MySQL管理工具MySQL Utilities — 恢复有故障的主(50)
亿网在故障成功转移后，往往需要恢复到最初的复制拓扑结构，并且使有故障的主重新再次为主。
假设故障转移后的拓扑结构是这样的，主server2:3312，从server3:3313, server4:3314, server:3315，现在需要将原来的主server1:3311再次成为主。手工执行这个过程的话，是非常繁琐的甚至还会导致复制失败，使用MySQL Utilities工具只需三个简单的步骤来搞定。
实例
解决上述问题需要考虑下面几个问题。首先必须停止运行mysqlfailover 实例，启动恢复旧的主 server1:3311。接着，设置旧的主为新主server2:3312的从。
| 1 2 3 4 5 6 | shell > mysqlreplicate — master = root @ server2 : 3312 — slave = root @ server1 : 3311 – rpl – user = rpl : rpl # master on trustauth.cn: … connected. # slave on trustauth.cn: … connected. # Checking for binary logging on master… # Setting up replication… # …done. |
接下来，切换到之前的主
| 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 | shell > mysqlrpladmin — master = root @ server2 : 3312 \ — slaves = root @ server2 : 3313 , root @ server4 : 3314 , root @ server5 : 3315 \ — rpl – user = rpl : rpl — new – master = root @ server1 : 3311 — demote – master switchover # Checking privileges. # Performing switchover from master at server2:3312 to slave at server1:3311. # Checking candidate slave prerequisites. # Checking slaves configuration to master. # Waiting for slaves to catch up to old master. # Stopping slaves. # Performing STOP on all slaves. # Demoting old master to be a slave to the new master. # Switching slaves to new master. # Starting all slaves. # Performing START on all slaves. # Checking slaves for errors. # Switchover complete. # # Replication Topology Health: + — — — — — + — — — – + — — — — – + — — — — + — — — — — — + — — — — – + | host | port | role | state | gtid_mode | health | + — — — — — + — — — – + — — — — – + — — — — + — — — — — — + — — — — – + | server1 | 3311 | MASTER | UP | ON | OK | | server2 | 3312 | SLAVE | UP | ON | OK | | server3 | 3313 | SLAVE | UP | ON | OK | | server4 | 3314 | SLAVE | UP | ON | OK | | server5 | 3315 | SLAVE | UP | ON | OK | + — — — — — + — — — – + — — — — – + — — — — + — — — — — — + — — — — – + # …done. |
恢复到初始的复制拓扑，并重新启动mysqlfailover （需要使用–force选项）。
| 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 | shell > mysqlfailover — master = root @ server1 : 3311 \ — slaves = root @ server2 : 3312 , root @ server3 : 3313 , root @ server4 : 3314 , server5 : 3315 \ — log = log . txt — rpl – user = rpl : rpl — force # Checking privileges. MySQL Replication Failover Utility Failover Mode = auto Next Interval = Sat Jul 27 02 : 17 : 12 2013 Master Information — — — — — — — — — Binary Log File Position Binlog_Do_DB Binlog_Ignore_DB master – bin . 000002 151 GTID Executed Set None Replication Health Status + — — — — — + — — — – + — — — — – + — — — — + — — — — — — + — — — — – + | host | port | role | state | gtid_mode | health | + — — — — — + — — — – + — — — — – + — — — — + — — — — — — + — — — — – + | server1 | 3311 | MASTER | UP | ON | OK | | server2 | 3312 | SLAVE | UP | ON | OK | | server3 | 3313 | SLAVE | UP | ON | OK | | server4 | 3314 | SLAVE | UP | ON | OK | | server5 | 3315 | SLAVE | UP | ON | OK | + — — — — — + — — — – + — — — — – + — — — — + — — — — — — + — — — — – + Q – quit R – refresh H – health G – GTID Lists U – UUIDs L – log entries |
权限
用户需要有配置复制的权限。