1. There are many configuration files for mysql. There name looks like my-huge.cnf, my-medium.cnf.... Select the best one for our system and copy it as /etc/my.cnf. 

2. open /etc/my.cnf(gedit, or vi).  Goto the "mysqld" section, and add a new line:
     skip-name-resolve    #Do not resolve hostnames.

3. restart mysql.