https://www.cnblogs.com/kevingrace/p/5569753.html
https://www.cnblogs.com/zhoujinyi/p/5704567.html
https://liwanggui.com/posts/mysql-gtid-replication/
https://liwanggui.com/posts/mysql-mha/
https://liwanggui.com/posts/mysql-maxscale-readwrite-separation/