Hi, Jay,
Thank you for your answer.
Sorry, I still do not understand your meaning.
I guess the two parameters you mentioned are log.flush.interval and
log.default.flush.interval.ms. However, these two parameters only control when
Kafka issues a flush (i.e., calling FileChannel.force()).
Fsync (fileOutputStream.getFD().sync()) is controlled by another parameter
log.default.flush.scheduler.interval.ms.
scheduler.schedule("kafka-recovery-point-checkpoint",
checkpointRecoveryPointOffsets,
delay = InitialTaskDelayMs,
period = flushCheckpointMs,
TimeUnit.MILLISECONDS)
This thread is only time-controlled. It does not check the number of messages.
Thank you,
Xiao Li
On Mar 5, 2015, at 11:59 AM, Jay Kreps <[email protected]> wrote:
> Hey Xiao,
>
> That's not quite right. Fsync is controlled by either a time based criteria
> (flush every 30 seconds) or a number of messages criteria. So if you set
> the number of messages to 1 the flush is synchronous with the write, which
> I think is what you are looking for.
>
> -Jay
