ServicePlacementStrategy

The field to apply the placement strategy against. For the `spread` placement strategy, valid values are `instanceId` (or `host`, which has the same effect), or any platform or custom attribute that's applied to a container instance, such as `attribute:ecs.availability-zone`. For the `binpack` placement strategy, valid values are `cpu` and `memory`. For the `random` placement strategy, this field is not used.

The type of placement strategy. The `random` placement strategy randomly places tasks on available candidates. The `spread` placement strategy spreads placement across available candidates evenly based on the `field` parameter. The `binpack` strategy places tasks on available candidates that have the least available amount of the resource that's specified with the `field` parameter. For example, if you binpack on memory, a task is placed on the instance with the least amount of remaining memory but still enough to run the task.