Package com.tangosol.net.cache

Class SimpleCacheStatistics

java.lang.Object

com.tangosol.util.Base

com.tangosol.net.cache.SimpleCacheStatistics

All Implemented Interfaces:

CacheStatistics, Serializable

public class SimpleCacheStatistics
extends Base
implements CacheStatistics, Serializable

Implementation of the CacheStatistics interface intended for use by a cache to maintain its statistics.

Since:

Coherence 2.2

Author:

cp 2003.06.02

See Also:

• Serialized Form

Nested Class Summary

Nested classes/interfaces inherited from class com.tangosol.util.Base

Base.LoggingWriter

Field Summary

Fields

Modifier and Type	Field	Description
protected long	m_cCacheHits	The rough (ie unsynchronized) number of calls that could be answered from the front or the back and were answered by data in the front map.
protected long	m_cCacheMisses	The rough (ie unsynchronized) number of calls that could be answered from the front or the back and were answered by data in the back map.
protected long	m_cCachePrunes	Total number of evictions triggered based on the size of the cache since the last statistics reset.
protected long	m_cCachePrunesMillis	Total number of milliseconds used for prune operations since the last statistics reset.
protected long	m_cCachePuts	Total number of put operations since the last statistics reset.
protected long	m_cHitsMillis	Total number of milliseconds used for get operations that were hits since the last statistics reset.
protected long	m_cMissesMillis	Total number of milliseconds used for get operations that were misses since the last statistics reset.
protected long	m_cPutsMillis	Total number of milliseconds used for put operations since the last statistics reset.

Fields inherited from class com.tangosol.util.Base

LOG_ALWAYS, LOG_CONFIG, LOG_DEBUG, LOG_ERR, LOG_INFO, LOG_MAX, LOG_MIN, LOG_QUIET, LOG_WARN, POWER_0, POWER_G, POWER_K, POWER_M, POWER_T, UNIT_D, UNIT_H, UNIT_M, UNIT_MS, UNIT_NS, UNIT_S, UNIT_US

Constructor Summary

Constructors

Constructor	Description
SimpleCacheStatistics()	Default constructor.

Method Summary

Modifier and Type	Method	Description
double	getAverageGetMillis()	Determine the average number of milliseconds per get() invocation since the cache statistics were last reset.
double	getAverageHitMillis()	Determine the average number of milliseconds per get() invocation that is a hit.
double	getAverageMissMillis()	Determine the average number of milliseconds per get() invocation that is a miss.
double	getAveragePruneMillis()	Calculate the average number of milliseconds that a prune takes.
double	getAveragePutMillis()	Determine the average number of milliseconds per put() invocation since the cache statistics were last reset.
long	getCacheHits()	Determine the rough number of cache hits since the cache statistics were last reset.
long	getCacheHitsMillis()	Determine the total number of milliseconds (since the last statistics reset) for the get() operations for which an entry existed in this map.
long	getCacheMisses()	Determine the rough number of cache misses since the cache statistics were last reset.
long	getCacheMissesMillis()	Determine the total number of milliseconds (since the last statistics reset) for the get() operations for which no entry existed in this map.
long	getCachePrunes()	Determine the rough number of cache pruning cycles since the cache statistics were last reset.
long	getCachePrunesMillis()	Determine the total number of milliseconds (since the last statistics reset) spent on cache pruning.
double	getHitProbability()	Determine the rough probability (0 <= p <= 1) that the next invocation will be a hit, based on the statistics collected since the last reset of the cache statistics.
long	getTotalGets()	Determine the total number of get() operations since the cache statistics were last reset.
long	getTotalGetsMillis()	Determine the total number of milliseconds spent on get() operations since the cache statistics were last reset.
long	getTotalPuts()	Determine the total number of put() operations since the cache statistics were last reset.
long	getTotalPutsMillis()	Determine the total number of milliseconds spent on put() operations since the cache statistics were last reset.
void	registerCachePrune(long lStartMillis)	Register a cache prune.
void	registerHit()	Register a cache hit (no timing information).
void	registerHit(long lStartMillis)	Register a cache hit.
void	registerHits(int cHits, long lStartMillis)	Register a multiple cache hit.
void	registerIncrementalCachePrune(long lStartMillis)	Register an incremental cache prune, which is to say that the time is accreted but the number of prunes does not increase.
void	registerMiss()	Register a cache miss (no timing information).
void	registerMiss(long lStartMillis)	Register a cache miss.
void	registerMisses(int cMisses, long lStartMillis)	Register a multiple cache miss.
void	registerPut(long lStartMillis)	Register a cache put.
void	registerPuts(int cPuts, long lStartMillis)	Register a multiple cache put.
void	resetHitStatistics()	Reset all of the cache statistics.
String	toString()	For debugging purposes, format the contents of the SimpleCachingStatistics in a human readable format.

