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
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
| 类型 | ip | prot | server-id |
|---|---|---|---|
| master | 192.168.56.100 | 3307 | 1003307 |
| slave | 192.168.56.200 | 3307 | 2003307 |
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 statusG
*************************** 1. row ***************************
Slave_IO_State:
Master_Host: 192.168.56.100
Master_User: repl
Master_Port: 3307
Connect_Retry: 60
Master_Log_File: my3307_binlog.000005
Read_Master_Log_Pos: 194
Relay_Log_File: mysqldb2-relay-bin.000010
Relay_Log_Pos: 375
Relay_Master_Log_File: my3307_binlog.000005
Slave_IO_Running: No
Slave_SQL_Running: No
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: 194
Relay_Log_Space: 585
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: NULL
Master_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: 1003307
Master_UUID: 3a068bf8-cdeb-11e8-8176-080027b0b461
Master_Info_File: mysql.slave_master_info
SQL_Delay: 0
SQL_Remaining_Delay: NULL
Slave_SQL_Running_State:
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: 3a068bf8-cdeb-11e8-8176-080027b0b461:1-12
Auto_Position: 1
Replicate_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my.cnf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
| 类型 | ip | prot | server-id |
|---|---|---|---|
| master | 192.168.56.100 | 3306 | 1003306 |
| slave | 192.168.56.200 | 3306 | 2003306 |
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 statusG
*************************** 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)