• docker 启动一个 redis


    redis容器里边的配置文件是需要在创建容器时映射进来的!!!

    先本地创建redis.conf文件--这个带中文翻译的,建议用下面全英文的。

    查看代码
    
    # Redis配置文件样例
    
    # Note on units: when memory size is needed, it is possible to specifiy
    # 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.
    
    # Redis默认不是以守护进程的方式运行,可以通过该配置项修改,使用yes启用守护进程
    # 启用守护进程后,Redis会把pid写到一个pidfile中,在/var/run/redis.pid
    daemonize no
    
    # 当Redis以守护进程方式运行时,Redis默认会把pid写入/var/run/redis.pid文件,可以通过pidfile指定
    pidfile /var/run/redis.pid
    
    # 指定Redis监听端口,默认端口为6379
    # 如果指定0端口,表示Redis不监听TCP连接
    port 6379
    
    # 绑定的主机地址
    # 你可以绑定单一接口,如果没有绑定,所有接口都会监听到来的连接
    # bind 127.0.0.1
    
    # 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 755
    
    # 当客户端闲置多长时间后关闭连接,如果指定为0,表示关闭该功能
    timeout 0
    
    # 指定日志记录级别,Redis总共支持四个级别:debug、verbose、notice、warning,默认为verbose
    # debug (很多信息, 对开发/测试比较有用)
    # 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 verbose
    
    # 日志记录方式,默认为标准输出,如果配置为redis为守护进程方式运行,而这里又配置为标准输出,则日志将会发送给/dev/null
    logfile stdout
    
    # 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
    
    # 设置数据库的数量,默认数据库为0,可以使用select <dbid>命令在连接上指定数据库id
    # dbid是从0到‘databases’-1的数目
    databases 16
    
    ################################ SNAPSHOTTING  #################################
    # 指定在多长时间内,有多少次更新操作,就将数据同步到数据文件,可以多个条件配合
    # 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.
    #
    #   满足以下条件将会同步数据:
    #   900秒(15分钟)内有1个更改
    #   300秒(5分钟)内有10个更改
    #   60秒内有10000个更改
    #   Note: 可以把所有“save”行注释掉,这样就取消同步操作了
    
    save 900 1
    save 300 10
    save 60 10000
    
    # 指定存储至本地数据库时是否压缩数据,默认为yes,Redis采用LZF压缩,如果为了节省CPU时间,可以关闭该选项,但会导致数据库文件变的巨大
    rdbcompression yes
    
    # 指定本地数据库文件名,默认值为dump.rdb
    dbfilename dump.rdb
    
    # 工作目录.
    # 指定本地数据库存放目录,文件名由上一个dbfilename配置项指定
    # 
    # Also the Append Only File will be created inside this directory.
    # 
    # 注意,这里只能指定一个目录,不能指定文件名
    dir ./
    
    ################################# REPLICATION #################################
    
    # 主从复制。使用slaveof从 Redis服务器复制一个Redis实例。注意,该配置仅限于当前slave有效
    # so for example it is possible to configure the slave to save the DB with a
    # different interval, or to listen to another port, and so on.
    # 设置当本机为slav服务时,设置master服务的ip地址及端口,在Redis启动时,它会自动从master进行数据同步
    # slaveof <masterip> <masterport>
    
    
    # 当master服务设置了密码保护时,slav服务连接master的密码
    # 下文的“requirepass”配置项可以指定密码
    # masterauth <master-password>
    
    # When a slave lost the connection with the master, or when the replication
    # is still in progress, the slave can act in two different ways:
    #
    # 1) if slave-serve-stale-data is set to 'yes' (the default) the slave will
    #    still reply to client requests, possibly with out of data data, or the
    #    data set may just be empty if this is the first synchronization.
    #
    # 2) if slave-serve-stale data is set to 'no' the slave will reply with
    #    an error "SYNC with master in progress" to all the kind of commands
    #    but to INFO and SLAVEOF.
    #
    slave-serve-stale-data yes
    
    # Slaves send PINGs to server in a predefined interval. It's possible to change
    # this interval with the repl_ping_slave_period option. The default value is 10
    # seconds.
    #
    # repl-ping-slave-period 10
    
