MySQL5.7在线开启/关闭GTID
MySQL5.7在线开启/关闭GTID
环境介绍
Part1:写在最前
截止本文撰写当日，MySQL5.7.16是官网的最新稳定版，本文将用MySQL5.7.16来进行演示。从MySQL5.6开始，支持了GTID复制模式，这种模式其实是把双刃剑，虽然容易搭建主从复制了，但使用不当，就容易出现一些错误，例如error 1236。在MySQL5.6如果开启GTID模式，需要在my.cnf中加入以下几个参数：
①log-bin=mysql-bin
②binlog_format=row
③log_slave_updates=1
④gtid_mode=ON
⑤enforce_gtid_consistency=ON
Warning:警告这里的一些参数不是动态参数，也就是需要重启mysql才能生效。
Part2:环境
[root@HE1 ~]# mysql -uroot -p Enter password: Welcome to the MySQL monitor. Commands end with ; or \g. Your MySQL connection id is 4 Server version: 5.7.16-log MySQL Community Server (GPL) Copyright (c) 2000, 2016, Oracle and/or its affiliates. All rights reserved. Oracle is a registered trademark of Oracle Corporation and/or its affiliates. Other names may be trademarks of their respective owners. Type 'help;' or '\h' for help. Type '\c' to clear the current input statement. mysql> select version(); +------------+ | version() | +------------+ | 5.7.16-log | +------------+ 1 row in set (0.00 sec) mysql> show global variables like 'log_slave%'; +-------------------+-------+ | Variable_name | Value | +-------------------+-------+ | log_slave_updates | OFF | +-------------------+-------+ 1 row in set (0.00 sec)
MySQL5.6开启GTID需要开启log_slave_updates参数，否则启动报错，而5.7不在需要开启该参数。
实战
Part1:搭建传统复制模式
本文环境HE1为从，HE3为主库
[root@HE1 ~]# mysql -uroot -p Enter password: Welcome to the MySQL monitor. Commands end with ; or \g. Your MySQL connection id is 7 Server version: 5.7.16-log MySQL Community Server (GPL) Copyright (c) 2000, 2016, Oracle and/or its affiliates. All rights reserved. Oracle is a registered trademark of Oracle Corporation and/or its affiliates. Other names may be trademarks of their respective owners. Type 'help;' or '\h' for help. Type '\c' to clear the current input statement. mysql> show slave status\G *************************** 1. row *************************** Slave_IO_State: Waiting for master to send event Master_Host: 192.168.1.250 Master_User: mysync Master_Port: 3306 Connect_Retry: 60 Master_Log_File: mysql-bin.000002 Read_Master_Log_Pos: 1694 Relay_Log_File: HE1-relay-bin.000002 Relay_Log_Pos: 320 Relay_Master_Log_File: mysql-bin.000002 Slave_IO_Running: Yes 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: 1694 Relay_Log_Space: 525 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: 0 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: 1250 Master_UUID: 82b160c7-9a8f-11e6-8412-000c29c6361d Master_Info_File: /data/mysql/master.info SQL_Delay: 0 SQL_Remaining_Delay: NULL Slave_SQL_Running_State: Slave has read all relay log; waiting for more updates 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: 0 Replicate_Rewrite_DB: Channel_Name: Master_TLS_Version: 1 row in set (0.00 sec)
Part2:传统复制模式切换为GTID
①主库从库都需执行以下命令
mysql> set global gtid_mode='OFF_PERMISSIVE'; Query OK, 0 rows affected (0.01 sec) mysql> set global gtid_mode='ON_PERMISSIVE'; Query OK, 0 rows affected (0.01 sec) mysql> set global enforce_gtid_consistency=ON; Query OK, 0 rows affected (0.00 sec) mysql> set global gtid_mode='ON'; Query OK, 0 rows affected (0.00 sec)
②主库插数从库执行
mysql> show master status; +------------------+----------+--------------+------------------+----------------------------------------+ | File | Position | Binlog_Do_DB | Binlog_Ignore_DB | Executed_Gtid_Set | +------------------+----------+--------------+------------------+----------------------------------------+ | mysql-bin.000005 | 154 | | | 82b160c7-9a8f-11e6-8412-000c29c6361d:1 | +------------------+----------+--------------+------------------+----------------------------------------+ 1 row in set (0.00 sec)
