To perform activities, such as system/Docker daemon updates or scaling down the cluster, you might need to remove an instance from the cluster.
By enabling container instance draining, you can remove the instance from the cluster without impacting the existing task. Amazon ECS prevents a new task being scheduled for placement in the container instance, when you set the instance as DRAINING.
For available resources, a replacement service task will start on other container instances. For PENDING state resources on the container, the instance will stop immediately. For RUNNING state resources on the container, the instance will stop and replace, as per the parameters in deployment configuration. The container instance ...