    # The following option sets a timeout for both Bulk transfer I/O timeout and
    # master data or ping response timeout. The default value is 60 seconds.
    #
    # It is important to make sure that this value is greater than the value
    # specified for repl-ping-slave-period otherwise a timeout will be detected
    # every time there is low traffic between the master and the slave.
    #
    # repl-timeout 60
    
    ################################## SECURITY ###################################
    
    # Warning: since Redis is pretty fast an outside user can try up to
    # 150k passwords per second against a good box. This means that you should
    # use a very strong password otherwise it will be very easy to break.
    # 设置Redis连接密码,如果配置了连接密码,客户端在连接Redis时需要通过auth <password>命令提供密码,默认关闭
    # requirepass foobared
    
    # Command renaming.
    #
    # It is possilbe to change the name of dangerous commands in a shared
    # environment. For instance the CONFIG command may be renamed into something
    # of hard to guess so that it will be still available for internal-use
    # tools but not available for general clients.
    #
    # Example:
    #
    # rename-command CONFIG b840fc02d524045429941cc15f59e41cb7be6c52
    #
    # It is also possilbe to completely kill a command renaming it into
    # an empty string:
    #
    # rename-command CONFIG ""
    
    ################################### LIMITS ####################################
    
    # 设置同一时间最大客户端连接数,默认无限制,Redis可以同时打开的客户端连接数为Redis进程可以打开的最大文件描述符数,
    # 如果设置maxclients 0,表示不作限制。当客户端连接数到达限制时,Redis会关闭新的连接并向客户端返回max Number of clients reached错误信息
    # maxclients 128
    
    # Don't use more memory than the specified amount of bytes.
    # When the memory limit is reached Redis will try to remove keys with an
    # EXPIRE set. It will try to start freeing keys that are going to expire
    # in little time and preserve keys with a longer time to live.
    # Redis will also try to remove objects from free lists if possible.
    #
    # If all this fails, Redis will start to reply with errors to commands
    # that will use more memory, like SET, LPUSH, and so on, and will continue
    # to reply to most read-only commands like GET.
    #
    # WARNING: maxmemory can be a good idea mainly if you want to use Redis as a
    # 'state' server or cache, not as a real DB. When Redis is used as a real
    # database the memory usage will grow over the weeks, it will be obvious if
    # it is going to use too much memory in the long run, and you'll have the time
    # to upgrade. With maxmemory after the limit is reached you'll start to get
    # errors for write operations, and this may even lead to DB inconsistency.
    # 指定Redis最大内存限制,Redis在启动时会把数据加载到内存中,达到最大内存后,Redis会先尝试清除已到期或即将到期的Key,
    # 当此方法处理后,仍然到达最大内存设置,将无法再进行写入操作,但仍然可以进行读取操作。
    # Redis新的vm机制,会把Key存放内存,Value会存放在swap区
    # maxmemory <bytes>
    
    # MAXMEMORY POLICY: how Redis will select what to remove when maxmemory
    # is reached? You can select among five behavior:
    # 
    # volatile-lru -> remove the key with an expire set using an LRU algorithm
    # allkeys-lru -> remove any key accordingly to the LRU algorithm
    # volatile-random -> remove a random key with an expire set
    # allkeys->random -> remove a random key, any key
    # volatile-ttl -> remove the key with the nearest expire time (minor TTL)
    # noeviction -> don't expire at all, just return an error on write operations
    # 
    # Note: with all the kind of policies, Redis will return an error on write
    #       operations, when there are not suitable keys for eviction.
    #
    #       At the date of writing this commands are: set setnx setex append
    #       incr decr rpush lpush rpushx lpushx linsert lset rpoplpush sadd
    #       sinter sinterstore sunion sunionstore sdiff sdiffstore zadd zincrby
    #       zunionstore zinterstore hset hsetnx hmset hincrby incrby decrby
    #       getset mset msetnx exec sort
    #
    # The default is:
    #
    # maxmemory-policy volatile-lru
    
