MySQL 基于 GTID 主从复制

GTID

定义

GTID 是 MySQL 事务标识，为每一个提交的事务都生成一个标识，并且是全局唯一的，这个特性是从 MySQL5.6 引进的。

组成

GTID 是由 UUID + TID，UUID 是MySQL的唯一标识，每个MySQL实例之间都是不同的。TID是代表了该实例上已经提交的事务数量，并且随着事务提交 单调递增。

优点

MySQL 主从基于 GTID 复制，不同于传统复制基于 binlog 日志位点。当主从切换时，MySQL从节点 自动根据事务 在新主库上找到复制位点。GTID复制时，会跳过已经执行过的事务。加强了数据库主备数据一致性。

搭建主从

主库数据备份

mysqldump -uroot -p123456 -h127.0.0.1 -P3307 --single-transaction --master-data=2 --triggers --routines  --all-databases > /backup/all.sql

主从开启GTID

主从库配置文件添加

gtid_mode = on   #开启gtid模式
enforce_gtid_consistency = on  #强制gtid一致性，开启后对特定的create table不被支持

之后重启主从数据库

GTID验证

登录主从验证

mysql> show variables like '%gtid%';
+---------------------------------------------------+-----------+
| Variable_name                                     | Value     |
+---------------------------------------------------+-----------+
| binlog_gtid_simple_recovery                       | ON        |
| enforce_gtid_consistency                          | ON        |
| group_replication_allow_local_disjoint_gtids_join | OFF       |
| group_replication_gtid_assignment_block_size      | 1000000   |
| gtid_executed_compression_period                  | 1000      |
| gtid_mode                                         | ON        |
| gtid_next                                         | AUTOMATIC |
| gtid_owned                                        |           |
| gtid_purged                                       |           |
| session_track_gtids                               | OFF       |
+---------------------------------------------------+-----------+
10 rows in set (0.01 sec)mysql> show master status\G
*************************** 1. row ***************************File: binlog.000016Position: 1658Binlog_Do_DB:Binlog_Ignore_DB:
Executed_Gtid_Set: aadaaaaa-adda-adda-aaaa-aaaaaaddaaaa:1-52,
b9193c37-89a7-11ee-8978-00155d68e7c7:1-9
1 row in set (0.00 sec)

可以看到，GTID 开启后执行 查看当前数据库状态。会多一个 Executed_Gtid_Set 指标

从库还原主库数据

root@LAPTOP-FPIQJ438:/usr/local/mysql-slave# mysql -uroot -p123456 -h127.0.0.1 -P3309
mysql: [Warning] Using a password on the command line interface can be insecure.
Welcome to the MySQL monitor.  Commands end with ; or \g.
Your MySQL connection id is 5
Server version: 5.7.38-log MySQL Community Server (GPL)Copyright (c) 2000, 2023, Oracle and/or its affiliates.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>
mysql>
mysql>
mysql>
mysql> source /backup/all.sql

主库创建复制用户

mysql> create user 'fz'@'%' identified by "123456";
Query OK, 0 rows affected (0.01 sec)mysql> grant replication slave on *.* to 'fz'@'%';
Query OK, 0 rows affected (0.00 sec)mysql>
mysql>
mysql> flush privileges;
Query OK, 0 rows affected (0.01 sec)

从库开启复制

mysql> stop slave;
Query OK, 0 rows affected, 1 warning (0.00 sec)mysql>
mysql>
mysql>
mysql>
mysql> reset slave ;
Query OK, 0 rows affected (0.01 sec)
mysql>
mysql>
mysql>
mysql> change master to master_host='127.0.0.1',master_user='fz',MASTER_PORT=3307,master_password='123456',master_auto_position=1;
Query OK, 0 rows affected, 1 warning (0.03 sec)mysql>
mysql>
mysql>
mysql> start slave;
Query OK, 0 rows affected (0.01 sec)

可以看到 GTID 复制不像传统的基于binlog复制。不需要 binlog文件 和 pos位置位点

从库验证

mysql> show slave status\G
*************************** 1. row ***************************Slave_IO_State: Waiting for master to send eventMaster_Host: 127.0.0.1Master_User: fzMaster_Port: 3307Connect_Retry: 60Master_Log_File: binlog.000016Read_Master_Log_Pos: 1658Relay_Log_File: LAPTOP-FPIQJ438-relay-bin.000002Relay_Log_Pos: 1777Relay_Master_Log_File: binlog.000016Slave_IO_Running: YesSlave_SQL_Running: YesReplicate_Do_DB:Replicate_Ignore_DB:Replicate_Do_Table:Replicate_Ignore_Table:Replicate_Wild_Do_Table:Replicate_Wild_Ignore_Table:Last_Errno: 0Last_Error:Skip_Counter: 0Exec_Master_Log_Pos: 1658Relay_Log_Space: 1986Until_Condition: NoneUntil_Log_File:Until_Log_Pos: 0Master_SSL_Allowed: NoMaster_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: NoLast_IO_Errno: 0Last_IO_Error:Last_SQL_Errno: 0Last_SQL_Error:Replicate_Ignore_Server_Ids:Master_Server_Id: 2Master_UUID: b9193c37-89a7-11ee-8978-00155d68e7c7Master_Info_File: mysql.slave_master_infoSQL_Delay: 0SQL_Remaining_Delay: NULLSlave_SQL_Running_State: Slave has read all relay log; waiting for more updatesMaster_Retry_Count: 86400Master_Bind:Last_IO_Error_Timestamp:Last_SQL_Error_Timestamp:Master_SSL_Crl:Master_SSL_Crlpath:Retrieved_Gtid_Set: b9193c37-89a7-11ee-8978-00155d68e7c7:2-9Executed_Gtid_Set: 1d48af6d-89a9-11ee-a07d-00155d68e7c7:1-2,
aadaaaaa-adda-adda-aaaa-aaaaaaddaaaa:1-52,
b9193c37-89a7-11ee-8978-00155d68e7c7:1-9Auto_Position: 1Replicate_Rewrite_DB:Channel_Name:Master_TLS_Version:
1 row in set (0.00 sec)