javax.management.monitor
Class CounterMonitor

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

public class CounterMonitor

extends Monitor

implements CounterMonitorMBean

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

A counter monitor sends a threshold notification when the value of the counter reaches or exceeds a threshold known as the comparison level. The notify flag must be set to true.
In addition, an offset mechanism enables particular counting intervals to be detected.

If the offset value is not zero, whenever the threshold is triggered by the counter value reaching a comparison level, that comparison level is incremented by the offset value. This is regarded as taking place instantaneously, that is before the count is incremented. Thus, for each level, the threshold triggers an event notification every time the count increases by an interval equal to the offset value.

If the counter can wrap around its maximum value, the modulus needs to be specified. The modulus is the value at which the counter is reset to zero.

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

• if (counter[t] - counter[t-GP]) is positive then V[t] = counter[t] - counter[t-GP]
• if (counter[t] - counter[t-GP]) is negative then V[t] = counter[t] - counter[t-GP] + MODULUS

This implementation of the counter monitor requires the observed attribute to be of the type integer (Byte, Integer, Short, Long).

Inner Class Summary

(package private) class

CounterMonitor.CounterThread

Fields inherited from class javax.management.monitor.Monitor

alreadyNotified, alreadyNotifieds, capacityIncrement, dbgTag, derivedGaugeTimeStamp, elementCount, isActive, logger, OBSERVED_ATTRIBUTE_ERROR_NOTIFIED, OBSERVED_ATTRIBUTE_TYPE_ERROR_NOTIFIED, OBSERVED_OBJECT_ERROR_NOTIFIED, RESET_FLAGS_ALREADY_NOTIFIED, RUNTIME_ERROR_NOTIFIED, sequenceNumber, server

Fields inherited from class javax.management.NotificationBroadcasterSupport

li

Constructor Summary

CounterMonitor()
Default Constructor.

Method Summary

java.lang.Number	getDerivedGauge() Deprecated. Replaced by getDerivedGauge(ObjectName)
java.lang.Number	getDerivedGauge(ObjectName object) Gets the derived gauge of the specified object, if this object is contained in the set of observed MBeans, or null otherwise.
long	getDerivedGaugeTimeStamp() Deprecated. Replaced by getDerivedGaugeTimeStamp(ObjectName)
long	getDerivedGaugeTimeStamp(ObjectName object) Gets the derived gauge timestamp of the specified object, if this object is contained in the set of observed MBeans, or null otherwise.
boolean	getDifferenceMode() Gets the value of the difference mode.
java.lang.Number	getInitThreshold() Gets the initial threshold value common to all observed objects.
java.lang.Number	getModulus() Gets the modulus value common to all observed MBeans.
MBeanNotificationInfo[]	getNotificationInfo() This method returns a NotificationInfo object containing the name of the Java class of the notification and the notification types sent by the counter monitor.
boolean	getNotify() Gets the notification's on/off switch value common to all observed MBeans.
java.lang.Number	getOffset() Gets the offset value.
java.lang.Number	getThreshold() Deprecated. Replaced by getThreshold(ObjectName)
java.lang.Number	getThreshold(ObjectName object) Gets the current threshold value of the specified object, if this object is contained in the set of observed MBeans, or null otherwise.
(package private) void	insertSpecificElementAt(int index) This method is called when adding a new observed object in the list.
void	preDeregister() This method allows the monitor MBean to perform any operations it needs before being de-registered by the MBean server.
(package private) void	removeSpecificElementAt(int index) This method is called when removing an observed object from the list.
void	setDifferenceMode(boolean value) Sets the difference mode flag value common to all observed MBeans.
void	setInitThreshold(java.lang.Number value) Sets the initial threshold value common to all observed objects.
void	setModulus(java.lang.Number value) Sets the modulus value common to all observed MBeans.
void	setNotify(boolean value) Sets the notification's on/off switch value common to all observed MBeans.
void	setOffset(java.lang.Number value) Sets the value of the offset.
void	setThreshold(java.lang.Number value) Deprecated. Replaced by setInitThreshold(java.lang.Number)
void	start() This method starts the counter monitor.
void	stop() This method stops the counter monitor.

