OS:Centos 7 Linux 3.10.0-229.el7.x86_64
MySQL: mysql57-community-release-el7-7.noarch.rpm
I installed MySQL server
Check below things to fix the issue
Check the permission of mysql data dir using below command. The ownership should be mysql:mysql
and the directory permission should be 700
# ls -ld /var/lib/mysql/
Check the permission of databases inside mysql data dir using below command. The ownership should be mysql:mysql for all the files inside that directory
# ls -lh /var/lib/mysql/
Check the listening network tcp ports using below command
# netstat -ntlp
Check the mysql log files for any error using below command.
# cat /var/log/mysql/mysqld.log
Try to start mysql using below command
# mysqld_safe --defaults-file=/etc/my.cf