https://blog.wongcw.com/2018/08/03/centos7-2-%e8%b0%83%e6%95%b4mysql%e6%95%b0%e6%8d%ae%e5%ba%93%e6%9c%80%e5%a4%a7%e8%bf%9e%e6%8e%a5%e6%95%b0/