本文实例讲述了MHA实现mysql主从数据库手动切换的方法，分享给大家供大家参考。具体方法如下：
一、准备工作
1、分别在Master和Slave执行如下,方便mha检查复制:
grant all privileges on *.* to 'root'@'10.1.1.234' identified by 'rootpass';
grant replication slave on *.* to 'jpsync'@'10.1.1.231' identified by 'jppasswd';
grant replication slave on *.* to 'jpsync'@'10.1.1.234' identified by 'jppasswd';
flush privileges;</div>
2、将master设置为只读
Query OK, 0 rows affected (0.00 sec)
mysql> show variables like 'read_only';
+---------------+-------+
| Variable_name | Value |
+---------------+-------+
| read_only | ON |
+---------------+-------+
1 row in set (0.00 sec)</div>
交互模式:
或非交互模式:
二、切换完以后，如何让10.1.1.231为主，10.1.1.234为从，操作步骤:
1、主上执行:
+-------------------------+----------+--------------+--------------------------------------+-------------------+
| File | Position | Binlog_Do_DB | Binlog_Ignore_DB | Executed_Gtid_Set |
+-------------------------+----------+--------------+--------------------------------------+-------------------+
| mysql-master-bin.000013 | 120 | denovo_ng | mysql,denovo,test,information_schema | |
+-------------------------+----------+--------------+--------------------------------------+-------------------+
1 row in set (0.00 sec)</div>
2、在10.1.1.234上执行如下sql命令；
master_password='jppasswd', master_log_file='mysql-master-bin.000013',master_log_pos=120;
mysql> show slave status＼G;
*************************** 1. row ***************************
Slave_IO_State: Waiting for master to send event
Master_Host: 10.1.1.231
Master_User: jpsync
Master_Port: 63306
Connect_Retry: 60
Master_Log_File: mysql-master-bin.000013
Read_Master_Log_Pos: 120
Relay_Log_File: compute-0-52-relay-bin.000002
Relay_Log_Pos: 290
Relay_Master_Log_File: mysql-master-bin.000013
Slave_IO_Running: Yes
Slave_SQL_Running: Yes</div>
3、查看master状态，并测试
+-----------+------+-------+-----------+--------------------------------------+
| Server_id | Host | Port | Master_id | Slave_UUID |
+-----------+------+-------+-----------+--------------------------------------+
| 1052 | | 63306 | 1025 | e25a3e4a-39c0-11e4-80cb-00259086c4b6 |
+-----------+------+-------+-----------+--------------------------------------+
1 row in set (0.00 sec)</div>
主库10.1.1.231上插入记录
Query OK, 1 row affected (0.00 sec)</div>
从库查询记录已经存在
+-----------+-----+-----------+--------------+----------+----------------+--------------+
| id | tag | ticket_id | candidate_id | duration | source_file_id | source_start |
+-----------+-----+-----------+--------------+----------+----------------+--------------+
| 555551111 | 1 | 55555 | 99999 | 44.11 | 2222 | 91919 |
+-----------+-----+-----------+--------------+----------+----------------+--------------+