Package org.opends.server.core

Class EntryCacheConfigManager.EntryCacheDispatcher

java.lang.Object
org.opends.server.api.MonitorProvider
org.opends.server.api.EntryCache<EntryCacheCfg>
org.opends.server.core.EntryCacheConfigManager.EntryCacheDispatcher
All Implemented Interfaces:
MeterBinder, ConfigurationChangeListener<EntryCacheCfg>, LocalBackendInitializationListener
Enclosing class:
EntryCacheConfigManager
public static final class EntryCacheConfigManager.EntryCacheDispatcher extends EntryCache<EntryCacheCfg> implements ConfigurationChangeListener<EntryCacheCfg>, LocalBackendInitializationListener
This class defines the entry cache dispatcher which acts as an arbiter for every entry cache implementation configured and installed within the Directory Server or acts an an empty cache if no implementation specific entry cache is configured. It does not actually store any entries, so all calls to the entry cache public API are routed to underlying entry cache according to the current configuration order and preferences.

This class records total-tries and misses metrics globally:

  • Try to retrieve an entry from multiple cache implementations: record one try.
  • None of the entry cache implementations have succeeded to retrieve the entry: record one miss.

  • Constructor Details

    • EntryCacheDispatcher

      public EntryCacheDispatcher()

  • Method Details

    • initializeEntryCache

      public void initializeEntryCache(ServerContext serverContext, EntryCacheCfg configuration) throws ConfigException, InitializationException
      Description copied from class: EntryCache
      Initializes this entry cache implementation so that it will be available for storing and retrieving entries.
      Overrides:
      initializeEntryCache in class EntryCache<EntryCacheCfg>
      Parameters:
      serverContext - The server context.
      configuration - The configuration to use to initialize the entry cache.
      Throws:
      ConfigException - If there is a problem with the provided configuration entry that would prevent this entry cache from being used.
      InitializationException - If a problem occurs during the initialization process that is not related to the configuration.

    • containsEntry

      public boolean containsEntry(Dn entryDN)
      Description copied from class: EntryCache
      Indicates whether the entry cache currently contains the entry with the specified DN. This method may be called without holding any locks if a point-in-time check is all that is required. Note that this method is called from @see #getEntry(DN entryDN, LockType lockType, List lockList)
      Specified by:
      containsEntry in class EntryCache<EntryCacheCfg>
      Parameters:
      entryDN - The DN for which to make the determination.
      Returns:
      true if the entry cache currently contains the entry with the specified DN, or false if not.

    • getEntry

      public SizedEntry getEntry(String backendID, long entryID)
      Description copied from class: EntryCache
      Retrieves the requested entry with its size, if it is present in the cache.
      Specified by:
      getEntry in class EntryCache<EntryCacheCfg>
      Parameters:
      backendID - ID of the backend associated with the entry to retrieve.
      entryID - The entry ID within the provided backend for the specified entry.
      Returns:
      The requested entry if it is present in the cache, or null if it is not present.

    • getEntry

      public SizedEntry getEntry(Dn entryDN)
      Description copied from class: EntryCache
      Retrieves the entry with its size, with the specified DN from the cache.
      Specified by:
      getEntry in class EntryCache<EntryCacheCfg>
      Parameters:
      entryDN - The DN of the entry to retrieve.
      Returns:
      The requested entry with its size if it is present in the cache, or null if it is not present.

    • putEntry

      public void putEntry(SizedEntry sizedEntry, String backendID, long entryID)
      Description copied from class: EntryCache
      Stores the provided entry in the cache. Note that the mechanism that it uses to achieve this is implementation-dependent, and it is acceptable for the entry to not actually be stored in any cache.
      Specified by:
      putEntry in class EntryCache<EntryCacheCfg>
      Parameters:
      sizedEntry - The entry to store in the cache.
      backendID - ID of the backend with which the entry is associated.
      entryID - The entry ID within the provided backend that uniquely identifies the specified entry.

    • putEntryIfAbsent

      public void putEntryIfAbsent(SizedEntry sizedEntry, String backendID, long entryID)
      Description copied from class: EntryCache
      Stores the provided entry in the cache only if it does not conflict with an entry that already exists. Note that the mechanism that it uses to achieve this is implementation-dependent, and it is acceptable for the entry to not actually be stored in any cache. However, this method must not overwrite an existing version of the entry.
      Specified by:
      putEntryIfAbsent in class EntryCache<EntryCacheCfg>
      Parameters:
      sizedEntry - The entry to store in the cache.
      backendID - ID of the backend with which the entry is associated.
      entryID - The entry ID within the provided backend that uniquely identifies the specified entry.

    • removeEntry

      public void removeEntry(Dn entryDN)
      Description copied from class: EntryCache
      Removes the specified entry from the cache.
      Specified by:
      removeEntry in class EntryCache<EntryCacheCfg>
      Parameters:
      entryDN - The DN of the entry to remove from the cache.

