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From Florian Hussonnois <fhussonn...@gmail.com>
Subject Re: Consumer Client - How to simulate heartbeats ?
Date Mon, 18 Apr 2016 13:28:00 GMT
Thank you very much, the example is really helpful.

My last question is : Why is it necessay to seek the consumer offsets into
the onPartitionsAssigned method ?

https://github.com/omkreddy/kafka-examples/blob/master/consumer/src/main/java/kafka/examples/consumer/advanced/AdvancedConsumer.java#L120

2016-04-15 15:06 GMT+02:00 Kamal C <kamaltarget@gmail.com>:

> Hi Florian,
>
> This may be helpful
>
> https://github.com/omkreddy/kafka-examples/blob/master/consumer/src/main/java/kafka/examples/consumer/advanced/AdvancedConsumer.java
>
> --Kamal
>
> On Fri, Apr 15, 2016 at 2:57 AM, Jason Gustafson <jason@confluent.io>
> wrote:
>
> > Hi Florian,
> >
> > It's actually OK if processing takes longer than the heartbeat interval,
> > but it does need to finish before the session timeout expires or the
> > consumer will be kicked out of the group (which typically is revealed by
> > commit failures). If the problem is just that the consumer is handling
> too
> > many messages at once, then Kafka 0.10 has an option to tune the number
> of
> > messages returned from poll() (max.poll.records), which may be helpful.
> We
> > also have a pause/resume API which allows you to call poll() without
> > consuming any data. That's the best option at the moment for 0.9
> consumers.
> >
> > For what it's worth, we've considered several times adding a heartbeat()
> > API, but the challenge is figuring out how to handle rebalancing.
> > Underneath the covers, we use heartbeats to find out when the group is
> > rebalancing, so a heartbeat() option would probably have to return a flag
> > indicating whether a rebalance was needed. If the group has begun
> > rebalancing, then you would need to call poll() before the expiration of
> > the session timeout so that the consumer can join the rebalance.
> > Alternatively, we could let heartbeat() complete the rebalance itself,
> but
> > then you'd have to be prepared to abort processing from the rebalance
> > callback. That's not really different from calling poll() after pausing
> > partitions though. The main problem in any case is that once a rebalance
> > begins, you have the duration of the session timeout to stop processing
> and
> > join the rebalance. We're seeing this problem pop up pretty much
> everywhere
> > that the consumer is used, so we're trying to think of some better
> options
> > to handle it.
> >
> > Thanks,
> > Jason
> >
> >
> > On Thu, Apr 14, 2016 at 12:32 PM, Florian Hussonnois <
> > fhussonnois@gmail.com>
> > wrote:
> >
> > > Hi everyone,
> > >
> > > I have a use case where a message can take longer than '
> > > heartbeat.interval.ms' to be processed by my application. As I
> > understand
> > > the heartbeats of consumer are done while the poll method is invoked.
> > >
> > > I would like to instantiate a worker thread to process the messages
> but I
> > > need to wait for the messages completion before polling again.
> > >
> > > Is there a way to force the consumer to make an heartbeat without
> polling
> > > new messages ?
> > >
> > > Thanks,
> > >
> > > --
> > > Florian HUSSONNOIS
> > >
> >
>



-- 
Florian HUSSONNOIS

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