Deze mag dicht alles is opgelost.
Dankzij Direct admin Support

Hello,

Find out where the actual mysql.sock is. You can do that by running:

netstat -l | grep mysql

it should show you the correct path. Also make sure that mysqld is running.
Often a restart of mysqld will fix the problem.

Once you locate where the file is, just create a symbolic link from /tmp/mysql.sock to the actual file:

ln -s /path/to/real/mysql.sock /tmp/mysql.sock