mysql gtid坑_通过mysqlbinlog --skip-gtids恢复后再备份可能造成的坑

版本

[root@uz22199 backup]# innobackupex --version

innobackupex version 2.4.8 Linux (x86_64) (revision id: 97330f7)

[root@uz22199 backup]# mysql -e"select @@version"

+------------+

| @@version |

+------------+

| 5.7.18-log |

+------------+

源库

表结构与数据

root@mysqldb 21:51: [fandb]> show create table users\G

***************************1. row ***************************

Table: users

Create Table: CREATE TABLE `users` (

`email` varchar(10) DEFAULT NULL,

UNIQUE KEY `email` (`email`)

) ENGINE=InnoDB DEFAULT CHARSET=utf8mb4

1 row in set (0.00 sec)

root@mysqldb 18:43: [fandb]> select* from users;

+-------+

| email | +-------+

| 1 |

| 10 |

| 20 |

| 30 |

| 5 | +-------+

插入一条数据

insert into users values(50); --GTID=1297

再删掉

delete from users where email=50; ----GTID=1298

当前Executed_Gtid_Set

root@mysqldb 18:35: [fandb]> show master status;

+------------------+----------+--------------+------------------+---------------------------------------------+

| mysql-bin.000005 | 495 | | | 5c351518-78ec-11e7-8e7a-005056a610c3:1-1298 | +------------------+----------+--------------+------------------+---------------------------------------------+

1 row in set (0.00 sec)

源库再次应用一下已经执行过得binlog, 再次应用insert into users values(50); 这一条

这里先不考虑有没有可能这样子去恢复数据,只做实验

[root@test43100 backup]# mysqlbinlog --skip-gtids --include-gtids='5c351518-78ec-11e7-8e7a-005056a610c3:1297' mysql-bin.000005 |mysql

root@mysqldb 18:43: [fandb]> select* from users;

+-------+

| email | +-------+

| 1 |

| 10 |

| 20 |

| 30 |

| 5 |

| 50 | +-------+

root@mysqldb 18:43: [fandb]> show master status;

+------------------+----------+--------------+------------------+---------------------------------------------+

| mysql-bin.000005 | 617 | | | 5c351518-78ec-11e7-8e7a-005056a610c3:1-1299 | +------------------+----------+--------------+------------------+---------------------------------------------+

源库Executed_Gtid_Set 已经到1299了

备份

innobackupex --user=backup --password='backup' --stream=tar /tmp | gzip -> full.tar.gz

170907 18:45:15 Backup created in directory '/tmp/'

MySQL binlog position: filename 'mysql-bin.000005', position '617', GTID of the last change '5c351518-78ec-11e7-8e7a-005056a610c3:1-1299'

170907 18:45:15 [00] Streaming

170907 18:45:15 [00] ...done

170907 18:45:15 [00] Streaming

170907 18:45:15 [00] ...done

xtrabackup: Transaction log of lsn (3112759) to (3112768) was copied.

170907 18:45:16 completed OK!

从备份输出信息和xtrabackup_binlog_info都可以看到,这个全备备份了1-1299

[root@uz22199 full2]# more xtrabackup_binlog_info

mysql-bin.000005 617 5c351518-78ec-11e7-8e7a-005056a610c3:1-1299

把备份随便搞到一个地方恢复出来

(恢复过程省略)

查看恢复出来的库的Executed_Gtid_Set

root@mysqldb 18:48: [(none)]> show master status;

+------------------+----------+--------------+------------------+---------------------------------------------+

| mysql-bin.000001 | 154 | | | 5c351518-78ec-11e7-8e7a-005056a610c3:1-1298 | +------------------+----------+--------------+------------------+---------------------------------------------+

1 row in set (0.00 sec)

虽然知道1298,但是50这条数据有了

root@mysqldb 18:43: [fandb]> select* from users;

+-------+

| email | +-------+

| 1 |

| 10 |

| 20 |

| 30 |

| 5 |

| 50 | +-------+

如果此时我们直接将该库作为从库,change master到源库,那么start slave会报错,1299会再执行一边insert 50,会报1062错误.这就是坑

而如果我们flush binary logs一次,再做全备

root@mysqldb 21:51: [fandb]> flush binary logs;

Query OK, 0 rows affected (0.19 sec)

root@mysqldb 21:59: [fandb]> show master status;

+------------------+----------+--------------+------------------+---------------------------------------------+

| mysql-bin.000006 | 194 | | | 5c351518-78ec-11e7-8e7a-005056a610c3:1-1299 | +------------------+----------+--------------+------------------+---------------------------------------------+

1 row in set (0.00 sec)

170907 22:00:58 Backup created in directory '/tmp/'

MySQL binlog position: filename 'mysql-bin.000006', position '194', GTID of the last change '5c351518-78ec-11e7-8e7a-005056a610c3:1-1299'

170907 22:00:58 [00] Streaming

170907 22:00:58 [00] ...done

170907 22:00:58 [00] Streaming

170907 22:00:58 [00] ...done

xtrabackup: Transaction log of lsn (3115326) to (3115335) was copied.

170907 22:00:58 completed OK!

