If you really want something that is peace-of-mind, you should just use something like rightscale.com. We have a giant ad server on there load balanced across

If you really want something that is peace-of-mind, you should just use something like rightscale.com. We have a giant ad server on there load balanced across 40 ec2 instances running perl code, seems to work well so far. Sometimes an instance will get fussy and we'll just create a new one from scratch by running scripts that essentially fetch everything needed from CPAN and installs, configures, and boots in one step. It's definitely a more expensive solution, but if you want peace of mind, that's probably the way to go.