部署环境：
操作系统版本：cent-os-7数据库版本：mysql-5.7master1的IP地址：192.168.1.100master2的IP地址：192.168.1.101
1.登录master1和master2分别修改my.cnf：
#======master1========#
server-id = 1
log-bin=mysql-bin
binlog-do-db = test
binlog-ignore-db = mysql
log-slave-updates
sync_binlog = 1
auto_increment_offset = 1
auto_increment_increment = 2
replicate-do-db = test
replicate-ignore-db = mysql,information_schema
#======master2========#
server-id = 2
log-bin=mysql-bin
binlog-do-db = test
binlog-ignore-db = mysql
log-slave-updates
sync_binlog = 1
auto_increment_offset = 2
auto_increment_increment = 2
replicate-do-db = test
replicate-ignore-db = mysql,information_schema
修改完后，重启服务。
2.创建同步账户
#======master1========#
mysql>grant replication slave on *.* to user@192.168.1.101 identified by "123";
mysql>flush privileges;
#======master1========#
mysql>grant replication slave on *.* to user@192.168.1.100 identified by "123";
mysql>flush privileges;
3.修改需同步的主数据库
#======master1========#
mysql>change master to
>master_host='192.168.1.101',master_user='user',master_password='123',
>master_log_file='mysql-bin.000001',master_log_pos=154;
>start slave;
#======master2========#
mysql>change master to
>master_host='192.168.1.100',master_user='user',master_password='123',
>master_log_file=' mysql-bin.00001',master_log_pos=154;
>start slave;
