org.jadice.util.mm.ckc.statistics

Class CacheStatistics

java.lang.Object

org.jadice.util.mm.ckc.statistics.CacheStatistics

All Implemented Interfaces:

CacheStatisticsMXBean

public class CacheStatistics
extends Object
implements CacheStatisticsMXBean

This class provides thread safe access to statistics like cache misses/hits/puts/gets and so on.

Constructor Summary

Constructors

Constructor and Description
CacheStatistics()

Method Summary

Modifier and Type	Method and Description
void	addCacheEvictions(long cacheEvictions)
void	addCacheGets(long cacheGets)
void	addCacheHits(long cacheHits)
void	addCacheMisses(long cacheMisses)
void	addCachePuts(long cachePuts)
void	addCacheRemovals(long cacheRemovals)
long	getCacheEvictions() Returns the total number of evictions from the cache.
long	getCacheGets() Returns the total number of get requests to the cache.
float	getCacheHitPercentage() This is a percentage representation of the positive cache efficiency, by computing how many get requests resulted in a hit in contrast to all get requests.
float	getCacheHitRatio() This is a measure of cache efficiency.
long	getCacheHits() Returns the number of get requests the cache found an entry for.
long	getCacheMisses() Returns the number of get requests the cache found NO entry for.
float	getCacheMissPercentage() This is a percentage representation of the negative cache efficiency, by computing for how many get requests no entry was found in contrast to all get requests .
float	getCacheMissRatio() Returns the ratio of cache accesses that did not find a requested entry in the cache.
long	getCachePuts() Returns the total number of put requests to the cache.
long	getCacheRemovals() Returns the total number of removal requests to the cache.
void	reset() Clears the statistics counters to 0 for the associated Cache.

Methods inherited from class java.lang.Object

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

Constructor Detail

CacheStatistics

public CacheStatistics()

Method Detail

getCacheHits

public long getCacheHits()

Description copied from interface: CacheStatisticsMXBean

Returns the number of get requests the cache found an entry for.

Specified by:

getCacheHits in interface CacheStatisticsMXBean

Returns:

the number of hits

addCacheHits

public void addCacheHits(long cacheHits)

getCacheMisses

public long getCacheMisses()

Description copied from interface: CacheStatisticsMXBean

Returns the number of get requests the cache found NO entry for.

Specified by:

getCacheMisses in interface CacheStatisticsMXBean

Returns:

the number of misses

addCacheMisses

public void addCacheMisses(long cacheMisses)

getCacheGets

public long getCacheGets()

Description copied from interface: CacheStatisticsMXBean

Returns the total number of get requests to the cache.

Note that this includes cache misses and hits and doesn't respect whether a key was found or not!

Specified by:

getCacheGets in interface CacheStatisticsMXBean

Returns:

the number of gets

addCacheGets

public void addCacheGets(long cacheGets)

getCachePuts

public long getCachePuts()

Description copied from interface: CacheStatisticsMXBean

Returns the total number of put requests to the cache.

Note that every put request is counted, even those who are immediately evicted.

Specified by:

getCachePuts in interface CacheStatisticsMXBean

Returns:

the number of puts

addCachePuts

public void addCachePuts(long cachePuts)

getCacheRemovals

public long getCacheRemovals()

Description copied from interface: CacheStatisticsMXBean

Returns the total number of removal requests to the cache.

Note that that every remove request is being counted, even those where nothing was removed. This doens't include evictions. For evictions refer to CacheStatisticsMXBean.getCacheEvictions()

Specified by:

getCacheRemovals in interface CacheStatisticsMXBean

Returns:

the number of manual removals

addCacheRemovals

public void addCacheRemovals(long cacheRemovals)

getCacheEvictions

public long getCacheEvictions()

Description copied from interface: CacheStatisticsMXBean

Returns the total number of evictions from the cache.

An eviction is an automatic removal of an cache entry in order to free space.

Specified by:

getCacheEvictions in interface CacheStatisticsMXBean

Returns:

the number of evictions

addCacheEvictions

public void addCacheEvictions(long cacheEvictions)

getCacheHitRatio

public float getCacheHitRatio()

This is a measure of cache efficiency.

It is calculated as: getCacheHits() divided by ().

Attention: Not thread safe since both gets can differ in time

Returns:

the percentage of successful hits, as a decimal e.g 75.

getCacheMissRatio

public float getCacheMissRatio()

Returns the ratio of cache accesses that did not find a requested entry in the cache.

This is calculated as getCacheMisses() divided by getCacheGets().

Attention: Not thread save since both gets can differ in time

Returns:

the percentage of accesses that failed to find anything

reset

public void reset()

Clears the statistics counters to 0 for the associated Cache.

Specified by:

reset in interface CacheStatisticsMXBean

getCacheHitPercentage

public float getCacheHitPercentage()

Description copied from interface: CacheStatisticsMXBean

This is a percentage representation of the positive cache efficiency, by computing how many get requests resulted in a hit in contrast to all get requests.

It calculates as: (CacheStatisticsMXBean.getCacheHits() / ()) * 100.

Specified by:

getCacheHitPercentage in interface CacheStatisticsMXBean

Returns:

the percentage of successful hits. So 75 states that 75% of all get requests resulted in a hit.

getCacheMissPercentage

public float getCacheMissPercentage()

Description copied from interface: CacheStatisticsMXBean

This is a percentage representation of the negative cache efficiency, by computing for how many get requests no entry was found in contrast to all get requests .

It calculates as: (CacheStatisticsMXBean.getCacheMisses() / ()) * 100.

Specified by:

getCacheMissPercentage in interface CacheStatisticsMXBean

Returns:

the percentage of accesses that failed to find anything