redis主从复制

  1. redis主从复制特点:
  • master可以拥有多个slave
  • 多个slave可以连接同一个master外,还可以连接到其他slave
  • 主从复制不会阻塞master,在同步数据时,master可以继续处理client请求
  • 提高系统的伸缩性
  • 可以在master禁用数据持久化,注释掉master配置文件中的所有save配置,只需在slave上配置数据持久化
  1. redis主从复制过程:

当配置好slave后,slave与master建立连接,然后发送sync命令。无论是第一次连接还是重新连接,master都会启动一个后台进程,将数据库快照保存到文件中,同时master主进程会开始收集新的写命令并缓存。后台进程完成写文件后,master就发送文件给slave,slave将文件保存到硬盘上,再加载到内存中,接着master就会把缓存的命令转发给slave,后续master将收到的写命令发送给slave。如果master同时收到多个slave发来的同步连接命令,master只会启动一个进程来写数据库镜像,然后发送给所有的slave。

  1. redis主从配置:
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    ### master
    daemonize yes
    pidfile /var/run/redis.pid
    port 6379
    timeout 300
    loglevel verbose
    logfile /usr/local/xiemx-redis/var/log/redis.log
    databases 16
    save 900 1
    save 300 10
    save 60 10000
    rdbcompression yes
    dbfilename dump.rdb
    dir /usr/local/xiemx-redis/var/data
    requirepass redis
    appendonly no
    appendfsync everysec
    no-appendfsync-on-rewrite no
    slowlog-log-slower-than 10000
    slowlog-max-len 1024
    vm-enabled no
    vm-swap-file /tmp/redis.swap
    vm-max-memory 0
    vm-page-size 32
    vm-pages 134217728
    vm-max-threads 4
    hash-max-zipmap-entries 512
    hash-max-zipmap-value 64
    list-max-ziplist-entries 512
    list-max-ziplist-value 64
    set-max-intset-entries 512
    activerehashing yes
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### slave
daemonize yes
pidfile /var/run/redis.pid
port 6379
timeout 300
loglevel verbose
logfile /usr/local/xiemx-redis/var/log/redis.log
databases 16
save 900 1
save 300 10
save 60 10000
rdbcompression yes
dbfilename dump.rdb
dir /usr/local/xiemx-redis/var/data
appendonly no
appendfsync everysec
no-appendfsync-on-rewrite no
slowlog-log-slower-than 10000
slowlog-max-len 1024
vm-enabled no
vm-swap-file /tmp/redis.swap
vm-max-memory 0
vm-page-size 32
vm-pages 134217728
vm-max-threads 4
hash-max-zipmap-entries 512
hash-max-zipmap-value 64
list-max-ziplist-entries 512
list-max-ziplist-value 64
set-max-intset-entries 512
activerehashing yes
slaveof 192.168.1.189 6379
masterauth redis
  1. redis复制测试
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查看master端日志:
[8930] 31 Jul 19:16:09 - Accepted 192.168.1.136:54774
[8930] 31 Jul 19:16:09 * Slave ask for synchronization
[8930] 31 Jul 19:16:09 * Starting BGSAVE for SYNC
[8930] 31 Jul 19:16:09 * Background saving started by pid 10782
[10782] 31 Jul 19:16:09 * DB saved on disk
[8930] 31 Jul 19:16:09 * Background saving terminated with success
[8930] 31 Jul 19:16:09 * Synchronization with slave succeeded
[8930] 31 Jul 19:16:14 - DB 0: 1 keys (0 volatile) in 4 slots HT.
[8930] 31 Jul 19:16:14 - 1 clients connected (1 slaves), 807320 bytes in use

查看slave端日志:
[24398] 01 Aug 10:16:10 * Connecting to MASTER...
[24398] 01 Aug 10:16:10 * MASTER SLAVE sync started: SYNC sent
[24398] 01 Aug 10:16:10 * MASTER SLAVE sync: receiving 25 bytes from master
[24398] 01 Aug 10:16:10 * MASTER SLAVE sync: Loading DB in memory
[24398] 01 Aug 10:16:10 * MASTER SLAVE sync: Finished with success
[24398] 01 Aug 10:16:15 - DB 0: 1 keys (0 volatile) in 4 slots HT.
[24398] 01 Aug 10:16:15 - 1 clients connected (0 slaves), 798960 bytes in use
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master端操作:
redis 127.0.0.1:6379> set k_m master
OK

slave端操作:
redis 127.0.0.1:6379> get k_m
"master"