org.apache.flink.runtime.instance

Class Instance

java.lang.Object

org.apache.flink.runtime.instance.Instance

All Implemented Interfaces:

SlotOwner

public class Instance
extends Object
implements SlotOwner

An instance represents a TaskManager registered at a JobManager and ready to receive work.

Constructor Summary

Constructors

Constructor and Description
Instance(TaskManagerGateway taskManagerGateway, TaskManagerLocation location, InstanceID id, HardwareDescription resources, int numberOfSlots) Constructs an instance reflecting a registered TaskManager.

Method Summary

Modifier and Type	Method and Description
SharedSlot	allocateSharedSlot(SlotSharingGroupAssignment sharingGroupAssignment) Allocates a shared slot on this TaskManager instance.
SimpleSlot	allocateSimpleSlot() Allocates a simple slot on this TaskManager instance.
void	cancelAndReleaseAllSlots()
InstanceID	getId()
long	getLastHeartBeat() Gets the timestamp of the last heartbeat.
int	getNumberOfAllocatedSlots()
int	getNumberOfAvailableSlots()
HardwareDescription	getResources()
TaskManagerGateway	getTaskManagerGateway() Returns the InstanceGateway of this Instance.
ResourceID	getTaskManagerID()
TaskManagerLocation	getTaskManagerLocation()
int	getTotalNumberOfSlots()
boolean	hasResourcesAvailable()
boolean	isAlive()
boolean	isStillAlive(long now, long cleanUpInterval) Checks whether the last heartbeat occurred within the last n milliseconds before the given timestamp now.
void	markDead()
void	removeSlotListener() Removes the listener that receives notifications for slot availability.
void	reportHeartBeat() Updates the time of last received heart beat to the current system time.
CompletableFuture<Boolean>	returnAllocatedSlot(LogicalSlot logicalSlot) Returns a slot that has been allocated from this instance.
void	setSlotAvailabilityListener(SlotAvailabilityListener slotAvailabilityListener) Sets the listener that receives notifications for slot availability.
String	toString()

Methods inherited from class java.lang.Object

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

Constructor Detail

Instance

public Instance(TaskManagerGateway taskManagerGateway,
                TaskManagerLocation location,
                InstanceID id,
                HardwareDescription resources,
                int numberOfSlots)

Constructs an instance reflecting a registered TaskManager.

Parameters:

taskManagerGateway - The actor gateway to communicate with the remote instance

location - The remote connection where the task manager receives requests.

id - The id under which the taskManager is registered.

resources - The resources available on the machine.

numberOfSlots - The number of task slots offered by this taskManager.

Method Detail

getTaskManagerID

public ResourceID getTaskManagerID()

getId

public InstanceID getId()

getResources

public HardwareDescription getResources()

getTotalNumberOfSlots

public int getTotalNumberOfSlots()

isAlive

public boolean isAlive()

markDead

public void markDead()

getLastHeartBeat

public long getLastHeartBeat()

Gets the timestamp of the last heartbeat.

Returns:

The timestamp of the last heartbeat.

reportHeartBeat

public void reportHeartBeat()

Updates the time of last received heart beat to the current system time.

isStillAlive

public boolean isStillAlive(long now,
                            long cleanUpInterval)

Checks whether the last heartbeat occurred within the last n milliseconds before the given timestamp now.

Parameters:

now - The timestamp representing the current time.

cleanUpInterval - The maximum time (in msecs) that the last heartbeat may lie in the past.

Returns:

True, if this taskManager is considered alive, false otherwise.

allocateSimpleSlot

public SimpleSlot allocateSimpleSlot()
                              throws InstanceDiedException

Allocates a simple slot on this TaskManager instance. This method returns null, if no slot is available at the moment.

Returns:

A simple slot that represents a task slot on this TaskManager instance, or null, if the TaskManager instance has no more slots available.

Throws:

InstanceDiedException - Thrown if the instance is no longer alive by the time the slot is allocated.

allocateSharedSlot

public SharedSlot allocateSharedSlot(SlotSharingGroupAssignment sharingGroupAssignment)
                              throws InstanceDiedException

Allocates a shared slot on this TaskManager instance. This method returns null, if no slot is available at the moment. The shared slot will be managed by the given SlotSharingGroupAssignment.

Parameters:

sharingGroupAssignment - The assignment group that manages this shared slot.

Returns:

A shared slot that represents a task slot on this TaskManager instance and can hold other (shared) slots, or null, if the TaskManager instance has no more slots available.

Throws:

InstanceDiedException - Thrown if the instance is no longer alive by the time the slot is allocated.

returnAllocatedSlot

public CompletableFuture<Boolean> returnAllocatedSlot(LogicalSlot logicalSlot)

Returns a slot that has been allocated from this instance. The slot needs have been canceled prior to calling this method.

The method will transition the slot to the "released" state. If the slot is already in state "released", this method will do nothing.

Specified by:

returnAllocatedSlot in interface SlotOwner

Parameters:

logicalSlot - The slot to return.

Returns:

Future which is completed with true, if the slot was returned, false if not.

cancelAndReleaseAllSlots

public void cancelAndReleaseAllSlots()

getTaskManagerGateway

public TaskManagerGateway getTaskManagerGateway()

Returns the InstanceGateway of this Instance. This gateway can be used to communicate with it.

Returns:

InstanceGateway associated with this instance

getTaskManagerLocation

public TaskManagerLocation getTaskManagerLocation()

getNumberOfAvailableSlots

public int getNumberOfAvailableSlots()

getNumberOfAllocatedSlots

public int getNumberOfAllocatedSlots()

hasResourcesAvailable

public boolean hasResourcesAvailable()

setSlotAvailabilityListener

public void setSlotAvailabilityListener(SlotAvailabilityListener slotAvailabilityListener)

Sets the listener that receives notifications for slot availability.

Parameters:

slotAvailabilityListener - The listener.

removeSlotListener

public void removeSlotListener()

Removes the listener that receives notifications for slot availability.

toString

public String toString()

Overrides:

toString in class Object