    # LRU and minimal TTL algorithms are not precise algorithms but approximated
    # algorithms (in order to save memory), so you can select as well the sample
    # size to check. For instance for default Redis will check three keys and
    # pick the one that was used less recently, you can change the sample size
    # using the following configuration directive.
    #
    # maxmemory-samples 3
    
    ############################## APPEND ONLY MODE ###############################
    
    # 
    # Note that you can have both the async dumps and the append only file if you
    # like (you have to comment the "save" statements above to disable the dumps).
    # Still if append only mode is enabled Redis will load the data from the
    # log file at startup ignoring the dump.rdb file.
    # 指定是否在每次更新操作后进行日志记录,Redis在默认情况下是异步的把数据写入磁盘,如果不开启,可能会在断电时导致一段时间内的数据丢失。
    # 因为redis本身同步数据文件是按上面save条件来同步的,所以有的数据会在一段时间内只存在于内存中。默认为no
    # IMPORTANT: Check the BGREWRITEAOF to check how to rewrite the append
    # log file in background when it gets too big.
    
    appendonly no
    
    # 指定更新日志文件名,默认为appendonly.aof
    # appendfilename appendonly.aof
    
    # The fsync() call tells the Operating System to actually write data on disk
    # instead to wait for more data in the output buffer. Some OS will really flush 
    # data on disk, some other OS will just try to do it ASAP.
    
    # 指定更新日志条件,共有3个可选值:
    # no:表示等操作系统进行数据缓存同步到磁盘(快)
    # always:表示每次更新操作后手动调用fsync()将数据写到磁盘(慢,安全)
    # everysec:表示每秒同步一次(折衷,默认值)
    
    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", that in pratical terms means that it is
    # possible to lost 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 will growth by the specified percentage.
    # 
    # This is how it works: Redis remembers the size of the AOF file after the
    # latest rewrite (or if no rewrite 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 precentage of zero in order to disable the automatic AOF
    # rewrite feature.
    
    auto-aof-rewrite-percentage 100
    auto-aof-rewrite-min-size 64mb
    
    ################################## 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 1024
    
    ################################ VIRTUAL MEMORY ###############################
    
    ### WARNING! Virtual Memory is deprecated in Redis 2.4
    ### The use of Virtual Memory is strongly discouraged.
    
    ### WARNING! Virtual Memory is deprecated in Redis 2.4
    ### The use of Virtual Memory is strongly discouraged.
    
    # Virtual Memory allows Redis to work with datasets bigger than the actual
    # amount of RAM needed to hold the whole dataset in memory.
    # In order to do so very used keys are taken in memory while the other keys
    # are swapped into a swap file, similarly to what operating systems do
    # with memory pages.
    # 指定是否启用虚拟内存机制,默认值为no,
    # VM机制将数据分页存放,由Redis将访问量较少的页即冷数据swap到磁盘上,访问多的页面由磁盘自动换出到内存中
    # 把vm-enabled设置为yes,根据需要设置好接下来的三个VM参数,就可以启动VM了
    vm-enabled no
    # vm-enabled yes
    
    # This is the path of the Redis swap file. As you can guess, swap files
    # can't be shared by different Redis instances, so make sure to use a swap
    # file for every redis process you are running. Redis will complain if the
    # swap file is already in use.
    #
    # Redis交换文件最好的存储是SSD(固态硬盘)
    # 虚拟内存文件路径,默认值为/tmp/redis.swap,不可多个Redis实例共享
    # *** WARNING *** if you are using a shared hosting the default of putting
    # the swap file under /tmp is not secure. Create a dir with access granted
    # only to Redis user and configure Redis to create the swap file there.
    vm-swap-file /tmp/redis.swap
    
    # With vm-max-memory 0 the system will swap everything it can. Not a good
    # default, just specify the max amount of RAM you can in bytes, but it's
    # better to leave some margin. For instance specify an amount of RAM
    # that's more or less between 60 and 80% of your free RAM.
    # 将所有大于vm-max-memory的数据存入虚拟内存,无论vm-max-memory设置多少,所有索引数据都是内存存储的(Redis的索引数据就是keys)
    # 也就是说当vm-max-memory设置为0的时候,其实是所有value都存在于磁盘。默认值为0
    vm-max-memory 0
    
