1.masterha_conf_host自动添加/删除数据库
在某些情况下我们需要在配置文件中添加mysql服务器实现对现有数据的扩展或者有故障的master已经修复好需要在现有环境中当做slave继续使用，那么我们就可以使用masterha_conf_host来实现。
在前面我们讲到rd-mysql-test1的master有问题导致启动failover，现在rd-mysql-test2成为新的master，现在rd-mysql-test1已经修复，我们将其作为slave继续使用：
现在的配置文件为：
[server default]manager_log=/var/log/masterha/app1/manager.logmanager_workdir=/var/log/masterha/app1master_binlog_dir=/data/mysqlpassword=123456ping_interval=1remote_workdir=/tmprepl_password=123456repl_user=repssh_port=1022ssh_user=rootuser=mha[server2]candidate_master=1check_repl_delay=0hostname=10.10.10.57port=3306[server3]hostname=10.10.10.58port=3306我们用masterha_conf_host来添加
[[email protected] mha]# masterha_conf_host --command=add --conf=/etc/mha/app1.cnf --block=server1 --hostname=10.10.10.56 --params="no_master=1;ignore_fail=1"Wrote server1 entry to /etc/mha/app1.cnf .[[email protected] mha]# cat app1.cnf [server default]manager_log=/var/log/masterha/app1/manager.logmanager_workdir=/var/log/masterha/app1master_binlog_dir=/data/mysqlpassword=123456ping_interval=1remote_workdir=/tmprepl_password=123456repl_user=repssh_port=1022ssh_user=rootuser=mha[server1]hostname=10.10.10.56ignore_fail=1no_master=1[server2]candidate_master=1check_repl_delay=0hostname=10.10.10.57port=3306[server3]hostname=10.10.10.58port=3306看到了吗？server1的模块已经添加到配置文件了，然后需要配置主从：
mysql> change master to master_host='10.10.10.57',master_port=3306,master_user='rep',master_password='123456',master_log_file='mysql-bin.000010',master_log_pos=120;mysql> start slave;[[email protected] app1]# nohup masterha_manager --conf=/etc/mha/app1.cnf --remove_dead_master_conf --ignore_last_failover < /dev/null > /var/log/masterha/app1/manager.log 2>&1 &ok,就这样我们我们添加了一台salve到当前架构了。
2.masterha_master_switch（关闭mha监控）
masterha_manager既可以用作监控也能够实现failover；而masterha_master_switch不能够用来监控，但是可以用来实现master的failover，也可以用来实现在线master切换。
参数：--master_state=dead,强制性使用参数，主要是dead和alive；如果设置为alive，则说明进行的在线master切换，但是master必须是alive的。
--dead_master_host=(hostname)，强制性使用参数，--dead_master_ip,--dead_master_port也可以使用
--new_master_host=(hostname),可选参数，如果设置了则会按照设置的参数将其作为新master，如果没有设置，则会和按照masterha_manager的自动failover的选举方式一样(检查candidate_master参数)进行选择。
--interactive=(0|1),互动模式为1(默认)，0为不互动
--ssh_reachable=(0|1|2),检查master的ssh是否正常，0为不同，1为通，2为未知。默认为2，会检查确认ssh的状态并更为0或1。如果master通过ssh可以登录，并且master_ip_failover_script或shutdown_script设置的话，则会执行stopssh命令；反之masterha_master_switch将会执行stop命令。另外，有故障的master如果ssh通的话，failover script还会copy二进制日志的。
--skip_change_master通过设置此参数，mha在应用为apply different relay logs后，会跳过执行change master和start slave，因此不会产生新的master，以便我们进行二次检查。
--skip_disable_read_only通过设置此参数，mha将不会在新的master执行set global read_only=0
--last_failover_minute,--ignore_last_failover,--wait_on_failover_error和masterha_manager中参数命令一样。
--remove_dead_master_conf执行完成后会清除配置文件中相应的模块。
(1)手动failover
互动模式(默认)
masterha_master_switch --conf=/etc/mha/app1.conf --master_state=dead --dead_master_host=10.10.10.56 --new_master_host=10.10.10.57 --interactive=1
non-interactive模式
masterha_master_switch --conf=/etc/mha/app1.conf --master_state=dead --dead_master_host=10.10.10.56 --new_master_host=10.10.10.57 --interactive=0
这种模式和masterha_manager效果是一样的，这适用于已经确定master已经dead，你想尽快完成failover。
(2)在线故障迁移
在某些情况下你想进行在线迁移，及时现在的master仍然正常运行。最典型的例子是你想更换硬件或升级master的硬件，例如更换raid卡，你就必须停机。在这些情况下，我们就需要将master在线迁移到其他服务器上。
在线切换开始前需要满足以下条件：
1.所有slave上的IO threads必须running
2.所有slave上的SQL threads必须running
3.所有slaves上的Seconds_Behind_Master(show slave status输出的)必须小于等于设置的--running_updates_limit秒数，默认--running_updates_limit=1
4.master上show processlist输出的内容，没有一个更新花费的时间大于设置的--running_updates_limit的秒数
参数如下：
--new_master_host=(hostname)
--orig_master_is_new_slave 在master switch完成后，老master将会作为一个新的salve继续运行。默认情况下，这个参数禁用。如果你使用这个参数，需要在配置文件中设置repl_password，因为它不知道新的master的复制密码。
--running_updates_limit=(seconds) 如果现在的master执行写操作的执行时间大于这个参数，或者任何一台slave的Seconds_Behind_Master大于这个参数，那么master switch将自动放弃。默认参数为1s
--remove_orig_master_conf 当master switch成功完成后，mha manager将自动将原master的区块从配置文件中删除，默认不删。
--skip_lock_all_tables 在master switch过程中，mha将会在原master上运行flush tables with read lock来保证数据不会更新。但是flush tables with read lock的非常耗时，因为需要等所有的读写操作文成后才会锁表，因此如果你确定原master上的数据不会更新的话，你可以避免使用这个参数。
开始在线迁移：
[[email protected] mha]# masterha_master_switch --master_state=alive --conf=/etc/mha/app1.cnf --new_master_host=10.10.10.58 --orig_master_is_new_slave --running_updates_limit=1000000Tue Aug 11 14:52:51 2015 - [info] MHA::MasterRotate version 0.56.Tue Aug 11 14:52:51 2015 - [info] Starting online master switch..Tue Aug 11 14:52:51 2015 - [info] Tue Aug 11 14:52:51 2015 - [info] * Phase 1: Configuration Check Phase..Tue Aug 11 14:52:51 2015 - [info] Tue Aug 11 14:52:51 2015 - [warning] Global configuration file /etc/masterha_default.cnf not found. Skipping.Tue Aug 11 14:52:51 2015 - [info] Reading application default configuration from /etc/mha/app1.cnf..Tue Aug 11 14:52:51 2015 - [info] Reading server configuration from /etc/mha/app1.cnf..Tue Aug 11 14:52:51 2015 - [info] GTID failover mode = 0Tue Aug 11 14:52:51 2015 - [info] Current Alive Master: 10.10.10.57(10.10.10.57:3306)Tue Aug 11 14:52:51 2015 - [info] Alive Slaves:Tue Aug 11 14:52:51 2015 - [info] 10.10.10.56(10.10.10.56:3306) Version=5.6.26-log (oldest major version between slaves) log-bin:enabledTue Aug 11 14:52:51 2015 - [info] Replicating from 10.10.10.57(10.10.10.57:3306)Tue Aug 11 14:52:51 2015 - [info] Not candidate for the new Master (no_master is set)Tue Aug 11 14:52:51 2015 - [info] 10.10.10.58(10.10.10.58:3306) Version=5.6.25-log (oldest major version between slaves) log-bin:enabledTue Aug 11 14:52:51 2015 - [info] Replicating from 10.10.10.57(10.10.10.57:3306)It is better to execute FLUSH NO_WRITE_TO_BINLOG TABLES on the master before switching. Is it ok to execute on 10.10.10.57(10.10.10.57:3306)? (YES/no): yesTue Aug 11 14:52:54 2015 - [info] Executing FLUSH NO_WRITE_TO_BINLOG TABLES. This may take long time..Tue Aug 11 14:52:54 2015 - [info] ok.Tue Aug 11 14:52:54 2015 - [info] Checking MHA is not monitoring or doing failover..Tue Aug 11 14:52:54 2015 - [info] Checking replication health on 10.10.10.56..Tue Aug 11 14:52:54 2015 - [info] ok.Tue Aug 11 14:52:54 2015 - [info] Checking replication health on 10.10.10.58..Tue Aug 11 14:52:54 2015 - [info] ok.Tue Aug 11 14:52:54 2015 - [info] 10.10.10.58 can be new master.Tue Aug 11 14:52:54 2015 - [info] From:10.10.10.57(10.10.10.57:3306) (current master) +--10.10.10.56(10.10.10.56:3306) +--10.10.10.58(10.10.10.58:3306)To:10.10.10.58(10.10.10.58:3306) (new master) +--10.10.10.56(10.10.10.56:3306) +--10.10.10.57(10.10.10.57:3306)Starting master switch from 10.10.10.57(10.10.10.57:3306) to 10.10.10.58(10.10.10.58:3306)? (yes/NO): yesTue Aug 11 14:52:58 2015 - [info] Checking whether 10.10.10.58(10.10.10.58:3306) is ok for the new master..Tue Aug 11 14:52:58 2015 - [info] ok.Tue Aug 11 14:52:58 2015 - [info] 10.10.10.57(10.10.10.57:3306): SHOW SLAVE STATUS returned empty result. To check replication filtering rules, temporarily executing CHANGE MASTER to a dummy host.Tue Aug 11 14:52:58 2015 - [info] 10.10.10.57(10.10.10.57:3306): Resetting slave pointing to the dummy host.Tue Aug 11 14:52:58 2015 - [info] ** Phase 1: Configuration Check Phase completed.Tue Aug 11 14:52:58 2015 - [info] Tue Aug 11 14:52:58 2015 - [info] * Phase 2: Rejecting updates Phase..Tue Aug 11 14:52:58 2015 - [info] master_ip_online_change_script is not defined. If you do not disable writes on the current master manually, applications keep writing on the current master. Is it ok to proceed? (yes/NO): noTue Aug 11 14:53:03 2015 - [info] Not typed yes. Stopping. at /usr/local/share/perl5/MHA/MasterRotate.pm line 320, <STDIN> line 3.报错master_ip_online_change_script is not defined，在迁移过程中需要用到master_ip_online_change脚本，因此我们需要在配置文件中加入master_ip_online_change_script=/usr/local/bin/master_ip_online_change。引入此脚本的目的在于用一种更好的方式锁表：a.通过drop user app_user来阻塞数据库的连接;b.等待1~2秒钟以便所有的数据库都disconnect；c.通过set global read_only=1阻塞所有的更新除了super；d.等待一段时间；e.通过flush tables with read lock阻塞所有的更新。
