Posted On: Nov 24, 2020

Amazon Elastic Container Service (Amazon ECS) Cluster Auto Scaling (CAS) now offers more responsive scaling when using EC2 Auto Scaling groups (ASGs) that span across Availability Zones (AZs) and instance types.

Before this launch, if your ASG did not confine to a single-AZ or used multiple instance types, the scaling speed was restricted by the minimum scaling step size defined in the capacity provider configuration. Now, CAS can estimate the optimal number of instances to add for such ASGs, similar to how it estimates for single AZ and instance type ASGs, making the scaling more responsive.

With CAS, the scaling policy of your ASG is managed by Amazon ECS through a capacity provider. You can configure the capacity provider to enable managed scaling of the ASG, reserve excess capacity in the ASG, and also to manage termination of instances in the ASG.

This new enhancement is enabled by default when using CAS and does not require you to take any action. To learn more, visit the Deep Dive on Amazon ECS Cluster Auto Scaling blog post and documentation.