    # Redis swap文件分成了很多的page,一个对象可以保存在多个page上面,但一个page上不能被多个对象共享,vm-page-size是要根据存储的数据大小来设定的。
    # 建议如果存储很多小对象,page大小最后设置为32或64bytes;如果存储很大的对象,则可以使用更大的page,如果不确定,就使用默认值
    vm-page-size 32
    
    # 设置swap文件中的page数量由于页表(一种表示页面空闲或使用的bitmap)是存放在内存中的,在磁盘上每8个pages将消耗1byte的内存
    # swap空间总容量为 vm-page-size * vm-pages
    #
    # With the default of 32-bytes memory pages and 134217728 pages Redis will
    # use a 4 GB swap file, that will use 16 MB of RAM for the page table.
    #
    # It's better to use the smallest acceptable value for your application,
    # but the default is large in order to work in most conditions.
    vm-pages 134217728
    
    # Max number of VM I/O threads running at the same time.
    # This threads are used to read/write data from/to swap file, since they
    # also encode and decode objects from disk to memory or the reverse, a bigger
    # number of threads can help with big objects even if they can't help with
    # I/O itself as the physical device may not be able to couple with many
    # reads/writes operations at the same time.
    # 设置访问swap文件的I/O线程数,最后不要超过机器的核数,如果设置为0,那么所有对swap文件的操作都是串行的,可能会造成比较长时间的延迟,默认值为4
    vm-max-threads 4
    
    ############################### ADVANCED CONFIG ###############################
    
    # Hashes are encoded in a special way (much more memory efficient) when they
    # have at max a given numer of elements, and the biggest element does not
    # exceed a given threshold. You can configure this limits with the following
    # configuration directives.
    # 指定在超过一定的数量或者最大的元素超过某一临界值时,采用一种特殊的哈希算法
    hash-max-zipmap-entries 512
    hash-max-zipmap-value 64
    
    # Similarly to hashes, small lists are also encoded in a special way in order
    # to save a lot of space. The special representation is only used when
    # you are under the following limits:
    list-max-ziplist-entries 512
    list-max-ziplist-value 64
    
    # Sets have a special encoding in just one case: when a set is composed
    # of just strings that happens to be integers in radix 10 in the range
    # of 64 bit signed integers.
    # The following configuration setting sets the limit in the size of the
    # set in order to use this special memory saving encoding.
    set-max-intset-entries 512
    
    # Similarly to hashes and lists, sorted sets are also specially encoded in
    # order to save a lot of space. This encoding is only used when the length and
    # elements of a sorted set are below the following limits:
    zset-max-ziplist-entries 128
    zset-max-ziplist-value 64
    
    # 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 an hash table
    # that is rhashing, the more rehashing "steps" are performed, so if the
    # server is idle the rehashing is never complete and some more memory is used
    # by the hash table.
    # 
    # The default is to use this millisecond 10 times every second in order to
    # active rehashing the main dictionaries, freeing memory when possible.
    #
    # If unsure:
    # use "activerehashing no" if you have hard latency requirements and it is
    # not a good thing in your environment that Redis can reply form time to time
    # to queries with 2 milliseconds delay.
    # 指定是否激活重置哈希,默认为开启
    activerehashing yes
    
    ################################## INCLUDES ###################################
    
    # 指定包含其他的配置文件,可以在同一主机上多个Redis实例之间使用同一份配置文件,而同时各实例又拥有自己的特定配置文件
    # include /path/to/local.conf
    # include /path/to/other.conf

    创建容器并持久化
    docker run -itd -p 6379:6379 --name localredis -v /Users/lucax/Desktop/工作/小工具脚本/B端测试平台/docker环境/redis/redis.conf:/etc/redis/redis.conf -v /Users/lucax/Desktop/工作/小工具脚本/B端测试平台/docker环境/redis/data:/data redis:4.0.9 redis-server /etc/redis/redis.conf --appendonly yes

    -d 以守护线程的方式运行(后台运行)
    -i 以交互模式运行容器
    -t 为容器重新分配一个伪输入终端 
    -p 映射容器服务的 6379 端口到宿主机的 6379 端口。外部可以直接通过宿主机ip:6379 访问到 Redis 的服务。