再次执行：
[[email protected] mha]# masterha_master_switch --master_state=alive --conf=/etc/mha/app1.cnf --new_master_host=10.10.10.58 --orig_master_is_new_slave --running_updates_limit=1000000Tue Aug 11 14:53:08 2015 - [info] MHA::MasterRotate version 0.56.Tue Aug 11 14:53:08 2015 - [info] Starting online master switch..Tue Aug 11 14:53:08 2015 - [info] Tue Aug 11 14:53:08 2015 - [info] * Phase 1: Configuration Check Phase..Tue Aug 11 14:53:08 2015 - [info] Tue Aug 11 14:53:08 2015 - [warning] Global configuration file /etc/masterha_default.cnf not found. Skipping.Tue Aug 11 14:53:08 2015 - [info] Reading application default configuration from /etc/mha/app1.cnf..Tue Aug 11 14:53:08 2015 - [info] Reading server configuration from /etc/mha/app1.cnf..Tue Aug 11 14:53:08 2015 - [info] GTID failover mode = 0Tue Aug 11 14:53:08 2015 - [info] Current Alive Master: 10.10.10.57(10.10.10.57:3306)Tue Aug 11 14:53:08 2015 - [info] Alive Slaves:Tue Aug 11 14:53:08 2015 - [info] 10.10.10.56(10.10.10.56:3306) Version=5.6.26-log (oldest major version between slaves) log-bin:enabledTue Aug 11 14:53:08 2015 - [info] Replicating from 10.10.10.57(10.10.10.57:3306)Tue Aug 11 14:53:08 2015 - [info] Not candidate for the new Master (no_master is set)Tue Aug 11 14:53:08 2015 - [info] 10.10.10.58(10.10.10.58:3306) Version=5.6.25-log (oldest major version between slaves) log-bin:enabledTue Aug 11 14:53:08 2015 - [info] Replicating from 10.10.10.57(10.10.10.57:3306)It is better to execute FLUSH NO_WRITE_TO_BINLOG TABLES on the master before switching. Is it ok to execute on 10.10.10.57(10.10.10.57:3306)? (YES/no): yesTue Aug 11 14:53:09 2015 - [info] Executing FLUSH NO_WRITE_TO_BINLOG TABLES. This may take long time..Tue Aug 11 14:53:09 2015 - [info] ok.Tue Aug 11 14:53:09 2015 - [info] Checking MHA is not monitoring or doing failover..Tue Aug 11 14:53:09 2015 - [info] Checking replication health on 10.10.10.56..Tue Aug 11 14:53:09 2015 - [info] ok.Tue Aug 11 14:53:09 2015 - [info] Checking replication health on 10.10.10.58..Tue Aug 11 14:53:09 2015 - [info] ok.Tue Aug 11 14:53:09 2015 - [info] 10.10.10.58 can be new master.Tue Aug 11 14:53:09 2015 - [info] From:10.10.10.57(10.10.10.57:3306) (current master) +--10.10.10.56(10.10.10.56:3306) +--10.10.10.58(10.10.10.58:3306)To:10.10.10.58(10.10.10.58:3306) (new master) +--10.10.10.56(10.10.10.56:3306) +--10.10.10.57(10.10.10.57:3306)Starting master switch from 10.10.10.57(10.10.10.57:3306) to 10.10.10.58(10.10.10.58:3306)? (yes/NO): yesTue Aug 11 14:53:11 2015 - [info] Checking whether 10.10.10.58(10.10.10.58:3306) is ok for the new master..Tue Aug 11 14:53:11 2015 - [info] ok.Tue Aug 11 14:53:11 2015 - [info] 10.10.10.57(10.10.10.57:3306): SHOW SLAVE STATUS returned empty result. To check replication filtering rules, temporarily executing CHANGE MASTER to a dummy host.Tue Aug 11 14:53:11 2015 - [info] 10.10.10.57(10.10.10.57:3306): Resetting slave pointing to the dummy host.Tue Aug 11 14:53:11 2015 - [info] ** Phase 1: Configuration Check Phase completed.Tue Aug 11 14:53:11 2015 - [info] Tue Aug 11 14:53:11 2015 - [info] * Phase 2: Rejecting updates Phase..Tue Aug 11 14:53:11 2015 - [info] Tue Aug 11 14:53:11 2015 - [info] Executing master ip online change script to disable write on the current master:Tue Aug 11 14:53:11 2015 - [info] /usr/local/bin/master_ip_online_change --command=stop --orig_master_host=10.10.10.57 --orig_master_ip=10.10.10.57 --orig_master_port=3306 --orig_master_user='mha' --orig_master_password='123456' --new_master_host=10.10.10.58 --new_master_ip=10.10.10.58 --new_master_port=3306 --new_master_user='mha' --new_master_password='123456' --orig_master_ssh_user=root --new_master_ssh_user=root --orig_master_ssh_port=1022 --new_master_ssh_port=1022 --orig_master_is_new_slaveUnknown option: orig_master_ssh_portUnknown option: new_master_ssh_portTue Aug 11 14:53:11 2015 290906 Set read_only on the new master.. ok.Tue Aug 11 14:53:11 2015 296385 Drpping app user on the orig master..Got Error: Undefined subroutine &main::FIXME_xxx_drop_app_user called at /usr/local/bin/master_ip_online_change line 152.Tue Aug 11 14:53:11 2015 - [error][/usr/local/share/perl5/MHA/ManagerUtil.pm, ln177] Got ERROR: at /usr/local/bin/masterha_master_switch line 53再次报错“Got Error: Undefined subroutine &main::FIXME_xxx_drop_app_user called at /usr/local/bin/master_ip_online_change line 152”
这是由于无法找到对FIXME_xxx_drop_app_user定义，由于perl不熟，我暂时注释掉相关drop user的行或FIXME_xxx等，不会影响其他过程。
其中需要注释掉的语句为：
FIXME_xxx_drop_app_user($orig_master_handler);
FIXME_xxx_create_app_user($new_master_handler);
再次执行：
[[email protected] mha]# masterha_master_switch --master_state=alive --conf=/etc/mha/app1.cnf --new_master_host=10.10.10.58 --orig_master_is_new_slave --running_updates_limit=1000000Tue Aug 11 15:08:11 2015 - [info] MHA::MasterRotate version 0.56.Tue Aug 11 15:08:11 2015 - [info] Starting online master switch..Tue Aug 11 15:08:11 2015 - [info] Tue Aug 11 15:08:11 2015 - [info] * Phase 1: Configuration Check Phase..Tue Aug 11 15:08:11 2015 - [info] Tue Aug 11 15:08:11 2015 - [warning] Global configuration file /etc/masterha_default.cnf not found. Skipping.Tue Aug 11 15:08:11 2015 - [info] Reading application default configuration from /etc/mha/app1.cnf..Tue Aug 11 15:08:11 2015 - [info] Reading server configuration from /etc/mha/app1.cnf..Tue Aug 11 15:08:12 2015 - [info] GTID failover mode = 0Tue Aug 11 15:08:12 2015 - [info] Current Alive Master: 10.10.10.57(10.10.10.57:3306)Tue Aug 11 15:08:12 2015 - [info] Alive Slaves:Tue Aug 11 15:08:12 2015 - [info] 10.10.10.56(10.10.10.56:3306) Version=5.6.26-log (oldest major version between slaves) log-bin:enabledTue Aug 11 15:08:12 2015 - [info] Replicating from 10.10.10.57(10.10.10.57:3306)Tue Aug 11 15:08:12 2015 - [info] Not candidate for the new Master (no_master is set)Tue Aug 11 15:08:12 2015 - [info] 10.10.10.58(10.10.10.58:3306) Version=5.6.25-log (oldest major version between slaves) log-bin:enabledTue Aug 11 15:08:12 2015 - [info] Replicating from 10.10.10.57(10.10.10.57:3306)It is better to execute FLUSH NO_WRITE_TO_BINLOG TABLES on the master before switching. Is it ok to execute on 10.10.10.57(10.10.10.57:3306)? (YES/no): yesTue Aug 11 15:08:13 2015 - [info] Executing FLUSH NO_WRITE_TO_BINLOG TABLES. This may take long time..Tue Aug 11 15:08:13 2015 - [info] ok.Tue Aug 11 15:08:13 2015 - [info] Checking MHA is not monitoring or doing failover..Tue Aug 11 15:08:13 2015 - [info] Checking replication health on 10.10.10.56..Tue Aug 11 15:08:13 2015 - [info] ok.Tue Aug 11 15:08:13 2015 - [info] Checking replication health on 10.10.10.58..Tue Aug 11 15:08:13 2015 - [info] ok.Tue Aug 11 15:08:13 2015 - [info] 10.10.10.58 can be new master.Tue Aug 11 15:08:13 2015 - [info] From:10.10.10.57(10.10.10.57:3306) (current master) +--10.10.10.56(10.10.10.56:3306) +--10.10.10.58(10.10.10.58:3306)To:10.10.10.58(10.10.10.58:3306) (new master) +--10.10.10.56(10.10.10.56:3306) +--10.10.10.57(10.10.10.57:3306)Starting master switch from 10.10.10.57(10.10.10.57:3306) to 10.10.10.58(10.10.10.58:3306)? (yes/NO): yesTue Aug 11 15:08:14 2015 - [info] Checking whether 10.10.10.58(10.10.10.58:3306) is ok for the new master..Tue Aug 11 15:08:14 2015 - [info] ok.Tue Aug 11 15:08:14 2015 - [info] 10.10.10.57(10.10.10.57:3306): SHOW SLAVE STATUS returned empty result. To check replication filtering rules, temporarily executing CHANGE MASTER to a dummy host.Tue Aug 11 15:08:14 2015 - [info] 10.10.10.57(10.10.10.57:3306): Resetting slave pointing to the dummy host.Tue Aug 11 15:08:14 2015 - [info] ** Phase 1: Configuration Check Phase completed.Tue Aug 11 15:08:14 2015 - [info] Tue Aug 11 15:08:14 2015 - [info] * Phase 2: Rejecting updates Phase..Tue Aug 11 15:08:14 2015 - [info] Tue Aug 11 15:08:14 2015 - [info] Executing master ip online change script to disable write on the current master:Tue Aug 11 15:08:14 2015 - [info] /usr/local/bin/master_ip_online_change --command=stop --orig_master_host=10.10.10.57 --orig_master_ip=10.10.10.57 --orig_master_port=3306 --orig_master_user='mha' --orig_master_password='123456' --new_master_host=10.10.10.58 --new_master_ip=10.10.10.58 --new_master_port=3306 --new_master_user='mha' --new_master_password='123456' --orig_master_ssh_user=root --new_master_ssh_user=root --orig_master_ssh_port=1022 --new_master_ssh_port=1022 --orig_master_is_new_slaveUnknown option: orig_master_ssh_portUnknown option: new_master_ssh_portTue Aug 11 15:08:14 2015 969366 Set read_only on the new master.. ok.Tue Aug 11 15:08:14 2015 974088 Drpping app user on the orig master..Tue Aug 11 15:08:14 2015 974826 Waiting all running 1 threads are disconnected.. (max 1500 milliseconds){'Time' => '332257','Command' => 'Daemon','db' => undef,'Id' => '1','Info' => undef,'User' => 'event_scheduler','State' => 'Waiting on empty queue','Host' => 'localhost'}Tue Aug 11 15:08:15 2015 475963 Waiting all running 1 threads are disconnected.. (max 1000 milliseconds){'Time' => '332258','Command' => 'Daemon','db' => undef,'Id' => '1','Info' => undef,'User' => 'event_scheduler','State' => 'Waiting on empty queue','Host' => 'localhost'}Tue Aug 11 15:08:15 2015 976758 Waiting all running 1 threads are disconnected.. (max 500 milliseconds){'Time' => '332258','Command' => 'Daemon','db' => undef,'Id' => '1','Info' => undef,'User' => 'event_scheduler','State' => 'Waiting on empty queue','Host' => 'localhost'}Tue Aug 11 15:08:16 2015 478138 Set read_only=1 on the orig master.. ok.Tue Aug 11 15:08:16 2015 480285 Waiting all running 1 queries are disconnected.. (max 500 milliseconds){'Time' => '332259','Command' => 'Daemon','db' => undef,'Id' => '1','Info' => undef,'User' => 'event_scheduler','State' => 'Waiting on empty queue','Host' => 'localhost'}Tue Aug 11 15:08:16 2015 979233 Killing all application threads..Tue Aug 11 15:08:16 2015 979903 done.Tue Aug 11 15:08:16 2015 - [info] ok.Tue Aug 11 15:08:16 2015 - [info] Locking all tables on the orig master to reject updates from everybody (including root):Tue Aug 11 15:08:16 2015 - [info] Executing FLUSH TABLES WITH READ LOCK..Tue Aug 11 15:08:16 2015 - [info] ok.Tue Aug 11 15:08:16 2015 - [info] Orig master binlog:pos is mysql-bin.000010:120.Tue Aug 11 15:08:16 2015 - [info] Waiting to execute all relay logs on 10.10.10.58(10.10.10.58:3306)..Tue Aug 11 15:08:16 2015 - [info] master_pos_wait(mysql-bin.000010:120) completed on 10.10.10.58(10.10.10.58:3306). Executed 0 events.Tue Aug 11 15:08:16 2015 - [info] done.Tue Aug 11 15:08:16 2015 - [info] Getting new master's binlog name and position..Tue Aug 11 15:08:16 2015 - [info] mysql-bin.000008:120Tue Aug 11 15:08:16 2015 - [info] All other slaves should start replication from here. Statement should be: CHANGE MASTER TO MASTER_HOST='10.10.10.58', MASTER_PORT=3306, MASTER_LOG_FILE='mysql-bin.000008', MASTER_LOG_POS=120, MASTER_USER='rep', MASTER_PASSWORD='xxx';Tue Aug 11 15:08:16 2015 - [info] Executing master ip online change script to allow write on the new master:Tue Aug 11 15:08:16 2015 - [info] /usr/local/bin/master_ip_online_change --command=start --orig_master_host=10.10.10.57 --orig_master_ip=10.10.10.57 --orig_master_port=3306 --orig_master_user='mha' --orig_master_password='123456' --new_master_host=10.10.10.58 --new_master_ip=10.10.10.58 --new_master_port=3306 --new_master_user='mha' --new_master_password='123456' --orig_master_ssh_user=root --new_master_ssh_user=root --orig_master_ssh_port=1022 --new_master_ssh_port=1022 --orig_master_is_new_slaveUnknown option: orig_master_ssh_portUnknown option: new_master_ssh_portTue Aug 11 15:08:17 2015 164390 Set read_only=0 on the new master.Tue Aug 11 15:08:17 2015 165561 Creating app user on the new master..Got Error: Undefined subroutine &main::FIXME_xxx_create_app_user called at /usr/local/bin/master_ip_online_change line 246.Tue Aug 11 15:08:17 2015 - [warning] Proceeding.Tue Aug 11 15:08:17 2015 - [info] Tue Aug 11 15:08:17 2015 - [info] * Switching slaves in parallel..Tue Aug 11 15:08:17 2015 - [info] Tue Aug 11 15:08:17 2015 - [info] -- Slave switch on host 10.10.10.56(10.10.10.56:3306) started, pid: 9445Tue Aug 11 15:08:17 2015 - [info] Tue Aug 11 15:08:17 2015 - [info] Log messages from 10.10.10.56 ...Tue Aug 11 15:08:17 2015 - [info] Tue Aug 11 15:08:17 2015 - [info] Waiting to execute all relay logs on 10.10.10.56(10.10.10.56:3306)..Tue Aug 11 15:08:17 2015 - [info] master_pos_wait(mysql-bin.000010:120) completed on 10.10.10.56(10.10.10.56:3306). Executed 0 events.Tue Aug 11 15:08:17 2015 - [info] done.Tue Aug 11 15:08:17 2015 - [info] Resetting slave 10.10.10.56(10.10.10.56:3306) and starting replication from the new master 10.10.10.58(10.10.10.58:3306)..Tue Aug 11 15:08:17 2015 - [info] Executed CHANGE MASTER.Tue Aug 11 15:08:17 2015 - [info] Slave started.Tue Aug 11 15:08:17 2015 - [info] End of log messages from 10.10.10.56 ...Tue Aug 11 15:08:17 2015 - [info] Tue Aug 11 15:08:17 2015 - [info] -- Slave switch on host 10.10.10.56(10.10.10.56:3306) succeeded.Tue Aug 11 15:08:17 2015 - [info] Unlocking all tables on the orig master:Tue Aug 11 15:08:17 2015 - [info] Executing UNLOCK TABLES..Tue Aug 11 15:08:17 2015 - [info] ok.Tue Aug 11 15:08:17 2015 - [info] Starting orig master as a new slave..Tue Aug 11 15:08:17 2015 - [info] Resetting slave 10.10.10.57(10.10.10.57:3306) and starting replication from the new master 10.10.10.58(10.10.10.58:3306)..Tue Aug 11 15:08:17 2015 - [info] Executed CHANGE MASTER.Tue Aug 11 15:08:17 2015 - [info] Slave started.Tue Aug 11 15:08:17 2015 - [info] All new slave servers switched successfully.Tue Aug 11 15:08:17 2015 - [info] Tue Aug 11 15:08:17 2015 - [info] * Phase 5: New master cleanup phase..Tue Aug 11 15:08:17 2015 - [info] Tue Aug 11 15:08:17 2015 - [info] 10.10.10.58: Resetting slave info succeeded.Tue Aug 11 15:08:17 2015 - [info] Switching master to 10.10.10.58(10.10.10.58:3306) completed successfully.ok，在线迁移成功了，我们可以登录mysql查看。
注意：1.orig_master_ssh_port和new_master_ssh_port在master_ip_online_change中不支持，此处是从配置中读取的。
2.在执行过程中若报一下错误：
Wed Aug 12 14:05:12 2015 - [error][/usr/local/share/perl5/MHA/MasterRotate.pm, ln262] We should not start online master switch when one of connections are running long queries on the new master(10.10.10.56(10.10.10.56:3306)). Currently 1 thread(s) are running.Details:{'Time' => '93075','Command' => 'Daemon','db' => undef,'Id' => '29','Info' => undef,'User' => 'event_scheduler','State' => 'Waiting on empty queue','Host' => 'localhost'}Wed Aug 12 14:05:12 2015 - [error][/usr/local/share/perl5/MHA/ManagerUtil.pm, ln177] Got ERROR: at /usr/local/bin/masterha_master_switch line 53这是由于new master上的event_scheduler导致，我们可以临时关闭下event_scheduler通过set global event_scheduler=0;待迁移完成后再开启。从以上看在线迁移主要经过以下过程：
a.配置检查阶段，选出并确定新master
b.拒绝更新阶段，阻塞原master使其不能进行写 ；在新master上执行最新relay logs；其他的salve从新的master进行复制；对新master配置可写
c.将原master转换成新slave
3.master_ip_failover
在普通的HA环境中，我们可以在master上配置虚拟ip（VIP），当master故障时，高可用软件如keepalived等可以将VIP漂移到备用机上。
mha manager会调用master_ip_failover_script三次，第一次是在进入监控master前，检查repl时使用；第二次是在调用shutdown_script前使用；第三次是在将relay log应用到新master后使用。
注：参数不用在配置文件中配置。
(1)首先我们需要根据实际情况更改master_ip_failover脚本，修改的地方已经用###标注处
