javax.management.monitor
Class GaugeMonitor

java.lang.Object
  |
  +--javax.management.NotificationBroadcasterSupport
        |
        +--javax.management.monitor.Monitor
              |
              +--javax.management.monitor.GaugeMonitor

All Implemented Interfaces:

GaugeMonitorMBean, MBeanRegistration, MonitorMBean, NotificationBroadcaster, NotificationEmitter

public class GaugeMonitor

extends Monitor

implements GaugeMonitorMBean

Defines a monitor MBean designed to observe the values of a gauge attribute.

A gauge monitor observes an attribute that is continuously variable with time. A gauge monitor sends notifications as follows:

• if the attribute value is increasing and becomes equal to or greater than the high threshold value, a threshold high notification is sent. The notify high flag must be set to true
  Subsequent crossings of the high threshold value do not cause further notifications unless the attribute value becomes equal to or less than the low threshold value.
• if the attribute value is decreasing and becomes equal to or less than the low threshold value, a threshold low notification is sent. The notify low flag must be set to true.
  Subsequent crossings of the low threshold value do not cause further notifications unless the attribute value becomes equal to or greater than the high threshold value.

This provides a hysteresis mechanism to avoid repeated triggering of notifications when the attribute value makes small oscillations around the high or low threshold value.

If the gauge difference mode is used, the value of the derived gauge is calculated as the difference between the observed gauge values for two successive observations.
The derived gauge value (V[t]) is calculated using the following method:

• V[t] = gauge[t] - gauge[t-GP]

This implementation of the gauge monitor requires the observed attribute to be of the type integer or floating-point (Byte, Integer, Short, Long, Float, Double).

Author:

Young Yang

Field Summary

Fields inherited from class javax.management.monitor.Monitor

observedObjects

Constructor Summary

GaugeMonitor()

Method Summary

void	addObservedObject(ObjectName objectName) Adds the specified object in the set of observed MBeans.
protected void	doMonitor(ObjectName observedObject, java.lang.Object value)
java.lang.Number	getDerivedGauge(ObjectName observedObject) Gets the derived gauge for the specified MBean.
long	getDerivedGaugeTimeStamp(ObjectName observedObject) Gets the derived gauge timestamp for the specified MBean.
boolean	getDifferenceMode() Gets the difference mode flag value.
java.lang.Number	getHighThreshold() Gets the high threshold value.
java.lang.Number	getLowThreshold() Gets the low threshold value.
MBeanNotificationInfo[]	getNotificationInfo() Returns a NotificationInfo object contaning the name of the Java class of the notification and the notification types sent.
boolean	getNotifyHigh() Gets the high notification's on/off switch value.
boolean	getNotifyLow() Gets the low notification's on/off switch value.
void	setDifferenceMode(boolean value) Sets the difference mode flag value.
void	setNotifyHigh(boolean value) Sets the high notification's on/off switch value.
void	setNotifyLow(boolean value) Sets the low notification's on/off switch value.
void	setThresholds(java.lang.Number highValue, java.lang.Number lowValue) Sets the high and the low threshold values.
void	start()
void	stop()

Methods inherited from class javax.management.monitor.Monitor

_start, _stop, containsObservedObject, getGranularityPeriod, getMonitorData, getObservedAttribute, getObservedObjects, isActive, postDeregister, postRegister, preDeregister, preRegister, removeObservedObject, sendNotification, setGranularityPeriod, setObservedAttribute

Methods inherited from class javax.management.NotificationBroadcasterSupport

addNotificationListener, handleNotification, removeNotificationListener, removeNotificationListener, sendNotification

Methods inherited from class java.lang.Object

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

Methods inherited from interface javax.management.monitor.MonitorMBean

containsObservedObject, getGranularityPeriod, getObservedAttribute, getObservedObjects, isActive, removeObservedObject, setGranularityPeriod, setObservedAttribute

Constructor Detail

GaugeMonitor

public GaugeMonitor()

Method Detail

start

public void start()

Specified by:

start in class Monitor

stop

public void stop()

Specified by:

stop in class Monitor

getDerivedGauge

public java.lang.Number getDerivedGauge(ObjectName observedObject)

Description copied from interface: GaugeMonitorMBean

Gets the derived gauge for the specified MBean.

Specified by:

getDerivedGauge in interface GaugeMonitorMBean

Parameters:

observedObject - the MBean for which the derived gauge is to be returned

Returns:

The derived gauge for the specified MBean if this MBean is in the set of observed MBeans, or null otherwise.

getDerivedGaugeTimeStamp

public long getDerivedGaugeTimeStamp(ObjectName observedObject)

Description copied from interface: GaugeMonitorMBean

Gets the derived gauge timestamp for the specified MBean.

