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(); --查询当前数据库版本
mysql> show global variables like 'log_slave%'; 查看日志是否开启,这里显示关闭,在5.7版本这里不用开启
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)
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)