起因：部署在服务器的项目长时间未访问报错
分析：数据库自动关闭造成的 参考链接解决：
查看所有tcp端口，确认mysql状态：netstat -ntlp
重启mysql ：service mysql start
1）问题1 重启中出现
Job for mysql.service failed because the control process exited with error code.See "systemctl status mysql.service" and "journalctl -xe" for details.
2）定位错误
tail /var/log/mysql/error.log
Cannot allocate memory for the buffer poolPlugin initialization aborted with error Generic error.
3）解决方法：参考链接