Methods inherited from class javax.management.monitor.Monitor

addObservedObject, containsObservedObject, getGranularityPeriod, getObservedAttribute, getObservedObject, getObservedObject, getObservedObjects, indexOf, insertElementAt, isActive, isFlagsReset, postDeregister, postRegister, preRegister, removeElementAt, removeObservedObject, resetAllAlreadyNotifiedFlags, resetAlreadyNotifiedFlag, sendNotification, setAlreadyNotifiedFlag, setGranularityPeriod, setObservedAttribute, setObservedObject, updateDeprecatedAlreadyNotifiedFlag

Methods inherited from class javax.management.NotificationBroadcasterSupport

addNotificationListener, handleNotification, handleNotification, removeNotificationListener, removeNotificationListener, sendNotification

Methods inherited from class java.lang.Object

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

Constructor Detail

CounterMonitor

public CounterMonitor()

Default Constructor.

Method Detail

getDerivedGauge

public java.lang.Number getDerivedGauge()

Deprecated. Replaced by getDerivedGauge(ObjectName)

Gets the value of the derived gauge. The derived gauge is either the exact value of the observed attribute, or the difference between the two consecutive observed values of the attribute.

Specified by:

getDerivedGauge in interface CounterMonitorMBean

Returns:

The value of the derived gauge as an instance of java.lang.Number.

getDerivedGauge

public java.lang.Number getDerivedGauge(ObjectName object)

Gets the derived gauge of the specified object, if this object is contained in the set of observed MBeans, or null otherwise.

Specified by:

getDerivedGauge in interface CounterMonitorMBean

Parameters:

object - the name of the object whose derived gauge is to be returned.

Returns:

The derived gauge of the specified object.

getDerivedGaugeTimeStamp

public long getDerivedGaugeTimeStamp()

Deprecated. Replaced by getDerivedGaugeTimeStamp(ObjectName)

Gets the value of the derived gauge time stamp. The derived gauge time stamp is the value(in the nearest miliseconds) when the notification was triggered.

Specified by:

getDerivedGaugeTimeStamp in interface CounterMonitorMBean

Returns:

long value representing the time the notification was triggered.

getDerivedGaugeTimeStamp

public long getDerivedGaugeTimeStamp(ObjectName object)

Gets the derived gauge timestamp of the specified object, if this object is contained in the set of observed MBeans, or null otherwise.

Specified by:

getDerivedGaugeTimeStamp in interface CounterMonitorMBean

Parameters:

object - the name of the object whose derived gauge timestamp is to be returned.

Returns:

The derived gauge timestamp of the specified object.

getDifferenceMode

public boolean getDifferenceMode()

Gets the value of the difference mode. If the difference mode is true, the difference mode option is set to calculate the value of the derived gauge.

Specified by:

getDifferenceMode in interface CounterMonitorMBean

Returns:

boolean value indicating whether the difference mode option is set.

setDifferenceMode

public void setDifferenceMode(boolean value)

Sets the difference mode flag value common to all observed MBeans.

Specified by:

setDifferenceMode in interface CounterMonitorMBean

Parameters:

value - boolean value representing the state of the difference mode.

See Also:

getDifferenceMode()

getModulus

public java.lang.Number getModulus()

Gets the modulus value common to all observed MBeans. Modulus is the value at which the counter is reset to zero.

Specified by:

getModulus in interface CounterMonitorMBean

Returns:

An instance of java.lang.Number giving the modulus value.

See Also:

setModulus(java.lang.Number)

setModulus

public void setModulus(java.lang.Number value)
                throws java.lang.IllegalArgumentException

Sets the modulus value common to all observed MBeans. Modulus is the value at which the counter is reset to zero.

Specified by:

setModulus in interface CounterMonitorMBean

Parameters:

value - An instance of java.lang.Number representing the modulus value for the derived gauge.

Throws:

java.lang.IllegalArgumentException - - The specified modulus is null or the modulus value is less than zero.

getNotify

public boolean getNotify()

Gets the notification's on/off switch value common to all observed MBeans.

Specified by:

getNotify in interface CounterMonitorMBean

Returns:

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

See Also:

setNotify(boolean)

setNotify

public void setNotify(boolean value)

Sets the notification's on/off switch value common to all observed MBeans.

