public class Scheduler.ShutdownHandler
extends Object
implements RejectedExecutionHandler

There is a way to shutdown the hierarchy of schedulers. You can do it in master scheduler via Scheduler.shutdownThreadPoolsAwaitingKilled() which kills the current master and children recursively. If alternatively a shared ExecutorService used by the master and children schedulers is shutdown from outside, then the Scheduler.ShutdownHandler is a hook calling current Scheduler.describeStopped(boolean). The method Scheduler.describeStopped(boolean) is again shutting down children schedulers recursively as well.