Chaos monkey preparing for the worst

http://techblog.netflix.com/2012/07/chaos-monkey-released-into-wild.html

The best defense against major unexpected failures is to fail often. By frequently causing failures, we force our services to be built in a way that is more resilient. Chaos Monkey is a service which runs in the Amazon Web Services (AWS) that seeks out Auto Scaling Groups (ASGs) and terminates instances (virtual machines) per group.