org.apache.flink.runtime.jobmanager.scheduler

Class Scheduler

java.lang.Object

org.apache.flink.runtime.jobmanager.scheduler.Scheduler

All Implemented Interfaces:

InstanceListener, SlotAvailabilityListener

public class Scheduler
extends Object
implements InstanceListener, SlotAvailabilityListener

The scheduler is responsible for distributing the ready-to-run tasks and assigning them to instances and slots.

Constructor Summary

Constructors

Constructor and Description
Scheduler()
Scheduler(ExecutorService executorService)

Method Summary

Modifier and Type	Method and Description
protected AllocatedSlot	getFreeSlotForTask(ExecutionVertex vertex, Iterable<Instance> requestedLocations) Gets a suitable instance to schedule the vertex execution to.
int	getNumberOfAvailableInstances()
int	getNumberOfAvailableSlots() NOTE: In the presence of multi-threaded operations, this number may be inexact.
int	getNumberOfInstancesWithAvailableSlots()
int	getNumberOfLocalizedAssignments()
int	getNumberOfNonLocalizedAssignments()
int	getNumberOfUnconstrainedAssignments()
int	getTotalNumberOfSlots()
void	instanceDied(Instance instance) Called when an instance died.
void	newInstanceAvailable(Instance instance) Called when a new instance becomes available.
void	newSlotAvailable(Instance instance)
AllocatedSlot	scheduleImmediately(ScheduledUnit task)
SlotAllocationFuture	scheduleQueued(ScheduledUnit task)
void	shutdown() Shuts the scheduler down.

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Constructor Detail

Scheduler

public Scheduler()

Scheduler

public Scheduler(ExecutorService executorService)

Method Detail

shutdown

public void shutdown()

Shuts the scheduler down. After shut down no more tasks can be added to the scheduler.

getNumberOfAvailableSlots

public int getNumberOfAvailableSlots()

NOTE: In the presence of multi-threaded operations, this number may be inexact.

Returns:

The number of empty slots, for tasks.

getTotalNumberOfSlots

public int getTotalNumberOfSlots()

scheduleImmediately

public AllocatedSlot scheduleImmediately(ScheduledUnit task)
                                  throws NoResourceAvailableException

Throws:

NoResourceAvailableException

scheduleQueued

public SlotAllocationFuture scheduleQueued(ScheduledUnit task)
                                    throws NoResourceAvailableException

Throws:

NoResourceAvailableException

getFreeSlotForTask

protected AllocatedSlot getFreeSlotForTask(ExecutionVertex vertex,
                                           Iterable<Instance> requestedLocations)

Gets a suitable instance to schedule the vertex execution to.

NOTE: This method does is not thread-safe, it needs to be synchronized by the caller.

Parameters:

vertex - The task to run.

Returns:

The instance to run the vertex on, it null, if no instance is available.

newSlotAvailable

public void newSlotAvailable(Instance instance)

Specified by:

newSlotAvailable in interface SlotAvailabilityListener

newInstanceAvailable

public void newInstanceAvailable(Instance instance)

Description copied from interface: InstanceListener

Called when a new instance becomes available.

Specified by:

newInstanceAvailable in interface InstanceListener

Parameters:

instance - The instance that became available.

instanceDied

public void instanceDied(Instance instance)

Description copied from interface: InstanceListener

Called when an instance died.

Specified by:

instanceDied in interface InstanceListener

Parameters:

instance - The instance that died.

getNumberOfAvailableInstances

public int getNumberOfAvailableInstances()

getNumberOfInstancesWithAvailableSlots

public int getNumberOfInstancesWithAvailableSlots()

getNumberOfUnconstrainedAssignments

public int getNumberOfUnconstrainedAssignments()

getNumberOfLocalizedAssignments

public int getNumberOfLocalizedAssignments()

getNumberOfNonLocalizedAssignments

public int getNumberOfNonLocalizedAssignments()