Article on the History of Spot Instances: Analyzing Spot Instance Pricing Change

I am a fan of Rackspace Spot, and use it personally. It started out being a pure play Kubernetes cluster provider, but recently they added support for VMs.

I was so impressed by its pricing and efforts at transparency that it motivated me to learn Kubernetes. I finally achieved the "cattle, not pets" nirvana. My Kubernetes cluster running a demo service costs me $14/month: $4/month for the spot instance, $10/month for the load balancer, and $free Kubernetes control plane (non-redundant; not intended for production). $14/month is an amazing value, as long as you know the limitations.

Although this article greatly emphasizes Rackspace's market-based prices, they do have some price controls. First, they have a reserve (floor) price on their compute. In their older data centers, it's $0.001/hr ($1/mo), while in their newer data centers it's 10x higher: $0.01/hr ($7/mo). Second, their bidding UI supports bids only in increments of $0.005/hr, so you actually can't bid $0.001: $0.005/hr ($4/mo) is the lowest supported. If everyone bids $0.005/hr to start, then is $0.001/hr even achievable as a market-clearing price?

Secondly, their pricing is not as sweet on everything else beyond spot compute. Load balancers are $10/mo each. On-demand instances are comparable to on-demand pricing in other cloud providers. (A 2 vCPU / 4 GB RAM instance in the older data center costs $27/mo; almost equal to AWS t4g EC2 instance with the same vCPU/RAM combo.)

Today I run a POC web service on Rackspace Spot, and I pay $14/month; this is the lowest achievable price on Rackspace Spot, and it is not production-quality.

If you run a production web service, your costs grow to $40/mo (redundant Kubernetes control plane) + $27/mo (on-demand cheapest instance) + $10/mo (load balancer) = $77/mo at a minimum. You'll also be paying for storage, but I don't include that. Spot instances don't even play a role here.

Is that still a great value compared to other providers? I am not sure. If it is, then Rackspace Spot marketing is focusing on the wrong thing. And if it's not a great value anymore, then it makes sense only if your workload is heavily dependent on interruptible compute.

This article renders really poorly on iPhone Safari - the left side of the text is cut off a little bit (the example the first header reads as "keaways" instead of takeaways).