第一步：找到my.cnf文件。在etc目录下，修改或添加下面三个地方

1 [mysqld] 2 character-set-server=utf8mb4 3 default_password_lifetime=0 4 datadir=/usr/local/mysql/data 5 socket=/usr/local/mysql/mysql.sock 6  7 [mysqld_safe] 8 log-error=/usr/local/mysql/logs/mysqld.log 9 pid-file=/usr/local/mysql/pids/mysqld.pid10 11 # Disabling symbolic-links is recommended to prevent assorted security risks12 symbolic-links=013 # Settings user and group are ignored when systemd is used.14 # If you need to run mysqld under a different user or group,15 # customize your systemd unit file for mariadb according to the16 # instructions in http://fedoraproject.org/wiki/Systemd17 18 [client]19 default-character-set=utf8mb420 # default-character-set=utf821 socket=/usr/local/mysql/mysql.sock22 23 [mysql]24 default-character-set=utf8mb425 socket=/usr/local/mysql/mysql.sock26 27 # include all files from the config directory28 #29 !includedir /etc/my.cnf.d

第二步：重启MySQL服务

备注：如果重启发生错误

# ps -aux | grep mysql //查看mysqld服务的端口

一堆东西，显示没什么异常

# netstat -apn | grep 3306 //直接看3306对应端口的情况

tcp 0 0 0.0.0.0:3306 0.0.0.0:* LISTEN 2896/mysqld

找到问题

[root@IM2_JH_OTT mysql-5.7.16]# kill 2896

[root@IM2_JH_OTT mysql-5.7.16]# service mysqld restart

把占用端口的服务2896kill掉再重启，问题得以解决

 

参考网址