Autoscaling Amazon ECS services based on custom metrics with Application Auto Scaling

Introduction

Application Auto Scaling is a web service for developers and system administrators who need a solution for automatically scaling their scalable resources for AWS services such as Amazon Elastic Container Service (Amazon ECS) services, Amazon DynamoDB tables, AWS Lambda Provisioned Concurrency, and more. Application Auto Scaling now offers support for scaling such resources using scaling policies that are based on custom Amazon CloudWatch metrics, which are evaluated against a metric math expression. In this post, we’ll demonstrate how this feature works using a sample scenario, which involves scaling an Amazon ECS service based on the average rate of HTTP requests handled by the service.

Background

Horizontal scalability is a critical aspect of cloud native applications. Application Auto Scaling integrates with several AWS services so that you can add scaling capabilities to meet your application’s demand. It can use one or more of the relevant predefined metrics available …