org.springframework.integration.monitor

Class ExponentialMovingAverageRatio

java.lang.Object

org.springframework.integration.monitor.ExponentialMovingAverageRatio

public class ExponentialMovingAverageRatio
extends java.lang.Object

Cumulative statistics for success ratio with higher weight given to recent data but without storing any history. Clients call success() or failure() when an event occurs, and the ratio of success to total events is accumulated. Older values are given exponentially smaller weight, with a decay factor determined by a duration chosen by the client. The rate measurement weights decay in two dimensions:

• in time according to the lapse period supplied: weight = exp((t0-t)/T) where t0 is the last measurement time, t is the current time and T is the lapse period)
• per measurement according to the lapse window supplied: weight = exp(-i/L) where L is the lapse window and i is the sequence number of the measurement.

Since:

2.0

Author:

Dave Syer

Constructor Summary

Constructors

Constructor and Description
ExponentialMovingAverageRatio(double lapsePeriod, int window)

Method Summary

Methods

Modifier and Type	Method and Description
void	failure() Add a new event with failed outcome.
int	getCount()
double	getMax()
double	getMean()
double	getMin()
double	getStandardDeviation()
Statistics	getStatistics()
double	getTimeSinceLastMeasurement()
void	reset()
void	success() Add a new event with successful outcome.
java.lang.String	toString()

Methods inherited from class java.lang.Object

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

Constructor Detail

ExponentialMovingAverageRatio

public ExponentialMovingAverageRatio(double lapsePeriod,
                             int window)

Parameters:

lapsePeriod - the exponential lapse rate for the rate average (in seconds)

window - the exponential lapse window (number of measurements)

Method Detail

success

public void success()

Add a new event with successful outcome.

failure

public void failure()

Add a new event with failed outcome.

reset

public void reset()

getCount

public int getCount()

Returns:

the number of measurements recorded

getTimeSinceLastMeasurement

public double getTimeSinceLastMeasurement()

Returns:

the time in seconds since the last measurement

getMean

public double getMean()

Returns:

the mean success rate

getStandardDeviation

public double getStandardDeviation()

Returns:

the approximate standard deviation of the success rate measurements

getMax

public double getMax()

Returns:

the maximum value recorded of the exponential weighted average (per measurement) success rate

getMin

public double getMin()

Returns:

the minimum value recorded of the exponential weighted average (per measurement) success rate

getStatistics

public Statistics getStatistics()

Returns:

summary statistics (count, mean, standard deviation etc.)

toString

public java.lang.String toString()

Overrides:

toString in class java.lang.Object