在主从复制的时候如果第二个虚拟机是复制过去的，需要修改
1. 首先要查找到mysql的安装地址
show variables like 'datadir';
+---------------+-----------------+
| Variable_name | Value |
+---------------+-----------------+
| datadir | /var/lib/mysql/ |
+---------------+-----------------+
1 row in set (0.00 sec)
//然后通过mysql生成一个uuid进行记录等会用于修改
select uuid()
+--------------------------------------+
| uuid() |
+--------------------------------------+
| 2674149f-5083-11e8-be4b-080027a1f331 |
+--------------------------------------+
2. 然后进入datadir目录
cd /var/lib/mysql/
vi auto.cnf
//修改server-uuid
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3.重启mysql
service mysqld restart