Placement constraints

Ocean supports both built‑in and custom ECS task placement constraints. These constraints let you decide where tasks run, such as on a specific instance type or in a particular Availability Zone. You can also create custom key‑value attributes and use them to control placement.

On‑demand lifecycle placement restraint

Ocean provides a custom placement restraint that lets you run certain tasks only on on‑demand instances. This is useful for workloads that must avoid interruption.

Use this format to require on‑demand lifecycle:

attribute:spotinst.io/container-instance-lifecycle==od

Use this feature

To use the on‑demand lifecycle placement restraint:

• Add the ecs:PutAttributes permission to the IAM role your ECS instances use. The autoscaler uses this permission to apply the lifecycle attribute to on‑demand instances when tasks request it.

• Contact Flexera Support by chat or email and request that ECS lifecycle support be enabled for your service.

How it works

When Ocean detects pending tasks that require the on‑demand lifecycle attribute, it launches an on‑demand instance and applies the attribute automatically. Tasks that include the lifecycle constraint are then placed only on those instances.