Making It Scalable: Adding an Auto Scaling Group

EC2 Auto Scaling groups (ASGs) are AWS’s implementation of autoscaling on an instance level, so they perform scaling activities with instances as the smallest unit. AWS also offers autoscaling for other services, for example, containers or lambda functions.

The main components of an ASG are the following:

• A launch template or launch configuration (outdated) to describe the instances used for autoscaling.
• A minimum, maximum, and desired size for the ASG.
• A load balancer to connect to so that the ASG is part of a target group (optional).
• Health checks to automatically replace faulty instances (optional but highly recommended).