Redis 安装，主从配置及Sentinel配置自动Failover

主页地址：http://redis.io/topics/sentinel

sentinel主要功能就是为Redis M-S(master,slaves)集群提供了

1)master存活检测

2)集群中M-S服务监控

3) 自动故障转移,M-S角色转换等能力,

从一个方面说是提高了redis集群的可用性.

#添加并编辑配置文件/etc/sentinel.conf，新增内容如下，也可在安装文件中负责sentinel配置文件并作适当修改：

[root@php1 ~]# cat /etc/sentinel.conf

port 26379

sentinel monitor mymaster 172.17.16.7 6379 2

sentinel auth-pass mymaster redispass

sentinel down-after-milliseconds mymaster 30000

sentinel failover-timeout mymaster 900000

sentinel can-failover mymaster yes

sentinel parallel-syncs mymaster 1

[root@mysql1 ~]# cat /etc/sentinel.conf

port 26479

sentinel monitor mymaster 172.17.16.7 6379 2

sentinel auth-pass mymaster redispass

sentinel down-after-milliseconds mymaster 30000

sentinel failover-timeout mymaster 900000

sentinel can-failover mymaster yes

sentinel parallel-syncs mymaster 1

[root@mysql3 ~]# cat /etc/sentinel.conf

port 26579

sentinel monitor mymaster 172.17.16.7 6379 2

sentinel auth-pass mymaster redispass

sentinel down-after-milliseconds mymaster 30000

sentinel failover-timeout mymaster 900000

sentinel can-failover mymaster yes

sentinel parallel-syncs mymaster 1

#在三个服务器中以sentinel模式启动redis-server

[root@php1 ~]# redis-server /etc/sentinel.conf --sentinel

[root@mysql1 ~]# redis-server /etc/sentinel.conf --sentinel

[root@mysql3 ~]# redis-server /etc/sentinel.conf --sentinel

#最后三台服务器sentinel输出如下：（注意每个机器输出对应的都是另外两台机器的IP）

#php1

[14047] 03 Nov 10:18:55.109 * +slave slave 172.17.16.22:6379 172.17.16.22 6379 @ mymaster 172.17.16.7 6379

[14047] 03 Nov 10:18:55.109 * +slave slave 172.17.16.21:6379 172.17.16.21 6379 @ mymaster 172.17.16.7 6379

[14047] 03 Nov 10:19:42.272 * +sentinel sentinel 172.17.16.21:26479 172.17.16.21 26479 @ mymaster 172.17.16.7 6379

[14047] 03 Nov 10:20:46.338 * +sentinel sentinel 172.17.16.22:26579 172.17.16.22 26579 @ mymaster 172.17.16.7 6379

#mysql1

[3512] 03 Nov 10:23:36.473 * +slave slave 172.17.16.22:6379 172.17.16.22 6379 @ mymaster 172.17.16.7 6379

[3512] 03 Nov 10:23:36.473 * +slave slave 172.17.16.21:6379 172.17.16.21 6379 @ mymaster 172.17.16.7 6379

[3512] 03 Nov 10:23:40.446 * +sentinel sentinel 172.17.16.7:26379 172.17.16.7 26379 @ mymaster 172.17.16.7 6379

[3512] 03 Nov 10:24:45.567 * +sentinel sentinel 172.17.16.22:26579 172.17.16.22 26579 @ mymaster 172.17.16.7 6379

#mysql3

[21428] 03 Nov 10:24:40.561 * +slave slave 172.17.16.22:6379 172.17.16.22 6379 @ mymaster 172.17.16.7 6379

[21428] 03 Nov 10:24:40.561 * +slave slave 172.17.16.21:6379 172.17.16.21 6379 @ mymaster 172.17.16.7 6379

[21428] 03 Nov 10:24:41.367 * +sentinel sentinel 172.17.16.7:26379 172.17.16.7 26379 @ mymaster 172.17.16.7 6379

[21428] 03 Nov 10:24:42.280 * +sentinel sentinel 172.17.16.21:26479 172.17.16.21 26479 @ mymaster 172.17.16.7 6379

#关掉mysql3上的redis-server服务

#每个sentinel将输出如下信息，表示认为slave 22已经宕机，剔除

[3512] 03 Nov 10:30:08.359 # +sdown slave 172.17.16.22:6379 172.17.16.22 6379 @ mymaster 172.17.16.7 6379

