#环境配置#
master IP:192.168.46.137  slave IP:192.168.46.138  database:v1

#编辑mysql的配置文件，增加以下内容#
vim etc/my.cnf
server-id=1
binlog-do-db=v1
relay-log=/var/lib/mysql/mysql-relay-bin
relay-log-index=/var/lib/mysql/mysql-relay-bin.index
log-error=/var/lib/mysql/mysql.err
master-info-file=/var/lib/mysql/mysql-master.info
relay-log-info-file=/var/lib/mysql/mysql-relay-log.info
log-bin=/var/lib/mysql/mysql-bin
编辑完成后，重启mysql，systemctl restart mysqld.service(centos7 直接使用systemctl命令)
创建一个复制用户，具有replication slave 权限
grant replication slave on *.* to 'user3'@'192.168.46.138' identified by 'user3';
用户名:user3  密码:user3
flush privileges;
#查看主库状态#
show master status;

记住FileSet和Position参数值，后面步骤会用到

#编辑从数据库配置文件，添加以下内容#
vim etc/my.cnf
server-id=2
replicate-do-db=v1
relay-log=/var/lib/mysql/mysql-relay-bin
relay-log-index=/var/lib/mysql/mysql-relay-bin.index
log-error=/var/lib/mysql/mysql.err
master-info-file=/var/lib/mysql/mysql-master.info
relay-log-info-file=/var/lib/mysql/mysql-relay-log.info
log-bin=/var/lib/mysql/mysql-bin
注意:两个数据库配置文件里的server-id不能相同
重启mysql
mysql -u root -pxxx
change master to master_host='192.168.46.137',master_user='user3',master_password='user3',master_log_file='mysql-bin.000003',master_log_pos=120;
#启动slave线程#
start slave;
# 查看slave状态,注意G后面没有分号#
show slave status\G

  红色箭头所指两个参数,如果都为Yes,说明配置成功,如果Slave_IO_Running为connecting,请检查防火墙，端口是否开放，FIle，Position参数是否一致，网络是否畅通等

到此，mysql主从配置完成，可以新增数据查看是否同步了