Package mondrian.rolap.agg

Class SegmentCacheManager

java.lang.Object
mondrian.rolap.agg.SegmentCacheManager
public class SegmentCacheManager extends Object

  • Field Details

    • thread

      public final Thread thread

    • cacheExecutor

      public final ExecutorService cacheExecutor
      Executor with which to send requests to external caches.

    • sqlExecutor

      public final ExecutorService sqlExecutor
      Executor with which to execute SQL requests.

      TODO: create using factory and/or configuration parameters. Executor should be shared within MondrianServer or target JDBC database.

    • segmentCacheWorkers

      public final List<SegmentCacheWorker> segmentCacheWorkers

    • compositeCache

      public final SegmentCache compositeCache

  • Constructor Details

    • SegmentCacheManager

      public SegmentCacheManager(MondrianServer server)

  • Method Details

    • loadCacheForStar

      public boolean loadCacheForStar(RolapStar star)
      Load external cached elements for received star. Similar to externalSegmentCreated but the index is created if not there.
      Parameters:
      star - the star for which the cache is loaded
      Returns:
      true if elements existed for this star.

    • execute

      public <T> T execute(SegmentCacheManager.Command<T> command)

    • getIndexRegistry

      public SegmentCacheManager.SegmentCacheIndexRegistry getIndexRegistry()

    • loadSucceeded

      public void loadSucceeded(RolapStar star, SegmentHeader header, SegmentBody body)
      Adds a segment to segment index.

      Called when a SQL statement has finished loading a segment.

      Does not add the segment to the external cache. That is a potentially long-duration operation, better carried out by a worker.

      Parameters:
      header - segment header
      body - segment body

    • loadFailed

      public void loadFailed(RolapStar star, SegmentHeader header, Throwable throwable)
      Informs cache manager that a segment load failed.

      Called when a SQL statement receives an error while loading a segment.

      Parameters:
      header - segment header
      throwable - Error

    • remove

      public void remove(RolapStar star, SegmentHeader header)
      Removes a segment from segment index.

      Call is asynchronous. It comes back immediately.

      Does not remove it from the external cache.

      Parameters:
      header - segment header

    • externalSegmentCreated

      public void externalSegmentCreated(SegmentHeader header, MondrianServer server)
      Tells the cache that a segment is newly available in an external cache.

    • externalSegmentDeleted

      public void externalSegmentDeleted(SegmentHeader header, MondrianServer server)
      Tells the cache that a segment is no longer available in an external cache.

    • printCacheState

      public void printCacheState(CacheControl.CellRegion region, PrintWriter pw, Locus locus)

    • shutdown

      public void shutdown()
      Shuts down this cache manager and all active threads and indexes.

    • getConverter

      public SegmentBuilder.SegmentConverter getConverter(RolapStar star, SegmentHeader header)

    • peek

      public SegmentWithData peek(CellRequest request)
      Makes a quick request to the aggregation manager to see whether the cell value required by a particular cell request is in external cache.

      'Quick' is relative. It is an asynchronous request (due to the aggregation manager being an actor) and therefore somewhat slow. If the segment is in cache, will save batching up future requests and re-executing the query. Win should be particularly noticeable for queries running on a populated cache. Without this feature, every query would require at least two iterations.

      Request does not issue SQL to populate the segment. Nor does it try to find existing segments for rollup. Those operations can wait until next phase.

      Client is responsible for adding the segment to its private cache.

      Parameters:
      request - Cell request
      Returns:
      Segment with data, or null if not in cache