我运行：sudo service mysql restart然后我得到了这个：
Job for mysql.service failed because the control process exited with error code.
See "systemctl status mysql.service" and "journalctl -xe" for details.
当我运行时systemctl status mysql.service我得到：
Oct 01 21:27:16 matthewserver systemd[1]: Failed to start MySQL Community Server.
Oct 01 21:27:17 matthewserver systemd[1]: mysql.service: Service hold-off time over, scheduling restart.
Oct 01 21:27:17 matthewserver systemd[1]: mysql.service: Scheduled restart job, restart counter is at 5.
Oct 01 21:27:17 matthewserver systemd[1]: Stopped MySQL Community Server.
Oct 01 21:27:17 matthewserver systemd[1]: mysql.service: Start request repeated too quickly.
Oct 01 21:27:17 matthewserver systemd[1]: mysql.service: Failed with result 'exit-code'.
Oct 01 21:27:17 matthewserver systemd[1]: Failed to start MySQL Community Server.
Oct 01 21:27:25 matthewserver systemd[1]: mysql.service: Start request repeated too quickly.
Oct 01 21:27:25 matthewserver systemd[1]: mysql.service: Failed with result 'exit-code'.
Oct 01 21:27:25 matthewserver systemd[1]: Failed to start MySQL Community Server.
为什么会出现这个问题？我该如何解决？