How to use

getCommitLogLowerBound

method

in

org.apache.cassandra.db.Memtable

  public CommitLogPosition call()
  {
    try
    {
      // we wait on the latch for the commitLogUpperBound to be set, and so that waiters
      // on this task can rely on all prior flushes being complete
      latch.await();
    }
    catch (InterruptedException e)
    {
      throw new IllegalStateException();
    }
    CommitLogPosition commitLogUpperBound = CommitLogPosition.NONE;
    // If a flush errored out but the error was ignored, make sure we don't discard the commit log.
    if (flushFailure == null && !memtables.isEmpty())
    {
      Memtable memtable = memtables.get(0);
      commitLogUpperBound = memtable.getCommitLogUpperBound();
      CommitLog.instance.discardCompletedSegments(metadata.cfId, memtable.getCommitLogLowerBound(), commitLogUpperBound);
    }
    metric.pendingFlushes.dec();
    if (flushFailure != null)
      throw Throwables.propagate(flushFailure);
    return commitLogUpperBound;
  }
}

/**
 * @return a Future yielding the commit log position that can be guaranteed to have been successfully written
 *         to sstables for this table once the future completes
 */
private ListenableFuture<CommitLogPosition> waitForFlushes()
{
  // we grab the current memtable; once any preceding memtables have flushed, we know its
  // commitLogLowerBound has been set (as this it is set with the upper bound of the preceding memtable)
  final Memtable current = data.getView().getCurrentMemtable();
  ListenableFutureTask<CommitLogPosition> task = ListenableFutureTask.create(() -> {
    logger.debug("forceFlush requested but everything is clean in {}", name);
    return current.getCommitLogLowerBound();
  });
  postFlushExecutor.execute(task);
  return task;
}

/**
 * @return a Future yielding the commit log position that can be guaranteed to have been successfully written
 *         to sstables for this table once the future completes
 */
private ListenableFuture<CommitLogPosition> waitForFlushes()
{
  // we grab the current memtable; once any preceding memtables have flushed, we know its
  // commitLogLowerBound has been set (as this it is set with the upper bound of the preceding memtable)
  final Memtable current = data.getView().getCurrentMemtable();
  ListenableFutureTask<CommitLogPosition> task = ListenableFutureTask.create(() -> {
    logger.debug("forceFlush requested but everything is clean in {}", name);
    return current.getCommitLogLowerBound();
  });
  postFlushExecutor.execute(task);
  return task;
}

/**
 * @return a Future yielding the commit log position that can be guaranteed to have been successfully written
 *         to sstables for this table once the future completes
 */
private ListenableFuture<CommitLogPosition> waitForFlushes()
{
  // we grab the current memtable; once any preceding memtables have flushed, we know its
  // commitLogLowerBound has been set (as this it is set with the upper bound of the preceding memtable)
  final Memtable current = data.getView().getCurrentMemtable();
  ListenableFutureTask<CommitLogPosition> task = ListenableFutureTask.create(() -> {
    logger.debug("forceFlush requested but everything is clean in {}", name);
    return current.getCommitLogLowerBound();
  });
  postFlushExecutor.execute(task);
  return task;
}

  public CommitLogPosition call()
  {
    try
    {
      // we wait on the latch for the commitLogUpperBound to be set, and so that waiters
      // on this task can rely on all prior flushes being complete
      latch.await();
    }
    catch (InterruptedException e)
    {
      throw new IllegalStateException();
    }
    CommitLogPosition commitLogUpperBound = CommitLogPosition.NONE;
    // If a flush errored out but the error was ignored, make sure we don't discard the commit log.
    if (flushFailure == null && !memtables.isEmpty())
    {
      Memtable memtable = memtables.get(0);
      commitLogUpperBound = memtable.getCommitLogUpperBound();
      CommitLog.instance.discardCompletedSegments(metadata.cfId, memtable.getCommitLogLowerBound(), commitLogUpperBound);
    }
    metric.pendingFlushes.dec();
    if (flushFailure != null)
      throw Throwables.propagate(flushFailure);
    return commitLogUpperBound;
  }
}

  public CommitLogPosition call()
  {
    try
    {
      // we wait on the latch for the commitLogUpperBound to be set, and so that waiters
      // on this task can rely on all prior flushes being complete
      latch.await();
    }
    catch (InterruptedException e)
    {
      throw new IllegalStateException();
    }
    CommitLogPosition commitLogUpperBound = CommitLogPosition.NONE;
    // If a flush errored out but the error was ignored, make sure we don't discard the commit log.
    if (flushFailure == null && !memtables.isEmpty())
    {
      Memtable memtable = memtables.get(0);
      commitLogUpperBound = memtable.getCommitLogUpperBound();
      CommitLog.instance.discardCompletedSegments(metadata.cfId, memtable.getCommitLogLowerBound(), commitLogUpperBound);
    }
    metric.pendingFlushes.dec();
    if (flushFailure != null)
      throw Throwables.propagate(flushFailure);
    return commitLogUpperBound;
  }
}