Package org.apache.hadoop.metrics2.impl

Class MetricsSystemImpl

java.lang.Object

org.apache.hadoop.metrics2.MetricsSystem

org.apache.hadoop.metrics2.impl.MetricsSystemImpl

All Implemented Interfaces:

MetricsSource, MetricsSystemMXBean

@Private
@Metrics(context="metricssystem")
public class MetricsSystemImpl
extends MetricsSystem
implements MetricsSource

A base class for metrics system singletons

Nested Class Summary

Nested classes/interfaces inherited from class org.apache.hadoop.metrics2.MetricsSystem

MetricsSystem.AbstractCallback, MetricsSystem.Callback

Constructor Summary

Constructors

Constructor	Description
MetricsSystemImpl()	Construct the system but not initializing (read config etc.) it.
MetricsSystemImpl(java.lang.String prefix)	Construct the metrics system

Method Summary

Modifier and Type	Method	Description
java.lang.String	currentConfig()
void	getMetrics(MetricsCollector builder, boolean all)	Get metrics from the metrics source
org.apache.hadoop.metrics2.impl.MetricsSinkAdapter	getSinkAdapter(java.lang.String name)
MetricsSource	getSource(java.lang.String name)
MetricsSystem	init(java.lang.String prefix)	Initialized the metrics system with a prefix.
void	publishMetricsNow()	Requests an immediate publish of all metrics from sources to sinks.
<T> T	register(java.lang.String name, java.lang.String desc, T source)	Register a metrics source
void	register(MetricsSystem.Callback callback)	Register a callback interface for JMX events
org.apache.hadoop.metrics2.impl.MetricsBuffer	sampleMetrics()	Sample all the sources for a snapshot of metrics/tags
boolean	shutdown()	Shutdown the metrics system completely (usually during server shutdown.) The MetricsSystemMXBean will be unregistered.
void	start()	Start the metrics system
void	startMetricsMBeans()	Start metrics MBeans
void	stop()	Stop the metrics system
void	stopMetricsMBeans()	Stop metrics MBeans.
void	unregisterSource(java.lang.String name)	Unregister a metrics source

Methods inherited from class org.apache.hadoop.metrics2.MetricsSystem

register

Methods inherited from class java.lang.Object

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

Constructor Detail

MetricsSystemImpl

public MetricsSystemImpl(java.lang.String prefix)

Construct the metrics system

Parameters:

prefix - for the system

MetricsSystemImpl

public MetricsSystemImpl()

Construct the system but not initializing (read config etc.) it.

Method Detail

init

public MetricsSystem init(java.lang.String prefix)

Initialized the metrics system with a prefix.

Specified by:

init in class MetricsSystem

Parameters:

prefix - the system will look for configs with the prefix

Returns:

the metrics system object itself

start

public void start()

Description copied from interface: MetricsSystemMXBean

Start the metrics system

Specified by:

start in interface MetricsSystemMXBean

stop

public void stop()

Description copied from interface: MetricsSystemMXBean

Stop the metrics system

Specified by:

stop in interface MetricsSystemMXBean

register

public <T> T register(java.lang.String name,
                      java.lang.String desc,
                      T source)

Description copied from class: MetricsSystem

Register a metrics source

Specified by:

register in class MetricsSystem

Type Parameters:

T - the actual type of the source object

Parameters:

name - of the source. Must be unique or null (then extracted from the annotations of the source object.)

desc - the description of the source (or null. See above.)

source - object to register

Returns:

the source object

unregisterSource

public void unregisterSource(java.lang.String name)

Description copied from class: MetricsSystem

Unregister a metrics source

Specified by:

unregisterSource in class MetricsSystem

Parameters:

name - of the source. This is the name you use to call register()

register

public <T extends MetricsSink> T register(java.lang.String name,
                                          java.lang.String description,
                                          T sink)

Description copied from class: MetricsSystem

Register a metrics sink

Specified by:

register in class MetricsSystem

Type Parameters:

T - the type of the sink

Parameters:

name - of the sink. Must be unique.

description - the description of the sink

sink - to register

Returns:

the sink

register

public void register(MetricsSystem.Callback callback)

Description copied from class: MetricsSystem

Register a callback interface for JMX events

Specified by:

register in class MetricsSystem

Parameters:

callback - the callback object implementing the MBean interface.

startMetricsMBeans

public void startMetricsMBeans()

Description copied from interface: MetricsSystemMXBean

Start metrics MBeans

Specified by:

startMetricsMBeans in interface MetricsSystemMXBean

stopMetricsMBeans

public void stopMetricsMBeans()

Description copied from interface: MetricsSystemMXBean

Stop metrics MBeans. Note, it doesn't stop the metrics system control MBean, i.e this interface.

Specified by:

stopMetricsMBeans in interface MetricsSystemMXBean

currentConfig

public java.lang.String currentConfig()

Specified by:

currentConfig in interface MetricsSystemMXBean

Returns:

the current config Avoided getConfig, as it'll turn into a "Config" attribute, which doesn't support multiple line values in jconsole.

publishMetricsNow

public void publishMetricsNow()

Requests an immediate publish of all metrics from sources to sinks.

Specified by:

publishMetricsNow in class MetricsSystem

sampleMetrics

@VisibleForTesting
public org.apache.hadoop.metrics2.impl.MetricsBuffer sampleMetrics()

Sample all the sources for a snapshot of metrics/tags

Returns:

the metrics buffer containing the snapshot

getMetrics

public void getMetrics(MetricsCollector builder,
                       boolean all)

Description copied from interface: MetricsSource

Get metrics from the metrics source

Specified by:

getMetrics in interface MetricsSource

Parameters:

builder - to contain the resulting metrics snapshot

all - if true, return all metrics even if unchanged.

shutdown

public boolean shutdown()

Description copied from class: MetricsSystem

Shutdown the metrics system completely (usually during server shutdown.) The MetricsSystemMXBean will be unregistered.

Specified by:

shutdown in class MetricsSystem

Returns:

true if shutdown completed

getSource

public MetricsSource getSource(java.lang.String name)

Specified by:

getSource in class MetricsSystem

Parameters:

name - of the metrics source

Returns:

the metrics source (potentially wrapped) object

getSinkAdapter

@VisibleForTesting
public org.apache.hadoop.metrics2.impl.MetricsSinkAdapter getSinkAdapter(java.lang.String name)