手动failover，这种场景意味着在业务上没有启用MHA自动切换功能，当主服务器故障时，人工手动调用MHA来进行故障切换操作，具体命令如下：
• 先关闭mha进程，确保不会自动执行切换
[root@mycat ~]# masterha_stop --conf=/etc/app1.cnf
• 再关闭maser主库
[root@master ~]# /etc/init.d/mysql.server stop
Shutting down MySQL............ SUCCESS!
• 执行手动切换
[root@mycat ~]# masterha_master_switch--master_state=dead --conf=/etc/app1.cnf --
dead_master_host=master --dead_master_port=3308--new_master_ip=192.168.237.131 --
new_master_port=3308
……
----- Failover Report -----
app1: MySQL Master failover master to slave1 succeeded
Master master is down!
Check MHA Manager logs at mycat for details.
Started manual(interactive) failover.
The latest slave slave1(192.168.237.130:3308) has allrelay logs for recovery.
Selected slave1 as a new master.
slave1: OK: Applying all logs succeeded.
slave2: This host has the latest relay log events.
Generating relay diff files from the latest slavesucceeded.
slave2: OK: Applying all logs succeeded. Slavestarted, replicating from slave1.
slave1: Resetting slave info succeeded.
Master failover to slave1(192.168.237.130:3308)completed successfully.