org.apache.hadoop.metrics.spi
Class NullContextWithUpdateThread

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

All Implemented Interfaces:

org.apache.hadoop.metrics.MetricsContext

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

A null context which has a thread calling periodically when monitoring is started. This keeps the data sampled correctly. In all other respects, this is like the NULL context: No data is emitted. This is suitable for Monitoring systems like JMX which reads the metrics when someone reads the data from JMX. The default impl of start and stop monitoring: is the AbstractMetricsContext is good enough.

Field Summary

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

DEFAULT_PERIOD

Constructor Summary

NullContextWithUpdateThread()
Creates a new instance of NullContextWithUpdateThread

Method Summary

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

close, createRecord, flush, getAllRecords, getAttribute, getAttributeTable, getContextFactory, getContextName, getPeriod, isMonitoring, newRecord, parseAndSetPeriod, registerUpdater, setPeriod, startMonitoring, stopMonitoring, unregisterUpdater

Methods inherited from class java.lang.Object

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

Constructor Detail

NullContextWithUpdateThread

@InterfaceAudience.Private
public NullContextWithUpdateThread()

Creates a new instance of NullContextWithUpdateThread