Specified by:

getDerivedGaugeTimeStamp in interface GaugeMonitorMBean

Parameters:

observedObject - the MBean for which the derived gauge timestamp is to be returned

Returns:

The derived gauge timestamp for the specified MBean if this MBean is in the set of observed MBeans, or null otherwise.

getHighThreshold

public java.lang.Number getHighThreshold()

Description copied from interface: GaugeMonitorMBean

Gets the high threshold value.

Specified by:

getHighThreshold in interface GaugeMonitorMBean

Returns:

The high threshold value.

getLowThreshold

public java.lang.Number getLowThreshold()

Description copied from interface: GaugeMonitorMBean

Gets the low threshold value.

Specified by:

getLowThreshold in interface GaugeMonitorMBean

Returns:

The low threshold value.

setThresholds

public void setThresholds(java.lang.Number highValue,
                          java.lang.Number lowValue)
                   throws java.lang.IllegalArgumentException

Description copied from interface: GaugeMonitorMBean

Sets the high and the low threshold values.

Specified by:

setThresholds in interface GaugeMonitorMBean

Parameters:

highValue - The high threshold value.

lowValue - The low threshold value.

Throws:

java.lang.IllegalArgumentException - The specified high/low threshold is null or the low threshold is greater than the high threshold or the high threshold and the low threshold are not of the same type.

getNotifyHigh

public boolean getNotifyHigh()

Description copied from interface: GaugeMonitorMBean

Gets the high notification's on/off switch value.

Specified by:

getNotifyHigh in interface GaugeMonitorMBean

Returns:

true if the gauge monitor notifies when exceeding the high threshold, false otherwise.

See Also:

GaugeMonitorMBean.setNotifyHigh(boolean)

setNotifyHigh

public void setNotifyHigh(boolean value)

Description copied from interface: GaugeMonitorMBean

Sets the high notification's on/off switch value.

Specified by:

setNotifyHigh in interface GaugeMonitorMBean

Parameters:

value - The high notification's on/off switch value.

See Also:

GaugeMonitorMBean.getNotifyHigh()

getNotifyLow

public boolean getNotifyLow()

Description copied from interface: GaugeMonitorMBean

Gets the low notification's on/off switch value.

Specified by:

getNotifyLow in interface GaugeMonitorMBean

Returns:

true if the gauge monitor notifies when exceeding the low threshold, false otherwise.

See Also:

GaugeMonitorMBean.setNotifyLow(boolean)

setNotifyLow

public void setNotifyLow(boolean value)

Description copied from interface: GaugeMonitorMBean

Sets the low notification's on/off switch value.

Specified by:

setNotifyLow in interface GaugeMonitorMBean

Parameters:

value - The low notification's on/off switch value.

See Also:

GaugeMonitorMBean.getNotifyLow()

getDifferenceMode

public boolean getDifferenceMode()

Description copied from interface: GaugeMonitorMBean

Gets the difference mode flag value.

Specified by:

getDifferenceMode in interface GaugeMonitorMBean

Returns:

true if the difference mode is used, false otherwise.

See Also:

GaugeMonitorMBean.setDifferenceMode(boolean)

setDifferenceMode

public void setDifferenceMode(boolean value)

Description copied from interface: GaugeMonitorMBean

Sets the difference mode flag value.

Specified by:

setDifferenceMode in interface GaugeMonitorMBean

Parameters:

value - The difference mode flag value.

See Also:

GaugeMonitorMBean.getDifferenceMode()

getNotificationInfo

public MBeanNotificationInfo[] getNotificationInfo()

Description copied from class: NotificationBroadcasterSupport

Returns a NotificationInfo object contaning the name of the Java class of the notification and the notification types sent.

Specified by:

getNotificationInfo in interface NotificationBroadcaster

Overrides:

getNotificationInfo in class NotificationBroadcasterSupport

doMonitor

protected void doMonitor(ObjectName observedObject,
                         java.lang.Object value)

Specified by:

doMonitor in class Monitor

addObservedObject

public void addObservedObject(ObjectName objectName)
                       throws java.lang.IllegalArgumentException

Description copied from interface: MonitorMBean

Adds the specified object in the set of observed MBeans.

Specified by:

addObservedObject in interface MonitorMBean

Specified by:

addObservedObject in class Monitor

Parameters:

objectName - The object to observe.

Throws:

java.lang.IllegalArgumentException - the specified object is null.