     //未加-it可能会运行不起来因为,Docker容器后台运行,就必须有一个前台进程,容器运行的命令不是那些一直挂起的命令(比如运行top,tail),会自动退出

    -v /usr/local/docker/redis.conf:/etc/redis/redis.conf //把宿主机配置好的redis.conf挂载到容器内的指定位置

    -v /usr/local/docker/data:/data //把redis持久化的数据挂载到宿主机内,做数据备份

    redis-server /etc/redis/redis.conf //使redis按照redis.conf的配置启动

    --appendonly yes //redis启动后数据持久化

    最后用的是这个配置文件才成功

    # 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 lookback 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 no
    
    # 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-Slave replication. Use slaveof to make a Redis instance a copy of
    # another Redis server. A few things to understand ASAP about Redis replication.
    #
    # 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 slaves.
    # 2) Redis slaves 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 slaves automatically try to reconnect to masters
    #    and resynchronize with them.
    #
    # slaveof <masterip> <masterport>
    
    # If the master is password protected (using the "requirepass" configuration
    # directive below) it is possible to tell the slave to authenticate before
    # starting the replication synchronization process, otherwise the master will
    # refuse the slave request.
    #
    # masterauth <master-password>
    
    # When a slave loses its connection with the master, or when the replication
    # is still in progress, the slave can act in two different ways:
    #
    # 1) if slave-serve-stale-data is set to 'yes' (the default) the slave 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 slave-serve-stale-data is set to 'no' the slave will reply with
    #    an error "SYNC with master in progress" to all the kind of commands
    #    but to INFO and SLAVEOF.
    #
    slave-serve-stale-data yes
    
    # You can configure a slave instance to accept writes or not. Writing against
    # a slave instance may be useful to store some ephemeral data (because data
    # written on a slave 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 slaves are read-only.
    #
    # Note: read only slaves are not designed to be exposed to untrusted clients
    # on the internet. It's just a protection layer against misuse of the instance.
    # Still a read only slave exports by default all the administrative commands
    # such as CONFIG, DEBUG, and so forth. To a limited extent you can improve
    # security of read only slaves using 'rename-command' to shadow all the
    # administrative / dangerous commands.
    slave-read-only yes
    
    # Replication SYNC strategy: disk or socket.
    #
    # -------------------------------------------------------
    # WARNING: DISKLESS REPLICATION IS EXPERIMENTAL CURRENTLY
    # -------------------------------------------------------
    #
    # New slaves and reconnecting slaves 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 slaves.
    # 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 slaves incrementally.
    # 2) Diskless: The Redis master creates a new process that directly writes the
    #              RDB file to slave sockets, without touching the disk at all.
    #
    # With disk-backed replication, while the RDB file is generated, more slaves
    # 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 slaves 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 slaves
    # 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 slaves.
    #
    # This is important since once the transfer starts, it is not possible to serve
    # new slaves arriving, that will be queued for the next RDB transfer, so the server
    # waits a delay in order to let more slaves 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
    
    # Slaves send PINGs to server in a predefined interval. It's possible to change
    # this interval with the repl_ping_slave_period option. The default value is 10
    # seconds.
    #
    # repl-ping-slave-period 10
    
    # The following option sets the replication timeout for:
    #
    # 1) Bulk transfer I/O during SYNC, from the point of view of slave.
    # 2) Master timeout from the point of view of slaves (data, pings).
    # 3) Slave timeout from the point of view of masters (REPLCONF ACK pings).
    #
    # It is important to make sure that this value is greater than the value
    # specified for repl-ping-slave-period otherwise a timeout will be detected
    # every time there is low traffic between the master and the slave.
    #
    # repl-timeout 60
    
    # Disable TCP_NODELAY on the slave socket after SYNC?
    #
    # If you select "yes" Redis will use a smaller number of TCP packets and
    # less bandwidth to send data to slaves. But this can add a delay for
    # the data to appear on the slave side, up to 40 milliseconds with
    # Linux kernels using a default configuration.
    #
    # If you select "no" the delay for data to appear on the slave side will
    # be reduced but more bandwidth will be used for replication.
    #
    # By default we optimize for low latency, but in very high traffic conditions
    # or when the master and slaves are many hops away, turning this to "yes" may
    # be a good idea.
    repl-disable-tcp-nodelay no
    
