org.apache.hadoop.mapreduce.v2.app

Class TaskHeartbeatHandler

java.lang.Object

org.apache.hadoop.service.AbstractService

org.apache.hadoop.mapreduce.v2.app.TaskHeartbeatHandler

All Implemented Interfaces:

Closeable, AutoCloseable, Service

public class TaskHeartbeatHandler
extends AbstractService

This class keeps track of tasks that have already been launched. It determines if a task is alive and running or marks a task as dead if it does not hear from it for a long time.

Nested Class Summary

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

Service.STATE

Constructor Summary

Constructors

Constructor and Description
TaskHeartbeatHandler(EventHandler eventHandler, Clock clock, int numThreads)

Method Summary

Methods

Modifier and Type	Method and Description
void	progressing(TaskAttemptId attemptID)
void	register(TaskAttemptId attemptID)
protected void	serviceInit(Configuration conf) All initialization code needed by a service.
protected void	serviceStart() Actions called during the INITED to STARTED transition.
protected void	serviceStop() Actions called during the transition to the STOPPED state.
void	unregister(TaskAttemptId attemptID)

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

Constructor Detail

TaskHeartbeatHandler

public TaskHeartbeatHandler(EventHandler eventHandler,
                    Clock clock,
                    int numThreads)

Method Detail

serviceInit

protected void serviceInit(Configuration conf)
                    throws Exception

Description copied from class: AbstractService

All initialization code needed by a service. This method will only ever be called once during the lifecycle of a specific service instance. Implementations do not need to be synchronized as the logic in AbstractService.init(Configuration) prevents re-entrancy. The base implementation checks to see if the subclass has created a new configuration instance, and if so, updates the base class value

Overrides:

serviceInit in class AbstractService

Parameters:

conf - configuration

Throws:

Exception - on a failure -these will be caught, possibly wrapped, and wil; trigger a service stop

serviceStart

protected void serviceStart()
                     throws Exception

Description copied from class: AbstractService

Actions called during the INITED to STARTED transition. This method will only ever be called once during the lifecycle of a specific service instance. Implementations do not need to be synchronized as the logic in AbstractService.start() prevents re-entrancy.

Overrides:

serviceStart in class AbstractService

Throws:

Exception - if needed -these will be caught, wrapped, and trigger a service stop

serviceStop

protected void serviceStop()
                    throws Exception

Description copied from class: AbstractService

Actions called during the transition to the STOPPED state. This method will only ever be called once during the lifecycle of a specific service instance. Implementations do not need to be synchronized as the logic in AbstractService.stop() prevents re-entrancy. Implementations MUST write this to be robust against failures, including checks for null references -and for the first failure to not stop other attempts to shut down parts of the service.

Overrides:

serviceStop in class AbstractService

Throws:

Exception - if needed -these will be caught and logged.

progressing

public void progressing(TaskAttemptId attemptID)

register

public void register(TaskAttemptId attemptID)

unregister

public void unregister(TaskAttemptId attemptID)