Spot Instances

Savings plans are great, but what if you want to save even more money? Allow me to introduce you to spot instances.

Imagine you're in AWS' shoes. You have to build out new racks of servers to keep up with demand, and you want to streamline things, so you install not just what you need today but what you think you'll need for the next few years.

This leads to a problem: what to do with all the new capacity that's not being used yet?

AWS lets you bid on this unused capacity with no long term commitment at a ~90% discount. With one small caveat.

Dear Zach,

I'll give you this massive discount, but be warned, at any time I may literally delete your server. Don't worry, I'll give you a 2-minute heads-up.

Love, Jeffy B

So, if you have a stateless application that only needs to do async or offline compute, spot instances might be the perfect choice. If a server dies, no worries, you can just start a new one and pick up where you left off.

But if you need to be always on, spot instances are not a good fit.