每当我尝试重新启动 mysql 服务器时，它都会显示以下错误
Enter password:
ERROR 2002 (HY000): Can't connect to local MySQL server through socket '/var/run/mysqld/mysqld.sock' (13)
我尝试使用
service mysql start
但它显示以下错误
Job for mysql.service failed because the control process exited with error code.
See "systemctl status mysql.service" and "journalctl -xe" for details.
服务状态mysql服务显示以下内容
mysql.service - MySQL Community Server
Loaded: loaded (/lib/systemd/system/mysql.service; enabled; vendor preset: en
Active: failed (Result: start-limit-hit) since Mon 2019-07-08 19:03:30 IST; 1
Process: 4070 ExecStartPre=/usr/share/mysql/mysql-systemd-start pre (code=exit
Jul 08 19:03:30 arnab systemd[1]: Failed to start MySQL Community Server.
Jul 08 19:03:30 arnab systemd[1]: mysql.service: Unit entered failed state.
Jul 08 19:03:30 arnab systemd[1]: mysql.service: Failed with result 'exit-code'.
Jul 08 19:03:30 arnab systemd[1]: mysql.service: Service hold-off time over, sch
Jul 08 19:03:30 arnab systemd[1]: Stopped MySQL Community Server.
Jul 08 19:03:30 arnab systemd[1]: mysql.service: Start request repeated too quic
Jul 08 19:03:30 arnab systemd[1]: Failed to start MySQL Community Server.
Jul 08 19:03:30 arnab systemd[1]: mysql.service: Unit entered failed state.
Jul 08 19:03:30 arnab systemd[1]: mysql.service: Failed with result 'start-limit
journalctl -xe 显示以下内容：
Unit mysql.service has finished shutting down.
Jul 08 19:03:30 arnab systemd[1]: mysql.service: Start request repeated too quickly.
Jul 08 19:03:30 arnab systemd[1]: Failed to start MySQL Community Server.
-- Subject: Unit mysql.service has failed
-- Defined-By: systemd
-- Support: http://lists.freedesktop.org/mailman/listinfo/systemd-devel
--
-- Unit mysql.service has failed.
--
-- The result is failed.
Jul 08 19:03:30 arnab systemd[1]: mysql.service: Unit entered failed state.
Jul 08 19:03:30 arnab systemd[1]: mysql.service: Failed with result 'start-limit-hit'.
Jul 08 19:05:01 arnab CRON[4094]: pam_unix(cron:session): session opened for user root by (uid=0)
Jul 08 19:05:01 arnab CRON[4095]: (root) CMD (command -v debian-sa1 > /dev/null && debian-sa1 1 1)
Jul 08 19:05:01 arnab CRON[4094]: pam_unix(cron:session): session closed for user root
错误是什么？
hosts文件内容如下：
127.0.0.1 localhost
127.0.1.1 arnab-HP-450-Notebook-PC
127.0.0.1 arnab
# The following lines are desirable for IPv6 capable hosts
::1 ip6-localhost ip6-loopback
fe00::0 ip6-localnet
ff00::0 ip6-mcastprefix
ff02::1 ip6-allnodes
ff02::2 ip6-allrouters