MySQL的GTID復制與傳統復制的相互轉換
1. GTID復制轉換成傳統復制
上篇博文已經介紹了MySQL 5.7版本的GTID復制模式的搭建，下面操作將GTID復制轉換成傳統復制模式。
1.1 環境准備
| 類型 | 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 查看當前主從狀態
記錄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: 192.168.56.100
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
根據上面記錄的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)
#參數解釋：
master_auto_position=0 表示禁用master_auto_position
1.5 啟動主從復制
root@localhost [test] 09:51:28>start slave;
1.6 在線關閉主從服務器的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 與 enforce_gtid_consistency=OFF 寫入配置文件my.cnf中，重啟之后也能生效。
2. 傳統復制轉換成GTID復制
此博文介紹了MySQL 5.7版本的傳統復制模式的搭建，下面操作將傳統復制轉換成GTID復制模式。
2.1 環境准備
| 類型 | ip | prot | server-id |
|---|---|---|---|
| master | 192.168.56.100 | 3306 | 1003306 |
| slave | 192.168.56.200 | 3306 | 2003306 |
2.2 將enforce_gtid_consistency設置為warn
在MySQL每個實例上， 將enforce_gtid_consistency設置為warn
root@localhost [(none)] 10:21:01> set @@global.enforce_gtid_consistency=warn;
【注意】：執行完這條語句后，如果出現GTID不兼容的語句用法，會在error log記錄相關信息，那么需要調整該程序避免不兼容的寫法，直到完全沒有不兼容的語句。
2.3 將enforce_gtid_consistency設置為on
在 2.2完成后，如果沒有不兼容語句，可以把MySQL每個實例的ENFORCE_GTID_CONSISTENCY值設置為on。
root@localhost [(none)] 11:05:11> set @@global.enforce_gtid_consistency=on;
Query OK, 0 rows affected (0.00 sec)
2.4 設置GTID模式為off_permissive
將所有MySQL實例的GTID模式設置為off_permissive
root@localhost [(none)] 11:06:55>SET @@GLOBAL.GTID_MODE = OFF_PERMISSIVE;
Query OK, 0 rows affected (0.01 sec)
2.5 設置GTID模式為on_permissive
root@localhost [(none)] 11:12:20> SET @@GLOBAL.GTID_MODE = ON_PERMISSIVE;
Query OK, 0 rows affected (0.01 sec)
2.6 檢查從庫Ongoing_anonymous_transaction_count狀態值
檢查從庫Ongoing_anonymous_transaction_count狀態值是否為0，如果為0，一味着沒有等待的事務，可以進行下一步操作
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 確保所有的匿名事務已經被完全復制到所有的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上使用函數：
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)
返回結果大於或等於0就說明匿名事務已經全部復制完成
2.8 設置GTID_MODE為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)