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Kafka, mail # user - producer.send atomic?


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Re: producer.send atomic?
Kane Kane 2013-10-16, 17:52
Hi, so yeah, as i see here:
https://git-wip-us.apache.org/repos/asf?p=kafka.git;a=blob;f=core/src/main/scala/kafka/producer/async/DefaultEventHandler.scala;h=c8326a8a991cdfebec0d86003d08ce8d2e2c6986;hb=HEAD#l94looks
like batch to a single broker is atomic indeed, what if i have
messages to all brokers in single batch? That means some requests might
succeed and others not?
does producer.send report which messages were successfully written and
which not?

Thanks!
On Wed, Oct 16, 2013 at 10:34 AM, Guozhang Wang <[EMAIL PROTECTED]> wrote:

> Hi Kane,
>
> If the producer is async, the send(requests) function call would not
> necessarily trigger the real sending action. The sending action is
> triggered either if enough time has elapsed or enough messages have been
> batched on the client side. One batch of messages to each broker will be
> either send successfully or not at all (in this sense "atomic"), and if
> failed the whole batch will be re-tried to that broker again.
>
> As for consumers (I am assuming high-level consumers here), since the
> consumers themselves will need to remember the offsets still which they
> have consumed, if the consume request fails the consumers will just
> re-issue the request starting with the previous offsets again.
>
> Guozhang
>
>
> On Wed, Oct 16, 2013 at 8:56 AM, Kane Kane <[EMAIL PROTECTED]> wrote:
>
> > Hello, as I understand send is not atomic, i.e. i have something like
> this
> > in my code:
> >
> >     val requests = new ArrayBuffer[KeyedMessage[AnyRef, AnyRef]]
> >     for (message <- messages) {
> >       requests += new KeyedMessage(topic, null, message, message)
> >     }
> >     producer.send(requests)
> >
> > That means batch can die in the middle?
> > Also what happens if during this write the broker that has some partition
> > leaders will die? The same question for consumer, what happens if broker
> > dies while consumer reading from it?
> >
> > Thanks.
> >
>
>
>
> --
> -- Guozhang
>