org.apache.ignite.internal.processors.cache.ratemetrics

Class HitRateMetrics

java.lang.Object

org.apache.ignite.internal.processors.cache.ratemetrics.HitRateMetrics

public class HitRateMetrics
extends Object

Accumulates approximate hit rate statistics. Calculates number of hits in last rateTimeInterval milliseconds. Algorithm is based on circular array of size hit counters, each is responsible for last corresponding time interval of rateTimeInterval/size milliseconds. Resulting number of hits is sum of all counters.

Implementation is nonblocking and protected from hits loss. Maximum relative error is 1/size. 2^56 - 1 hits per interval can be accumulated without numeric overflow.

Constructor Summary

Constructors

Constructor and Description
HitRateMetrics(int rateTimeInterval, int size)

Method Summary

Methods

Modifier and Type	Method and Description
void	clear() Clear metrics.
long	getRate()
void	onHit() Mark one hit.
void	onHits(long hits) Mark multiple hits.

Methods inherited from class java.lang.Object

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

Constructor Detail

HitRateMetrics

public HitRateMetrics(int rateTimeInterval,
              int size)

Parameters:

rateTimeInterval - Rate time interval.

size - Number of counters.

Method Detail

onHit

public void onHit()

Mark one hit.

onHits

public void onHits(long hits)

Mark multiple hits.

Parameters:

hits - Number of hits.

getRate

public long getRate()

Returns:

Total number of hits in last rateTimeInterval milliseconds.

clear

public void clear()

Clear metrics.