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Contents
  1. 1. 系统环境
  2. 2. docker-compose配置文件
  3. 3. 主库的配置文件
    1. 3.1. 网络及基础配置项
    2. 3.2. RDB持久化
    3. 3.3. AOF持久化
  4. 4. 从库配置
    1. 4.1. 主从配置
  5. 5. 启动/停止redis主从配置
  6. 6. 致谢&参考

写这篇blog的原因是为了方便快捷地一键搭建redis主从复制，本身用docker搭建redis确实已经方便很多，不过如果要配置外挂的配置文件，外挂的volume路径，需要在命令行中输入很多参数，着实不是很方便，而主从复制一般都要3个实例，每次都单独设置的话。。。解释那么多，归到一个字还是：懒–程序员的优良品格。大多数参数都在配置文件中配置完成，然后docker-compose up一个命令，简洁而迅速，何乐而不为。

系统环境

按照惯例，还是列一下我们用到的系统环境和软件版本信息：

  • RHEL/CentOS 7
  • Dokcer & Docker compose
  • Redis

假设我们要搭建一主两从的架构，可以假设服务器的目录结构如下：

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/app/redis                  -- 根目录
├── redis-master            -- 主节点目录
    ├──conf                 -- 配置文件目录
        ├──redis.conf       -- 主节点配置文件
    ├──data                 -- 主节点数据目录
├── redis-slave1            -- 从节点1目录
    ├──conf                 -- 配置文件目录
        ├──redis.conf       -- 从节点1配置文件
    ├──data                 -- 从节点1数据目录
├── redis-slave2            -- 从节点2目录
    ├──conf                 -- 配置文件目录
        ├──redis.conf       -- 从节点2配置文件
    ├──data                 -- 从节点2数据目录
├── docker-compose.yml      -- compose的配置文件

docker-compose配置文件

直接自上而下先从docker-compose.yml配置文件看起。

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version: '3'

services:
  # 主节点的容器
  redis-server-master:
    image: redis
    container_name: redis-server-master
    restart: always
    ports:
      - 6379:6379
    environment:
      TZ: "Asia/Shanghai"
    volumes:
      # 映射配置文件和数据目录
      - /app/redis/redis-master/conf/redis.conf:/usr/local/etc/redis/redis.conf
      - /app/redis/redis-master/data:/data:Z
    command: ["redis-server", "/usr/local/etc/redis/redis.conf"]
  # 从节点1的容器
  redis-server-slave-1:
    image: redis
    container_name: redis-server-slave-1
    restart: always
    ports:
        - 6380:6379
    depends_on:
      - redis-server-master
    environment:
      TZ: "Asia/Shanghai"
    volumes:
      - /app/redis/redis-slave1/conf/redis.conf:/usr/local/etc/redis/redis.conf
      - /app/redis/redis-slave1/data:/data:Z
    command: ["redis-server", "/usr/local/etc/redis/redis.conf"]
  # 从节点2的容器
  redis-server-slave-2:
    image: redis
    container_name: redis-server-slave-2
    restart: always
    ports:
        - 6381:6379
    depends_on:
      - redis-server-master
    environment:
      TZ: "Asia/Shanghai"
    volumes:
      - /app/redis/redis-slave2/conf/redis.conf:/usr/local/etc/redis/redis.conf
      - /app/redis/redis-slave2/data:/data:Z
    command: ["redis-server", "/usr/local/etc/redis/redis.conf"]

compose的配置文件其实不难理解

  • 分别将本地的6379-6381 3个端口作为1主2从的redis容器节点
  • 将容器内部的配置文件映射到宿主机的对应目录，将容器内部的数据文件目录指定挂载到宿主机数据文件目录
  • command命令表示采用配置文件方式启动容器

