Just a quick post, for something that seems to happen for no particular reason. If (like me) you don’t fancy changing where MySQL places the unix socket, simply create a symbolic link from where it puts it by default in Zend Server CE.
sudo ln -s /usr/local/zend/mysql/tmp/mysql.sock /tmp/mysql.sock
I cannot locate the mysql.sock in either location – any ideas? Its driving me mad.
If it doesn’t exist at all I’m afraid the first port of call would probably be to re-install Zend Server (CE) which current versions I believe should leave your databases intact (I think that’s how I resolved the problem when the same issue happened to me not long after the original blog post)