可以看到gtid_set下面有数了，这说明已经开启了gtid模式
Part3:GTID变更为传统模式
mysql> stop slave;-----从库执行 Query OK, 0 rows affected (0.00 sec) mysql> set global gtid_mode='ON_PERMISSIVE'; Query OK, 0 rows affected (0.00 sec) mysql> set global gtid_mode='OFF_PERMISSIVE'; Query OK, 0 rows affected (0.01 sec) mysql> CHANGE MASTER TO MASTER_AUTO_POSITION=0; Query OK, 0 rows affected (0.05 sec) mysql> set global gtid_mode='OFF'; Query OK, 0 rows affected (0.00 sec) mysql> start slave; Query OK, 0 rows affected (0.00 sec) mysql> show variables like '%gtid%'; +----------------------------------+----------------------------------------+ | Variable_name | Value | +----------------------------------+----------------------------------------+ | binlog_gtid_simple_recovery | ON | | enforce_gtid_consistency | ON | | gtid_executed_compression_period | 1000 | | gtid_mode | OFF | | gtid_next | AUTOMATIC | | gtid_owned | | | gtid_purged | 82b160c7-9a8f-11e6-8412-000c29c6361d:1 | | session_track_gtids | OFF | +----------------------------------+----------------------------------------+ 8 rows in set (0.01 sec)
可以看到这里GTID模式已经关了，下面再次开启GTID模式来观察id的变化
mysql> set global gtid_mode='OFF_PERMISSIVE'; Query OK, 0 rows affected (0.01 sec) mysql> set global gtid_mode='ON_PERMISSIVE'; Query OK, 0 rows affected (0.01 sec) mysql> set global enforce_gtid_consistency=ON; Query OK, 0 rows affected (0.00 sec) mysql> set global gtid_mode='ON'; Query OK, 0 rows affected (0.01 sec) mysql> mysql> mysql> show variables like '%gtid%'; +----------------------------------+----------------------------------------+ | Variable_name | Value | +----------------------------------+----------------------------------------+ | binlog_gtid_simple_recovery | ON | | enforce_gtid_consistency | ON | | gtid_executed_compression_period | 1000 | | gtid_mode | ON | | gtid_next | AUTOMATIC | | gtid_owned | | | gtid_purged | 82b160c7-9a8f-11e6-8412-000c29c6361d:1 | | session_track_gtids | OFF | +----------------------------------+----------------------------------------+ 8 rows in set (0.00 sec) 主库做操作，从库执行如下命令会看到gtid_set的值在变化 mysql> show master status; +------------------+----------+--------------+------------------+------------------------------------------+ | File | Position | Binlog_Do_DB | Binlog_Ignore_DB | Executed_Gtid_Set | +------------------+----------+--------------+------------------+------------------------------------------+ | mysql-bin.000011 | 154 | | | 82b160c7-9a8f-11e6-8412-000c29c6361d:1-2 | +------------------+----------+--------------+------------------+------------------------------------------+ 1 row in set (0.00 sec) mysql> show master status; +------------------+----------+--------------+------------------+------------------------------------------+ | File | Position | Binlog_Do_DB | Binlog_Ignore_DB | Executed_Gtid_Set | +------------------+----------+--------------+------------------+------------------------------------------+ | mysql-bin.000011 | 154 | | | 82b160c7-9a8f-11e6-8412-000c29c6361d:1-3 | +------------------+----------+--------------+------------------+------------------------------------------+ 1 row in set (0.00 sec)
——总结——
MySQL5.7开启/关闭GTID，不用重启mysql，这大大提高了GTID的易用性。由于笔者的水平有限，编写时间也很仓促，文中难免会出现一些错误或者不准确的地方，不妥之处恳请读者批评指正。
