How ECS handles non‑service tasks

Non‑service tasks depend entirely on the available resources in your cluster. If there’s not enough CPU or memory at the time you submit the task:

• The task may fail to launch with resource‑related errors.

• ECS doesn’t retry non‑service tasks the way it retries service tasks.

• The task starts only after enough resources become available on an existing instance or a new instance is launched.

Why this behavior occurs

Services have autoscaling and deployment logic that keeps tasks running. Non‑service tasks don’t.

Because they're standalone, ECS won’t repeatedly attempt to place them. Instead, placement happens only when the cluster has available capacity.