Package com.codahale.metrics

Class SlidingTimeWindowMovingAverages

java.lang.Object

com.codahale.metrics.SlidingTimeWindowMovingAverages

All Implemented Interfaces:

MovingAverages

public class SlidingTimeWindowMovingAverages
extends Object
implements MovingAverages

A triple of simple moving average rates (one, five and fifteen minutes rates) as needed by Meter.

The averages are unweighted, i.e. they include strictly only the events in the sliding time window, every event having the same weight. Unlike the the more widely used ExponentialMovingAverages implementation, with this class the moving average rate drops immediately to zero if the last marked event is older than the time window.

A Meter with SlidingTimeWindowMovingAverages works similarly to a Histogram with an SlidingTimeWindowArrayReservoir, but as a Meter needs to keep track only of the count of events (not the events itself), the memory overhead is much smaller. SlidingTimeWindowMovingAverages uses buckets with just one counter to accumulate the number of events (one bucket per seconds, giving 900 buckets for the 15 minutes time window).

Constructor Summary

Constructors

Constructor	Description
SlidingTimeWindowMovingAverages()	Creates a new SlidingTimeWindowMovingAverages.
SlidingTimeWindowMovingAverages(Clock clock)	Creates a new SlidingTimeWindowMovingAverages.

Method Summary

Modifier and Type	Method	Description
double	getM15Rate()	Returns the fifteen-minute moving average rate
double	getM1Rate()	Returns the one-minute moving average rate
double	getM5Rate()	Returns the five-minute moving average rate
void	tickIfNecessary()	Tick the internal clock of the MovingAverages implementation if needed (according to the internal ticking interval)
void	update(long n)	Update all three moving averages with n events having occurred since the last update.

Methods inherited from class java.lang.Object

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

Constructor Detail

SlidingTimeWindowMovingAverages

public SlidingTimeWindowMovingAverages()

Creates a new SlidingTimeWindowMovingAverages.

SlidingTimeWindowMovingAverages

public SlidingTimeWindowMovingAverages(Clock clock)

Creates a new SlidingTimeWindowMovingAverages.

Parameters:

clock - the clock to use for the meter ticks

Method Detail

update

public void update(long n)

Description copied from interface: MovingAverages

Update all three moving averages with n events having occurred since the last update.

Specified by:

update in interface MovingAverages

tickIfNecessary

public void tickIfNecessary()

Description copied from interface: MovingAverages

Tick the internal clock of the MovingAverages implementation if needed (according to the internal ticking interval)

Specified by:

tickIfNecessary in interface MovingAverages

getM15Rate

public double getM15Rate()

Description copied from interface: MovingAverages

Returns the fifteen-minute moving average rate

Specified by:

getM15Rate in interface MovingAverages

Returns:

the fifteen-minute moving average rate

getM5Rate

public double getM5Rate()

Description copied from interface: MovingAverages

Returns the five-minute moving average rate

Specified by:

getM5Rate in interface MovingAverages

Returns:

the five-minute moving average rate

getM1Rate

public double getM1Rate()

Description copied from interface: MovingAverages

Returns the one-minute moving average rate

Specified by:

getM1Rate in interface MovingAverages

Returns:

the one-minute moving average rate