What is the mechanism to get load on a box to trigger an autoscaling group in AWS?

Question

I've got my web servers set up to autoscale at certain times of the day.

I can measure the load on the box using scripts executed by Consul - and this can trigger events at certain thresholds.

I want to push these two together and trigger autoscaling at certain load levels. (Assume CPU load at 75% is the threshold).

My question is: What is the mechanism to get load on a box to trigger an autoscaling group in AWS?

Assumptions:

• I was not planning to use AWS Cloudwatch - but am interested if this is the solution.
• I'm more interested in the autoscale triggering interface. Is it a queue or a rest endpoint?

Answer 1

As @mahdi said, you can easily use AWS Cloudwatch to do this.

However, if you want Consul (or anything outside the scope of an AWS "service") to do it, you can use lambda.

You would create a lambda function that scales your instance up or down (or both). Lambda can have many triggers, such as an HTTP endpoint through API Gateway. If you already have Consul set up to do it (sounds like you do since you said can trigger events at certain thresholds.) just make it issue the HTTP request to API Gateway to scale up or down.