MYSQL一主二从

1.主库操作

1.开启binlog
[root@db01 ~]# cat /etc/my.cnf
[mysqld]
basedir = /usr/local/mysql
datadir = /usr/local/mysql/data
port=3306
socket=/tmp/mysql.sock
server_id=1  #主库这里写 1
log_err=/usr/local/mysql/data/mysql.err
log_bin=/usr/local/mysql/data/mysql-bin

2.重启并连接数据库

[root@db01 ~]# systemctl restart mysqld
[root@db01 ~]# mysql

3.主库授权一个用户，给从库用来连接

mysql> grant replication slave on *.* to rep@'172.16.1.%' identified by '123';
Query OK, 0 rows affected (0.18 sec)

4.主库查看binlog信息

mysql> show master status;
+------------------+----------+--------------+------------------+-------------------+
| File             | Position | Binlog_Do_DB | Binlog_Ignore_DB | Executed_Gtid_Set |
+------------------+----------+--------------+------------------+-------------------+
| mysql-bin.000001 |      120 |              |                  |                   |
+------------------+----------+--------------+------------------+-------------------+
1 row in set (0.00 sec)

2.从库"1"操作

1.编辑配置文件
[root@db02 ~]# cat /etc/my.cnf
[mysqld]
basedir = /usr/local/mysql
datadir = /usr/local/mysql/data
port=3306
socket=/tmp/mysql.sock
server_id=2  #从库这里写 2
log_err=/usr/local/mysql/data/mysql.err
log_bin=/usr/local/mysql/data/mysql-bin
#从库需要知道的主库信息
#主库的IP
#连接主库用的用户和密码
#binlog信息

2.重启并连接数据库

[root@db01 ~]# systemctl restart mysqld
[root@db01 ~]# mysql

3.配置主从

mysql> change master to
    -> master_host='172.16.1.51', #主库的ip
    -> master_user='rep',         #从库连接主库的用户  （主从复制专属用户）
    -> master_password='123',     #从库连接主库的用户的密码
    -> master_log_file='mysql-bin.000001', #主库上获取到的"file"名称
    -> master_log_pos=120,   #主库上获取到的"pos"值
    -> master_port=3306;     #主库服务器的端口

4.开启IO线程和sql线程

mysql> start slave;
Query OK, 0 rows affected (0.08 sec)

3.从库"2"操作

1.编辑配置文件
[root@db02 ~]# cat /etc/my.cnf
[mysqld]
basedir = /usr/local/mysql
datadir = /usr/local/mysql/data
port=3306
socket=/tmp/mysql.sock
server_id=3  #从库这里写 3
log_err=/usr/local/mysql/data/mysql.err
log_bin=/usr/local/mysql/data/mysql-bin
#从库需要知道的主库信息
#主库的IP
#连接主库用的用户和密码
#binlog信息

2.重启并连接数据库

[root@db01 ~]# systemctl restart mysqld
[root@db01 ~]# mysql

3.配置主从

mysql> change master to
    -> master_host='172.16.1.51', #主库的ip
    -> master_user='rep',         #从库连接主库的用户  （主从复制专属用户）
    -> master_password='123',     #从库连接主库的用户的密码
    -> master_log_file='mysql-bin.000001', #主库上获取到的"file"名称
    -> master_log_pos=120,   #主库上获取到的"pos"值
    -> master_port=3306;     #主库服务器的端口

4.开启IO线程和sql线程

mysql> start slave;
Query OK, 0 rows affected (0.08 sec)

每个数据库的server_id 必须不一致。

5.查看主从状态

mysql> show slave statusG
*************************** 1. row ***************************
               Slave_IO_State: Waiting for master to send event
                  Master_Host: 172.16.1.51
                  Master_User: rep
                  Master_Port: 3306
                Connect_Retry: 60
              Master_Log_File: mysql-bin.000001
          Read_Master_Log_Pos: 208
               Relay_Log_File: db03-relay-bin.000002
                Relay_Log_Pos: 371
        Relay_Master_Log_File: mysql-bin.000001
             Slave_IO_Running: Yes  #这里要是yes 
            Slave_SQL_Running: Yes  #这里要是yes
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