替代AWS上的专色实例的内置自动缩放组

Question

I am currently using spot instances managed with auto-scaling groups. However, ASG has a number of shortcomings for use with spot instances. For example, it cannot launch instances of a different instance type if the current type is experiencing a price spike across all availability zones. It can't even re-distribute the number of running instances across zones (if one zone has a price spike, you're down 30% in the number of running instances.)

Are there any software solutions that I could run which would replace built-in AWS Auto-Scaling Groups? I've heard of SpotInst and Batchly, but I do not trust them. Basically, I think their business plan involves being bought out and killed by Amazon, like what happened to ClusterK. The evidence for this is the bizarre pricing policies and other red flags. I need something that I can self-host and depend on.

Answer 1

AWS recently released Auto Scaling for Spot Fleets which seems to fit your use case pretty well. You can define the cluster capacity in terms of vCPU that you need, choose the instance types you'd like to use and their weights and let AWS manage the rest. They will provision spot instances at their current market price up to a limit you can define per instance type (as before), but integrating Auto Scaling capabilities.

You can find more information here. https://aws.amazon.com/blogs/aws/new-auto-scaling-for-ec2-spot-fleets/

Answer 2

It's unlikely that you're going to find something that takes into account everything you want. But because everything in Amazon is an API, so you can write that yourself. There are lots of ways to do that.

For example, you could write a small script (bash, ruby, python etc) that shells out the AWS CLI to get the price, then shells out to launch boxes. For bonus points, use the native AWS SDK library instead of shelling out. (That will be slightly easier to handle errors, etc.) For even more bonus points, open source it, and hope that other people to improve on it!

This script can run on your home computer, or on a t1.micro for $5/month. Or you could write it in node.js, and run it on Lambda for pennies per month.

Answer 3

Here at Spotinst, these are exactly the problems we built Elastigroup to solve. Elastigroup enables running simultaneously on as many instance types and availability zones (within a region) as you'd like. This is coupled with several things to maintain production availability:

1. Our algorithm makes live choices for the best Spot markets in terms of price and availability.

2. When an interruption happens, we predict it about 15 minutes in advance and take all the necessary steps to ensure (and insure) the capacity of your group.

3. In the extreme case that none of the markets have Spot availability, we simply fall back to an on-demand instance.

We have a great relationship with AWS and work closely with both their technical and business teams to provide our joined customers with the best experience possible. As we manage resources inside your own AWS account, I wouldn't put the relationship between us as a concern, to begin with.