Placeholder pods are not cleaned up timely when the Spark driver fails

When a Spark job is gang scheduled, if the driver pod fails immediately upon running (e.g. due to an error in the Spark application code), the placeholder pods will still try to reserve resources. They won't be terminated until after the configured timeout has passed, even though they should have been cleaned up the moment that the driver failed. Because we already knew at that point, none of the executors would have a chance to start. 
Something probably needs to be done at the Spark operator plugin level to activate placeholder cleanup to release resources sooner.

Edit: Actually a fix needs to be developed without the Spark operator plugin because the user might not be using it. The Spark job could well have been submitted via spark-submit.