vBulletin Database Error!

[ccw]

Recently I receive thousands of spam attacks which leads to thousands of emails like this:

Database error in vBulletin :

mysql_connect() [<a href='function.mysql-connect'>function.mysql-connect</a>]: Too many connections /var/www/vhost/forums.datanumen.com/htdocs/includes/class_core.php on line 317

MySQL Error :
Error Number :
Request Date : Thursday, June 26th 2014 @ 07:37:35 AM
Error Date : Thursday, June 26th 2014 @ 07:37:36 AM
Script : http://forums.datanumen.com/member.p...pe=user&page=3
Referrer :
IP Address : 37.58.100.73
Username :
Classname : vB_Database
MySQL Version :


How to block the spam and prevent such a problem?

Thanks