Methods inherited from class com.tangosol.util.Base

azzert, azzert, azzert, azzertFailed, breakLines, breakLines, capitalize, checkNotEmpty, checkNotNull, checkRange, computeSafeWaitTime, decimalValue, dup, dup, ensureBigDecimal, ensureClassLoader, ensureRuntimeException, ensureRuntimeException, equals, equalsDeep, err, err, err, err, err, escape, formatDateTime, getCallerStackFrame, getCommonMonitor, getCommonMonitor, getCommonMonitor, getContextClassLoader, getContextClassLoader, getDeepMessage, getErr, getLastSafeTimeMillis, getLog, getMaxDecDigits, getMaxHexDigits, getOriginalException, getOut, getProcessRandom, getRandom, getRandomBinary, getRandomBinary, getRandomString, getSafeTimeMillis, getStackFrame, getStackFrames, getStackTrace, getStackTrace, getStackTrace, getThreadFactory, getTimeZone, getUpTimeMillis, hashCode, hexValue, indentString, indentString, isDecimal, isHex, isLogEcho, isOctal, log, log, log, log, log, makeInteger, makeLong, makeThread, mergeArray, mergeBooleanArray, mergeByteArray, mergeCharArray, mergeDoubleArray, mergeFloatArray, mergeIntArray, mergeLongArray, mod, mod, octalValue, out, out, out, out, out, pad, parseBandwidth, parseBandwidth, parseDelimitedString, parseHex, parseHex, parseMemorySize, parseMemorySize, parsePercentage, parseTime, parseTime, parseTimeNanos, parseTimeNanos, printStackTrace, randomize, randomize, randomize, randomize, read, read, read, read, read, read, read, replace, setErr, setLog, setLogEcho, setOut, sleep, toBandwidthString, toBandwidthString, toCharEscape, toCrc, toCrc, toCrc, toCrc, toCrc, toDecString, toDelimitedString, toDelimitedString, toDelimitedString, toDelimitedString, toHex, toHex, toHexDump, toHexEscape, toHexEscape, toHexEscape, toHexEscape, toHexString, toMemorySizeString, toMemorySizeString, toQuotedCharEscape, toQuotedStringEscape, toSqlString, toString, toString, toStringEscape, toUnicodeEscape, trace, trace, trace, trace, trace, trace, trace, trace, trace, truncateString, truncateString, wait

Methods inherited from class java.lang.Object

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

Field Details

m_cCacheHits

protected volatile long m_cCacheHits

The rough (ie unsynchronized) number of calls that could be answered from the front or the back and were answered by data in the front map.

m_cHitsMillis

protected volatile long m_cHitsMillis

Total number of milliseconds used for get operations that were hits since the last statistics reset.

m_cCacheMisses

protected volatile long m_cCacheMisses

The rough (ie unsynchronized) number of calls that could be answered from the front or the back and were answered by data in the back map.

m_cMissesMillis

protected volatile long m_cMissesMillis

Total number of milliseconds used for get operations that were misses since the last statistics reset.

m_cCachePuts

protected volatile long m_cCachePuts

Total number of put operations since the last statistics reset.

m_cPutsMillis

protected volatile long m_cPutsMillis

Total number of milliseconds used for put operations since the last statistics reset.

m_cCachePrunes

protected volatile long m_cCachePrunes

Total number of evictions triggered based on the size of the cache since the last statistics reset.

m_cCachePrunesMillis

protected volatile long m_cCachePrunesMillis

Total number of milliseconds used for prune operations since the last statistics reset.

Constructor Details

SimpleCacheStatistics

public SimpleCacheStatistics()

Default constructor.

Method Details

getTotalGets

public long getTotalGets()

Determine the total number of get() operations since the cache statistics were last reset.

Specified by:

getTotalGets in interface CacheStatistics

Returns:

the total number of get() operations

getTotalGetsMillis

public long getTotalGetsMillis()

Determine the total number of milliseconds spent on get() operations since the cache statistics were last reset.

Specified by:

getTotalGetsMillis in interface CacheStatistics

Returns:

the total number of milliseconds processing get() operations

getAverageGetMillis

public double getAverageGetMillis()

Determine the average number of milliseconds per get() invocation since the cache statistics were last reset.

Specified by:

getAverageGetMillis in interface CacheStatistics

Returns:

the average number of milliseconds per get() operation

getTotalPuts

public long getTotalPuts()

Determine the total number of put() operations since the cache statistics were last reset.

Specified by:

getTotalPuts in interface CacheStatistics

Returns:

the total number of put() operations

getTotalPutsMillis

public long getTotalPutsMillis()

Determine the total number of milliseconds spent on put() operations since the cache statistics were last reset.

Specified by:

getTotalPutsMillis in interface CacheStatistics

Returns:

the total number of milliseconds processing put() operations

getAveragePutMillis

public double getAveragePutMillis()

Determine the average number of milliseconds per put() invocation since the cache statistics were last reset.

