How to solving Phpmyadmin [Ubuntu] - the local server's socket is not correctly configured

this video will help you how to solving the Phpmyadmin error in ubuntu.
ERROR :
the server is not responding (or the local server's socket is not correctly configured)

and if you trying to login by terminal :
mysql -u root -p

will showing an error like this :
Can't connect to local MySQL server through socket

SOLVING :
1. kill the processid of mysql by terminal
2. restart mysql with: sudo service mysql restart
3. try login again by phpmyadmin

[sergiubcv]

But why does this error happen? can't I prevent it? Has it already happened to me 3 times in a year? Thanks!