org.apache.slider.server.appmaster.actions

Class QueueService

java.lang.Object

org.apache.hadoop.service.AbstractService

org.apache.slider.server.services.workflow.WorkflowExecutorService<ExecutorService>

org.apache.slider.server.appmaster.actions.QueueService

All Implemented Interfaces:

Closeable, AutoCloseable, Runnable, org.apache.hadoop.service.Service, QueueAccess

public class QueueService
extends WorkflowExecutorService<ExecutorService>
implements Runnable, QueueAccess

The Queue service provides immediate and scheduled queues, as well as an executor thread that moves queued actions from the scheduled queue to the immediate one.

This code to be revisited to see if all that was needed is the single scheduled queue, implicitly making actions immediate by giving them an execution time of "now". It would force having a sequence number to all actions, one which the queue would have to set from its (monotonic, thread-safe) counter on every submission, with a modified comparison operator. This would guarantee that earlier submissions were picked before later ones.

Nested Class Summary

Nested classes/interfaces inherited from interface org.apache.hadoop.service.Service

org.apache.hadoop.service.Service.STATE

Field Summary

Fields

Modifier and Type	Field and Description
BlockingDeque<AsyncAction>	actionQueue Immediate actions.
static String	NAME
DelayQueue<AsyncAction>	scheduledActions Actions to be scheduled in the future

Constructor Summary

Constructors

Constructor and Description
QueueService() Create a queue instance with a single thread executor

Method Summary

Methods

Modifier and Type	Method and Description
protected void	flushActionQueue(Class<? extends AsyncAction> clazz) Flush an action queue of all types of a specific action
boolean	hasQueuedActionWithAttribute(int attr) Look in the immediate queue for any actions of a specific attribute
boolean	isCompleted() Check to see if the queue executor has completed
RenewingAction<? extends AsyncAction>	lookupRenewingAction(String name) Look up a renewing action
void	put(AsyncAction action) Put an action on the immediate queue -to be executed when the queue reaches it.
boolean	remove(AsyncAction action) Remove an action from the queues.
boolean	removeRenewingAction(String name) Remove a renewing action
void	renewing(String name, RenewingAction<? extends AsyncAction> renewingAction) Add a named renewing action
void	run() Run until the queue has been told to stop
void	schedule(AsyncAction action) Put a delayed action: this will only be added to the main queue after its action time has been reached
protected void	serviceStop() Stop the service by scheduling an ActionStopQueue action ..if the processor thread is working this will propagate through and stop the queue handling after all other actions complete.

Methods inherited from class org.apache.slider.server.services.workflow.WorkflowExecutorService

execute, getExecutor, setExecutor, stopExecutor, submit

Methods inherited from class org.apache.hadoop.service.AbstractService

close, getBlockers, getConfig, getFailureCause, getFailureState, getLifecycleHistory, getName, getServiceState, getStartTime, init, isInState, noteFailure, putBlocker, registerGlobalListener, registerServiceListener, removeBlocker, serviceInit, serviceStart, setConfig, start, stop, toString, unregisterGlobalListener, unregisterServiceListener, waitForServiceToStop

Methods inherited from class java.lang.Object

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

Field Detail

NAME

public static final String NAME

See Also:

Constant Field Values

actionQueue

public final BlockingDeque<AsyncAction> actionQueue

Immediate actions.

scheduledActions

public final DelayQueue<AsyncAction> scheduledActions

Actions to be scheduled in the future

Constructor Detail

QueueService

public QueueService()

Create a queue instance with a single thread executor

Method Detail

put

public void put(AsyncAction action)

Description copied from interface: QueueAccess

Put an action on the immediate queue -to be executed when the queue reaches it.

Specified by:

put in interface QueueAccess

Parameters:

action - action to queue

schedule

public void schedule(AsyncAction action)

Description copied from interface: QueueAccess

Put a delayed action: this will only be added to the main queue after its action time has been reached

Specified by:

schedule in interface QueueAccess

Parameters:

action - action to queue

remove

public boolean remove(AsyncAction action)

Description copied from interface: QueueAccess

Remove an action from the queues.

Specified by:

remove in interface QueueAccess

Parameters:

action - action to remove

Returns:

true if the action was removed

renewing

public void renewing(String name,
            RenewingAction<? extends AsyncAction> renewingAction)

Description copied from interface: QueueAccess

Add a named renewing action

Specified by:

renewing in interface QueueAccess

Parameters:

name - name

renewingAction - wrapped action

lookupRenewingAction

public RenewingAction<? extends AsyncAction> lookupRenewingAction(String name)

Description copied from interface: QueueAccess

Look up a renewing action

Specified by:

lookupRenewingAction in interface QueueAccess

Parameters:

name - name of the action

Returns:

the action or null if none was found

removeRenewingAction

public boolean removeRenewingAction(String name)

Description copied from interface: QueueAccess

Remove a renewing action

Specified by:

removeRenewingAction in interface QueueAccess

Parameters:

name - action name name of the action

Returns:

true if the action was found and removed.

serviceStop

protected void serviceStop()
                    throws Exception

Stop the service by scheduling an ActionStopQueue action ..if the processor thread is working this will propagate through and stop the queue handling after all other actions complete.

Overrides:

serviceStop in class WorkflowExecutorService<ExecutorService>

Throws:

Exception

flushActionQueue

protected void flushActionQueue(Class<? extends AsyncAction> clazz)

Flush an action queue of all types of a specific action

Parameters:

clazz -

hasQueuedActionWithAttribute

public boolean hasQueuedActionWithAttribute(int attr)

Description copied from interface: QueueAccess

Look in the immediate queue for any actions of a specific attribute

Specified by:

hasQueuedActionWithAttribute in interface QueueAccess

run

public void run()

Run until the queue has been told to stop

Specified by:

run in interface Runnable

isCompleted

public boolean isCompleted()

Check to see if the queue executor has completed

Returns:

the status