    # Set the replication backlog size. The backlog is a buffer that accumulates
    # slave data when slaves are disconnected for some time, so that when a slave
    # wants to reconnect again, often a full resync is not needed, but a partial
    # resync is enough, just passing the portion of data the slave missed while
    # disconnected.
    #
    # The bigger the replication backlog, the longer the time the slave can be
    # disconnected and later be able to perform a partial resynchronization.
    #
    # The backlog is only allocated once there is at least a slave connected.
    #
    # repl-backlog-size 1mb
    
    # After a master has no longer connected slaves for some time, the backlog
    # will be freed. The following option configures the amount of seconds that
    # need to elapse, starting from the time the last slave disconnected, for
    # the backlog buffer to be freed.
    #
    # Note that slaves never free the backlog for timeout, since they may be
    # promoted to masters later, and should be able to correctly "partially
    # resynchronize" with the slaves: hence they should always accumulate backlog.
    #
    # A value of 0 means to never release the backlog.
    #
    # repl-backlog-ttl 3600
    
    # The slave priority is an integer number published by Redis in the INFO output.
    # It is used by Redis Sentinel in order to select a slave to promote into a
    # master if the master is no longer working correctly.
    #
    # A slave with a low priority number is considered better for promotion, so
    # for instance if there are three slaves 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 slave as not able to perform the
    # role of master, so a slave with priority of 0 will never be selected by
    # Redis Sentinel for promotion.
    #
    # By default the priority is 100.
    slave-priority 100
    
    # It is possible for a master to stop accepting writes if there are less than
    # N slaves connected, having a lag less or equal than M seconds.
    #
    # The N slaves need to be in "online" state.
    #
    # The lag in seconds, that must be <= the specified value, is calculated from
    # the last ping received from the slave, that is usually sent every second.
    #
    # This option does not GUARANTEE that N replicas will accept the write, but
    # will limit the window of exposure for lost writes in case not enough slaves
    # are available, to the specified number of seconds.
    #
    # For example to require at least 3 slaves with a lag <= 10 seconds use:
    #
    # min-slaves-to-write 3
    # min-slaves-max-lag 10
    #
    # Setting one or the other to 0 disables the feature.
    #
    # By default min-slaves-to-write is set to 0 (feature disabled) and
    # min-slaves-max-lag is set to 10.
    
    # A Redis master is able to list the address and port of the attached
    # slaves 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 slave 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 slave is obtained
    # in the following way:
    #
    #   IP: The address is auto detected by checking the peer address
    #   of the socket used by the slave to connect with the master.
    #
    #   Port: The port is communicated by the slave during the replication
    #   handshake, and is normally the port that the slave is using to
    #   list for connections.
    #
    # However when port forwarding or Network Address Translation (NAT) is
    # used, the slave may be actually reachable via different IP and port
    # pairs. The following two options can be used by a slave 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.
    #
    # slave-announce-ip 5.5.5.5
    # slave-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 slaves 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 slaves attached to an instance with maxmemory on,
    # the size of the output buffers needed to feed the slaves are subtracted
    # from the used memory count, so that network problems / resyncs will
    # not trigger a loop where keys are evicted, and in turn the output
    # buffer of slaves is full with DELs of keys evicted triggering the deletion
    # of more keys, and so forth until the database is completely emptied.
    #
    # In short... if you have slaves attached it is suggested that you set a lower
    # limit for maxmemory so that there is some free RAM on the system for slave
    # output buffers (but this is not needed if the policy is 'noeviction').
    #
    # 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
    
    ############################# 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 slave performs a full resynchronization with
    #    its master, the content of the whole database is removed in order to
    #    load the RDB file just transfered.
    #
    # 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
    slave-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.
    #
    # This is currently turned off by default in order to avoid the surprise
    # of a format change, but will at some point be used as the default.
    aof-use-rdb-preamble no
    
