https://vborg.vbsupport.ru/showthread.php?t=272014
The server has maxed out the number of MySQL connections it allows. You can try turning persistent connections off in your config.php:
$config['MasterServer']['usepconnect'] = 0;
But if you still have problems after that, you will need to raise this limit. Here is more info on that error:
http://dev.mysql.com/doc/refman/5.0/...nnections.html