use strict;use warnings FATAL => 'all';use Getopt::Long;use MHA::DBHelper;my ( $command, $ssh_user, $orig_master_host, $orig_master_ip, $orig_master_port, $new_master_host, $new_master_ip, $new_master_port, $new_master_user, $new_master_password);###################################################################my $vip = '10.10.10.60';my $key = '1';my $ssh_start_vip = "/sbin/ifconfig eth0:$key $vip";my $ssh_stop_vip = "/sbin/ifconfig eth0:$key $vip down";####################################################################GetOptions( 'command=s' => \$command, 'ssh_user=s' => \$ssh_user, 'orig_master_host=s' => \$orig_master_host, 'orig_master_ip=s' => \$orig_master_ip, 'orig_master_port=i' => \$orig_master_port, 'new_master_host=s' => \$new_master_host, 'new_master_ip=s' => \$new_master_ip, 'new_master_port=i' => \$new_master_port, 'new_master_user=s' => \$new_master_user, 'new_master_password=s' => \$new_master_password,);exit &main();sub main {########################################################################### print "\n\n script test ++++++ $ssh_stop_vip+++$ssh_start_vip+++ \n\n";########################################################################### if ( $command eq "stop" || $command eq "stopssh" ) { # $orig_master_host, $orig_master_ip, $orig_master_port are passed. # If you manage master ip address at global catalog database, # invalidate orig_master_ip here. my $exit_code = 1; eval {############################################################################## print "disable the VIP on old master: $orig_master_host \n"; &stop_vip();############################################################################## $exit_code = 0; }; if ($@) { warn "Got Error: $@\n"; exit $exit_code; } exit $exit_code; } elsif ( $command eq "start" ) { # all arguments are passed. # If you manage master ip address at global catalog database, # activate new_master_ip here. # You can also grant write access (create user, set read_only=0, etc) here. my $exit_code = 10; eval {##################################################################################### print "enable the VIP: $vip on the new master: $new_master_host \n"; &start_vip();####################################################################################### my $new_master_handler = new MHA::DBHelper(); # args: hostname, port, user, password, raise_error_or_not $new_master_handler->connect( $new_master_ip, $new_master_port, $new_master_user, $new_master_password, 1 ); ## Set read_only=0 on the new master $new_master_handler->disable_log_bin_local(); print "Set read_only=0 on the new master.\n"; $new_master_handler->disable_read_only(); ## Creating an app user on the new master # print "Creating app user on the new master..\n"; # FIXME_xxx_create_user( $new_master_handler->{dbh} ); # $new_master_handler->enable_log_bin_local(); # $new_master_handler->disconnect(); # ## Update master ip on the catalog database, etc # FIXME_xxx; $exit_code = 0; }; if ($@) { warn $@; # If you want to continue failover, exit 10. exit $exit_code; } exit $exit_code; } elsif ( $command eq "status" ) { print "check the status of the script .. OK \n"; # do nothing exit 0; } else { &usage(); exit 1; }}##############################################################################sub start_vip() { `ssh $ssh_user\@$new_master_host \" $ssh_start_vip \"`;}sub stop_vip() { return 0 unless ($ssh_user); `ssh $ssh_user\@$orig_master_host \" $ssh_stop_vip \"`;}##############################################################################sub usage { print"Usage: master_ip_failover --command=start|stop|stopssh|status --orig_master_host=host --orig_master_ip=ip --orig_master_port=port --new_master_host=host --new_master_ip=ip --new_master_port=port\n";}修改的主要内容是当master故障时，会触发脚本将master的vip停掉，在选出的新master上启动vip，并将read_only置为0使其可写。我们通过停掉10.10.10.58上的mysql进程，failover过程请看/var/log/masterha/manager.log
Wed Aug 12 11:00:25 2015 - [warning] shutdown_script is not defined.Wed Aug 12 11:00:25 2015 - [info] Set master ping interval 1 seconds.Wed Aug 12 11:00:25 2015 - [warning] secondary_check_script is not defined. It is highly recommended setting it to check master reachability from two or more routes.Wed Aug 12 11:00:25 2015 - [info] Starting ping health check on 10.10.10.58(10.10.10.58:3306)..Wed Aug 12 11:00:25 2015 - [info] Ping(SELECT) succeeded, waiting until MySQL doesn't respond..Wed Aug 12 11:01:00 2015 - [warning] Got error on MySQL select ping: 2006 (MySQL server has gone away)Wed Aug 12 11:01:01 2015 - [info] HealthCheck: SSH to 10.10.10.58 is reachable.Wed Aug 12 11:01:01 2015 - [warning] Got error on MySQL connect: 2013 (Lost connection to MySQL server at 'reading initial communication packet', system error: 111)Wed Aug 12 11:01:01 2015 - [warning] Connection failed 2 time(s)..Wed Aug 12 11:01:02 2015 - [warning] Got error on MySQL connect: 2013 (Lost connection to MySQL server at 'reading initial communication packet', system error: 111)Wed Aug 12 11:01:02 2015 - [warning] Connection failed 3 time(s)..Wed Aug 12 11:01:03 2015 - [warning] Got error on MySQL connect: 2013 (Lost connection to MySQL server at 'reading initial communication packet', system error: 111)Wed Aug 12 11:01:03 2015 - [warning] Connection failed 4 time(s)..Wed Aug 12 11:01:03 2015 - [warning] Master is not reachable from health checker!Wed Aug 12 11:01:03 2015 - [warning] Master 10.10.10.58(10.10.10.58:3306) is not reachable!Wed Aug 12 11:01:03 2015 - [warning] SSH is reachable.Wed Aug 12 11:01:03 2015 - [warning] Global configuration file /etc/masterha_default.cnf not found. Skipping.Wed Aug 12 11:01:03 2015 - [info] Reading application default configuration from /etc/mha/app1.cnf..Wed Aug 12 11:01:03 2015 - [info] Reading server configuration from /etc/mha/app1.cnf..Wed Aug 12 11:01:03 2015 - [info] GTID failover mode = 0Wed Aug 12 11:01:03 2015 - [info] Dead Servers:Wed Aug 12 11:01:03 2015 - [info] 10.10.10.58(10.10.10.58:3306)Wed Aug 12 11:01:03 2015 - [info] Alive Servers:Wed Aug 12 11:01:03 2015 - [info] 10.10.10.56(10.10.10.56:3306)Wed Aug 12 11:01:03 2015 - [info] 10.10.10.57(10.10.10.57:3306)Wed Aug 12 11:01:03 2015 - [info] Alive Slaves:Wed Aug 12 11:01:03 2015 - [info] 10.10.10.56(10.10.10.56:3306) Version=5.6.26-log (oldest major version between slaves) log-bin:enabledWed Aug 12 11:01:03 2015 - [info] Replicating from 10.10.10.58(10.10.10.58:3306)Wed Aug 12 11:01:03 2015 - [info] Not candidate for the new Master (no_master is set)Wed Aug 12 11:01:03 2015 - [info] 10.10.10.57(10.10.10.57:3306) Version=5.6.25-log (oldest major version between slaves) log-bin:enabledWed Aug 12 11:01:03 2015 - [info] Replicating from 10.10.10.58(10.10.10.58:3306)Wed Aug 12 11:01:03 2015 - [info] Primary candidate for the new Master (candidate_master is set)Wed Aug 12 11:01:03 2015 - [info] Checking slave configurations..Wed Aug 12 11:01:03 2015 - [warning] relay_log_purge=0 is not set on slave 10.10.10.56(10.10.10.56:3306).Wed Aug 12 11:01:03 2015 - [info] Checking replication filtering settings..Wed Aug 12 11:01:03 2015 - [info] Replication filtering check ok.Wed Aug 12 11:01:03 2015 - [info] Master is down!Wed Aug 12 11:01:03 2015 - [info] Terminating monitoring script.Wed Aug 12 11:01:03 2015 - [info] Got exit code 20 (Master dead).Wed Aug 12 11:01:03 2015 - [info] MHA::MasterFailover version 0.56.Wed Aug 12 11:01:03 2015 - [info] Starting master failover.Wed Aug 12 11:01:03 2015 - [info]Wed Aug 12 11:01:03 2015 - [info] * Phase 1: Configuration Check Phase..Wed Aug 12 11:01:03 2015 - [info]Wed Aug 12 11:01:04 2015 - [info] GTID failover mode = 0Wed Aug 12 11:01:04 2015 - [info] Dead Servers:Wed Aug 12 11:01:04 2015 - [info] 10.10.10.58(10.10.10.58:3306)Wed Aug 12 11:01:04 2015 - [info] Checking master reachability via MySQL(double check)...Wed Aug 12 11:01:04 2015 - [info] ok.Wed Aug 12 11:01:04 2015 - [info] Alive Servers:Wed Aug 12 11:01:04 2015 - [info] 10.10.10.56(10.10.10.56:3306)Wed Aug 12 11:01:04 2015 - [info] 10.10.10.57(10.10.10.57:3306)Wed Aug 12 11:01:04 2015 - [info] Alive Slaves:Wed Aug 12 11:01:04 2015 - [info] 10.10.10.56(10.10.10.56:3306) Version=5.6.26-log (oldest major version between slaves) log-bin:enabledWed Aug 12 11:01:04 2015 - [info] Replicating from 10.10.10.58(10.10.10.58:3306)Wed Aug 12 11:01:04 2015 - [info] Not candidate for the new Master (no_master is set)Wed Aug 12 11:01:04 2015 - [info] 10.10.10.57(10.10.10.57:3306) Version=5.6.25-log (oldest major version between slaves) log-bin:enabledWed Aug 12 11:01:04 2015 - [info] Starting Non-GTID based failover.Wed Aug 12 11:01:04 2015 - [info]Wed Aug 12 11:01:04 2015 - [info] ** Phase 1: