Cody,
We do not have an umbrella JIRA for this, but rather a case-by-case JIRA
ticket / KIP for API changes in consumer.
If you feel strong about some specific change on the consumer API, please
feel free to create a new KIP with the detailed motivation and proposed
modifications.
Guozhang
On Fri, Mar 11, 2016 at 12:28 PM, Cody Koeninger <c...@koeninger.org> wrote:
> Is there a KIP or Jira related to " working on improving these cases
> with improved APIs " ?
>
> I saw that there was some discussion of it in KIP-41, but that seemed
> to have been resolved in favor of keeping everything inside of poll()
>
> On Fri, Mar 11, 2016 at 11:17 AM, Guozhang Wang <wangg...@gmail.com>
> wrote:
> > Cody, Mansi:
> >
> > All good points! Let me try to answer them one-by-one.
> >
> > About this specific issue, as I suggested in the JIRA we can separate the
> > case about resetting offset upon initializing a partition to fetch, from
> > the case that fetching offset out-of-range in the auto.offset.reset
> config.
> > These two scenarios are indeed quite different and it's reasonable
> treating
> > them differently.
> >
> > About passing a consumer context to the rebalance callback's constructor,
> > we left it for user's flexibility: if you want to use Kafka to commit
> > offsets, for example, then you pass the consumer reference to the
> callback;
> > if you use an external service to store offsets, you can pass a JDBC
> > connector, for example, to the callback; for some data mirroring you can
> > even pass in another producer client into it. Always enforcing the
> consumer
> > context could be convenient (i.e. you do not need to pass in the argument
> > to the constructor yourself) for some use cases, but not necessarily all.
> >
> > About wrapping coordination protocols (partition assignment, heartbeat)
> > inside "poll()" behind the scene, we implemented the APIs in this way in
> > order to abstract the underlying details from the users, and also to
> > provide a simple "single-thread-poll-loop" design pattern in the new
> > Consumer. We realized that it does actually make some of the use cases
> more
> > awkward, and are working on improving these cases with improved APIs as
> > well. Let us know if you have any suggestions about this.
> >
> > Guozhang
> >
> >
> >
> >
> >
> >
> > On Thu, Mar 10, 2016 at 7:53 AM, Mansi Shah <mansis...@maprtech.com>
> wrote:
> >
> >> I second the need for having a consumer context passed to rebalance
> >> callback. I have ran into issues several times because of that.
> >>
> >> About - subscribe vs assign - I have not read through your spark code
> yet
> >> (will do by eod), so I am not sure what you mean (other than I do agree
> >> that new partitions should be consumed automatically). I guess we can
> >> continue this discussion on the spark list then :-)
> >>
> >> Thanks
> >> Mansi.
> >>
> >> On Thu, Mar 10, 2016 at 7:43 AM, Cody Koeninger <c...@koeninger.org>
> >> wrote:
> >>
> >> > Mansi, I'd agree that the fact that everything is tied up in poll
> >> > seems like the source of the awkward behavior.
> >> >
> >> > Regarding assign vs subscribe, most people using the spark integration
> >> > are just going to want to provide a topic name, not go figure out a
> >> > bunch of partitions. They're also going to be surprised if things
> >> > suddenly blow up once a partition is added, or that partition doesn't
> >> > start being consumed (we already have that second issue today).
> >> >
> >> > Thats why separating the behavior of auto offset reset seems like the
> >> > best idea I've heard so far.
> >> >
> >> > Consumer rebalance listeners are still probably going to be necessary
> >> > for people who are storing offsets externally.
