MySQL 5.7 以上版本才能使用

		
 master1  ---------> master2
    ^                   |
    |                   |
    |                   |
    |                   V
 master4  <--------- master3
 		
		

MySQL 5.7 以上版本才能使用

		
 master1    master2    master3    master4
    |          |          |          |
    |          |          |          |
    |          |          |          |
    `--------------------------------'
                    |
                    V
                  Slave
 		
		

slave 配置

		
slave> change master to master_host="172.16.0.1", master_port=3306, master_user="replication",master_password="password" for channel="master1";
slave> change master to master_host="172.16.0.2", master_port=3306, master_user="replication",master_password="password" for channel="master2";

slave> start slave for channel="master1";
slave> start slave for channel="master2";
		
		

检查从服务器状态

		
slave > SHOW SLAVE STATUS FOR CHANNEL="master1"\G
slave > SHOW SLAVE STATUS FOR CHANNEL="master2"\G		
		
		

测试,分别在两个主服务器上创建数据库，然后查看从数据库同步结果.

		
master1 > create database master1;
master2 > create database master2;

slave > show databases like 'master%';
+--------------------+
| Database (master%) |
+--------------------+
| master1            |
| master2            |