Configuration Check Phase completed.Wed Aug 12 11:01:04 2015 - [info]Wed Aug 12 11:01:04 2015 - [info] * Phase 2: Dead Master Shutdown Phase..Wed Aug 12 11:01:04 2015 - [info]Wed Aug 12 11:01:04 2015 - [info] Forcing shutdown so that applications never connect to the current master..Wed Aug 12 11:01:04 2015 - [info] Executing master IP deactivation script:Wed Aug 12 11:01:04 2015 - [info] /usr/local/bin/master_ip_failover --orig_master_host=10.10.10.58 --orig_master_ip=10.10.10.58 --orig_master_port=3306 --command=stopssh --ssh_user=root script test ++++++ /sbin/ifconfig eth0:1 10.10.10.60 down+++/sbin/ifconfig eth0:1 10.10.10.60+++disable the VIP on old master: 10.10.10.58Wed Aug 12 11:01:04 2015 - [info] done.Wed Aug 12 11:01:04 2015 - [warning] shutdown_script is not set. Skipping explicit shutting down of the dead master.Wed Aug 12 11:01:04 2015 - [info] * Phase 3: Master Recovery Phase..Wed Aug 12 11:01:04 2015 - [info]Wed Aug 12 11:01:04 2015 - [info] * Phase 3.1: Getting Latest Slaves Phase..Wed Aug 12 11:01:04 2015 - [info]Wed Aug 12 11:01:04 2015 - [info] The latest binary log file/position on all slaves is mysql-bin.000008:120Wed Aug 12 11:01:04 2015 - [info] Latest slaves (Slaves that received relay log files to the latest):Wed Aug 12 11:01:04 2015 - [info] 10.10.10.56(10.10.10.56:3306) Version=5.6.26-log (oldest major version between slaves) log-bin:enabledWed Aug 12 11:01:04 2015 - [info] Replicating from 10.10.10.58(10.10.10.58:3306)Wed Aug 12 11:01:04 2015 - [info] Not candidate for the new Master (no_master is set)Wed Aug 12 11:01:04 2015 - [info] 10.10.10.57(10.10.10.57:3306) Version=5.6.25-log (oldest major version between slaves) log-bin:enabledWed Aug 12 11:01:04 2015 - [info] Replicating from 10.10.10.58(10.10.10.58:3306)Wed Aug 12 11:01:04 2015 - [info] Primary candidate for the new Master (candidate_master is set)Wed Aug 12 11:01:04 2015 - [info] The oldest binary log file/position on all slaves is mysql-bin.000008:120Wed Aug 12 11:01:04 2015 - [info] Oldest slaves:Wed Aug 12 11:01:04 2015 - [info] 10.10.10.56(10.10.10.56:3306) Version=5.6.26-log (oldest major version between slaves) log-bin:enabledWed Aug 12 11:01:04 2015 - [info] Replicating from 10.10.10.58(10.10.10.58:3306)Wed Aug 12 11:01:04 2015 - [info] Not candidate for the new Master (no_master is set)Wed Aug 12 11:01:04 2015 - [info] 10.10.10.57(10.10.10.57:3306) Version=5.6.25-log (oldest major version between slaves) log-bin:enabledWed Aug 12 11:01:04 2015 - [info] Replicating from 10.10.10.58(10.10.10.58:3306)Wed Aug 12 11:01:04 2015 - [info] Primary candidate for the new Master (candidate_master is set)Wed Aug 12 11:01:04 2015 - [info]Wed Aug 12 11:01:04 2015 - [info] * Phase 3.2: Saving Dead Master's Binlog Phase..Wed Aug 12 11:01:04 2015 - [info]Wed Aug 12 11:01:04 2015 - [info] Fetching dead master's binary logs.. Creating /tmp if not exists.. ok. Concat binary/relay logs from mysql-bin.000008 pos 120 to mysql-bin.000011 EOF into /tmp/saved_master_binlog_from_10.10.10.58_3306_20150812110103.binlog .. Binlog Checksum enabled Dumping binlog format description event, from position 0 to 120.. ok. Dumping effective binlog data from /data/mysql/mysql-bin.000008 position 120 to tail(143).. ok. Dumping binlog head events (rotate events), skipping format description events from /data/mysql/mysql-bin.000009.. Binlog Checksum enableddumped up to pos 120. ok.dumped up to pos 120. ok. Dumping effective binlog data from /data/mysql/mysql-bin.000010 position 120 to tail(143).. ok. Dumping binlog head events (rotate events), skipping format description events from /data/mysql/mysql-bin.000011.. Binlog Checksum enableddumped up to pos 120. ok. Dumping effective binlog data from /data/mysql/mysql-bin.000011 position 120 to tail(143).. ok. Binlog Checksum enabled Concat succeeded.Wed Aug 12 11:01:05 2015 - [info] HealthCheck: SSH to 10.10.10.56 is reachable.Wed Aug 12 11:01:05 2015 - [info] HealthCheck: SSH to 10.10.10.57 is reachable.Wed Aug 12 11:01:06 2015 - [info] Finding the latest slave that has all relay logs for recovering other slaves..Wed Aug 12 11:01:06 2015 - [info] All slaves received relay logs to the same position. No need to resync each other.Wed Aug 12 11:01:06 2015 - [info] Searching new master from slaves..Wed Aug 12 11:01:06 2015 - [info] Candidate masters from the configuration file:Wed Aug 12 11:01:06 2015 - [info] 10.10.10.57(10.10.10.57:3306) Version=5.6.25-log (oldest major version between slaves) log-bin:enabledWed Aug 12 11:01:06 2015 - [info] Replicating from 10.10.10.58(10.10.10.58:3306)Wed Aug 12 11:01:06 2015 - [info] Primary candidate for the new Master (candidate_master is set)Wed Aug 12 11:01:06 2015 - [info] Replicating from 10.10.10.58(10.10.10.58:3306)Wed Aug 12 11:01:06 2015 - [info] New master is 10.10.10.57(10.10.10.57:3306)Wed Aug 12 11:01:06 2015 - [info] Starting master failover..Wed Aug 12 11:01:06 2015 - [info]From:10.10.10.58(10.10.10.58:3306) (current master) +--10.10.10.56(10.10.10.56:3306) +--10.10.10.57(10.10.10.57:3306)To:10.10.10.57(10.10.10.57:3306) (new master) +--10.10.10.56(10.10.10.56:3306)Wed Aug 12 11:01:06 2015 - [info]Wed Aug 12 11:01:06 2015 - [info] * Phase 3.3: New Master Diff Log Generation Phase..Wed Aug 12 11:01:06 2015 - [info]Wed Aug 12 11:01:06 2015 - [info]Wed Aug 12 11:01:06 2015 - [info] * Phase 3.4: Master Log Apply Phase..Wed Aug 12 11:01:06 2015 - [info]Wed Aug 12 11:01:06 2015 - [info] *NOTICE: If any error happens from this phase, manual recovery is needed.Wed Aug 12 11:01:06 2015 - [info] Starting recovery on 10.10.10.57(10.10.10.57:3306)..Wed Aug 12 11:01:06 2015 - [info] Generating diffs succeeded.Wed Aug 12 11:01:06 2015 - [info] Waiting until all relay logs are applied.Wed Aug 12 11:01:06 2015 - [info] done.Wed Aug 12 11:01:06 2015 - [info] Getting slave status..Wed Aug 12 11:01:06 2015 - [info] This slave(10.10.10.57)'s Exec_Master_Log_Pos equals to Read_Master_Log_Pos(mysql-bin.000008:120). No need to recover from Exec_Master_Log_Pos.Wed Aug 12 11:01:06 2015 - [info] Connecting to the target slave host 10.10.10.57, running recover script..Wed Aug 12 11:01:06 2015 - [info]MySQL client version is 5.6.25. Using --binary-mode.Applying differential binary/relay log files /tmp/saved_master_binlog_from_10.10.10.58_3306_20150812110103.binlog on 10.10.10.57:3306. This may take long time...Applying log files succeeded.Wed Aug 12 11:01:06 2015 - [info] All relay logs were successfully applied.Wed Aug 12 11:01:06 2015 - [info] Getting new master's binlog name and position..Wed Aug 12 11:01:06 2015 - [info] mysql-bin.000010:120 script test ++++++ /sbin/ifconfig eth0:1 10.10.10.60 down+++/sbin/ifconfig eth0:1 10.10.10.60+++enable the VIP: 10.10.10.60 on the new master: 10.10.10.57Set read_only=0 on the new master.Wed Aug 12 11:01:06 2015 - [info] OK.Wed Aug 12 11:01:06 2015 - [info] ** Finished master recovery successfully.Wed Aug 12 11:01:06 2015 - [info] * Phase 3: Master Recovery Phase completed.Wed Aug 12 11:01:06 2015 - [info]Wed Aug 12 11:01:06 2015 - [info] * Phase 4: Slaves Recovery Phase..Wed Aug 12 11:01:06 2015 - [info]Wed Aug 12 11:01:06 2015 - [info] * Phase 4.1: Starting Parallel Slave Diff Log Generation Phase..Wed Aug 12 11:01:06 2015 - [info]Wed Aug 12 11:01:06 2015 - [info]Wed Aug 12 11:01:06 2015 - [info] Log messages from 10.10.10.56 ...Wed Aug 12 11:01:06 2015 - [info]Wed Aug 12 11:01:06 2015 - [info] This server has all relay logs. No need to generate diff files from the latest slave.Wed Aug 12 11:01:06 2015 - [info] End of log messages from 10.10.10.56.Wed Aug 12 11:01:06 2015 - [info] -- 10.10.10.56(10.10.10.56:3306) has the latest relay log events.Wed Aug 12 11:01:06 2015 - [info] Generating relay diff files from the latest slave succeeded.Wed Aug 12 11:01:06 2015 - [info]Wed Aug 12 11:01:06 2015 - [info] * Phase 4.2: Starting Parallel Slave Log Apply Phase..Wed Aug 12 11:01:06 2015 - [info]Wed Aug 12 11:01:06 