MySQL的GTID复制与传统复制的相互转换
1. GTID复制转换成传统复制 1.1 环境准备1.2 停止slave1.3 查看当前主从状态1.4 change master1.5 启动主从复制1.6 在线关闭主从服务器的GTID2. 传统复制转换成GTID复制 2.1 环境准备2.2 将enforce_gtid_consistency设置为warn2.3 将enforce_gtid_consistency设置为on2.4 设置GTID模式为off_permissive2.5 设置GTID模式为on_permissive2.6 检查从库Ongoing_anonymous_transaction_count状态值2.7 确保所有的匿名事务已经被完全复制到所有的slave上2.8 设置GTID_MODE为on2.9 change master1. GTID复制转换成传统复制
上篇博文已经介绍了MySQL 5.7版本的GTID复制模式的搭建，下面操作将GTID复制转换成传统复制模式。
1.1 环境准备
1.2 停止slave
root@localhost [(none)] 09:38:41>stop slave
1.3 查看当前主从状态
记录Relay_Master_Log_File和Exec_Master_Log_Pos信息。
root@localhost [(none)] 09:41:22>show slave status\G*************************** 1. row ***************************Slave_IO_State: Master_Host: 192.168.56.100Master_User: replMaster_Port: 3307Connect_Retry: 60Master_Log_File: my3307_binlog.000005Read_Master_Log_Pos: 194Relay_Log_File: mysqldb2-relay-bin.000010Relay_Log_Pos: 375Relay_Master_Log_File: my3307_binlog.000005Slave_IO_Running: NoSlave_SQL_Running: NoReplicate_Do_DB: Replicate_Ignore_DB: Replicate_Do_Table: Replicate_Ignore_Table: Replicate_Wild_Do_Table: Replicate_Wild_Ignore_Table: Last_Errno: 0Last_Error: Skip_Counter: 0Exec_Master_Log_Pos: 194Relay_Log_Space: 585Until_Condition: NoneUntil_Log_File: Until_Log_Pos: 0Master_SSL_Allowed: NoMaster_SSL_CA_File: Master_SSL_CA_Path: Master_SSL_Cert: Master_SSL_Cipher: Master_SSL_Key: Seconds_Behind_Master: NULLMaster_SSL_Verify_Server_Cert: NoLast_IO_Errno: 0Last_IO_Error: Last_SQL_Errno: 0Last_SQL_Error: Replicate_Ignore_Server_Ids: Master_Server_Id: 1003307Master_UUID: 3a068bf8-cdeb-11e8-8176-080027b0b461Master_Info_File: mysql.slave_master_infoSQL_Delay: 0SQL_Remaining_Delay: NULLSlave_SQL_Running_State: Master_Retry_Count: 86400Master_Bind: Last_IO_Error_Timestamp: Last_SQL_Error_Timestamp: Master_SSL_Crl: Master_SSL_Crlpath: Retrieved_Gtid_Set: Executed_Gtid_Set: 3a068bf8-cdeb-11e8-8176-080027b0b461:1-12Auto_Position: 1Replicate_Rewrite_DB: Channel_Name: Master_TLS_Version: 1 row in set (0.00 sec)
1.4 change master
根据上面记录的Relay_Master_Log_File和Exec_Master_Log_Pos信息，change master：
root@localhost [(none)] 09:41:26>change master to master_log_file='my3307_binlog.000005',master_log_pos=194,master_auto_position=0;Query OK, 0 rows affected (0.01 sec)#参数解释：master_auto_position=0 表示禁用master_auto_position
1.5 启动主从复制
root@localhost [test] 09:51:28>start slave;
1.6 在线关闭主从服务器的GTID
