How to set up autoscaling for ECS cluster that uses scheduled tasks and no service?

Question

I have an ECS cluster which i have an ec2 instance tied to and a scheduled task set to run daily using the 'Scheduled Tasks' functionality on the ECS dashboard.

This task runs aa bunch of containers that are each relatively expensive in memory, and this is compounded even more so with all the containers running at once.

I do not currently have a service set up for the ECS cluster and it is my understanding that for my goals, running a set task on some interval, a service would not be used.

AWS's definition of a service in there ECS docs says:

An Amazon ECS service enables you to run and maintain a specified number of instances of a task definition simultaneously in an Amazon ECS cluster.

Since this is not what I want; instead i need to just run a task on some scheduled interval i gather i do not need an service tied to my ECS cluster.

My question is on how to set up autoscaling for my scheduled tasks? The only references i can find to auto scaling within an ECS cluster are to do with creating ecs services that auto scale - which again, is not what I want (at least from how i understand ecs services to work).

What I need is for my ec2 instances to auto scale with my scheduled task running, allocating more resources as need for the task to run. Would I just need to set up auto scaling on the specific ec2 instance the ecs cluster is tied to from within the ec2 dashboard or is there some other way to do this from ECS directly?

Answer 1

I want; instead, I need to just run a task on some scheduled interval I gather I do not need a service tied to my ECS cluster.

For the above use case better to use fargate and you will not maintain or worry about auto-scaling scheduling , all you need to setup schedule task and AWS will take care of memory and other resources required for your task plus you will only pay for the resources that were used by you ECS task , unlike EC2 type task where you pay for the container instance.

AWS Fargate is a serverless compute engine for containers that works with both Amazon Elastic Container Service (ECS) and Amazon Elastic Kubernetes Service (EKS). Fargate makes it easy for you to focus on building your applications. Fargate removes the need to provision and manage servers, lets you specify and pay for resources per application , and improves security through application isolation by design.

aws fargate

Create a cloud watch rule base on some schedule that will trigger the task, make sure that the container exit once it completes the job, fargate will automatically stop the container.

cloudwatch-event-rule-to-invoke-an-ecs-task