    ################################ 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 slave of a failing master will avoid to start a failover if its data
    # looks too old.
    #
    # There is no simple way for a slave to actually have an exact measure of
    # its "data age", so the following two checks are performed:
    #
    # 1) If there are multiple slaves able to failover, they exchange messages
    #    in order to try to give an advantage to the slave with the best
    #    replication offset (more data from the master processed).
    #    Slaves will try to get their rank by offset, and apply to the start
    #    of the failover a delay proportional to their rank.
    #
    # 2) Every single slave computes the time of the last interaction with
    #    its master. This can be the last ping or command received (if the master
    #    is still in the "connected" state), or the time that elapsed since the
    #    disconnection with the master (if the replication link is currently down).
    #    If the last interaction is too old, the slave will not try to failover
    #    at all.
    #
    # The point "2" can be tuned by user. Specifically a slave will not perform
    # the failover if, since the last interaction with the master, the time
    # elapsed is greater than:
    #
    #   (node-timeout * slave-validity-factor) + repl-ping-slave-period
    #
    # So for example if node-timeout is 30 seconds, and the slave-validity-factor
    # is 10, and assuming a default repl-ping-slave-period of 10 seconds, the
    # slave will not try to failover if it was not able to talk with the master
    # for longer than 310 seconds.
    #
    # A large slave-validity-factor may allow slaves with too old data to failover
    # a master, while a too small value may prevent the cluster from being able to
    # elect a slave at all.
    #
    # For maximum availability, it is possible to set the slave-validity-factor
    # to a value of 0, which means, that slaves will always try to failover the
    # master regardless of the last time they interacted with the master.
    # (However they'll always try to apply a delay proportional to their
    # offset rank).
    #
    # Zero is the only value able to guarantee that when all the partitions heal
    # the cluster will always be able to continue.
    #
    # cluster-slave-validity-factor 10
    
    # Cluster slaves are able to migrate to orphaned masters, that are masters
    # that are left without working slaves. This improves the cluster ability
    # to resist to failures as otherwise an orphaned master can't be failed over
    # in case of failure if it has no working slaves.
    #
    # Slaves migrate to orphaned masters only if there are still at least a
    # given number of other working slaves for their old master. This number
    # is the "migration barrier". A migration barrier of 1 means that a slave
    # will migrate only if there is at least 1 other working slave for its master
    # and so forth. It usually reflects the number of slaves you want for every
    # master in your cluster.
    #
    # Default is 1 (slaves migrate only if their masters remain with at least
    # one slave). To disable migration just set it to a very large value.
    # A value of 0 can be set but is useful only for debugging and dangerous
    # in production.
    #
    # cluster-migration-barrier 1
    
    # 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 slaves 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-slave-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
    
    # 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
    # slave  -> slave clients
    # pubsub -> clients subscribed to at least one pubsub channel or pattern
    #
    # The syntax of every client-output-buffer-limit directive is the following:
    #
    # client-output-buffer-limit <class> <hard limit> <soft limit> <soft seconds>
    #
    # A client is immediately disconnected once the hard limit is reached, or if
    # the soft limit is reached and remains reached for the specified number of
    # seconds (continuously).
    # So for instance if the hard limit is 32 megabytes and the soft limit is
    # 16 megabytes / 10 seconds, the client will get disconnected immediately
    # if the size of the output buffers reach 32 megabytes, but will also get
    # disconnected if the client reaches 16 megabytes and continuously overcomes
    # the limit for 10 seconds.
    #
    # By default normal clients are not limited because they don't receive data
    # without asking (in a push way), but just after a request, so only
    # asynchronous clients may create a scenario where data is requested faster
    # than it can read.
    #
    # Instead there is a default limit for pubsub and slave clients, since
    # subscribers and slaves receive data in a push fashion.
    #
    # Both the hard or the soft limit can be disabled by setting them to zero.
    client-output-buffer-limit normal 0 0 0
    client-output-buffer-limit slave 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
    
    # 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
    
    # 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 25
    
    # Maximal effort for defrag in CPU percentage
    # active-defrag-cycle-max 75
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  • 原文地址:https://www.cnblogs.com/kaibindirver/p/16027477.html
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