TaskScheduler may end up releasing containers and getting stuck without enough resources

if (hitFinalMatchLevel) {
            // Are there any pending requests at any priority?
            // release if there are tasks or this is not a session
            if (!taskRequests.isEmpty() || !appContext.isSession()) {
              LOG.info("Releasing held container as either there are pending but "
                + " unmatched requests or this is not a session"
                + ", containerId=" + heldContainer.container.getId()
                + ", pendingTasks=" + !taskRequests.isEmpty()
                + ", isSession=" + appContext.isSession()
                + ". isNew=" + isNew);
              releaseUnassignedContainers(
                Lists.newArrayList(heldContainer.container));
            }