Specified by:

setNotify in interface CounterMonitorMBean

Parameters:

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

See Also:

getNotify()

getOffset

public java.lang.Number getOffset()

Gets the offset value. Offset enables particular counting intervals to be detected.

Specified by:

getOffset in interface CounterMonitorMBean

Returns:

An instance of java.lang.Number giving the value of the offset.

setOffset

public void setOffset(java.lang.Number value)
               throws java.lang.IllegalArgumentException

Sets the value of the offset.

Specified by:

setOffset in interface CounterMonitorMBean

Parameters:

value - An instance of java.lang.Number giving the value offset.

Throws:

java.lang,IllegalArgumentException - - The specified offset is null or the offset value is less than zero.

getThreshold

public java.lang.Number getThreshold()

Deprecated. Replaced by getThreshold(ObjectName)

Gets the threshold value of the first object in the set of observed MBeans. Threshold is the maximum value of that the attribute can reach. If the attribute reaches this comparison level or is greater than this level, notification is triggered.

Specified by:

getThreshold in interface CounterMonitorMBean

Returns:

An instance of java.lang.Number giving the value of the threshold.

See Also:

setThreshold(Number)

setThreshold

public void setThreshold(java.lang.Number value)
                  throws java.lang.IllegalArgumentException

Deprecated. Replaced by setInitThreshold(java.lang.Number)

Sets the initial threshold value. Threshold is the maximum value of that the attribute can reach. If the attribute reaches this comparison level or is greater than this level , notification is triggered.

Specified by:

setThreshold in interface CounterMonitorMBean

Parameters:

value - An instance of java.lang.Number which is the value of the threshold.

Throws:

java.lang.IllegalArgumentException - The specified threshold is null or the threshold value is less than zero.

See Also:

getThreshold()

getThreshold

public java.lang.Number getThreshold(ObjectName object)

Gets the current threshold value of the specified object, if this object is contained in the set of observed MBeans, or null otherwise.

Specified by:

getThreshold in interface CounterMonitorMBean

Parameters:

object - the name of the object whose threshold is to be returned.

Returns:

The threshold value of the specified object.

See Also:

setThreshold(java.lang.Number)

getInitThreshold

public java.lang.Number getInitThreshold()

Gets the initial threshold value common to all observed objects.

Specified by:

getInitThreshold in interface CounterMonitorMBean

Returns:

The initial threshold.

See Also:

setInitThreshold(java.lang.Number)

setInitThreshold

public void setInitThreshold(java.lang.Number value)
                      throws java.lang.IllegalArgumentException

Sets the initial threshold value common to all observed objects.
The current threshold of every object in the set of observed MBeans is updated consequently.

Specified by:

setInitThreshold in interface CounterMonitorMBean

Parameters:

value - The initial threshold value.

Throws:

java.lang.IllegalArgumentException - The specified threshold is null or the threshold value is less than zero.

See Also:

getInitThreshold()

start

public void start()

This method starts the counter monitor.

Overrides:

start in class Monitor

stop

public void stop()

This method stops the counter monitor.

Overrides:

stop in class Monitor

preDeregister

public void preDeregister()
                   throws java.lang.Exception

This method allows the monitor MBean to perform any operations it needs before being de-registered by the MBean server. Stops the monitor.

Resets the threshold values.

Overrides:

preDeregister in class Monitor

Throws:

java.lang.Exception -

getNotificationInfo

public MBeanNotificationInfo[] getNotificationInfo()

This method returns a NotificationInfo object containing the name of the Java class of the notification and the notification types sent by the counter monitor.

Overrides:

getNotificationInfo in class Monitor

Returns:

An Array of MBeanNotificationInfo objects.

insertSpecificElementAt

void insertSpecificElementAt(int index)

This method is called when adding a new observed object in the list. It updates all the counter specific arrays.

Overrides:

insertSpecificElementAt in class Monitor

Parameters:

index - The index of the observed object.

removeSpecificElementAt

void removeSpecificElementAt(int index)

This method is called when removing an observed object from the list. It updates all the counter specific arrays.

Overrides:

removeSpecificElementAt in class Monitor

Parameters:

index - The index of the observed object.