edu.snu.coral.runtime.master.scheduler

Interface PendingTaskGroupQueue

All Known Implementing Classes:

SingleJobTaskGroupQueue

@ThreadSafe
 @DefaultImplementation(value=SingleJobTaskGroupQueue.class)
public interface PendingTaskGroupQueue

Keep tracks of all pending task groups. Scheduler enqueues the TaskGroups to schedule to this queue. SchedulerRunner refers to this queue when scheduling TaskGroups.

Method Summary

Modifier and Type	Method and Description
void	close() Closes and cleans up this queue.
Optional<ScheduledTaskGroup>	dequeue() Dequeues the next TaskGroup to be scheduled.
void	enqueue(ScheduledTaskGroup scheduledTaskGroup) Enqueues a TaskGroup to this PQ.
boolean	isEmpty() Checks whether there are schedulable TaskGroups in the queue or not.
void	onJobScheduled(PhysicalPlan physicalPlanForJob) Registers a job to this queue in case the queue needs to understand the topology of the job DAG.
void	removeTaskGroupsAndDescendants(String stageIdOfTaskGroups) Removes a stage and its descendant stages from this queue.

Method Detail

enqueue

void enqueue(ScheduledTaskGroup scheduledTaskGroup)

Enqueues a TaskGroup to this PQ.

Parameters:

scheduledTaskGroup - to enqueue.

dequeue

Optional<ScheduledTaskGroup> dequeue()

Dequeues the next TaskGroup to be scheduled.

Returns:

an optional of the the next TaskGroup to be scheduled, an empty optional if no such TaskGroup exists.

onJobScheduled

void onJobScheduled(PhysicalPlan physicalPlanForJob)

Registers a job to this queue in case the queue needs to understand the topology of the job DAG.

Parameters:

physicalPlanForJob - the job to schedule.

removeTaskGroupsAndDescendants

void removeTaskGroupsAndDescendants(String stageIdOfTaskGroups)

Removes a stage and its descendant stages from this queue. This is to be used for fault tolerance purposes, say when a stage fails and all affected TaskGroups must be removed.

Parameters:

stageIdOfTaskGroups - for the stage to begin the removal recursively.

isEmpty

boolean isEmpty()

Checks whether there are schedulable TaskGroups in the queue or not.

Returns:

true if there are schedulable TaskGroups in the queue, false otherwise.

close

void close()

Closes and cleans up this queue.