#重新启动mysql3上的redis-server服务

#每个sentinel将输出如下信息，表示认为slave 22已经重新启动，新增到集群中

[3512] 03 Nov 10:31:28.901 * +reboot slave 172.17.16.22:6379 172.17.16.22 6379 @ mymaster 172.17.16.7 6379

[3512] 03 Nov 10:31:29.115 # -sdown slave 172.17.16.22:6379 172.17.16.22 6379 @ mymaster 172.17.16.7 6379

#关掉主php1的redis-server服务

#将重新选举主服务器并重新配置连接到新的主服务器：

#php1上输出：

[14047] 03 Nov 10:29:49.888 # +sdown master mymaster 172.17.16.7 6379

[14047] 03 Nov 10:29:51.188 # +odown master mymaster 172.17.16.7 6379 #quorum 3/2

[14047] 03 Nov 10:29:59.189 # +failover-detected master mymaster 172.17.16.7 6379

[14047] 03 Nov 10:29:59.689 * +slave-reconf-inprog slave 172.17.16.22:6379 172.17.16.22 6379 @ mymaster 172.17.16.7 6379

[14047] 03 Nov 10:30:00.789 * +slave-reconf-done slave 172.17.16.22:6379 172.17.16.22 6379 @ mymaster 172.17.16.7 6379

[14047] 03 Nov 10:30:00.888 # +failover-end master mymaster 172.17.16.7 6379

[14047] 03 Nov 10:30:00.888 # +switch-master mymaster 172.17.16.7 6379 172.17.16.21 6379

[14047] 03 Nov 10:30:00.990 * +slave slave 172.17.16.22:6379 172.17.16.22 6379 @ mymaster 172.17.16.21 6379

[14047] 03 Nov 10:30:01.058 * +sentinel sentinel 172.17.16.21:26479 172.17.16.21 26479 @ mymaster 172.17.16.21 6379

[14047] 03 Nov 10:30:05.956 * +sentinel sentinel 172.17.16.22:26579 172.17.16.22 26579 @ mymaster 172.17.16.21 6379

[14047] 03 Nov 10:30:30.988 # +sdown slave 172.17.16.7:6379 172.17.16.7 6379 @ mymaster 172.17.16.21 6379

#mysql1上输出：

[3512] 03 Nov 10:33:49.516 # +sdown master mymaster 172.17.16.7 6379

[3512] 03 Nov 10:33:49.716 # +odown master mymaster 172.17.16.7 6379 #quorum 3/2

[3512] 03 Nov 10:33:49.716 # +failover-triggered master mymaster 172.17.16.7 6379

[3512] 03 Nov 10:33:49.716 # +failover-state-wait-start master mymaster 172.17.16.7 6379 #starting in 8139 milliseconds

[3512] 03 Nov 10:33:57.893 # +failover-state-select-slave master mymaster 172.17.16.7 6379

[3512] 03 Nov 10:33:57.997 # +selected-slave slave 172.17.16.21:6379 172.17.16.21 6379 @ mymaster 172.17.16.7 6379

[3512] 03 Nov 10:33:57.997 * +failover-state-send-slaveof-noone slave 172.17.16.21:6379 172.17.16.21 6379 @ mymaster 172.17.16.7 6379

[3512] 03 Nov 10:33:58.101 * +failover-state-wait-promotion slave 172.17.16.21:6379 172.17.16.21 6379 @ mymaster 172.17.16.7 6379

[3496] 03 Nov 10:33:58.101 * MASTER MODE enabled (user request)

[3512] 03 Nov 10:33:58.741 # +promoted-slave slave 172.17.16.21:6379 172.17.16.21 6379 @ mymaster 172.17.16.7 6379

[3512] 03 Nov 10:33:58.741 # +failover-state-reconf-slaves master mymaster 172.17.16.7 6379

[3512] 03 Nov 10:33:58.849 * +slave-reconf-sent slave 172.17.16.22:6379 172.17.16.22 6379 @ mymaster 172.17.16.7 6379

[3512] 03 Nov 10:33:58.957 * +slave-reconf-inprog slave 172.17.16.22:6379 172.17.16.22 6379 @ mymaster 172.17.16.7 6379

