org.apache.hadoop.yarn.event

Class AsyncDispatcher

java.lang.Object

org.apache.hadoop.service.AbstractService

org.apache.hadoop.yarn.event.AsyncDispatcher

All Implemented Interfaces:

Closeable, AutoCloseable, org.apache.hadoop.service.Service, Dispatcher

@InterfaceAudience.Public
 @InterfaceStability.Evolving
public class AsyncDispatcher
extends org.apache.hadoop.service.AbstractService
implements Dispatcher

Dispatches Events in a separate thread. Currently only single thread does that. Potentially there could be multiple channels for each event type class and a thread pool can be used to dispatch the events.

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
protected Map<Class<? extends Enum>,EventHandler>	eventDispatchers

Constructor Summary

Constructors

Constructor and Description
AsyncDispatcher()
AsyncDispatcher(BlockingQueue<Event> eventQueue)
AsyncDispatcher(String dispatcherName) Set a name for this dispatcher thread.

Method Summary

Modifier and Type	Method and Description
void	addMetrics(EventTypeMetrics metrics, Class<? extends Enum> eventClass)
void	disableExitOnDispatchException()
protected void	dispatch(Event event)
EventHandler<Event>	getEventHandler()
int	getEventQueueSize()
protected boolean	isDrained()
protected boolean	isEventThreadWaiting()
protected boolean	isStopped()
void	register(Class<? extends Enum> eventType, EventHandler handler)
protected void	serviceInit(org.apache.hadoop.conf.Configuration conf)
protected void	serviceStart()
protected void	serviceStop()
void	setDrainEventsOnStop()

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, 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

eventDispatchers

protected final Map<Class<? extends Enum>,EventHandler> eventDispatchers

Constructor Detail

AsyncDispatcher

public AsyncDispatcher()

AsyncDispatcher

public AsyncDispatcher(BlockingQueue<Event> eventQueue)

AsyncDispatcher

public AsyncDispatcher(String dispatcherName)

Set a name for this dispatcher thread.

Parameters:

dispatcherName - name of the dispatcher thread

Method Detail

disableExitOnDispatchException

@VisibleForTesting
public void disableExitOnDispatchException()

serviceInit

protected void serviceInit(org.apache.hadoop.conf.Configuration conf)
                    throws Exception

Overrides:

serviceInit in class org.apache.hadoop.service.AbstractService

Throws:

Exception

serviceStart

protected void serviceStart()
                     throws Exception

Overrides:

serviceStart in class org.apache.hadoop.service.AbstractService

Throws:

Exception

setDrainEventsOnStop

public void setDrainEventsOnStop()

serviceStop

protected void serviceStop()
                    throws Exception

Overrides:

serviceStop in class org.apache.hadoop.service.AbstractService

Throws:

Exception

dispatch

protected void dispatch(Event event)

register

public void register(Class<? extends Enum> eventType,
                     EventHandler handler)

Specified by:

register in interface Dispatcher

getEventHandler

public EventHandler<Event> getEventHandler()

Specified by:

getEventHandler in interface Dispatcher

isEventThreadWaiting

@VisibleForTesting
protected boolean isEventThreadWaiting()

isDrained

protected boolean isDrained()

isStopped

protected boolean isStopped()

addMetrics

public void addMetrics(EventTypeMetrics metrics,
                       Class<? extends Enum> eventClass)

getEventQueueSize

public int getEventQueueSize()