主库的配置文件

接下来我们来看主库的配置文件，其实只要你对redis的配置文件有足够深入的了解，这里不管是主还是从的redis的配置文件也就没什么难度。
话说回来，redis官方给出了一个配置文件的完整示例，有兴趣的同学可以去下载了然后逐条都过一遍，读懂了所有的配置项，基本redis的基本用法和一些常见的例如持久化和主从配置这些也就清楚了。
另外还是一个老的观点，要想在IT这条路上走的深走的远，英语水平一定要跟上。

主库完整的配置文件因为比较长，我就不全部列出来了，只列出来关键的一些item

网络及基础配置项

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# allow connect from remote
#bind 127.0.0.1

# 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

# 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 123456

# 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

# 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.
# When Redis is supervised by upstart or systemd, this parameter has no impact.
# Must be "no" when launched redis through DOCKER.
daemonize no

# 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 debug

# 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 /data/redis.log

  • protected-mode no
    我们当时需要客户端来接入使用redis，所以需要关闭protected 模式

  • requirepass 123456
    接入密码，这里我是为了本地测试，所以设置的弱密码，生产环境中，我们的redis接入密码需要配置成强密码

  • tcp-backlog 511
    tcp连接队列，关于tcp全连接队列的介绍，参见我以前的一篇blog：【Nginx】记一次Nginx生产环境的Trouble Shooting过程

  • daemonize no
    我们的redis实例是通过docker启动的，所以这里必须配置为no

  • loglevel debug
    看注释很容易理解，在我们研究和学习测试的时候，debug可以帮我们看到更多log信息；生产环境中，我们建议用notice就好

  • logfile /data/redis.log
    log文件的具体路径，这里笔者踩了坑，研究了好久，因为我们在docker-compose.yml文件中，已经配置好了volumn的挂载目录，所以这里的配置文件实际上就是在容器内部的文件路径，不需要配置成宿主机的路径。

RDB持久化

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# Save the DB to disk.
#
# 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:
#
# save ""
#
# 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.
#
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 no

# 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 /data/
  • dir /data/
    同上，redis配置文件中的路径都是容器内部的路径，我们会通过compose配置文件将其挂载到宿主机的对应目录上。

AOF持久化

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############################# 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 https://redis.io/topics/persistence for more information.

appendonly yes

# 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, then continues loading the AOF
# tail.
aof-use-rdb-preamble yes
  • appendonly yes
    同时使用RDB和AOF的方式来实现redis的数据持久化

总的来说，你可以使用官方的配置文件，然后修改一些自己用得着的配置项，其他项就保留官方建议即可，所有的配置项含义，英文的注释里面都写的非常详细了。

从库配置

基本上，从库的配置文件和主库一模一样，因为无论是监听端口还是本地文件目录，我们均通过最顶层的compose配置文件做了相应的配置了，这里需要单独说明的是，因为是主从配置，所以从库的配置文件中，需要特别说明主从配置的信息。

主从配置

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################################# REPLICATION #################################

# Master-Replica replication. Use replicaof to make a Redis instance a copy of
# another Redis server. A few things to understand ASAP about Redis replication.
#
#   +------------------+      +---------------+
#   |      Master      | ---> |    Replica    |
#   | (receive writes) |      |  (exact copy) |
#   +------------------+      +---------------+
#
# 1) Redis replication is asynchronous, but you can configure a master to
#    stop accepting writes if it appears to be not connected with at least
#    a given number of replicas.
# 2) Redis replicas are able to perform a partial resynchronization with the
#    master if the replication link is lost for a relatively small amount of
#    time. You may want to configure the replication backlog size (see the next
#    sections of this file) with a sensible value depending on your needs.
# 3) Replication is automatic and does not need user intervention. After a
#    network partition replicas automatically try to reconnect to masters
#    and resynchronize with them.
#
# replicaof <masterip> <masterport>

replicaof 10.0.0.123 6379

# If the master is password protected (using the "requirepass" configuration
# directive below) it is possible to tell the replica to authenticate before
# starting the replication synchronization process, otherwise the master will
# refuse the replica request.
#
# masterauth <master-password>
#
# However this is not enough if you are using Redis ACLs (for Redis version
# 6 or greater), and the default user is not capable of running the PSYNC
# command and/or other commands needed for replication. In this case it's
# better to configure a special user to use with replication, and specify the
# masteruser configuration as such:
#
# masteruser <username>
#
# When masteruser is specified, the replica will authenticate against its
# master using the new AUTH form: AUTH <username> <password>.

