I've been scaring the students and staff at Bristol University with a new presentation, Farms, Fabrics and Clouds.

In which it is argued that the ability to instantiate Virtual Machine images for $0.10/CPU hour brings about a fundamental change in how applications are viewed and designed.

You no longer achieve reliability through investment in extra hardware, you no longer have to estimate load in advance. You don't even get static IP addresses or the ability to mount persistent storage as part of the filesystem. Instead you have to design for rapid shift in load, dynamic, failover and recovery. You have to plan for the filestore being on the network somewhere -explicitly- and you have to embrace this dynamic world from the outset.

I didn't demo the EC2 components for SmartFrog that I don't have fully stable yet; getting a network connection and bringing up multiple hosts then SSH-ing was enough. It's nice to let the audience pick a number and bring up that many machines -it shows that the infrastructure really is agile.