Package org.apache.hadoop.yarn.util

Class AbstractLivelinessMonitor<O>

java.lang.Object

org.apache.hadoop.service.AbstractService

org.apache.hadoop.yarn.util.AbstractLivelinessMonitor<O>

All Implemented Interfaces:

Closeable, AutoCloseable, Service

@Public
@Evolving
public abstract class AbstractLivelinessMonitor<O>
extends AbstractService

A simple liveliness monitor with which clients can register, trust the component to monitor liveliness, get a call-back on expiry and then finally unregister.

Nested Class Summary

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

Service.STATE

Field Summary

Fields

Modifier and Type	Field	Description
static final int	DEFAULT_EXPIRE

Constructor Summary

Constructors

Constructor	Description
AbstractLivelinessMonitor(String name)
AbstractLivelinessMonitor(String name, Clock clock)

Method Summary

Modifier and Type	Method	Description
protected abstract void	expire(O ob)
protected long	getExpireInterval(O o)
void	receivedPing(O ob)
void	register(O ob)
void	register(O ob, long expireTime)
void	resetTimer()
protected void	serviceStart()	Actions called during the INITED to STARTED transition.
protected void	serviceStop()	Actions called during the transition to the STOPPED state.
protected void	setExpireInterval(long expireInterval)
protected void	setMonitorInterval(long monitorInterval)
protected void	setResetTimeOnStart(boolean resetTimeOnStart)
void	unregister(O ob)

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, 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 Details

DEFAULT_EXPIRE

public static final int DEFAULT_EXPIRE

See Also:

• Constant Field Values

Constructor Details

AbstractLivelinessMonitor

public AbstractLivelinessMonitor(String name,
 Clock clock)

AbstractLivelinessMonitor

public AbstractLivelinessMonitor(String name)

Method Details

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.

expire

protected abstract void expire(O ob)

setExpireInterval

protected void setExpireInterval(long expireInterval)

getExpireInterval

protected long getExpireInterval(O o)

setMonitorInterval

protected void setMonitorInterval(long monitorInterval)

receivedPing

public void receivedPing(O ob)

register

public void register(O ob)

register

public void register(O ob,
 long expireTime)

unregister

public void unregister(O ob)

resetTimer

public void resetTimer()

setResetTimeOnStart

protected void setResetTimeOnStart(boolean resetTimeOnStart)