I notice foursquare.com resolves to ec2, was the mongodb that got overloaded also on ec2? Can you tell us in what way did it get "overloaded" (iowait, mem/swa

I notice foursquare.com resolves to ec2, was the mongodb that got overloaded also on ec2? Can you tell us in what way did it get "overloaded" (iowait, mem/swap, raw-cpu)?