforming
    # and should be used instead.
    # 进程管道ID文件，运行起来的时候，如果你没有指定路径，那么就默认该路径
    pidfile /var/run/redis_6379.pid
    
    # Redis日志级别（4个级别）根据实际情况进行使用
    # 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
    
    # 日志名字
    # 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 ""
    
    # 系统日志默认关闭的
    # 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
    
    # 如果开启就以Redis开头
    # Specify the syslog identity.
    # syslog-ident redis
    
    # 指定syslog，值可以是USER或LOCALO-LOCAL7
    # Specify the syslog facility. Must be USER or between LOCAL0-LOCAL7.
    # syslog-facility local0
    # To disable the built in crash log, which will possibly produce cleaner core
    # dumps when they are needed, uncomment the following:
    #
    # crash-log-enabled no
    
    # To disable the fast memory check that's run as part of the crash log, which
    # will possibly let redis terminate sooner, uncomment the following:
    #
    # crash-memcheck-enabled no
    
    # Redis默认16库
    # 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 and syslog logging is
    # disabled. 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 no
    
    # By default, Redis modifies the process title (as seen in 'top' and 'ps') to
    # provide some runtime information. It is possible to disable this and leave
    # the process name as executed by setting the following to no.
    set-proc-title yes
    
    # When changing the process title, Redis uses the following template to construct
    # the modified title.
    #
    # Template variables are specified in curly brackets. The following variables are
    # supported:
    #
    # {title}           Name of process as executed if parent, or type of child process.
    # {listen-addr}     Bind address or '*' followed by TCP or TLS port listening on, or
    #                   Unix socket if only that's available.
    # {server-mode}     Special mode, i.e. "[sentinel]" or "[cluster]".
    # {port}            TCP port listening on, or 0.
    # {tls-port}        TLS port listening on, or 0.
    # {unixsocket}      Unix domain socket listening on, or "".
    # {config-file}     Name of configuration file used.
    #
    proc-title-template "{title} {listen-addr} {server-mode}"

### SNAPSHOTTING快照 ###

################################ SNAPSHOTTING  ################################
    
    # Save the DB to disk.
    #
    # 持久化保存命令格式：save [多少秒] [改变次数]
    # save <seconds> <changes>
    #
    # Redis will save the DB if both the given number of seconds and the given
    # number of write operations against the DB occurred.
    #
    # Snapshotting can be completely disabled with a single empty string argument
    # as in following example:
    #
    # 开启就是禁用的意思
    # save ""
    #
    # 1、3600秒内(1小时)，只要Redis有 1 key被改动1过，就出发持久化机制
    # 2、300秒(5分钟)key被改动过100次
    # 3、60秒(1分钟)，有10000次变更，就触发持久化
    # Unless specified otherwise, by default Redis will save the DB:
    #   * After 3600 seconds (an hour) if at least 1 key changed
    #   * After 300 seconds (5 minutes) if at least 100 keys changed
    #   * After 60 seconds if at least 10000 keys changed
    #
    # You can set these explicitly by uncommenting the three following lines.
    #
    # 我们可以根据需求要设置，这里假如模拟2分钟内修改10，就让他触发持久化
    save 120 10
    # save 3600 1
    # save 300 100
    # 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?
    # 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
    
    # Enables or disables full sanitation checks for ziplist and listpack etc when
    # loading an RDB or RESTORE payload. This reduces the chances of a assertion or
    # crash later on while processing commands.
    # Options:
    #   no         - Never perform full sanitation
    #   yes        - Always perform full sanitation
    #   clients    - Perform full sanitation only for user connections.
    #                Excludes: RDB files, RESTORE commands received from the master
    #                connection, and client connections which have the
    #                skip-sanitize-payload ACL flag.
    # The default should be 'clients' but since it currently affects cluster
    # resharding via MIGRATE, it is temporarily set to 'no' by default.
    #
    # sanitize-dump-payload no
    
    # The filename where to dump the DB
    dbfilename dump.rdb
    
    # Remove RDB files used by replication in instances without persistence
    # enabled. By default this option is disabled, however there are environments
    # where for regulations or other security concerns, RDB files persisted on
    # disk by masters in order to feed replicas, or stored on disk by replicas
    # in order to load them for the initial synchronization, should be deleted
    # ASAP. Note that this option ONLY WORKS in instances that have both AOF
    # and RDB persistence disabled, otherwise is completely ignored.
    #
    # An alternative (and sometimes better) way to obtain the same effect is
    # to use diskless replication on both master and replicas instances. However
    # in the case of replicas, diskless is not always an option.
    rdb-del-sync-files no
    
    # 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 /usr/local/var/db/redis/

### SECURITY安全 ###

> Config get requirepass \#查看密码
> 
> Config set requirepass \#设置密码
> 
> config get dir \#查看路径（启动如果指定Redis配置文件，路径就不一样的）

################################## SECURITY ###################################
    
    ...
    # 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 <password> as usually, or more explicitly with AUTH default <password>
    # if they follow the new protocol: both will work.
    #
    # The requirepass is not compatable with aclfile option and the ACL LOAD
    # command, these will cause requirepass to be ignored.
    #
    # requirepass foobared
    ...

### CLIENTS限制 ###

################################### 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'.
    #
    # 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.
    #
    # 最大可以连接10000
    # maxclients 10000

### MEMORY MANAGEMENT 内存管理 ###

面试题：Redis是内存数据库，它的缓存过期策略你是如何理解和配置的？

> 内存是有限的，假如现在存10000个数据，但是发现100个已经两个月都没有用过，而且数据特别大，这是我们就需要最大内存策略或者过期策略/缓存策略。
> 
> 《最大记忆策略： 雷迪斯如何选择在最大记忆时删除什么？已到达。您可以从以下行为中选择一个：》

############################## MEMORY MANAGEMENT ################################
    # 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>
    
    # 《最大记忆策略： Redis如何选择在最大记忆时删除什么？已到达。您可以从以下行为中选择一个：》
    # MAXMEMORY POLICY: how Redis will select what to remove when maxmemory
    # is reached. You can select one from the following behaviors:
    #
    # 1、volatile-lru：使用LRU算法移除key，只对设置了过期时间的键
    # 2、allkeys-lru：使用LUR算法移除key
    # 3、volatile-random：在过期集合中移除随机key
    # 4、allkeys-random：移除随机的key
    # 5、volatile-ttl：移除那些TTL值最小的key，即那些最近要过期的key
    # 6、noeviction：不进行移除，针对写操作，只是返回错误信息（默认使用，实际开始修改的）
    # 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:
    #
    # 默认《永不过期策略》
    # 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. By default Redis will check five keys and pick the one that was
    # used least 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.
    #
    # 设置样本数量，LRU算法和最小TTL算法都并非是精确的算法，而是估值算法，所以你可以设置样本的大小，redis默认会检查这么多个key并选择其中LRU的那个。默认5个
    # maxmemory-samples 5

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