de.is24.util.monitoring
Class Timer

java.lang.Object
  de.is24.util.monitoring.Counter
      de.is24.util.monitoring.Timer

All Implemented Interfaces:

Reportable

public class Timer
extends Counter

Currently a subclass of counter although this makes no sense and should be refactored
Timers count and measure timed events.
Timers allow adding timer measurements, implicitly incrementing the count

 Examples
    DB Query duration
    rendering duration
    parsing time of xml input
 

Note that operations might not appear consistent especially with only a few measurements as none of the timer operations are atomic. With many measurements these inconsistencies should not be notable anymore though.

Author:

OSchmitz

Field Summary

private static org.apache.log4j.Logger	LOGGER
private AtomicLong	timerSum
private AtomicLong	timerSumOfSquares

Constructor Summary

Timer(String name)
This class is only constructed by InApplicationMonitor

Method Summary

void	accept(ReportVisitor aVisitor) Implements the visitor pattern to read this StateValueProvider
void	addMeasurement(long durationInMillis) Add a timer measurement for this timer. The application decides which unit to use for timing.
double	getTimerAvg() Note that this calculation might be notably inconsistent unless there are many measurements as a timer is not atomic.
double	getTimerStdDev() Note that this calculation might be notably inconsistent unless there are many measurements as a timer is not atomic.
long	getTimerSum()
void	initializeMeasurement() initialize with 0

Methods inherited from class de.is24.util.monitoring.Counter

getCount, getName, increment, increment, initialize

Methods inherited from class java.lang.Object

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

Field Detail

LOGGER

private static final org.apache.log4j.Logger LOGGER

timerSum

private final AtomicLong timerSum

timerSumOfSquares

private final AtomicLong timerSumOfSquares

Constructor Detail

Timer

Timer(String name)

This class is only constructed by InApplicationMonitor

Parameters:

name - name of this Timer

Method Detail

accept

public void accept(ReportVisitor aVisitor)

Implements the visitor pattern to read this StateValueProvider

Specified by:

accept in interface Reportable

Overrides:

accept in class Counter

addMeasurement

public void addMeasurement(long durationInMillis)

Add a timer measurement for this timer.
The application decides which unit to use for timing. Milliseconds are suggested and some ReportVisitor implementations may imply this.

Parameters:

durationInMillis -

initializeMeasurement

public void initializeMeasurement()

initialize with 0

getTimerSum

public long getTimerSum()

Returns:

the sum of all timer measurements.

getTimerAvg

public double getTimerAvg()

Note that this calculation might be notably inconsistent unless there are many measurements as a timer is not atomic.

Returns:

the average of all timer measurements.

getTimerStdDev

public double getTimerStdDev()

Note that this calculation might be notably inconsistent unless there are many measurements as a timer is not atomic.

Returns:

the standard deviation of all timer measurements.