[3496] 03 Nov 10:33:59.080 * Slave ask for synchronization

[3496] 03 Nov 10:33:59.080 * Starting BGSAVE for SYNC

[3496] 03 Nov 10:33:59.081 * Background saving started by pid 3515

[3515] 03 Nov 10:33:59.086 * DB saved on disk

[3515] 03 Nov 10:33:59.087 * RDB: 0 MB of memory used by copy-on-write

[3496] 03 Nov 10:33:59.188 * Background saving terminated with success

[3496] 03 Nov 10:33:59.189 * Synchronization with slave succeeded

[3512] 03 Nov 10:33:59.994 * +slave-reconf-done slave 172.17.16.22:6379 172.17.16.22 6379 @ mymaster 172.17.16.7 6379

[3512] 03 Nov 10:34:00.093 # +failover-end master mymaster 172.17.16.7 6379

[3512] 03 Nov 10:34:00.093 # +switch-master mymaster 172.17.16.7 6379 172.17.16.21 6379

[3512] 03 Nov 10:34:00.194 * +slave slave 172.17.16.22:6379 172.17.16.22 6379 @ mymaster 172.17.16.21 6379

[3512] 03 Nov 10:34:00.325 * +sentinel sentinel 172.17.16.7:26379 172.17.16.7 26379 @ mymaster 172.17.16.21 6379

[3512] 03 Nov 10:34:05.192 * +sentinel sentinel 172.17.16.22:26579 172.17.16.22 26579 @ mymaster 172.17.16.21 6379

[3512] 03 Nov 10:34:30.134 # +sdown slave 172.17.16.7:6379 172.17.16.7 6379 @ mymaster 172.17.16.21 6379

#mysql3上输出：

[21428] 03 Nov 10:33:49.343 # +sdown master mymaster 172.17.16.7 6379

[21428] 03 Nov 10:33:49.543 # +odown master mymaster 172.17.16.7 6379 #quorum 2/2

[21428] 03 Nov 10:33:58.896 # +failover-detected master mymaster 172.17.16.7 6379

[21428] 03 Nov 10:33:59.836 * +slave-reconf-inprog slave 172.17.16.22:6379 172.17.16.22 6379 @ mymaster 172.17.16.7 6379

[21428] 03 Nov 10:33:59.836 * +slave-reconf-done slave 172.17.16.22:6379 172.17.16.22 6379 @ mymaster 172.17.16.7 6379

[21428] 03 Nov 10:33:59.940 # +failover-end master mymaster 172.17.16.7 6379

[21428] 03 Nov 10:33:59.940 # +switch-master mymaster 172.17.16.7 6379 172.17.16.21 6379

[21428] 03 Nov 10:34:00.045 * +slave slave 172.17.16.22:6379 172.17.16.22 6379 @ mymaster 172.17.16.21 6379

[21428] 03 Nov 10:34:00.293 * +sentinel sentinel 172.17.16.21:26479 172.17.16.21 26479 @ mymaster 172.17.16.21 6379

[21428] 03 Nov 10:34:00.325 * +sentinel sentinel 172.17.16.7:26379 172.17.16.7 26379 @ mymaster 172.17.16.21 6379

[21428] 03 Nov 10:34:29.989 # +sdown slave 172.17.16.7:6379 172.17.16.7 6379 @ mymaster 172.17.16.21 6379

#查看主从关系：（mysql1为主，mysql3为从，如果php1重新启动，也将为从服务器加入到新的集群）

[root@mysql1 ~]# redis-cli -h 127.0.0.1 -p 6379 -a redispass info replication

# Replication

role:master

connected_slaves:1

slave0:172.17.16.22,6379,online

[root@mysql3 ~]# redis-cli -h 127.0.0.1 -p 6379 -a redispass info replication

# Replication

role:slave

master_host:172.17.16.21

master_port:6379

master_link_status:up

master_last_io_seconds_ago:1

master_sync_in_progress:0

slave_priority:100

slave_read_only:1

connected_slaves:0

#重新启动php1，检查mysql1的主从关系

[root@mysql1 ~]# redis-cli -h 127.0.0.1 -p 6379 -a redispass info replication

# Replication

role:master

connected_slaves:2

slave0:172.17.16.22,6379,online

slave1:172.17.16.7,6379,online

切换成功。