MySQL主从复制

保证mysql服务均开启bin_log
保证mysql服务器之间,server_id不重复
保证mysql服务器之间,ip互通

当前MySQL版本: 8.0.23 (其他版本可查看相关版本的官方文档)

1. 主库

查询ip

ifconfig

192.168.0.2

是否开启bin_log

mysql -uroot -p

进入 mysql 客户端命令行交互界面

show variables like “%log_bin%”;

+---------------------------------+-----------------------------------+
| Variable_name                   | Value                             |
+---------------------------------+-----------------------------------+
| log_bin                         | ON                                |
| log_bin_basename                | /usr/local/var/mysql/binlog       |
| log_bin_index                   | /usr/local/var/mysql/binlog.index |
| log_bin_trust_function_creators | OFF                               |
| log_bin_use_v1_row_events       | OFF                               |
| sql_log_bin                     | ON                                |
+---------------------------------+-----------------------------------+
6 rows in set (0.00 sec)

主库当前的binlog文件,以及Position

查看服务器正在写入 binlog 文件名和位置

show master status\G;

*************************** 1. row ***************************
             File: binlog.000024
         Position: 156
     Binlog_Do_DB: 
 Binlog_Ignore_DB: 
Executed_Gtid_Set: 
1 row in set (0.00 sec)

检查server_id

各个mysql服务器之间,server_id不能重复,否则复制时会报错;

SHOW GLOBAL VARIABLES LIKE ‘server_id’;

+---------------+-------+
| Variable_name | Value |
+---------------+-------+
| server_id     | 1     |
+---------------+-------+
1 row in set (0.00 sec)

SET GLOBAL server_id = 101;

添加提供给从库使用的用户,用户从主库拉取数据

该用户只开放给 host为192.168.0.3的主机使用
> CREATE USER 'sync_user'@'192.168.0.3' IDENTIFIED BY 'hello@2024';
赋予从库权限
> grant replication slave on `*.*` to 'sync_user'@'192.168.0.3';

开放给任何host使用
> CREATE USER 'sync_user'@'%' IDENTIFIED BY 'hello@2024';
> grant replication slave on `*.*` to 'sync_user'@'%';

2. 从库

ip: 192.168.0.3

mysql -uroot -p

检查server_id,保证不与主库相同

SHOW GLOBAL VARIABLES LIKE ‘server_id’;

执行同步命令，设置主服务器ip，同步账号密码，同步位置

change master to master_host=’192.168.0.2’,master_port=3306,
master_user=’sync_user’,master_password=’hello@2024’,
master_log_file=’binlog.000024’,master_log_pos=156;

注意点:master_log_file 和 master_log_pos 是主库上的binlog文件名和位置点

开启同步功能

start slave;

检查同步状态

show slave status\G;

*************************** 1. row ***************************
Slave_IO_State: Waiting for master to send event
Master_Host: 172.17.2.40
Master_User: photorepl
Master_Port: 4331
Connect_Retry: 60
Master_Log_File: mysql-bin.005502
Read_Master_Log_Pos: 64401238
Relay_Log_File: mysqld-relay-bin.015418
Relay_Log_Pos: 13456757
Relay_Master_Log_File: mysql-bin.005152
Slave_IO_Running: Yes
Slave_SQL_Running: Yes
Replicate_Do_DB: 
Replicate_Ignore_DB: mysql
Replicate_Do_Table: 
Replicate_Ignore_Table: 
Replicate_Wild_Do_Table: photo.%
Replicate_Wild_Ignore_Table: mysql.%
Last_Errno: 0
Last_Error: 

主要看Slave_IO_Running 和 Slave_SQL_Running 是否正常,为Yes则正常;若有异常可以查看Last_Error分析原因

停止同步

STOP SLAVE;

RESET SLAVE;

配置笔记