We saw that our clusters didn’t scale even when we were using 80% CPU across all three nodes. To addres this, we’ll configure an Auto Scaling Group (ASG) for our cluster.
Go to the AWS Console and select EC2 from Services.
On the left navigation bar, select Auto Scaling Groups.
Each Cluster gets its own Auto Scaling Group. Go ahead and check off the one you need. In the next section, select Automatic scaling, followed by Add Policy.
For “Policy type” select “Simple scaling”
Enter a name for the policy, for example,
This policy must be triggered by a CloudWatch alarm, which we’ll set up in the next section. For now, click Create a CloudWatch alarm.