masterauth 123456

# When a replica loses its connection with the master, or when the replication
# is still in progress, the replica can act in two different ways:
#
# 1) if replica-serve-stale-data is set to 'yes' (the default) the replica will
#    still reply to client requests, possibly with out of date data, or the
#    data set may just be empty if this is the first synchronization.
#
# 2) If replica-serve-stale-data is set to 'no' the replica will reply with
#    an error "SYNC with master in progress" to all commands except:
#    INFO, REPLICAOF, AUTH, PING, SHUTDOWN, REPLCONF, ROLE, CONFIG, SUBSCRIBE,
#    UNSUBSCRIBE, PSUBSCRIBE, PUNSUBSCRIBE, PUBLISH, PUBSUB, COMMAND, POST,
#    HOST and LATENCY.
#
replica-serve-stale-data yes

# You can configure a replica instance to accept writes or not. Writing against
# a replica instance may be useful to store some ephemeral data (because data
# written on a replica will be easily deleted after resync with the master) but
# may also cause problems if clients are writing to it because of a
# misconfiguration.
#
# Since Redis 2.6 by default replicas are read-only.
#
# Note: read only replicas are not designed to be exposed to untrusted clients
# on the internet. It's just a protection layer against misuse of the instance.
# Still a read only replica exports by default all the administrative commands
# such as CONFIG, DEBUG, and so forth. To a limited extent you can improve
# security of read only replicas using 'rename-command' to shadow all the
# administrative / dangerous commands.
replica-read-only yes

# Replication SYNC strategy: disk or socket.
#
# New replicas and reconnecting replicas that are not able to continue the
# replication process just receiving differences, need to do what is called a
# "full synchronization". An RDB file is transmitted from the master to the
# replicas.
#
# The transmission can happen in two different ways:
#
# 1) Disk-backed: The Redis master creates a new process that writes the RDB
#                 file on disk. Later the file is transferred by the parent
#                 process to the replicas incrementally.
# 2) Diskless: The Redis master creates a new process that directly writes the
#              RDB file to replica sockets, without touching the disk at all.
#
# With disk-backed replication, while the RDB file is generated, more replicas
# can be queued and served with the RDB file as soon as the current child
# producing the RDB file finishes its work. With diskless replication instead
# once the transfer starts, new replicas arriving will be queued and a new
# transfer will start when the current one terminates.
#
# When diskless replication is used, the master waits a configurable amount of
# time (in seconds) before starting the transfer in the hope that multiple
# replicas will arrive and the transfer can be parallelized.
#
# With slow disks and fast (large bandwidth) networks, diskless replication
# works better.
repl-diskless-sync no

# When diskless replication is enabled, it is possible to configure the delay
# the server waits in order to spawn the child that transfers the RDB via socket
# to the replicas.
#
# This is important since once the transfer starts, it is not possible to serve
# new replicas arriving, that will be queued for the next RDB transfer, so the
# server waits a delay in order to let more replicas arrive.
#
# The delay is specified in seconds, and by default is 5 seconds. To disable
# it entirely just set it to 0 seconds and the transfer will start ASAP.
repl-diskless-sync-delay 5

