org.apache.hadoop.metrics2.impl
Class MetricsSystemImpl

java.lang.Object
  org.apache.hadoop.metrics2.impl.MetricsSystemImpl

All Implemented Interfaces:

MetricsSystem, MetricsSystemMXBean

public class MetricsSystemImpl
extends Object
implements MetricsSystem

A base class for metrics system singletons

Nested Class Summary

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

MetricsSystem.AbstractCallback, MetricsSystem.Callback

Constructor Summary

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

MetricsSystemImpl(String prefix)
Construct the metrics system

Method Summary

String	currentConfig()
void	init(String prefix) Initialized the metrics system with a prefix.
void	refreshMBeans() Force a refresh of MBeans
void	register(MetricsSystem.Callback callback) Register a callback interface for JMX events
<T extends MetricsSink> T	register(String name, String description, T sink) Register a metrics sink
<T extends MetricsSource> T	register(String name, String desc, T source) Register a metrics source
void	shutdown() Shutdown the metrics system completely (usually during server shutdown.) The MetricsSystemMXBean will be unregistered.
void	start() Start the metrics system
void	stop() Stop the metrics system

Methods inherited from class java.lang.Object

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

Constructor Detail

MetricsSystemImpl

public MetricsSystemImpl(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 void init(String prefix)

Initialized the metrics system with a prefix.

Parameters:

prefix - the system will look for configs with the prefix

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 extends MetricsSource> T register(String name,
                                            String desc,
                                            T source)

Description copied from interface: MetricsSystem

Register a metrics source

Specified by:

register in interface MetricsSystem

Type Parameters:

T - the type of the source

Parameters:

name - of the source. Must be unique.

desc - the description of the source.

source - to register

Returns:

the source

register

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

Description copied from interface: MetricsSystem

Register a metrics sink

Specified by:

register in interface 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 interface: MetricsSystem

Register a callback interface for JMX events

Specified by:

register in interface MetricsSystem

Parameters:

callback - the callback object implementing the MBean interface.

refreshMBeans

public void refreshMBeans()

Description copied from interface: MetricsSystemMXBean

Force a refresh of MBeans

Specified by:

refreshMBeans in interface MetricsSystemMXBean

currentConfig

public String currentConfig()

Specified by:

currentConfig in interface MetricsSystemMXBean

Returns:

the current config Note, avoid getConfig, as it'll turn it into an attribute, which doesn't support multiple lines in the values.

shutdown

public void shutdown()

Description copied from interface: MetricsSystem

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

Specified by:

shutdown in interface MetricsSystem