org.apache.hadoop.metrics.spi

Class CompositeContext

java.lang.Object

org.apache.hadoop.metrics.spi.AbstractMetricsContext

org.apache.hadoop.metrics.spi.CompositeContext

All Implemented Interfaces:

MetricsContext

@InterfaceAudience.Public
@InterfaceStability.Evolving
public class CompositeContext
extends AbstractMetricsContext

Nested Class Summary

Nested classes/interfaces inherited from class org.apache.hadoop.metrics.spi.AbstractMetricsContext

AbstractMetricsContext.MetricMap, AbstractMetricsContext.TagMap

Field Summary

Fields inherited from interface org.apache.hadoop.metrics.MetricsContext

DEFAULT_PERIOD

Constructor Summary

Constructors

Constructor and Description
CompositeContext()

Method Summary

Methods

Modifier and Type	Method and Description
void	close() Stops monitoring and frees buffered data, returning this object to its initial state.
protected void	emitRecord(String contextName, String recordName, OutputRecord outRec) Sends a record to the metrics system.
protected void	flush() Called each period after all records have been emitted, this method does nothing.
void	init(String contextName, ContextFactory factory) Initializes the context.
boolean	isMonitoring() Return true if all subcontexts are monitoring.
MetricsRecord	newRecord(String recordName) Subclasses should override this if they subclass MetricsRecordImpl.
void	registerUpdater(Updater updater) Registers a callback to be called at time intervals determined by the configuration.
void	startMonitoring() Starts or restarts monitoring, the emitting of metrics records.
void	stopMonitoring() Stops monitoring.
void	unregisterUpdater(Updater updater) Removes a callback, if it exists.

Methods inherited from class org.apache.hadoop.metrics.spi.AbstractMetricsContext

createRecord, getAllRecords, getAttribute, getAttributeTable, getContextFactory, getContextName, getPeriod, parseAndSetPeriod, remove, setPeriod, update

Methods inherited from class java.lang.Object

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

Constructor Detail

CompositeContext

@InterfaceAudience.Private
public CompositeContext()

Method Detail

init

@InterfaceAudience.Private
public void init(String contextName,
                                  ContextFactory factory)

Description copied from class: AbstractMetricsContext

Initializes the context.

Specified by:

init in interface MetricsContext

Overrides:

init in class AbstractMetricsContext

Parameters:

contextName - The given name for this context

factory - The creator of this context

newRecord

@InterfaceAudience.Private
public MetricsRecord newRecord(String recordName)

Description copied from class: AbstractMetricsContext

Subclasses should override this if they subclass MetricsRecordImpl.

Overrides:

newRecord in class AbstractMetricsContext

Parameters:

recordName - the name of the record

Returns:

newly created instance of MetricsRecordImpl or subclass

emitRecord

@InterfaceAudience.Private
protected void emitRecord(String contextName,
                                        String recordName,
                                        OutputRecord outRec)
                   throws IOException

Description copied from class: AbstractMetricsContext

Sends a record to the metrics system.

Specified by:

emitRecord in class AbstractMetricsContext

Throws:

IOException

flush

@InterfaceAudience.Private
protected void flush()
              throws IOException

Description copied from class: AbstractMetricsContext

Called each period after all records have been emitted, this method does nothing. Subclasses may override it in order to perform some kind of flush.

Overrides:

flush in class AbstractMetricsContext

Throws:

IOException

startMonitoring

@InterfaceAudience.Private
public void startMonitoring()
                     throws IOException

Description copied from class: AbstractMetricsContext

Starts or restarts monitoring, the emitting of metrics records.

Specified by:

startMonitoring in interface MetricsContext

Overrides:

startMonitoring in class AbstractMetricsContext

Throws:

IOException

stopMonitoring

@InterfaceAudience.Private
public void stopMonitoring()

Description copied from class: AbstractMetricsContext

Stops monitoring. This does not free buffered data.

Specified by:

stopMonitoring in interface MetricsContext

Overrides:

stopMonitoring in class AbstractMetricsContext

See Also:

AbstractMetricsContext.close()

isMonitoring

@InterfaceAudience.Private
public boolean isMonitoring()

Return true if all subcontexts are monitoring.

Specified by:

isMonitoring in interface MetricsContext

Overrides:

isMonitoring in class AbstractMetricsContext

close

@InterfaceAudience.Private
public void close()

Description copied from class: AbstractMetricsContext

Stops monitoring and frees buffered data, returning this object to its initial state.

Specified by:

close in interface MetricsContext

Overrides:

close in class AbstractMetricsContext

registerUpdater

@InterfaceAudience.Private
public void registerUpdater(Updater updater)

Description copied from class: AbstractMetricsContext

Registers a callback to be called at time intervals determined by the configuration.

Specified by:

registerUpdater in interface MetricsContext

Overrides:

registerUpdater in class AbstractMetricsContext

Parameters:

updater - object to be run periodically; it should update some metrics records

unregisterUpdater

@InterfaceAudience.Private
public void unregisterUpdater(Updater updater)

Description copied from class: AbstractMetricsContext

Removes a callback, if it exists.

Specified by:

unregisterUpdater in interface MetricsContext

Overrides:

unregisterUpdater in class AbstractMetricsContext

Parameters:

updater - object to be removed from the callback list