# -----------------------------------------------------------------------------
# WARNING: RDB diskless load is experimental. Since in this setup the replica
# does not immediately store an RDB on disk, it may cause data loss during
# failovers. RDB diskless load + Redis modules not handling I/O reads may also
# cause Redis to abort in case of I/O errors during the initial synchronization
# stage with the master. Use only if you know what you are doing.
# -----------------------------------------------------------------------------
#
# Replica can load the RDB it reads from the replication link directly from the
# socket, or store the RDB to a file and read that file after it was completely
# received from the master.
#
# In many cases the disk is slower than the network, and storing and loading
# the RDB file may increase replication time (and even increase the master's
# Copy on Write memory and salve buffers).
# However, parsing the RDB file directly from the socket may mean that we have
# to flush the contents of the current database before the full rdb was
# received. For this reason we have the following options:
#
# "disabled"    - Don't use diskless load (store the rdb file to the disk first)
# "on-empty-db" - Use diskless load only when it is completely safe.
# "swapdb"      - Keep a copy of the current db contents in RAM while parsing
#                 the data directly from the socket. note that this requires
#                 sufficient memory, if you don't have it, you risk an OOM kill.
repl-diskless-load disabled

# Replicas send PINGs to server in a predefined interval. It's possible to
# change this interval with the repl_ping_replica_period option. The default
# value is 10 seconds.
#
repl-ping-replica-period 10

# The following option sets the replication timeout for:
#
# 1) Bulk transfer I/O during SYNC, from the point of view of replica.
# 2) Master timeout from the point of view of replicas (data, pings).
# 3) Replica timeout from the point of view of masters (REPLCONF ACK pings).
#
# It is important to make sure that this value is greater than the value
# specified for repl-ping-replica-period otherwise a timeout will be detected
# every time there is low traffic between the master and the replica. The default
# value is 60 seconds.
#
# repl-timeout 60

# Disable TCP_NODELAY on the replica socket after SYNC?
#
# If you select "yes" Redis will use a smaller number of TCP packets and
# less bandwidth to send data to replicas. But this can add a delay for
# the data to appear on the replica side, up to 40 milliseconds with
# Linux kernels using a default configuration.
#
# If you select "no" the delay for data to appear on the replica side will
# be reduced but more bandwidth will be used for replication.
#
# By default we optimize for low latency, but in very high traffic conditions
# or when the master and replicas are many hops away, turning this to "yes" may
# be a good idea.
repl-disable-tcp-nodelay no

# Set the replication backlog size. The backlog is a buffer that accumulates
# replica data when replicas are disconnected for some time, so that when a
# replica wants to reconnect again, often a full resync is not needed, but a
# partial resync is enough, just passing the portion of data the replica
# missed while disconnected.
#
# The bigger the replication backlog, the longer the replica can endure the
# disconnect and later be able to perform a partial resynchronization.
#
# The backlog is only allocated if there is at least one replica connected.
#
# repl-backlog-size 1mb

# After a master has no connected replicas for some time, the backlog will be
# freed. The following option configures the amount of seconds that need to
# elapse, starting from the time the last replica disconnected, for the backlog
# buffer to be freed.
#
# Note that replicas never free the backlog for timeout, since they may be
# promoted to masters later, and should be able to correctly "partially
# resynchronize" with other replicas: hence they should always accumulate backlog.
#
# A value of 0 means to never release the backlog.
#
# repl-backlog-ttl 3600

# The replica priority is an integer number published by Redis in the INFO
# output. It is used by Redis Sentinel in order to select a replica to promote
# into a master if the master is no longer working correctly.
#
# A replica with a low priority number is considered better for promotion, so
# for instance if there are three replicas with priority 10, 100, 25 Sentinel
# will pick the one with priority 10, that is the lowest.
#
# However a special priority of 0 marks the replica as not able to perform the
# role of master, so a replica with priority of 0 will never be selected by
# Redis Sentinel for promotion.
#
# By default the priority is 100.
replica-priority 100

# -----------------------------------------------------------------------------
# By default, Redis Sentinel includes all replicas in its reports. A replica
# can be excluded from Redis Sentinel's announcements. An unannounced replica
# will be ignored by the 'sentinel replicas <master>' command and won't be
# exposed to Redis Sentinel's clients.
#
# This option does not change the behavior of replica-priority. Even with
# replica-announced set to 'no', the replica can be promoted to master. To
# prevent this behavior, set replica-priority to 0.
#
# replica-announced yes