2015 - [info] -- Slave recovery on host 10.10.10.56(10.10.10.56:3306) started, pid: 11795. Check tmp log /var/log/masterha/app1/10.10.10.56_3306_20150812110103.log if it takes time..Wed Aug 12 11:01:07 2015 - [info]Wed Aug 12 11:01:07 2015 - [info] Log messages from 10.10.10.56 ...Wed Aug 12 11:01:07 2015 - [info]Wed Aug 12 11:01:06 2015 - [info] Sending binlog..Wed Aug 12 11:01:07 2015 - [info] Starting recovery on 10.10.10.56(10.10.10.56:3306)..Wed Aug 12 11:01:07 2015 - [info] Generating diffs succeeded.Wed Aug 12 11:01:07 2015 - [info] Waiting until all relay logs are applied.Wed Aug 12 11:01:07 2015 - [info] done.Wed Aug 12 11:01:07 2015 - [info] Getting slave status..Wed Aug 12 11:01:07 2015 - [info] This slave(10.10.10.56)'s Exec_Master_Log_Pos equals to Read_Master_Log_Pos(mysql-bin.000008:120). No need to recover from Exec_Master_Log_Pos.Wed Aug 12 11:01:07 2015 - [info] Connecting to the target slave host 10.10.10.56, running recover script..Wed Aug 12 11:01:07 2015 - [info] Executing command: apply_diff_relay_logs --command=apply --slave_user='mha' --slave_host=10.10.10.56 --slave_ip=10.10.10.56 --slave_port=3306 --apply_files=/tmp/saved_master_binlog_from_10.10.10.58_3306_20150812110103.binlog --workdir=/tmp --target_version=5.6.26-log --timestamp=20150812110103 --handle_raw_binlog=1 --disable_log_bin=0 --manager_version=0.56 --slave_pass=xxxWed Aug 12 11:01:07 2015 - [info]MySQL client version is 5.6.26. Using --binary-mode.Applying differential binary/relay log files /tmp/saved_master_binlog_from_10.10.10.58_3306_20150812110103.binlog on 10.10.10.56:3306. This may take long time...Applying log files succeeded.Wed Aug 12 11:01:07 2015 - [info] All relay logs were successfully applied.Wed Aug 12 11:01:07 2015 - [info] Resetting slave 10.10.10.56(10.10.10.56:3306) and starting replication from the new master 10.10.10.57(10.10.10.57:3306)..Wed Aug 12 11:01:07 2015 - [info] Executed CHANGE MASTER.Wed Aug 12 11:01:07 2015 - [info] Slave started.Wed Aug 12 11:01:07 2015 - [info] End of log messages from 10.10.10.56.Wed Aug 12 11:01:07 2015 - [info] -- Slave recovery on host 10.10.10.56(10.10.10.56:3306) succeeded.Wed Aug 12 11:01:07 2015 - [info] All new slave servers recovered successfully.Wed Aug 12 11:01:07 2015 - [info]Wed Aug 12 11:01:07 2015 - [info] * Phase 5: New master cleanup phase..Wed Aug 12 11:01:07 2015 - [info]Wed Aug 12 11:01:07 2015 - [info] Resetting slave info on the new master..Wed Aug 12 11:01:07 2015 - [info] 10.10.10.57: Resetting slave info succeeded.Wed Aug 12 11:01:07 2015 - [info] Master failover to 10.10.10.57(10.10.10.57:3306) completed successfully.Wed Aug 12 11:01:07 2015 - [info] Deleted server3 entry from /etc/mha/app1.cnf .Wed Aug 12 11:01:07 2015 - [info]----- Failover Report -----app1: MySQL Master failover 10.10.10.58(10.10.10.58:3306) to 10.10.10.57(10.10.10.57:3306) succeededMaster 10.10.10.58(10.10.10.58:3306) is down!Check MHA Manager logs at rd-mysql-test4:/var/log/masterha/app1/manager.log for details.Started automated(non-interactive) failover.Invalidated master IP address on 10.10.10.58(10.10.10.58:3306)The latest slave 10.10.10.56(10.10.10.56:3306) has all relay logs for recovery.Selected 10.10.10.57(10.10.10.57:3306) as a new master.10.10.10.57(10.10.10.57:3306): OK: Applying all logs succeeded.10.10.10.57(10.10.10.57:3306): OK: Activated master IP address.10.10.10.56(10.10.10.56:3306): This host has the latest relay log events.Generating relay diff files from the latest slave succeeded.10.10.10.56(10.10.10.56:3306): OK: Applying all logs succeeded. Slave started, replicating from 10.10.10.57(10.10.10.57:3306)10.10.10.57(10.10.10.57:3306): Resetting slave info succeeded.Master failover to 10.10.10.57(10.10.10.57:3306) completed successfully.
当failover完成后，我们观察VIP已经在新的master上了。
[[email protected] mha4mysql-node-0.56]# ip a1: lo: <LOOPBACK,UP,LOWER_UP> mtu 16436 qdisc noqueue state UNKNOWN link/loopback 00:00:00:00:00:00 brd 00:00:00:00:00:00 inet 127.0.0.1/8 scope host lo inet6 ::1/128 scope host valid_lft forever preferred_lft forever2: eth0: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc mq state UP qlen 1000 link/ether 00:50:56:87:37:af brd ff:ff:ff:ff:ff:ff inet 10.10.10.57/16 brd 10.10.255.255 scope global eth0 inet 10.10.10.60/8 brd 10.255.255.255 scope global eth0:1 inet6 fe80::250:56ff:fe87:37af/64 scope link valid_lft forever preferred_lft forever注意：1.可能在生产环境中ssh端口不为22，通过在配置文件配置ssh_port=XXXX，由于版本的问题，某些脚本可能不支持非22端口。
2.引入vip后，我们需要修改master_ip_online_failover脚本，因为我们在使用masterha_master_switch实现切换时会在配置文件中配置master_ip_online_failover_script
4.master_ip_online_change
前面我们在使用masterha_master_swith实现master切换时会使用master_ip_online_failover进行锁表使老master不再写入数据从而实现在切换过程中数据库的一致性。在上面提到的ha环境中，failover过程中通过master_ip_failover实现vip漂移，但若在在线迁移过程中，就需要用到master_ip_online_change实现vip漂移了，当然还得需要我们修改脚本。
ps:仍然注释掉（FIXME_xxx_drop_app_user($orig_master_handler);FIXME_xxx_create_app_user($new_master_handler);）
修改后的脚本如下（修改处已用###标注）：
use strict;use warnings FATAL => 'all';use Getopt::Long;use MHA::DBHelper;use MHA::NodeUtil;use Time::HiRes qw( sleep gettimeofday tv_interval );use Data::Dumper;my $_tstart;my $_running_interval = 0.1;my ( $command, $orig_master_is_new_slave, $orig_master_host, $orig_master_ip, $orig_master_port, $orig_master_user, $orig_master_password, $orig_master_ssh_user, $new_master_host, $new_master_ip, $new_master_port, $new_master_user, $new_master_password, $new_master_ssh_user,);###########################################################################my $vip = '10.10.10.60';my $key = "1";my $ssh_start_vip = "/sbin/ifconfig eth0:$key $vip";my $ssh_stop_vip = "/sbin/ifconfig eth0:$key $vip down";###########################################################################GetOptions( 'command=s' => \$command, 'orig_master_is_new_slave' => \$orig_master_is_new_slave, 'orig_master_host=s' => \$orig_master_host, 'orig_master_ip=s' => \$orig_master_ip, 'orig_master_port=i' => \$orig_master_port, 'orig_master_user=s' => \$orig_master_user, 'orig_master_password=s' => \$orig_master_password, 'orig_master_ssh_user=s' => \$orig_master_ssh_user, 'new_master_host=s' => \$new_master_host, 'new_master_ip=s' => \$new_master_ip, 'new_master_port=i' => \$new_master_port, 'new_master_user=s' => \$new_master_user, 'new_master_password=s' => \$new_master_password, 'new_master_ssh_user=s' => \$new_master_ssh_user,);exit &main();sub current_time_us { my ( $sec, $microsec ) = gettimeofday(); my $curdate = localtime($sec); return $curdate . " " . sprintf( "%06d", $microsec );}sub sleep_until { my $elapsed = tv_interval($_tstart); if ( $_running_interval > $elapsed ) { sleep( $_running_interval - $elapsed ); }}sub get_threads_util { my $dbh = shift; my $my_connection_id = shift; my $running_time_threshold = shift; my $type = shift; $running_time_threshold = 0 unless ($running_time_threshold); $type = 0 unless ($type); my @threads; my $sth = $dbh->prepare("SHOW PROCESSLIST"); $sth->execute(); while ( my $ref = $sth->fetchrow_hashref() ) { my $id = $ref->{Id}; my $user = $ref->{User}; my $host = $ref->{Host}; my $command = $ref->{Command}; my $state = $ref->{State}; my $query_time = $ref->{Time}; my $info = $ref->{Info}; $info =~ s/^\s*(.*?)