Package net.sf.ehcache.management

Class CacheStatistics

  • All Implemented Interfaces:
    java.io.Serializable, CacheStatisticsMBean
    public class CacheStatistics
extends java.lang.Object
implements CacheStatisticsMBean, java.io.Serializable
    A JMX CacheStatistics decorator for an ehcache Statistics class.

    An immutable Cache statistics implementation}

    This is like a value object, with the added ability to clear cache statistics on the cache. That ability does not survive any Serialization of this class. On deserialization the cache can be considered disconnected.

    The accuracy of these statistics are determined by the value of {#getStatisticsAccuracy()} at the time the statistic was computed.

    Because this class maintains a reference to an Ehcache, any references held to this class will precent the Ehcache from getting garbage collected.

    Since:
    1.3
    Version:
    $Id$
    Author:
    Greg Luck
    See Also:
    Serialized Form

    • Constructor Detail

      • CacheStatistics

        public CacheStatistics​(Ehcache ehcache)
        Constructs an object from an ehcache statistics object
        Parameters:
        ehcache - the backing ehcache

    • Method Detail

      • getAssociatedCacheName

        public java.lang.String getAssociatedCacheName()
        Specified by:
        getAssociatedCacheName in interface CacheStatisticsMBean
        Returns:
        the name of the Ehcache, or null is there no associated cache

      • getInMemoryHits

        public long getInMemoryHits()
        Number of times a requested item was found in the Memory Store.
        Specified by:
        getInMemoryHits in interface CacheStatisticsMBean
        Returns:
        the number of times a requested item was found in memory

      • getOffHeapHits

        public long getOffHeapHits()
        Number of times a requested item was found in the off-heap store.
        Specified by:
        getOffHeapHits in interface CacheStatisticsMBean
        Returns:
        the number of times a requested item was found in off-heap

      • getOnDiskHits

        public long getOnDiskHits()
        Number of times a requested item was found in the Disk Store.
        Specified by:
        getOnDiskHits in interface CacheStatisticsMBean
        Returns:
        the number of times a requested item was found on Disk, or 0 if there is no disk storage configured.

      • getCacheMisses

        public long getCacheMisses()
        Warning. This statistic is recorded as a long. If the statistic is large than Integer#MAX_VALUE precision will be lost.
        Specified by:
        getCacheMisses in interface CacheStatisticsMBean
        Returns:
        the number of times a requested element was not found in the cache

      • getInMemoryMisses

        public long getInMemoryMisses()
        Specified by:
        getInMemoryMisses in interface CacheStatisticsMBean
        Returns:
        the number of times a requested element was not found in the memory cache

      • getOffHeapMisses

        public long getOffHeapMisses()
        Specified by:
        getOffHeapMisses in interface CacheStatisticsMBean
        Returns:
        the number of times a requested element was not found in the off-heap cache

      • getOnDiskMisses

        public long getOnDiskMisses()
        Specified by:
        getOnDiskMisses in interface CacheStatisticsMBean
        Returns:
        the number of times a requested element was not found in the disk cache

      • getObjectCount

        public long getObjectCount()
        Specified by:
        getObjectCount in interface CacheStatisticsMBean
        Returns:
        the number of elements in the ehcache, with a varying degree of accuracy, depending on accuracy setting.

      • getWriterQueueLength

        public long getWriterQueueLength()
        Gets the size of the write-behind queue, if any. The value is for all local buckets
        Specified by:
        getWriterQueueLength in interface CacheStatisticsMBean
        Returns:
        Elements waiting to be processed by the write behind writer. -1 if no write-behind

      • getWriterMaxQueueSize

        public int getWriterMaxQueueSize()
        Gets the maximum size of the write-behind queue, if any.
        Specified by:
        getWriterMaxQueueSize in interface CacheStatisticsMBean
        Returns:
        Maximum elements waiting to be processed by the write behind writer. -1 if no write-behind

      • getMemoryStoreObjectCount

        public long getMemoryStoreObjectCount()
        Gets the number of objects in the MemoryStore
        Specified by:
        getMemoryStoreObjectCount in interface CacheStatisticsMBean
        Returns:
        the MemoryStore size which is always a count unadjusted for duplicates or expiries

      • getOffHeapStoreObjectCount

        public long getOffHeapStoreObjectCount()
        Gets the number of objects in the OffHeapStore
        Specified by:
        getOffHeapStoreObjectCount in interface CacheStatisticsMBean
        Returns:
        the OffHeapStore size which is always a count unadjusted for duplicates or expiries

      • getDiskStoreObjectCount

        public long getDiskStoreObjectCount()
        Gets the number of objects in the DiskStore
        Specified by:
        getDiskStoreObjectCount in interface CacheStatisticsMBean
        Returns:
        the DiskStore size which is always a count unadjusted for duplicates or expiries

      • getEhcache

        public Ehcache getEhcache()
        Return the backing cache.
        Returns:
        the backing cache, if one is connected. On Serialization the transient Ehcache reference is dropped.

      • getCacheHitPercentage

        public double getCacheHitPercentage()
        Returns the percentage of cache accesses that found a requested item in the cache.
        Specified by:
        getCacheHitPercentage in interface CacheStatisticsMBean
        Returns:
        the percentage of successful hits

      • getCacheMissPercentage

        public double getCacheMissPercentage()
        Returns the percentage of cache accesses that did not find a requested element in the cache.
        Specified by:
        getCacheMissPercentage in interface CacheStatisticsMBean
        Returns:
        the percentage of accesses that failed to find anything

      • getInMemoryHitPercentage

        public double getInMemoryHitPercentage()
        Returns the percentage of cache accesses that found a requested item cached in-memory.
        Specified by:
        getInMemoryHitPercentage in interface CacheStatisticsMBean
        Returns:
        the percentage of successful hits from the MemoryStore

      • getOffHeapHitPercentage

        public double getOffHeapHitPercentage()
        Returns the percentage of cache accesses that found a requested item cached off-heap.
        Specified by:
        getOffHeapHitPercentage in interface CacheStatisticsMBean
        Returns:
        the percentage of successful hits from the OffHeapStore

      • getOnDiskHitPercentage

        public double getOnDiskHitPercentage()
        Returns the percentage of cache accesses that found a requested item cached on disk.
        Specified by:
        getOnDiskHitPercentage in interface CacheStatisticsMBean
        Returns:
        the percentage of successful hits from the DiskStore.

      • getCacheHits

        public long getCacheHits()
        The number of times a requested item was found in the cache.
        Specified by:
        getCacheHits in interface CacheStatisticsMBean
        Returns:
        the number of times a requested item was found in the cache