Signup for an Account at
Web-Tech-Center.com, it's free while they're in BETA. That way you'll be easily able to monitor your servers, and get an immediate alert if something is going down or out of shape.
You might also login via SSH and keep the "t" command running, with "Shift+M" you can sort the biggest Memmory eaters to the top, and when the Server goes down again your SSH terminal will freeze with the biggest memory eater at that time on top