[root@uz22199 full3]# more xtrabackup_binlog_info

mysql-bin.000006 194 5c351518-78ec-11e7-8e7a-005056a610c3:1-1299

Executed_Gtid_Set依旧是1-1299

再次将备份恢复出来,查看新恢复出来的库

root@mysqldb 22:02: [(none)]> show master status;

+------------------+----------+--------------+------------------+---------------------------------------------+

| mysql-bin.000001 | 154 | | | 5c351518-78ec-11e7-8e7a-005056a610c3:1-1299 | +------------------+----------+--------------+------------------+---------------------------------------------+

此时恢复出来的库Executed_Gtid_Set为1-1299了

总结

那么要么以后通过mysqlbinlog –skip-gtids 恢复数据之后flush 一下binary logs;

要么恢复出来的库都手动根据xtrabackup_binlog_info去set global gtid_purged

又做了一次

源库:

root@mysqldb 17:14: [(none)]> flush binary logs;

Query OK, 0 rows affected (0.24 sec)

root@mysqldb 17:16: [(none)]> show master status;

+------------------+----------+--------------+------------------+---------------------------------------------+

| mysql-bin.000008 | 194 | | | 5c351518-78ec-11e7-8e7a-005056a610c3:1-1300 | +------------------+----------+--------------+------------------+---------------------------------------------+

root@mysqldb 17:17: [(none)]> select * from fandb.users order by 1;

+-------+

| email | +-------+

| 1 |

| 10 |

| 20 |

| 30 |

| 5 |

| 50 |

| 60 | +-------+

7 rows in set (0.00 sec)

root@mysqldb 17:23: [(none)]> insert into fandb.users values(70);

Query OK, 1 row affected (0.06 sec)

root@mysqldb 17:23: [(none)]> show master status;

+------------------+----------+--------------+------------------+---------------------------------------------+

| mysql-bin.000008 | 448 | | | 5c351518-78ec-11e7-8e7a-005056a610c3:1-1301 | +------------------+----------+--------------+------------------+---------------------------------------------+

1 row in set (0.00 sec)

root@mysqldb 17:24: [(none)]> delete from fandb.users where email=70;

Query OK, 1 row affected (0.05 sec)

root@mysqldb 17:24: [(none)]> show master status;

+------------------+----------+--------------+------------------+---------------------------------------------+

| mysql-bin.000008 | 702 | | | 5c351518-78ec-11e7-8e7a-005056a610c3:1-1302 | +------------------+----------+--------------+------------------+---------------------------------------------+

1 row in set (0.00 sec)

root@mysqldb 17:24: [(none)]> select * from fandb.users order by 1;

+-------+

| email | +-------+

| 1 |

| 10 |

| 20 |

| 30 |

| 5 |

| 50 |

| 60 | +-------+

7 rows in set (0.00 sec)

mysqlbinlog --skip-gtids --include-gtids='5c351518-78ec-11e7-8e7a-005056a610c3:1301' /data/mysqldata/3306/binlog/mysql-bin.000008 |mysql

root@mysqldb 17:26: [(none)]> show master status;

+------------------+----------+--------------+------------------+---------------------------------------------+

| mysql-bin.000008 | 956 | | | 5c351518-78ec-11e7-8e7a-005056a610c3:1-1303 | +------------------+----------+--------------+------------------+---------------------------------------------+

1 row in set (0.00 sec)

root@mysqldb 17:26: [(none)]> select * from fandb.users order by 1;

+-------+

| email | +-------+

| 1 |

| 10 |

| 20 |

| 30 |

| 5 |

| 50 |

| 60 |

| 70 | +-------+

8 rows in set (0.00 sec)

innobackupex --user=backup --password='backup' --stream=tar /tmp | gzip -> full4.tar.gz

MySQL binlog position: filename 'mysql-bin.000008', position '956', GTID of the last change '5c351518-78ec-11e7-8e7a-005056a610c3:1-1303'

170908 17:27:42 [00] Streaming

170908 17:27:42 [00] ...done

170908 17:27:42 [00] Streaming

170908 17:27:42 [00] ...done

xtrabackup: Transaction log of lsn (3121237) to (3121246) was copied.

170908 17:27:42 completed OK!

[root@uz22199 full4]# more xtrabackup_binlog_info

mysql-bin.000008 956 5c351518-78ec-11e7-8e7a-005056a610c3:1-1303

[root@uz22199 full4]# more xtrabackup_binlog_pos_innodb mysql-bin.000008 956

恢复出来的库:

root@mysqldb 17:31: [(none)]> show master status;

+------------------+----------+--------------+------------------+---------------------------------------------+

| mysql-bin.000001 | 154 | | | 5c351518-78ec-11e7-8e7a-005056a610c3:1-1300 | +------------------+----------+--------------+------------------+---------------------------------------------+

1 row in set (0.00 sec)

root@mysqldb 17:31: [(none)]> select * from fandb.users;

+-------+

| email | +-------+

| 1 |

| 10 |

| 20 |

| 30 |

| 5 |

| 50 |

| 60 |

| 70 | +-------+

8 rows in set (0.00 sec)

root@mysqldb 17:37: [(none)]> reset slave all;

Query OK, 0 rows affected (0.03 sec)

root@mysqldb 17:38: [(none)]> change master to master_host='10.4.3.100',master_port=3306,master_user='repl',master_password='repl',master_auto_position=1;

Query OK, 0 rows affected, 2 warnings (0.26 sec)

root@mysqldb 17:38: [(none)]> start slave;

Last_SQL_Error: Could not execute Write_rows event on table fandb.users; Duplicate entry '70' for key 'email', Error_code: 1062; handler error HA_ERR_FOUND_DUPP_KEY; the event's master log mysql-bin.000008, end_log_pos 417