We are going to complement the metrics we already have with OS-specific information. This will include more detailed information about the CPU, disk usage, and memory.

When browsing the EC2 metrics, you will notice that you can query those metrics, from the Auto Scaling group:

It is important to retain this ability to query a set of metrics by specific criteria, especially by Auto Scaling groups. To provide the same capability to our custom metrics, we need to make a change to our CloudFormation template, to allow our EC2 instances to get the Auto Scaling group information.