\s*$/$1/ if defined($info); next if ( $my_connection_id == $id ); next if ( defined($query_time) && $query_time < $running_time_threshold ); next if ( defined($command) && $command eq "Binlog Dump" ); next if ( defined($user) && $user eq "system user" ); next if ( defined($command) && $command eq "Sleep" && defined($query_time) && $query_time >= 1 ); if ( $type >= 1 ) { next if ( defined($command) && $command eq "Sleep" ); next if ( defined($command) && $command eq "Connect" ); } if ( $type >= 2 ) { next if ( defined($info) && $info =~ m/^select/i ); next if ( defined($info) && $info =~ m/^show/i ); } push @threads, $ref; } return @threads;}sub main { if ( $command eq "stop" ) { ## Gracefully killing connections on the current master # 1. Set read_only= 1 on the new master # 2. DROP USER so that no app user can establish new connections # 3. Set read_only= 1 on the current master # 4. Kill current queries # * Any database access failure will result in script die. my $exit_code = 1; eval { ## Setting read_only=1 on the new master (to avoid accident) my $new_master_handler = new MHA::DBHelper(); # args: hostname, port, user, password, raise_error(die_on_error)_or_not $new_master_handler->connect( $new_master_ip, $new_master_port, $new_master_user, $new_master_password, 1 ); print current_time_us() . " Set read_only on the new master.. "; $new_master_handler->enable_read_only(); if ( $new_master_handler->is_read_only() ) { print "ok.\n"; } else { die "Failed!\n"; } $new_master_handler->disconnect(); # Connecting to the orig master, die if any database error happens my $orig_master_handler = new MHA::DBHelper(); $orig_master_handler->connect( $orig_master_ip, $orig_master_port, $orig_master_user, $orig_master_password, 1 ); ## Drop application user so that nobody can connect. Disabling per-session binlog beforehand $orig_master_handler->disable_log_bin_local(); print current_time_us() . " Drpping app user on the orig master..\n";########################################################################### #FIXME_xxx_drop_app_user($orig_master_handler);########################################################################### ## Waiting for N * 100 milliseconds so that current connections can exit my $time_until_read_only = 15; $_tstart = [gettimeofday]; my @threads = get_threads_util( $orig_master_handler->{dbh}, $orig_master_handler->{connection_id} ); while ( $time_until_read_only > 0 && $#threads >= 0 ) { if ( $time_until_read_only % 5 == 0 ) { printf"%s Waiting all running %d threads are disconnected.. (max %d milliseconds)\n", current_time_us(), $#threads + 1, $time_until_read_only * 100; if ( $#threads < 5 ) { print Data::Dumper->new( [$_] )->Indent(0)->Terse(1)->Dump . "\n" foreach (@threads); } } sleep_until(); $_tstart = [gettimeofday]; $time_until_read_only--; @threads = get_threads_util( $orig_master_handler->{dbh}, $orig_master_handler->{connection_id} ); } ## Setting read_only=1 on the current master so that nobody(except SUPER) can write print current_time_us() . " Set read_only=1 on the orig master.. "; $orig_master_handler->enable_read_only(); if ( $orig_master_handler->is_read_only() ) { print "ok.\n"; } else { die "Failed!\n"; } ## Waiting for M * 100 milliseconds so that current update queries can complete my $time_until_kill_threads = 5; @threads = get_threads_util( $orig_master_handler->{dbh}, $orig_master_handler->{connection_id} ); while ( $time_until_kill_threads > 0 && $#threads >= 0 ) { if ( $time_until_kill_threads % 5 == 0 ) { printf"%s Waiting all running %d queries are disconnected.. (max %d milliseconds)\n", current_time_us(), $#threads + 1, $time_until_kill_threads * 100; if ( $#threads < 5 ) { print Data::Dumper->new( [$_] )->Indent(0)->Terse(1)->Dump . "\n" foreach (@threads); } } sleep_until(); $_tstart = [gettimeofday]; $time_until_kill_threads--; @threads = get_threads_util( $orig_master_handler->{dbh}, $orig_master_handler->{connection_id} ); }########################################################################### print "disable the VIP on old master: $orig_master_host \n"; &stop_vip();########################################################################### ## Terminating all threads print current_time_us() . " Killing all application threads..\n"; $orig_master_handler->kill_threads(@threads) if ( $#threads >= 0 ); print current_time_us() . " done.\n"; $orig_master_handler->enable_log_bin_local(); $orig_master_handler->disconnect(); ## After finishing the script, MHA executes FLUSH TABLES WITH READ LOCK $exit_code = 0; }; if ($@) { warn "Got Error: $@\n"; exit $exit_code; } exit $exit_code; } elsif ( $command eq "start" ) { ## Activating master ip on the new master # 1. Create app user with write privileges # 2. Moving backup script if needed # 3. Register new master's ip to the catalog database my $exit_code = 10; eval { my $new_master_handler = new MHA::DBHelper(); # args: hostname, port, user, password, raise_error_or_not $new_master_handler->connect( $new_master_ip, $new_master_port, $new_master_user, $new_master_password, 1 ); ## Set read_only=0 on the new master $new_master_handler->disable_log_bin_local(); print current_time_us() . " Set read_only=0 on the new master.\n"; $new_master_handler->disable_read_only(); ## Creating an app user on the new master print current_time_us() . " Creating app user on the new master..\n";########################################################################### #FIXME_xxx_create_app_user($new_master_handler);########################################################################### $new_master_handler->enable_log_bin_local(); $new_master_handler->disconnect(); ## Update master ip on the catalog database, etc############################################################################### print "enable the VIP: $vip on the new master: $new_master_host \n "; &start_vip();############################################################################### $exit_code = 0; }; if ($@) { warn "Got Error: $@\n"; exit $exit_code; } exit $exit_code; } elsif ( $command eq "status" ) { # do nothing exit 0; } else { &usage(); exit 1; }}###########################################################################sub start_vip() { `ssh $new_master_ssh_user\@$new_master_host \" $ssh_start_vip \"`;}sub stop_vip() { `ssh $orig_master_ssh_user\@$orig_master_host \" $ssh_stop_vip \"`;}###########################################################################sub usage { print"Usage: master_ip_online_change --command=start|stop|status --orig_master_host=host --orig_master_ip=ip --orig_master_port=port --new_master_host=host --new_master_ip=ip --new_master_port=port\n"; die;}过程如下：[[email protected] mha]# masterha_master_switch --master_state=alive --conf=/etc/mha/app1.cnf --new_master_host=10.10.10.56 --orig_master_is_new_slave --running_updates_limit=1000000Wed Aug 12 14:11:23 2015 - [info] MHA::MasterRotate version 0.56.Wed Aug 12 14:11:23 2015 - [info] Starting online master switch..Wed Aug 12 14:11:23 2015 - [info] Wed Aug 12 14:11:23 2015 - [info] * Phase 1: Configuration Check Phase..Wed Aug 12 14:11:23 2015 - [info] Wed Aug 12 14:11:23 2015 - [warning] Global configuration file /etc/masterha_default.cnf not found. Skipping.Wed Aug 12 14:11:23 2015 - [info] Reading application default configuration from /etc/mha/app1.cnf..Wed Aug 12 14:11:23 2015 - [info] Reading server configuration from /etc/mha/app1.cnf..Wed Aug 12 14:11:23 2015 - [info] GTID failover mode = 0Wed Aug 12 14:11:23 2015 - [info] Current Alive Master: 10.10.10.57(10.10.10.57:3306)Wed Aug 12 14:11:23 2015 - [info] Alive Slaves:Wed Aug 12 14:11:23 2015 - [info] 10.10.10.56(10.10.10.56:3306) Version=5.6.26-log (oldest major version between slaves) log-bin:enabledWed Aug 12 14:11:23 2015 - [info] Replicating from 10.10.10.57(10.10.10.57:3306)Wed Aug 12 14:11:23 2015 - [info] 10.10.10.58(10.10.10.58:3306) Version=5.6.25-log (oldest major version between slaves) log-bin:enabledWed Aug 12 14:11:23 2015 - [info] Replicating from 10.10.10.57(10.10.10.57:3306)Wed Aug 12 14:11:23 2015 - [info] Primary candidate for the new Master (candidate_master is set)It is better to execute FLUSH NO_WRITE_TO_BINLOG TABLES on the master before switching. Is it ok to execute on 10.10.10.57(10.10.10.57:3306)? (YES/no): yesWed Aug 12 14:11:24 2015 - [info] Executing FLUSH NO_WRITE_TO_BINLOG TABLES. This may take long time..Wed Aug 12 14:11:24 2015 - [info] ok.Wed Aug 12 14:11:24 2015 - [info] Checking MHA is not monitoring or doing failover..Wed Aug 12 14:11:24 2015 - [info] Checking replication health on 10.10.10.56..Wed Aug 12 14:11:24 2015 - [info] ok.Wed Aug 12 14:11:24 2015 - [info] Checking