Specified by:

getAveragePutMillis in interface CacheStatistics

Returns:

the average number of milliseconds per put() operation

getCacheHits

public long getCacheHits()

Determine the rough number of cache hits since the cache statistics were last reset.

A cache hit is a read operation invocation (e.g. get()) for which an entry exists in this map.

Specified by:

getCacheHits in interface CacheStatistics

Returns:

the number of get() calls that have been served by existing cache entries

getCacheHitsMillis

public long getCacheHitsMillis()

Determine the total number of milliseconds (since the last statistics reset) for the get() operations for which an entry existed in this map.

Specified by:

getCacheHitsMillis in interface CacheStatistics

Returns:

the total number of milliseconds for the get() operations that were hits

getAverageHitMillis

public double getAverageHitMillis()

Determine the average number of milliseconds per get() invocation that is a hit.

Specified by:

getAverageHitMillis in interface CacheStatistics

Returns:

the average number of milliseconds per cache hit

getCacheMisses

public long getCacheMisses()

Determine the rough number of cache misses since the cache statistics were last reset.

A cache miss is a get() invocation that does not have an entry in this map.

Specified by:

getCacheMisses in interface CacheStatistics

Returns:

the number of get() calls that failed to find an existing cache entry because the requested key was not in the cache

getCacheMissesMillis

public long getCacheMissesMillis()

Determine the total number of milliseconds (since the last statistics reset) for the get() operations for which no entry existed in this map.

Specified by:

getCacheMissesMillis in interface CacheStatistics

Returns:

the total number of milliseconds (since the last statistics reset) for the get() operations that were misses

getAverageMissMillis

public double getAverageMissMillis()

Determine the average number of milliseconds per get() invocation that is a miss.

Specified by:

getAverageMissMillis in interface CacheStatistics

Returns:

the average number of milliseconds per cache miss

getHitProbability

public double getHitProbability()

Determine the rough probability (0 <= p <= 1) that the next invocation will be a hit, based on the statistics collected since the last reset of the cache statistics.

Specified by:

getHitProbability in interface CacheStatistics

Returns:

the cache hit probability (0 <= p <= 1)

getCachePrunes

public long getCachePrunes()

Determine the rough number of cache pruning cycles since the cache statistics were last reset.

For the LocalCache implementation, this refers to the number of times that the prune() method is executed.

Specified by:

getCachePrunes in interface CacheStatistics

Returns:

the total number of cache pruning cycles (since the last statistics reset)

getCachePrunesMillis

public long getCachePrunesMillis()

Determine the total number of milliseconds (since the last statistics reset) spent on cache pruning.

For the LocalCache implementation, this refers to the time spent in the prune() method.

Specified by:

getCachePrunesMillis in interface CacheStatistics

Returns:

the total number of milliseconds (since the last statistics reset) for cache pruning operations

getAveragePruneMillis

public double getAveragePruneMillis()

Calculate the average number of milliseconds that a prune takes.

Returns:

the average number of milliseconds spent per pruning cycle

resetHitStatistics

public void resetHitStatistics()

Reset all of the cache statistics.

Note that the method name implies that only the hit statistics are cleared, which is not the case; all of the statistics are cleared.

Specified by:

resetHitStatistics in interface CacheStatistics

toString

public String toString()

For debugging purposes, format the contents of the SimpleCachingStatistics in a human readable format.

Overrides:

toString in class Object

Returns:

a String representation of this object

registerHit

public void registerHit()

Register a cache hit (no timing information).

registerHit

public void registerHit(long lStartMillis)

Register a cache hit.

Parameters:

lStartMillis - the time when the get operation started

registerHits

public void registerHits(int cHits,
 long lStartMillis)

Register a multiple cache hit.

Parameters:

cHits - the number of hits

lStartMillis - the time when the get operation started

registerMiss

public void registerMiss()

Register a cache miss (no timing information).

registerMiss

public void registerMiss(long lStartMillis)

Register a cache miss.

Parameters:

lStartMillis - the time when the get operation started

registerMisses

public void registerMisses(int cMisses,
 long lStartMillis)

Register a multiple cache miss.

Parameters:

cMisses - the number of misses

lStartMillis - the time when the get operation started

registerPut

public void registerPut(long lStartMillis)

Register a cache put.

Parameters:

lStartMillis - the time when the put operation started

registerPuts

public void registerPuts(int cPuts,
 long lStartMillis)

Register a multiple cache put.

Parameters:

cPuts - the number of puts

lStartMillis - the time when the put operation started

registerCachePrune

public void registerCachePrune(long lStartMillis)

Register a cache prune.

Parameters:

lStartMillis - the time when the prune operation started

registerIncrementalCachePrune

public void registerIncrementalCachePrune(long lStartMillis)

Register an incremental cache prune, which is to say that the time is accreted but the number of prunes does not increase.

Parameters:

lStartMillis - the time when the prune operation started

Since:

Coherence 3.5