Ejemplo n.º 1
0
  /**
   * Delete log segments whose contents have been turned into SSTables. NOT threadsafe.
   *
   * <p>param @ context The commitLog context . param @ id id of the columnFamily being flushed to
   * disk.
   */
  private void discardCompletedSegmentsInternal(
      CommitLogSegment.CommitLogContext context, Integer id) throws IOException {
    if (logger.isDebugEnabled())
      logger.debug("discard completed log segments for " + context + ", column family " + id + ".");

    /*
     * log replay assumes that we only have to look at entries past the last
     * flush position, so verify that this flush happens after the last. See CASSANDRA-936
     */
    assert context.position >= context.getSegment().getHeader().getPosition(id)
        : "discard at "
            + context
            + " is not after last flush at "
            + context.getSegment().getHeader().getPosition(id);
    /*
     * Loop through all the commit log files in the history. Now process
     * all files that are older than the one in the context. For each of
     * these files the header needs to modified by resetting the dirty
     * bit corresponding to the flushed CF.
     */
    Iterator<CommitLogSegment> iter = segments.iterator();
    while (iter.hasNext()) {
      CommitLogSegment segment = iter.next();
      CommitLogHeader header = segment.getHeader();
      if (segment.equals(context.getSegment())) {
        // we can't just mark the segment where the flush happened clean,
        // since there may have been writes to it between when the flush
        // started and when it finished. so mark the flush position as
        // the replay point for this CF, instead.
        if (logger.isDebugEnabled())
          logger.debug("Marking replay position " + context.position + " on commit log " + segment);
        header.turnOn(id, context.position);
        segment.writeHeader();
        break;
      }

      header.turnOff(id);
      if (header.isSafeToDelete()) {
        logger.info("Discarding obsolete commit log:" + segment);
        segment.close();
        DeletionService.submitDelete(segment.getHeaderPath());
        DeletionService.submitDelete(segment.getPath());
        // usually this will be the first (remaining) segment, but not always, if segment A contains
        // writes to a CF that is unflushed but is followed by segment B whose CFs are all flushed.
        iter.remove();
      } else {
        if (logger.isDebugEnabled())
          logger.debug(
              "Not safe to delete commit log " + segment + "; dirty is " + header.dirtyString());
        segment.writeHeader();
      }
    }
  }
Ejemplo n.º 2
0
 private boolean manages(String name) {
   for (CommitLogSegment segment : segments) {
     if (segment.getPath().endsWith(name)) return true;
   }
   return false;
 }