Amazon says its new EC2 Spot Instances offering lets user bid on unused EC2 capacity and run those instances for as long as their bid exceeds the current Spot Price. The price will change based on supply and demand and is not for everyone obviously.
Amazon says applications suited to this kind of pricing model might be image and video processing, conversion and rendering, scientific research data processing and financial modeling and analysis, all typical EC2 use cases already.
From Amazon’s perspective, it might as well sell as much of its unused capacity as it can, even if it is just for cents on the dollar. Presumably there’s a way through the AWS console for users to be alerted when the bids and pricing changes to warn them if they are about to lose their instance to someone willing to pay more for it. That sounds like a nightmare waiting to happen.
There is a feature called Persistent Request that supposedly prevents your instance from terminating before it has finished your job, but you might want to try this out a few times before you do anything real on it!
Hats off to Amazon though for continuing to innovate around pricing and during it’s peak season too.