MySQL:主从切换


          MySQL:主从复制(Replication)搭建  介绍了 MySQL 主从配置过程,这篇 blog 介绍手工主从切换过程。
 
一 环境信息
主库  192.168.2.37/3306     主机名 db1
备库  192.168.2.38/3306     主机名 db2
版本  5.6.20
备注: 主从节点 mysql 安装略,Replication 安装略。


二 主从切换
--主,备节点都要创建 Replication 用户

 
 

create user 'rep1'@'192.168.2.%' identified by 'rep1abcd1243d';GRANT REPLICATION SLAVE ON *.* TO 'rep1'@'192.168.2.%';


--查询从库状态

 
 

root@localhost:francs>show slave status\G


--查询主库状态

 
 

root@localhost:francs>show slave hosts;+-----------+-------------------+------+-----------+--------------------------------------+| Server_id | Host              | Port | Master_id | Slave_UUID                           |+-----------+-------------------+------+-----------+--------------------------------------+|         2 | 192.168.2.38(db2) | 3306 |         1 | ad397a06-7c56-11e4-b2fb-000c29dcb3b5 |+-----------+-------------------+------+-----------+--------------------------------------+1 row in set (0.00 sec)


--从库: 停止 IO_THREAD 线程

 
 

root@localhost:francs>stop slave IO_THREAD;root@localhost:francs>show slave status\G*************************** 1. row ***************************               Slave_IO_State:                   Master_Host: 192.168.2.37                  Master_User: rep1                  Master_Port: 3306                Connect_Retry: 60              Master_Log_File: bin-log.000001          Read_Master_Log_Pos: 362               Relay_Log_File: db2-relay-bin.000002                Relay_Log_Pos: 523        Relay_Master_Log_File: bin-log.000001             Slave_IO_Running: No            Slave_SQL_Running: Yes              Replicate_Do_DB:           Replicate_Ignore_DB:            Replicate_Do_Table:        Replicate_Ignore_Table:       Replicate_Wild_Do_Table:   Replicate_Wild_Ignore_Table:                    Last_Errno: 0                   Last_Error:                  Skip_Counter: 0          Exec_Master_Log_Pos: 362              Relay_Log_Space: 694              Until_Condition: None               Until_Log_File:                 Until_Log_Pos: 0           Master_SSL_Allowed: No           Master_SSL_CA_File:            Master_SSL_CA_Path:               Master_SSL_Cert:             Master_SSL_Cipher:                Master_SSL_Key:         Seconds_Behind_Master: NULLMaster_SSL_Verify_Server_Cert: No                Last_IO_Errno: 0                Last_IO_Error:                Last_SQL_Errno: 0               Last_SQL_Error:   Replicate_Ignore_Server_Ids:              Master_Server_Id: 1                  Master_UUID: 0c130d47-22bb-11e4-aaaa-000c2986ac80             Master_Info_File: mysql.slave_master_info                    SQL_Delay: 0          SQL_Remaining_Delay: NULL      Slave_SQL_Running_State: Slave has read all relay log; waiting for the slave I/O thread to update it           Master_Retry_Count: 86400                  Master_Bind:       Last_IO_Error_Timestamp:      Last_SQL_Error_Timestamp:                Master_SSL_Crl:            Master_SSL_Crlpath:            Retrieved_Gtid_Set:             Executed_Gtid_Set:                 Auto_Position: 01 row in set (0.00 sec)


--激活从库(从库上操作)

 
 

root@localhost:francs>stop slave;root@localhost:francs>reset master;root@localhost:francs>reset slave all;root@localhost:francs>show binary logs;+----------------+-----------+| Log_name       | File_size |+----------------+-----------+| bin-log.000001 |       120 |+----------------+-----------+1 row in set (0.00 sec)

备注:reset slave all 命令会删除从库的 replication 参数,之后 show slave status\G 的信息返回为空。

--将原来主库变为从库

 
 

  CHANGE MASTER TO   MASTER_HOST='192.168.2.38',   MASTER_PORT=3306,   MASTER_USER='rep1',   MASTER_PASSWORD='rep1abcd1243d',   MASTER_LOG_FILE='bin-log.000001',   MASTER_LOG_POS=120;   root@localhost:francs>start slave;root@localhost:francs show slave status\G

备注:这步执行之后,发现 db1 日志文件报了以下错误,提示 db1 连接不上 db2。

--db1 日志报错

 
 

2015-03-02 14:24:14 26198 [ERROR] Slave I/O: error connecting to master '[email protected]:3306' - retry-time: 60  retries: 8, Error_code: 1045


--解决过程

 
 

--连接测试[mysql@db1 ~]$ mysql -h 192.168.2.38 -P 3306 -urep1 备注:居然不需要密码能直接能连上。--测试匿名用户[mysql@db1 ~]$ mysql -h 192.168.2.38 -P 3306 -urep2 备注:依然不需要密码。--原因分析root@localhost:francs>select Host,User,Password from mysql.user where User='';+-----------+------+----------+| Host      | User | Password |+-----------+------+----------+| localhost |      |          || db1       |      |          |+-----------+------+----------+备注: 原来 db2 节点上存在 User 为空的的两行,表示匿名用户可以连接数据库, 删除这两行,之后  flush privileges;--再连接测试[mysql@db1 ~]$ mysql -h 192.168.2.38 -P 3306 -urep1 备注:这次连接需要密码了。之后再次观看 db1 同步日志,不再报错。



三 数据验证
             主从切换后db2 为主节点, db1 为备节点,在 db2 节点上插入一条数据测试同步是否正常。
   
--db2 上执行

 
 

root@localhost:francs>insert into test_sr(id) values(30);Query OK, 1 row affected (0.03 sec)root@localhost:francs>select * from test_sr order by id desc limit 1;+------+---------------------+| id   | create_time         |+------+---------------------+|   30 | 2015-03-02 15:19:53 |+------+---------------------+1 row in set (0.00 sec)


--db1 上验证

 
 

root@localhost:francs>select * from test_sr order by id desc limit 1;+------+---------------------+| id   | create_time         |+------+---------------------+|   30 | 2015-03-02 15:19:53 |+------+---------------------+1 row in set (0.00 sec)

备注:数据同步正常,以上是对 MySQL 主备切换的初次了解,后续再补充。


四 参考

  • MySQL:主从复制(Replication)搭建

  • RESET SLAVE

  • RESET MASTER

  • mysql主从切换

出处http://francs3.blog.163.com/blog/static/405767272015224150620/

你可能感兴趣的:(mysql,status,Blog,create,identified)