In 0.7, without producer ack, there is no easy way to ensure produced data
reaches the server. For example, send.writeCompletely(channel) returns when
the data is in socket buffer. If a broker goes down before producer's
socket buffer is flushed, the data is lost and producer won't get any
exceptions.
Thanks,
Jun
On Mon, Jun 25, 2012 at 11:49 PM, R S <mypostbo...@gmail.com> wrote:
> Hi Jun ,
>
> In the case mentioned below , in 0.7 if send (in SyncProducer) call is
> complete without any exception does that mean message
> has successfully reached the broker .
>
> from the code i see this
> private def send(send: BoundedByteBufferSend) {
> ..............
>
> try {
> send.writeCompletely(channel)
> } catch {
> case e : java.io.IOException =>
> // no way to tell if write succeeded. Disconnect and re-throw
> exception to let client handle retry
> disconnect()
> throw e
> case e2 =>
> throw e2
> }
>
> Is there a way to know if the last offset has changed or not from Producer
> side to make sure we do not send the new message again?
>
> -rks
>
> On Mon, Jun 25, 2012 at 8:52 PM, Jun Rao <jun...@gmail.com> wrote:
>
> > Tarun,
> >
> > In 0.7, there is no producer side ack.
> >
> > In 0.8, sync producer will wait for an ack and is blocking. If the ack is
> > lost because a broker is down, sync producer will timeout and it's up to
> > the caller to decide what to do. If the caller chooses to resend, it's
> > possible for duplicated messages to show up in the broker.
> >
> > Thanks,
> >
> > Jun
> >
> > On Mon, Jun 25, 2012 at 8:12 AM, Tarun Kumar <agrawal.taru...@gmail.com
> > >wrote:
> >
> > > Hi,
> > >
> > > I have a couple of questions related to Sync Producer.
> > >
> > > 1. From what i know (please correct me if i am wrong), Sync producer
> send
> > > is a blocking call. Until acknowledgement is received from broker, next
> > > message is not sent by producer.
> > >
> > > 2. what if ack is lost. Is there any kind of timeout till when producer
> > > waits for ack. If yes, does it try to resend same message?
> > > If yes, duplicate message might reach to broker (due to previous
> > message's
> > > ack timeout). How does kafka avoids that?
> > >
> > > 3. What are different possibilities of duplicate messages being stored
> at
> > > broker?
> > >
> > > Thanks,
> > > Tarun
> > >
> >
>
