Package wt.jmx.core.mbeans

Class GarbageCollectionMonitor

java.lang.Object

javax.management.StandardMBean

wt.jmx.core.StandardMBean

wt.jmx.core.SelfAwareMBean

wt.jmx.core.mbeans.GarbageCollectionMonitor

All Implemented Interfaces:

DynamicMBean, MBeanRegistration, NotificationBroadcaster, NotificationEmitter, BaseObjectNamed, GarbageCollectionMonitorMBean, SelfEmailingMBean

public class GarbageCollectionMonitor
extends SelfAwareMBean
implements GarbageCollectionMonitorMBean, NotificationEmitter

Implementation of GarbageCollectionMonitorMBean.

This class is non-final so as to allow subclassing and overriding of getCurrentGCMillis().

Supported API: true

Extendable: true

Field Summary

Fields inherited from interface wt.jmx.core.mbeans.GarbageCollectionMonitorMBean

GC_THRESHOLD_EXCEEDED_INITIAL_NOTIF_TYPE, GC_THRESHOLD_EXCEEDED_NO_LONGER_NOTIF_TYPE, GC_THRESHOLD_EXCEEDED_STILL_NOTIF_TYPE

Constructor Summary

Constructors

Constructor	Description
GarbageCollectionMonitor()	No arg constructor.

Method Summary

Modifier and Type	Method	Description
protected long	getCurrentGCMillis()	Method which determines a metric for the total number of milliseconds spent in GC since application startup.

Methods inherited from class wt.jmx.core.SelfAwareMBean

deregister, destroy, getBaseObjectName, getObjectName, getObjectNameOnPreRegister, getOwnerMBean, getSelfAwareMBean, init, isInited, isRegistered, isStarted, onDestroy, onInit, postDeregister, postRegister, preDeregister, preRegister, register, register, register, resetObjectName, setOwnerMBean, start, stop

Methods inherited from class wt.jmx.core.StandardMBean

cacheMBeanInfo, cacheMBeanInfoInInstance, emailThisMBean, getAttributes, getCachedInstanceMBeanInfo, getCachedMBeanInfo, getDescription, getDescription, getDescription, getDescription, getImpact, getMBeanInfo, getParameterName, setAttributes

Methods inherited from class javax.management.StandardMBean

getAttribute, getClassName, getConstructors, getDescription, getDescription, getDescription, getImplementation, getImplementationClass, getMBeanInterface, getParameterName, invoke, setAttribute, setImplementation

Methods inherited from class java.lang.Object

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

Methods inherited from interface wt.jmx.core.mbeans.SelfEmailingMBean

emailThisMBean

Constructor Details

GarbageCollectionMonitor

public GarbageCollectionMonitor()
                         throws NotCompliantMBeanException

No arg constructor.

Supported API: true

Throws:

NotCompliantMBeanException

Method Details

getCurrentGCMillis

protected long getCurrentGCMillis()

Method which determines a metric for the total number of milliseconds spent in GC since application startup.

This method is left as protected and the overall class as non-final to allow this method to be overriden since there are different ways one might compute this result given the sparsity of information provided by the underlying GarbageCollectorMXBeans and the goal of arriving at a metric which best gauges the impact garbage collection has on the application.

This implementation considers only garbage collectors which operate upon the old or tenured generation as being significant -- as these garbage collectors generally pause other threads at times and generally present more of a bottleneck than other collectors which are often only a small drain on CPU time by comparison.

Supported API: true