Deletes one or more task definitions.

You must deregister a task definition revision before you delete it. For more information, see DeregisterTaskDefinition.

When you delete a task definition revision, it is immediately transitions from the INACTIVE to DELETE_IN_PROGRESS. Existing tasks and services that reference a DELETE_IN_PROGRESS task definition revision continue to run without disruption. Existing services that reference a DELETE_IN_PROGRESS task definition revision can still scale up or down by modifying the service's desired count.

You can't use a DELETE_IN_PROGRESS task definition revision to run new tasks or create new services. You also can't update an existing service to reference a DELETE_IN_PROGRESS task definition revision.

A task definition revision will stay in DELETE_IN_PROGRESS status until all the associated tasks and services have been terminated.