上一篇博客我们介绍了Redis Sentinel的安装配置，详情可参考链接：Redis Sentinel--安装配置，今天主要做几个简单的测试Case

Redis Sentinel API

ping 正常会返回pong
sentinel masters  返回被监视的所有master及状态
sentinel master <master name> 返回指定的master及状态
setntinel slaves <master name> 返回slave及状态
sentinel sentinels <master name> 返回sentinel及状态
sentinel get-master-addr-by-name mymaster 返回现在的master IP和Port
sentinel reset * 清理已经移除的master-slave或者sentinel信息
sentinel failover <master name>手动执行故障转移
sentinel ckquorum <master name> 返回(OK 3 usable Sentinels. Quorum and failover authorization can be reached)
sentinel flushconfig 如果sentinel.conf丢失，可以使用这个命令生成新的配置文件

添加Sentinel

增加一个sentinel很简单，直接配置好sentinel.conf文件，开启一个sentinel即可;

添加时最好一个添加结束后，再添加另外一个，不要同时添加，可以每隔30秒添加一个sentinel;

通过SENTINEL MASTER mastername中的num-other-sentinels来查看是否成功添加sentinel。

[root@sht-sgmhadoopdn-04 redis]# cat sentinel.conf
daemonize yes
port 26379
logfile "sentinel.log"
dir "/usr/local/redis"
protected-mode no
sentinel myid 79393e76e002cb64db92fb8bcb88d79f2d85a82b
sentinel monitor mymaster 172.16.101.59 6379 2[root@sht-sgmhadoopdn-04 redis]# src/redis-sentinel sentinel.conf172.16.101.54:26379> sentinel master mymaster
33) "num-other-sentinels"
34) "3"

移除Sentinel

删除一个sentinel稍微复杂一点，sentinel永远不会删除一个已经存在过的sentinel，即使它已经与组织失去联系

Step:

(1) Stop the Sentinel process of the Sentinel you want to remove.

(2) Send a SENTINEL RESET * command to all the other Sentinel instances (instead of * you can use the exact master name if you want to reset just a single master). One after the other, waiting at least 30 seconds between instances.

(3) Check that all the Sentinels agree about the number of Sentinels currently active, by inspecting the output of SENTINEL MASTER mastername of every Sentinel.

[root@sht-sgmhadoopdn-04 redis]# ps -ef|grep redis
root     17510     1  0 18:34 ?        00:00:03 src/redis-sentinel *:26379 [sentinel]
[root@sht-sgmhadoopdn-04 redis]# kill -9 17510

在其他的每个sentinel节点上，每个隔30s执行

172.16.101.54:26379> sentinel reset *
172.16.101.55:26379> sentinel reset *
172.16.101.56:26379> sentinel reset *
172.16.101.54:26379> sentinel master mymaster
33) "num-other-sentinels"
34) "2"

移除一个老的master或不可用的slave

[root@sht-sgmhadoopdn-01 redis]# ps -ef|grep redis
root     15261     1  0 Aug05 ?        00:05:55 src/redis-server 172.16.101.58:6379
root     19768 19394  0 21:09 pts/2    00:00:00 grep --color=auto redis
[root@sht-sgmhadoopdn-01 redis]# kill -9 15261
172.16.101.54:26379> sentinel masters31) "num-slaves"32) "2"

在每个sentinel节点上，每个隔30s执行

172.16.101.54:26379> sentinel reset mymaster
172.16.101.55:26379> sentinel reset mymaster
172.16.101.56:26379> sentinel reset mymaster172.16.101.54:26379> sentinel masters31) "num-slaves"32) "1"