I had this error just now, and couldn't post for a while:

Warning: Can't connect to local MySQL server through socket '/var/lib/mysql/mysql.sock' (2) in /usr/local/apache/sites/dvdtalk.com/htdocs/forum/admin/db_mysql.php on line 40

Warning: MySQL Connection Failed: Can't connect to local MySQL server through socket '/var/lib/mysql/mysql.sock' (2) in /usr/local/apache/sites/dvdtalk.com/htdocs/forum/admin/db_mysql.php on line 40

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I've had that problem before. I think it corrected itself in a matter of minutes, but I can't remember for sure.

once in a while I have to reboot the database, shouldn't last more than a few moments

I had only seen it a few times in the last couple years or so, so it's no biggie.