org.apache.hadoop.metrics.spi
Class NullContextWithUpdateThread

java.lang.Object
  extended by org.apache.hadoop.metrics.spi.AbstractMetricsContext
      extended by 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



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