org.apache.hadoop.metrics.spi
Class NullContext

java.lang.Object
  org.apache.hadoop.metrics.spi.AbstractMetricsContext
      org.apache.hadoop.metrics.spi.NullContext

All Implemented Interfaces:

MetricsContext

public class NullContext
extends AbstractMetricsContext

Null metrics context: a metrics context which does nothing. Used as the default context, so that no performance data is emitted if no configuration data is found.

Field Summary

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

DEFAULT_PERIOD

Constructor Summary

NullContext()
Creates a new instance of NullContext

Method Summary

protected void	emitRecord(String contextName, String recordName, OutputRecord outRec) Do-nothing version of emitRecord
protected void	remove(MetricsRecordImpl record) Do-nothing version of remove
void	startMonitoring() Do-nothing version of startMonitoring
protected void	update(MetricsRecordImpl record) Do-nothing version of update

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

close, createRecord, flush, getAttribute, getAttributeTable, getContextFactory, getContextName, getPeriod, init, isMonitoring, newRecord, registerUpdater, setPeriod, stopMonitoring, unregisterUpdater

Methods inherited from class java.lang.Object

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

Constructor Detail

NullContext

public NullContext()

Creates a new instance of NullContext

Method Detail

startMonitoring

public void startMonitoring()

Do-nothing version of startMonitoring

Specified by:

startMonitoring in interface MetricsContext

Overrides:

startMonitoring in class AbstractMetricsContext

emitRecord

protected void emitRecord(String contextName,
                          String recordName,
                          OutputRecord outRec)

Do-nothing version of emitRecord

Specified by:

emitRecord in class AbstractMetricsContext

update

protected void update(MetricsRecordImpl record)

Do-nothing version of update

Overrides:

update in class AbstractMetricsContext

remove

protected void remove(MetricsRecordImpl record)

Do-nothing version of remove

Overrides:

remove in class AbstractMetricsContext