重启Mysql服务无法成功：

[root@wangerxiao ~]# systemctl  restart   mysql.service     
Job for mysql.service failed because the control process exited with error code. See "systemctl status mysql.service" and "journalctl -xe" for details.

查看详细信息后为：

[root@wangerxiao ~]# systemctl status mysql.service
* mysql.service - LSB: start and stop MySQL
   Loaded: loaded (/etc/rc.d/init.d/mysql; bad; vendor preset: disabled)
   Active: failed (Result: exit-code) since Thu 2016-12-22 18:06:42 CST; 19s ago
     Docs: man:systemd-sysv-generator(8)
  Process: 8821 ExecStop=/etc/rc.d/init.d/mysql stop (code=exited, status=0/SUCCESS)
  Process: 8892 ExecStart=/etc/rc.d/init.d/mysql start (code=exited, status=1/FAILURE)


Dec 22 18:06:38 wangerxiao systemd[1]: Starting LSB: start and stop MySQL...
Dec 22 18:06:42 wangerxiao mysql[8892]: Starting MySQL.... ERROR! The server quit without updating PID file (/usr/local/mysql/var/wangerxiao.pid).
Dec 22 18:06:42 wangerxiao systemd[1]: mysql.service: control process exited, code=exited status=1
Dec 22 18:06:42 wangerxiao systemd[1]: Failed to start LSB: start and stop MySQL.
Dec 22 18:06:42 wangerxiao systemd[1]: Unit mysql.service entered failed state.
Dec 22 18:06:42 wangerxiao systemd[1]: mysql.service failed.

原因为新的版本的Mysql编码格式的设置有所改变：

[root@wangerxiao ~]# vim  /etc/my.conf     
  1 [client]
  2 #default-character-set = utf8   //将该行注释
  3 #password   = your_password
  4 port        = 3306
  5 socket      = /tmp/mysql.sock
  6 
  7 [mysqld]
  8 
  9 #default-character-set = utf8   //将改行注释
 10 port        = 3306
 11 socket      = /tmp/mysql.sock
 12 datadir = /usr/local/mysql/var
 13 skip-external-locking
 14 key_buffer_size = 64M
 15 max_allowed_packet = 1M
 16 table_open_cache = 256
 17 sort_buffer_size = 1M
 18 net_buffer_length = 8K
 19 read_buffer_size = 1M
 20 read_rnd_buffer_size = 512K
 21 myisam_sort_buffer_size = 16M
 22 thread_cache_size = 32
 23 query_cache_size = 32M
 24 tmp_table_size = 64M

保存修改后重启服务，服务生效

注：新版本的Mysql的编码格式设置为
在[mysqld]下把default-character-set=utf8换成
character-set-server=utf8就可以了