Package org.apache.jackrabbit.oak.api.jmx

Interface CacheStatsMBean

All Known Subinterfaces:
DataStoreCacheStatsMBean, PersistentCacheStatsMBean
All Known Implementing Classes:
AbstractCacheStats, CacheStats, CacheStatsMBeanWrapper
@ProviderType public interface CacheStatsMBean

  • Field Summary

    Fields
    Modifier and Type
    Field
    Description
    static final String
    TYPE
     

  • Method Summary

    Modifier and Type
    Method
    Description
    String
    cacheInfoAsString()
    Gathers the stats of the cache for logging.
    long
    estimateCurrentWeight()
    Total weight of the complete cache.
    double
    getAverageLoadPenalty()
    Returns the average time spent loading new values.
    long
    getElementCount()
    Get the number of elements/objects in the cache.
    long
    getEvictionCount()
    Returns the number of times an entry has been evicted.
    long
    getHitCount()
    Returns the number of times org.apache.jackrabbit.guava.common.cache.Cache lookup methods have returned a cached value.
    double
    getHitRate()
    Returns the ratio of cache requests which were hits.
    long
    getLoadCount()
    Returns the total number of times that org.apache.jackrabbit.guava.common.cache.Cache lookup methods attempted to load new values.
    long
    getLoadExceptionCount()
    Returns the number of times org.apache.jackrabbit.guava.common.cache.Cache lookup methods threw an exception while loading a new value.
    double
    getLoadExceptionRate()
    Returns the ratio of cache loading attempts which threw exceptions.
    long
    getLoadSuccessCount()
    Returns the number of times org.apache.jackrabbit.guava.common.cache.Cache lookup methods have successfully loaded a new value.
    long
    getMaxTotalWeight()
    The maximum weight of entries the cache may contain.
    long
    getMissCount()
    Returns the number of times org.apache.jackrabbit.guava.common.cache.Cache lookup methods have returned an uncached (newly loaded) value, or null.
    double
    getMissRate()
    Returns the ratio of cache requests which were misses.
    String
    getName()
     
    long
    getRequestCount()
    Returns the number of times org.apache.jackrabbit.guava.common.cache.Cache lookup methods have returned either a cached or uncached value.
    long
    getTotalLoadTime()
    Returns the total number of nanoseconds the cache has spent loading new values.
    void
    resetStats()
    Reset the cache stats

  • Field Details

  • Method Details

    • getName

      String getName()

    • getRequestCount

      long getRequestCount()
      Returns the number of times org.apache.jackrabbit.guava.common.cache.Cache lookup methods have returned either a cached or uncached value. This is defined as getHitCount + getMissCount.

    • getHitCount

      long getHitCount()
      Returns the number of times org.apache.jackrabbit.guava.common.cache.Cache lookup methods have returned a cached value.

    • getHitRate

      double getHitRate()
      Returns the ratio of cache requests which were hits. This is defined as getHitCount / getRequestCount, or 1.0 when getRequestCount == 0. Note that getHitRate + getMissRate =~ 1.0.

    • getMissCount

      long getMissCount()
      Returns the number of times org.apache.jackrabbit.guava.common.cache.Cache lookup methods have returned an uncached (newly loaded) value, or null. Multiple concurrent calls to org.apache.jackrabbit.guava.common.cache.Cache lookup methods on an absent value can result in multiple misses, all returning the results of a single cache load operation.

    • getMissRate

      double getMissRate()
      Returns the ratio of cache requests which were misses. This is defined as getMissCount / getRequestCount, or 0.0 when getRequestCount == 0. Note that getHitRate + getMissRate =~ 1.0. Cache misses include all requests which weren't cache hits, including requests which resulted in either successful or failed loading attempts, and requests which waited for other threads to finish loading. It is thus the case that getMissCount >= getLoadSuccessCount + getLoadExceptionCount. Multiple concurrent misses for the same key will result in a single load operation.

    • getLoadCount

      long getLoadCount()
      Returns the total number of times that org.apache.jackrabbit.guava.common.cache.Cache lookup methods attempted to load new values. This includes both successful load operations, as well as those that threw exceptions. This is defined as getLoadSuccessCount + getLoadExceptionCount.

    • getLoadSuccessCount

      long getLoadSuccessCount()
      Returns the number of times org.apache.jackrabbit.guava.common.cache.Cache lookup methods have successfully loaded a new value. This is always incremented in conjunction with getMissCount(), though getMissCount is also incremented when an exception is encountered during cache loading (see getLoadExceptionCount()). Multiple concurrent misses for the same key will result in a single load operation.

    • getLoadExceptionCount

      long getLoadExceptionCount()
      Returns the number of times org.apache.jackrabbit.guava.common.cache.Cache lookup methods threw an exception while loading a new value. This is always incremented in conjunction with getMissCount, though getMissCount is also incremented when cache loading completes successfully (see getLoadSuccessCount()). Multiple concurrent misses for the same key will result in a single load operation.

    • getLoadExceptionRate

      double getLoadExceptionRate()
      Returns the ratio of cache loading attempts which threw exceptions. This is defined as getLoadExceptionCount / (getLoadSuccessCount + getLoadExceptionCount), or 0.0 when getLoadSuccessCount + getLoadExceptionCount == 0.

    • getTotalLoadTime

      long getTotalLoadTime()
      Returns the total number of nanoseconds the cache has spent loading new values. This can be used to calculate the miss penalty. This value is increased every time getLoadSuccessCount or getLoadExceptionCount is incremented.

    • getAverageLoadPenalty

      double getAverageLoadPenalty()
      Returns the average time spent loading new values. This is defined as getTotalLoadTime / (getLoadSuccessCount + getLoadExceptionCount).

    • getEvictionCount

      long getEvictionCount()
      Returns the number of times an entry has been evicted. This count does not include manual org.apache.jackrabbit.guava.common.cache.Cache#invalidate invalidations.

    • getElementCount

      long getElementCount()
      Get the number of elements/objects in the cache.
      Returns:
      the number of elements

    • getMaxTotalWeight

      long getMaxTotalWeight()
      The maximum weight of entries the cache may contain.
      Returns:
      the maximum total weight of entries the cache may contain

    • estimateCurrentWeight

      long estimateCurrentWeight()
      Total weight of the complete cache. Depending on implementation it might be the amount of RAM taken by the cache
      Returns:
      to weight of the cache

    • cacheInfoAsString

      String cacheInfoAsString()
      Gathers the stats of the cache for logging.

    • resetStats

      void resetStats()
      Reset the cache stats