Redis Sentinel实现Failover

redis版本：2.8.17

 

服务器规划：

10.50.13.34(6379 master)

10.50.13.35(6379 slave)

10.50.13.36(6379 slave)

10.50.13.37(6379 slave)

 

一、安装redis

tar zxf redis-2.8.17.tar.gz

cd redis-2.8.17

make

make install

mv redis-2.8.17 /app/sinova/redis

cd /app/sinova/redis

mkdir bin,conf,rdb,log

mv redis.conf sentinel.conf conf

find -maxdepth 1 -type f -delete

cd src

mv mkreleasehdr.sh redis-benchmark redis-sentinel redis-server redis-cli redis-check-aof redis-check-dump ../bin/

 

二、配置redis

redis.conf配置文件修改如下内容：

master配置：

daemonize yes

pidfile /app/sinova/redis/redis.pid 

logfile  /app/sinova/redis/log/redis.log

dir /app/sinova/redis/rdb

slave配置：

daemonize yes

pidfile /app/sinova/redis/redis.pid 

logfile  /app/sinova/redis/log/redis.log

dir /app/sinova/redis/rdb

slaveof 10.50.13.34 6379

 

三、配置sentinel

daemonize yes

logfile "/app/sinova/redis/log/sentinel.log"

 

sentinel monitor mymaster 10.50.13.34 6379 2

sentinel down-after-milliseconds mymaster 30000

sentinel failover-timeout mymaster 60000

sentinel parallel-syncs mymaster 1

 

四、启动redis

先启动master，然后再启动slave，命令相同，如下：

/app/sinova/redis/bin/redis-server /app/sinova/redis/conf/redis.conf

 

启动后查看主从状态：

 redis-cli info Replication
# Replication
role:master
connected_slaves:3
slave0:ip=10.50.13.35,port=6379,state=online,offset=29,lag=0
slave1:ip=10.50.13.36,port=6379,state=online,offset=29,lag=0
slave2:ip=10.50.13.37,port=6379,state=online,offset=29,lag=0
master_repl_offset:29
repl_backlog_active:1
repl_backlog_size:1048576
repl_backlog_first_byte_offset:2
repl_backlog_histlen:28

 

五、启动sentinel

先启动master，然后再启动slave，命令相同，如下：

/app/sinova/redis/bin/redis-sentinel /app/sinova/redis/conf/sentinel.conf

 

在master上查看/app/sinova/redis/log/sentinel.log   #slave下也有此日志，可以看到内容有变化

$ cat sentinel.log
                _._                                                  
           _.-``__ ''-._                                             
      _.-``    `.  `_.  ''-._           Redis 2.8.17 (00000000/0) 64 bit
  .-`` .-```.  ```\/    _.,_ ''-._                                   
 (    '      ,       .-`  | `,    )     Running in sentinel mode
 |`-._`-...-` __...-.``-._|'` _.-'|     Port: 26379
 |    `-._   `._    /     _.-'    |     PID: 16995
  `-._    `-._  `-./  _.-'    _.-'                                   
 |`-._`-._    `-.__.-'    _.-'_.-'|                                  
 |    `-._`-._        _.-'_.-'    |           http://redis.io        
  `-._    `-._`-.__.-'_.-'    _.-'                                   
 |`-._`-._    `-.__.-'    _.-'_.-'|                                  
 |    `-._`-._        _.-'_.-'    |                                  
  `-._    `-._`-.__.-'_.-'    _.-'                                   
      `-._    `-.__.-'    _.-'                                       
          `-._        _.-'                                           
              `-.__.-'

[16995] 15 Sep 15:30:11.226 # Sentinel runid is cac946f212073a0e7c353e058dc7c83c9c62a161
[16995] 15 Sep 15:30:11.226 # +monitor master mymaster 10.50.13.34 6379 quorum 2
[16995] 15 Sep 15:30:11.228 * +slave slave 10.50.13.35:6379 10.50.13.35 6379 @ mymaster 10.50.13.34 6379
[16995] 15 Sep 15:30:11.228 * +slave slave 10.50.13.36:6379 10.50.13.36 6379 @ mymaster 10.50.13.34 6379
[16995] 15 Sep 15:30:11.228 * +slave slave 10.50.13.37:6379 10.50.13.37 6379 @ mymaster 10.50.13.34 6379
[16995] 15 Sep 15:30:13.264 * +sentinel sentinel 10.50.13.35:26379 10.50.13.35 26379 @ mymaster 10.50.13.34 6379
[16995] 15 Sep 15:30:13.306 * +sentinel sentinel 10.50.13.37:26379 10.50.13.37 26379 @ mymaster 10.50.13.34 6379
[16995] 15 Sep 15:30:13.312 * +sentinel sentinel 10.50.13.36:26379 10.50.13.36 26379 @ mymaster 10.50.13.34 6379

 

 

六、测试

停掉master上的redis

$ redis-cli shutdown

 

查看日志：

[16995] 15 Sep 15:33:54.131 # +sdown master mymaster 10.50.13.34 6379

[16995] 15 Sep 15:33:54.139 # +new-epoch 1

[16995] 15 Sep 15:33:54.145 # +vote-for-leader c6e609a1978e5cdb68ead8983ba88568aa85180d 1

[16995] 15 Sep 15:33:54.215 # +odown master mymaster 10.50.13.34 6379 #quorum 4/2

[16995] 15 Sep 15:33:54.215 # Next failover delay: I will not start a failover before Tue Sep 15 15:35:54 2015

[16995] 15 Sep 15:33:55.339 # +config-update-from sentinel 10.50.13.36:26379 10.50.13.36 26379 @ mymaster 10.50.13.34 6379

[16995] 15 Sep 15:33:55.339 # +switch-master mymaster 10.50.13.34 6379 10.50.13.36 6379

[16995] 15 Sep 15:33:55.339 * +slave slave 10.50.13.37:6379 10.50.13.37 6379 @ mymaster 10.50.13.36 6379

[16995] 15 Sep 15:33:55.344 * +slave slave 10.50.13.35:6379 10.50.13.35 6379 @ mymaster 10.50.13.36 6379

[16995] 15 Sep 15:33:55.350 * +slave slave 10.50.13.34:6379 10.50.13.34 6379 @ mymaster 10.50.13.36 6379

 

可以看到新的master为10.50.13.36

 

原来的master恢复后，会加入slave的行列：

查看sentinel.log：

[16995] 15 Sep 15:40:33.897 # -sdown slave 10.50.13.34:6379 10.50.13.34 6379 @ mymaster 10.50.13.36 6379

 

 

Sentinel在实现Failover过程中，会自动修改redis.conf和sentinel.conf的配置。