解决报错 Can not connect to local MySQL server through socket

     1.启动命令

systemctl start mysqld.service 或者 /etc/init.d/mysqld start   结果同样的错误

     2.错误是:

      Job for mysqld.service failed. See 'systemctl status mysqld.service' and 'journalctl -xn' for details.

     3.按照提示输入命令

      systemctl status mysqld.service 或者 journalctl -xn

      命令后提示:

        mysqld.service - SYSV: MySQL database server.

    Loaded: loaded (/etc/rc.d/init.d/mysqld)

    Active: failed (Result: exit-code) since Tue 2017-03-14 09:00:45 CST; 9s ago

  Process: 2550 ExecStart=/etc/rc.d/init.d/mysqld start (code=exited, status=1/FAILURE)

  Starting SYSV: MySQL database server....

  MySQL Daemon failed to start.

Starting mysqld:  [FAILED]

mysqld.service: control process exited, code=exited status=1

Failed to start SYSV: MySQL database server..

Unit mysqld.service entered failed state.

    4.进一步查看日志:

       vi /var/log/mysqld.log

        如下:

         [ERROR] /usr/sbin/mysqld: Can't create/write to file '/var/run/mysqld/mysqld.pid' (Errcode: 2 - No such file or directory)

[ERROR] Can't start server: can't create PID file: No such file or directory

    5.创建该目录

        mkdir -p /var/run/mysqld/

    6.启动mysql服务

     /etc/init.d/mysqld start

     错误和原来一致

   7.查看日志:

     如下:

          [ERROR] /usr/sbin/mysqld: Can't create/write to file '/var/run/mysqld/mysqld.pid' (Errcode: 13 - Permission denied)

          [ERROR] Can't start server: can't create PID file: Permission denied

    8.授权

      chown mysql.mysql /var/run/mysqld/

   9.启动

      /etc/init.d/mysqld start

      Starting mysqld (via systemctl):                           [  OK  ]