Over the past hour I've been struggling with what seems like an attack on my VPS hosting service. Technical support have reported as follows:
It seems your server was being hit hard by the following IPs ... They were creating so many apache processes your server was running out of RAM which was causing the services to fail.
I run almost exclusively WordPress websites (The IP's originate in Romania ... and one of the high-traffic websites on the host is a WordPress Romanian install). Is there something I can do in WordPress to prevent this? (search forums and plugins - and couldn't find anything that seemed relevant to this).