Containers-roadmap: [ECS] [RFC]: Automated instance termination protection management

[coultn]

Request for comment: please share your thoughts on this proposed improvement to ECS!

With this improvement, ECS will control which cluster instances in an EC2 Auto Scaling Group (ASG) can be terminated when the ASG scales in.

• EC2 ASG already has an instance protection feature. This is a flag for each instance that, when set, prevents the ASG from terminating the instance when the ASG is scaling in.

• ECS will automatically set the instance protection flag on ECS cluster instances as needed, with the following objectives: (1) instances running few or no tasks should be preferred for termination over instances running many tasks; (2) if termination of an instance would cause an ECS service with an AZ spread strategy to reduce the number of AZs running service tasks, do not terminate the instance.

[coultn]

This has launched as part of ECS cluster auto scaling: https://aws.amazon.com/blogs/aws/aws-ecs-cluster-auto-scaling-is-now-generally-available/