root@localhost [test] 09:55:01> set global gtid_mode=on_permissive;Query OK, 0 rows affected (0.01 sec)root@localhost [test] 09:55:25> set global gtid_mode=off_permissive;Query OK, 0 rows affected (0.01 sec)root@localhost [test] 09:55:58> set global gtid_mode=off;Query OK, 0 rows affected (0.01 sec)root@localhost [test] 09:56:09> set global enforce_gtid_consistency = 0;Query OK, 0 rows affected (0.00 sec)root@localhost [test] 09:57:34> show variables like '%gtid%';+----------------------------------+-----------+| Variable_name| Value|+----------------------------------+-----------+| binlog_gtid_simple_recovery| ON || enforce_gtid_consistency | OFF || gtid_executed_compression_period | 1000|| gtid_mode | OFF || gtid_next | AUTOMATIC || gtid_owned | || gtid_purged | || session_track_gtids | OFF |+----------------------------------+-----------+8 rows in set (0.01 sec)可以把 gtid_mode=off 与 enforce_gtid_consistency=OFF 写入配置文件f中，重启之后也能生效。
2. 传统复制转换成GTID复制
此博文介绍了MySQL 5.7版本的传统复制模式的搭建，下面操作将传统复制转换成GTID复制模式。
2.1 环境准备
2.2 将enforce_gtid_consistency设置为warn
在MySQL每个实例上， 将enforce_gtid_consistency设置为warn
root@localhost [(none)] 10:21:01> set @@global.enforce_gtid_consistency=warn;
【注意】：执行完这条语句后，如果出现GTID不兼容的语句用法，会在error log记录相关信息，那么需要调整该程序避免不兼容的写法，直到完全没有不兼容的语句。
2.3 将enforce_gtid_consistency设置为on
在2.2完成后，如果没有不兼容语句，可以把MySQL每个实例的ENFORCE_GTID_CONSISTENCY值设置为on。
root@localhost [(none)] 11:05:11> set @@global.enforce_gtid_consistency=on;Query OK, 0 rows affected (0.00 sec)
2.4 设置GTID模式为off_permissive
将所有MySQL实例的GTID模式设置为off_permissive
root@localhost [(none)] 11:06:55>SET @@GLOBAL.GTID_MODE = OFF_PERMISSIVE;Query OK, 0 rows affected (0.01 sec)
2.5 设置GTID模式为on_permissive
root@localhost [(none)] 11:12:20> SET @@GLOBAL.GTID_MODE = ON_PERMISSIVE;Query OK, 0 rows affected (0.01 sec)
2.6 检查从库Ongoing_anonymous_transaction_count状态值
检查从库Ongoing_anonymous_transaction_count状态值是否为0，如果为0，一味着没有等待的事务，可以进行下一步操作
root@localhost [(none)] 11:13:09>SHOW STATUS LIKE 'ONGOING_ANONYMOUS_TRANSACTION_COUNT';+-------------------------------------+-------+| Variable_name | Value |+-------------------------------------+-------+| Ongoing_anonymous_transaction_count | 0|+-------------------------------------+-------+1 row in set (0.00 sec)
2.7 确保所有的匿名事务已经被完全复制到所有的slave上
root@localhost [(none)] 11:29:55>show slave status\G*************************** 1. row ***************************...Relay_Master_Log_File: my3306_binlog.000090...Exec_Master_Log_Pos: 194...#在slave上使用函数：root@localhost [(none)] 11:30:01>SELECT MASTER_POS_WAIT('my3306_binlog.000090', 194);+----------------------------------------------+| MASTER_POS_WAIT('my3306_binlog.000090', 194) |+----------------------------------------------+| 0 |+----------------------------------------------+1 row in set (0.00 sec)返回结果大于或等于0就说明匿名事务已经全部复制完成
2.8 设置GTID_MODE为on
root@localhost [(none)] 11:31:36>SET @@GLOBAL.GTID_MODE = ON;Query OK, 0 rows affected (0.01 sec)
2.9 change master
root@localhost [(none)] 11:37:17>STOP slave;Query OK, 0 rows affected (0.00 sec)root@localhost [(none)] 11:37:24>change master to master_auto_position=1;Query OK, 0 rows affected (0.00 sec)root@localhost [(none)] 11:37:52>start slave;Query OK, 0 rows affected (0.00 sec)
