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:
- MetricsContext
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.
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 |
NullContextWithUpdateThread
public NullContextWithUpdateThread()
- Creates a new instance of NullContextWithUpdateThread
init
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 contextfactory
- The creator of this context
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
Copyright © 2009 The Apache Software Foundation