stabilityStatus 
  The stability status. This indicates whether the task set has reached a steady state. If the following conditions are met, the task set are in STEADY_STATE:
- The task - runningCountis equal to the- computedDesiredCount.
- The - pendingCountis- 0.
- There are no tasks that are running on container instances in the - DRAININGstatus.
- All tasks are reporting a healthy status from the load balancers, service discovery, and container health checks. 
If any of those conditions aren't met, the stability status returns STABILIZING.