# It is possible for a master to stop accepting writes if there are less than
# N replicas connected, having a lag less or equal than M seconds.
#
# The N replicas need to be in "online" state.
#
# The lag in seconds, that must be <= the specified value, is calculated from
# the last ping received from the replica, that is usually sent every second.
#
# This option does not GUARANTEE that N replicas will accept the write, but
# will limit the window of exposure for lost writes in case not enough replicas
# are available, to the specified number of seconds.
#
# For example to require at least 3 replicas with a lag <= 10 seconds use:
#
# min-replicas-to-write 3
# min-replicas-max-lag 10
#
# Setting one or the other to 0 disables the feature.
#
# By default min-replicas-to-write is set to 0 (feature disabled) and
# min-replicas-max-lag is set to 10.

# A Redis master is able to list the address and port of the attached
# replicas in different ways. For example the "INFO replication" section
# offers this information, which is used, among other tools, by
# Redis Sentinel in order to discover replica instances.
# Another place where this info is available is in the output of the
# "ROLE" command of a master.
#
# The listed IP address and port normally reported by a replica is
# obtained in the following way:
#
#   IP: The address is auto detected by checking the peer address
#   of the socket used by the replica to connect with the master.
#
#   Port: The port is communicated by the replica during the replication
#   handshake, and is normally the port that the replica is using to
#   listen for connections.
#
# However when port forwarding or Network Address Translation (NAT) is
# used, the replica may actually be reachable via different IP and port
# pairs. The following two options can be used by a replica in order to
# report to its master a specific set of IP and port, so that both INFO
# and ROLE will report those values.
#
# There is no need to use both the options if you need to override just
# the port or the IP address.
#
replica-announce-ip 10.0.0.143
replica-announce-port 6380

  • replicaof
    因为是从库，所以需要指明主库的地址，这里笔者有踩了个坑，因为在我本的mac机上测试时，我这里填写的地址写成了127.0.0.1，结果一直提示主从复制失败，主库的日志上一直显示0个replicas，从库的日志上，每隔1秒就会去尝试连接主库，但是每次都显示Master is currently unable to PSYNC but should be in the future: -NOMASTERLINK这样的错误，所以这里的ip地址要是网卡的ip地址才可以。

  • masterauth 123456
    主库的连接密码

  • replica-serve-stale-data yes
    看注释，当主从连接出问题时，依旧可以响应客户端的请求，如果设置成no，则所有请求都会被挂起直至主从恢复

  • replica-announce-ip
    如果我们用docker启动redis，看到的ip和端口其实是容器内部的，如果不对这两个配置做修改，在master日志中看到的两个从节点的ip和端口有可能会是一样的，因为都是各自docker容器内部的ip和端口。

启动/停止redis主从配置

配置好了后，我们只需要回到redis所在的目录，然后执行

1
docker-compose up -d

就可以完成3台redis实例的启动，并自动完成RDB和AOF的实例化，且自动完成主从配置，我们可以从3个实例的各自log文件中看到详细的运行状态，同时，在各个redis实例的data目录下，会有3个文件出现：

  1. redis.log
    redis的日志文件，记录了所有的运行、client连接、主从复制等步骤的详细日志。
  2. dump.rdb
    RDB的数据快照文件
  3. appendonly.aof
    AOF方式的持久化文件

想要停止redis，只需要下面一条简单的命令即可：

1
docker-compose stop

至此，简洁快速的redis主从配置就搭建好了。

致谢&参考

Contents
  1. 1. 系统环境
  2. 2. docker-compose配置文件
  3. 3. 主库的配置文件
    1. 3.1. 网络及基础配置项
    2. 3.2. RDB持久化
    3. 3.3. AOF持久化
  4. 4. 从库配置
    1. 4.1. 主从配置
  5. 5. 启动/停止redis主从配置
  6. 6. 致谢&参考