Just curious how he got $0.11/hr for a "spot" instance of g2.2xlarge? Amazon's "on demand" pricing of that config w/ Windows on their website is $0.767/hr.
On-demand and spot prices are two different things. Keep looking at the pricing page and you will see. Spot prices fluctuate constantly and your instance is auto-killed when the spot prices rises above the maximum price you are willing to pay.
Thanks, I wasn't aware of the spot pricing (never scrolled that far down the very long pricing page :)
I'm not sure that I understand the economics of the spot option from Amazon's POV since it seems that a person who needed persistent servers could set their spot max price at the same price as an on-demand instance and always be ahead by doing it that way (with the caveat that there would be a short interruption if forced to switch to on-demand).
For someone who needs cheapest possible compute power with a flexible schedule, spot arbitrage makes sense of course.
> it seems that a person who needed persistent servers could set their spot max price at the same price as an on-demand instance and always be ahead by doing it that way
Not if you need persistence: the spot price can go above the on-demand price. So if you set your max spot price to the on-demand price your instance might get terminated.
> set their spot max price at the same price as an on-demand instance
People have played that game before and lost. Spot pricing can and has gone above the on-demand prices. It is normally a great way to save money, but there's no way to avoid the possibility of having your instance terminated. If that's not something you've built around then you have to stick to on-demand (or reserved).
Sounds about right. For example, Oregon 2b averages around $0.18/hour. Different AZs are drastically different. Some of them hover around the demand price while others are rock bottom.