    • clear

      public void clear()
      Description copied from class: EntryCache
      Removes all entries from the cache. The cache should still be available for future use.
      Specified by:
      clear in class EntryCache<EntryCacheCfg>

    • clearBackend

      public void clearBackend(String backendID)
      Description copied from class: EntryCache
      Removes all entries from the cache that are associated with the provided backend.
      Specified by:
      clearBackend in class EntryCache<EntryCacheCfg>
      Parameters:
      backendID - ID of the backend for which to flush the associated entries.

    • isConfigurationChangeAcceptable

      public boolean isConfigurationChangeAcceptable(EntryCacheCfg configuration, List<LocalizableMessage> unacceptableReasons)
      Description copied from interface: ConfigurationChangeListener
      Indicates whether the proposed change to the configuration is acceptable to this change listener.
      Specified by:
      isConfigurationChangeAcceptable in interface ConfigurationChangeListener<EntryCacheCfg>
      Parameters:
      configuration - The new configuration containing the changes.
      unacceptableReasons - A list that can be used to hold messages about why the provided configuration is not acceptable.
      Returns:
      Returns true if the proposed change is acceptable, or false if it is not.

    • applyConfigurationChange

      public ConfigChangeResult applyConfigurationChange(EntryCacheCfg configuration)
      Description copied from interface: ConfigurationChangeListener
      Applies the configuration changes to this change listener.
      Specified by:
      applyConfigurationChange in interface ConfigurationChangeListener<EntryCacheCfg>
      Parameters:
      configuration - The new configuration containing the changes.
      Returns:
      Returns information about the result of changing the configuration.

    • getEntryCount

      public long getEntryCount()
      Description copied from class: EntryCache
      Retrieves the current number of entries stored within the cache.
      Specified by:
      getEntryCount in class EntryCache<EntryCacheCfg>
      Returns:
      The current number of entries stored within the cache.

    • getMemoryUsage

      public long getMemoryUsage()
      Description copied from class: EntryCache
      Retrieves the current amount of memory used by this cache in bytes.
      Specified by:
      getMemoryUsage in class EntryCache<EntryCacheCfg>
      Returns:
      The current amount of memory used by this cache in bytes.

    • toVerboseString

      public String toVerboseString()
      Description copied from class: EntryCache
      Return a verbose string representation of the current cache maps. This is useful primary for debugging and diagnostic purposes such as in the entry cache unit tests.

      This method is invoked by unit tests for debugging.

      Specified by:
      toVerboseString in class EntryCache<EntryCacheCfg>
      Returns:
      String verbose string representation of the current cache maps in the following format: dn:id:backend one cache entry map representation per line or null if all maps are empty.

    • setOrderedEntryCaches

      public void setOrderedEntryCaches(List<EntryCache<?>> orderedEntryCaches)
      Sets the current cache order array.
      Parameters:
      orderedEntryCaches - The current cache order array.

    • performBackendPostFinalizationProcessing

      public void performBackendPostFinalizationProcessing(String backendId, Predicate<Dn> handlesEntry)
      Description copied from interface: LocalBackendInitializationListener
      Performs any processing that may be required whenever a backend is finalized. This method will be invoked after the backend has been taken out of service and after it has been finalized.
      Specified by:
      performBackendPostFinalizationProcessing in interface LocalBackendInitializationListener
      Parameters:
      backendId - The backend ID of the backend that has been taken out of service.
      handlesEntry - A predicate which can be used for determining whether the finalized backend contained an entry.

    • computeMonitorInstanceDn

      protected Dn computeMonitorInstanceDn()
      Description copied from class: MonitorProvider
      Returns the monitor instance DN for this monitor provider.
      Overrides:
      computeMonitorInstanceDn in class EntryCache<EntryCacheCfg>
      Returns:
      the monitor instance DN.

    • newMeterRegistryHolder

      protected MeterRegistryHolder newMeterRegistryHolder(MeterRegistry parent)
      Description copied from class: EntryCache
      Creates a MeterRegistryHolder with the appropriate name prefixes and tags.
      Overrides:
      newMeterRegistryHolder in class EntryCache<EntryCacheCfg>
      Parameters:
      parent - The meter registry to be decorated.
      Returns:
      The meter registry holder.

    • finalizeEntryCache

      public void finalizeEntryCache()
      Description copied from class: EntryCache
      Performs any necessary cleanup work (e.g., flushing all cached entries and releasing any other held resources) that should be performed when the server is to be shut down or the entry cache destroyed or replaced.
      Specified by:
      finalizeEntryCache in class EntryCache<EntryCacheCfg>

    • recordTry

      protected void recordTry()
      Description copied from class: EntryCache
      Records an attempt to retrieve an entry from this cache.
      Overrides:
      recordTry in class EntryCache<EntryCacheCfg>

    • recordMiss

      protected void recordMiss()
      Description copied from class: EntryCache
      Records a failure to retrieve an entry from this cache.
      Overrides:
      recordMiss in class EntryCache<EntryCacheCfg>