Individual servers are expected to go down from time to time. Even entire datacenters will drop offline for short periods from time to time. Amazon knows this

Individual servers are expected to go down from time to time. Even entire datacenters will drop offline for short periods from time to time. Amazon knows this and builds their system to be tolerant of pieces dropping off. Further, Amazon recommends that other sites do this, and have built EC2 and their other cloud stuff specifically so that you can do it without too much headache. There are plenty of sites running off of EC2 (Amazon included) that don't drop off the internet every time a downtime happens. They're the ones who prepared for such an eventuality ahead of time (and paid for the extra infrastructure needed to do something about it).