replication health on 10.10.10.58..Wed Aug 12 14:11:24 2015 - [info] ok.Wed Aug 12 14:11:24 2015 - [info] 10.10.10.56 can be new master.Wed Aug 12 14:11:24 2015 - [info] From:10.10.10.57(10.10.10.57:3306) (current master) +--10.10.10.56(10.10.10.56:3306) +--10.10.10.58(10.10.10.58:3306)To:10.10.10.56(10.10.10.56:3306) (new master) +--10.10.10.58(10.10.10.58:3306) +--10.10.10.57(10.10.10.57:3306)Starting master switch from 10.10.10.57(10.10.10.57:3306) to 10.10.10.56(10.10.10.56:3306)? (yes/NO): yesWed Aug 12 14:11:25 2015 - [info] Checking whether 10.10.10.56(10.10.10.56:3306) is ok for the new master..Wed Aug 12 14:11:25 2015 - [info] ok.Wed Aug 12 14:11:25 2015 - [info] 10.10.10.57(10.10.10.57:3306): SHOW SLAVE STATUS returned empty result. To check replication filtering rules, temporarily executing CHANGE MASTER to a dummy host.Wed Aug 12 14:11:25 2015 - [info] 10.10.10.57(10.10.10.57:3306): Resetting slave pointing to the dummy host.Wed Aug 12 14:11:25 2015 - [info] ** Phase 1: Configuration Check Phase completed.Wed Aug 12 14:11:25 2015 - [info] Wed Aug 12 14:11:25 2015 - [info] * Phase 2: Rejecting updates Phase..Wed Aug 12 14:11:25 2015 - [info] Wed Aug 12 14:11:25 2015 - [info] Executing master ip online change script to disable write on the current master:Wed Aug 12 14:11:25 2015 - [info] /usr/local/bin/master_ip_online_change --command=stop --orig_master_host=10.10.10.57 --orig_master_ip=10.10.10.57 --orig_master_port=3306 --orig_master_user='mha' --orig_master_password='123456' --new_master_host=10.10.10.56 --new_master_ip=10.10.10.56 --new_master_port=3306 --new_master_user='mha' --new_master_password='123456' --orig_master_ssh_user=root --new_master_ssh_user=root --orig_master_is_new_slaveWed Aug 12 14:11:25 2015 710013 Set read_only on the new master.. ok.Wed Aug 12 14:11:25 2015 711731 Drpping app user on the orig master..Wed Aug 12 14:11:25 2015 712040 Waiting all running 1 threads are disconnected.. (max 1500 milliseconds){'Time' => '415248','Command' => 'Daemon','db' => undef,'Id' => '1','Info' => undef,'User' => 'event_scheduler','State' => 'Waiting on empty queue','Host' => 'localhost'}Wed Aug 12 14:11:26 2015 215501 Waiting all running 1 threads are disconnected.. (max 1000 milliseconds){'Time' => '415248','Command' => 'Daemon','db' => undef,'Id' => '1','Info' => undef,'User' => 'event_scheduler','State' => 'Waiting on empty queue','Host' => 'localhost'}Wed Aug 12 14:11:26 2015 713698 Waiting all running 1 threads are disconnected.. (max 500 milliseconds){'Time' => '415249','Command' => 'Daemon','db' => undef,'Id' => '1','Info' => undef,'User' => 'event_scheduler','State' => 'Waiting on empty queue','Host' => 'localhost'}Wed Aug 12 14:11:27 2015 214327 Set read_only=1 on the orig master.. ok.Wed Aug 12 14:11:27 2015 214975 Waiting all running 1 queries are disconnected.. (max 500 milliseconds){'Time' => '415249','Command' => 'Daemon','db' => undef,'Id' => '1','Info' => undef,'User' => 'event_scheduler','State' => 'Waiting on empty queue','Host' => 'localhost'}disable the VIP on old master: 10.10.10.57 Wed Aug 12 14:11:27 2015 790437 Killing all application threads..Wed Aug 12 14:11:27 2015 791066 done.Wed Aug 12 14:11:27 2015 - [info] ok.Wed Aug 12 14:11:27 2015 - [info] Locking all tables on the orig master to reject updates from everybody (including root):Wed Aug 12 14:11:27 2015 - [info] Executing FLUSH TABLES WITH READ LOCK..Wed Aug 12 14:11:27 2015 - [info] ok.Wed Aug 12 14:11:27 2015 - [info] Orig master binlog:pos is mysql-bin.000010:120.Wed Aug 12 14:11:27 2015 - [info] Waiting to execute all relay logs on 10.10.10.56(10.10.10.56:3306)..Wed Aug 12 14:11:27 2015 - [info] master_pos_wait(mysql-bin.000010:120) completed on 10.10.10.56(10.10.10.56:3306). Executed 0 events.Wed Aug 12 14:11:27 2015 - [info] done.Wed Aug 12 14:11:27 2015 - [info] Getting new master's binlog name and position..Wed Aug 12 14:11:27 2015 - [info] mysql-bin.000008:120Wed Aug 12 14:11:27 2015 - [info] All other slaves should start replication from here. Statement should be: CHANGE MASTER TO MASTER_HOST='10.10.10.56', MASTER_PORT=3306, MASTER_LOG_FILE='mysql-bin.000008', MASTER_LOG_POS=120, MASTER_USER='rep', MASTER_PASSWORD='xxx';Wed Aug 12 14:11:27 2015 - [info] Executing master ip online change script to allow write on the new master:Wed Aug 12 14:11:27 2015 - [info] /usr/local/bin/master_ip_online_change --command=start --orig_master_host=10.10.10.57 --orig_master_ip=10.10.10.57 --orig_master_port=3306 --orig_master_user='mha' --orig_master_password='123456' --new_master_host=10.10.10.56 --new_master_ip=10.10.10.56 --new_master_port=3306 --new_master_user='mha' --new_master_password='123456' --orig_master_ssh_user=root --new_master_ssh_user=root --orig_master_is_new_slaveWed Aug 12 14:11:27 2015 863530 Set read_only=0 on the new master.Wed Aug 12 14:11:27 2015 863991 Creating app user on the new master..enable the VIP: 10.10.10.60 on the new master: 10.10.10.56 Wed Aug 12 14:11:27 2015 - [info] ok.Wed Aug 12 14:11:27 2015 - [info] Wed Aug 12 14:11:27 2015 - [info] * Switching slaves in parallel..Wed Aug 12 14:11:27 2015 - [info] Wed Aug 12 14:11:27 2015 - [info] -- Slave switch on host 10.10.10.58(10.10.10.58:3306) started, pid: 12018Wed Aug 12 14:11:27 2015 - [info] Wed Aug 12 14:11:28 2015 - [info] Log messages from 10.10.10.58 ...Wed Aug 12 14:11:28 2015 - [info] Wed Aug 12 14:11:27 2015 - [info] Waiting to execute all relay logs on 10.10.10.58(10.10.10.58:3306)..Wed Aug 12 14:11:27 2015 - [info] master_pos_wait(mysql-bin.000010:120) completed on 10.10.10.58(10.10.10.58:3306). Executed 0 events.Wed Aug 12 14:11:27 2015 - [info] done.Wed Aug 12 14:11:27 2015 - [info] Resetting slave 10.10.10.58(10.10.10.58:3306) and starting replication from the new master 10.10.10.56(10.10.10.56:3306)..Wed Aug 12 14:11:27 2015 - [info] Executed CHANGE MASTER.Wed Aug 12 14:11:27 2015 - [info] Slave started.Wed Aug 12 14:11:28 2015 - [info] End of log messages from 10.10.10.58 ...Wed Aug 12 14:11:28 2015 - [info] Wed Aug 12 14:11:28 2015 - [info] -- Slave switch on host 10.10.10.58(10.10.10.58:3306) succeeded.Wed Aug 12 14:11:28 2015 - [info] Unlocking all tables on the orig master:Wed Aug 12 14:11:28 2015 - [info] Executing UNLOCK TABLES..Wed Aug 12 14:11:28 2015 - [info] ok.Wed Aug 12 14:11:28 2015 - [info] Starting orig master as a new slave..Wed Aug 12 14:11:28 2015 - [info] Resetting slave 10.10.10.57(10.10.10.57:3306) and starting replication from the new master 10.10.10.56(10.10.10.56:3306)..Wed Aug 12 14:11:28 2015 - [info] Executed CHANGE MASTER.Wed Aug 12 14:11:28 2015 - [info] Slave started.Wed Aug 12 14:11:28 2015 - [info] All new slave servers switched successfully.Wed Aug 12 14:11:28 2015 - [info] Wed Aug 12 14:11:28 2015 - [info] * Phase 5: New master cleanup phase..Wed Aug 12 14:11:28 2015 - [info] Wed Aug 12 14:11:28 2015 - [info] 10.10.10.56: Resetting slave info succeeded.Wed Aug 12 14:11:28 2015 - [info] Switching master to 10.10.10.56(10.10.10.56:3306) completed successfully.注：1.在执行过程中若报一下错误：
Wed Aug 12 14:05:12 2015 - [error][/usr/local/share/perl5/MHA/MasterRotate.pm, ln262] We should not start online master switch when one of connections are running long queries on the new master(10.10.10.56(10.10.10.56:3306)). Currently 1 thread(s) are running.Details:{'Time' => '93075','Command' => 'Daemon','db' => undef,'Id' => '29','Info' => undef,'User' => 'event_scheduler','State' => 'Waiting on empty queue','Host' => 'localhost'}Wed Aug 12 14:05:12 2015 - [error][/usr/local/share/perl5/MHA/ManagerUtil.pm, ln177] Got ERROR: at /usr/local/bin/masterha_master_switch line 53这是由于new master上的event_scheduler导致，我们可以临时关闭下event_scheduler通过set global event_scheduler=0;待迁移完成后再开启。
2.此过程中的注意事项请参考上面masterha_master_switch调用master_ip_online_change
好了，内容不少，需要我们自己慢慢消化。
可以参考官网：https://code.google.com/p/mysql-master-ha/wiki/Parameters
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