> >> >
> >> > On Thu, Mar 10, 2016 at 9:27 AM, Mansi Shah <mansis...@maprtech.com>
> >> > wrote:
> >> > > Guozhang
> >> > >
> >> > > Sorry for joining the party a little late. I have been thinking
> about
> >> > this
> >> > > whole awkward behavior of having to call poll(0) to actually make
> the
> >> > > underlying subscriptions take effect. Is the core reason for this
> >> design
> >> > > the fact that poll is also the actual heartbeat and you want to make
> >> the
> >> > > listener group assignments through poll - so that timeouts and
> >> > > reassignments can all go through poll? So I think clubbing liveness
> >> with
> >> > > poll (which in effect clubs consumer group assignments and hence
> >> metadata
> >> > > fetch with poll) is the real cause of this design. Were there issues
> >> > where
> >> > > you were seeing active consumers not calling poll that led to this
> >> design
> >> > > choice? I tried to look for a relevant JIRA but could not find one -
> >> can
> >> > > you please point me to something if you have it handy?
> >> > >
> >> > > Btw this would also means that your proposal to do the actual
> >> assignments
> >> > > through seek might not be ideal since there can still be indefinite
> >> time
> >> > > between seek and poll (just like between subscribe and poll) and the
> >> > > consumer could timeout even before the first poll is called?
> >> > >
> >> > >
> >> > > @Cody in your case if you really have only one consumer and it is
> going
> >> > to
> >> > > get all the partitions of the topic anyway - then you might as well
> >> > > subscribe using "assign" call instead of "subscribe" call. That will
> >> make
> >> > > at least your code cleaner and I do not think you are gaining
> anything
> >> > with
> >> > > the listener group functionality anyway?
> >> > >
> >> > > - Mansi.
> >> > >
> >> > >
> >> > >
> >> > > On Wed, Mar 9, 2016 at 8:35 PM, Guozhang Wang <wangg...@gmail.com>
> >> > wrote:
> >> > >
> >> > >> In order to do anything meaningful with the consumer itself in
> >> rebalance
> >> > >> callback (e.g. commit offset), you would need to hold on the
> consumer
> >> > >> reference; admittedly it sounds a bit awkward, but by design we
> choose
> >> > to
> >> > >> not enforce it in the interface itself.
> >> > >>
> >> > >> Guozhang
> >> > >>
> >> > >> On Wed, Mar 9, 2016 at 3:39 PM, Cody Koeninger <c...@koeninger.org
> >
> >> > wrote:
> >> > >>
> >> > >> > So what about my comments regarding the consumer rebalance
> listener
> >> > >> > interface not providing access to a consumer? I can probably
> work
> >> > around
> >> > >> > it, but it seems odd.
> >> > >> > On Mar 9, 2016 5:04 PM, "Guozhang Wang" <wangg...@gmail.com>
> wrote:
> >> > >> >
> >> > >> > > One thing proposed by Jason:
> >> > >> > >
> >> > >> > > If you want to only reset offset upon initialization, and by
> >> > >> > initialization
> >> > >> > > you mean "no committed offset", you can do sth. like the
> following
> >> > in
> >> > >> > > rebalance callback.
> >> > >> > >
> >> > >> > > @Override
> >> > >> > >
> >> > >> > > public void
> >> > >> > onPartitionsAssigned(Collection<TopicPartition>
> >> > >> > > partitions) {
> >> > >> > >
> >> > >> > > for (TopicPartition partition : partitions)
> >> > >> > >
> >> > >> > > if (consumer.committed(partition) ==
> null)
> >> > >> > >
> >> > >> > >
> consumer.seekToBeginning(partition);
> >> > >> > >
> >> > >> > > }
> >> > >> > >
> >> > >> > >
> >> > >> > > Guozhang
> >> > >> > >
> >> > >> > > On Wed, Mar 9, 2016 at 2:11 PM, Guozhang Wang <
> wangg...@gmail.com
> >> >
> >> > >> > wrote:
> >> > >> > >
> >> > >> > > > Filed https://issues.apache.org/jira/browse/KAFKA-3370.
> >> > >> > > >
> >> > >> > > > On Wed, Mar 9, 2016 at 1:11 PM, Cody Koeninger <
> >> > c...@koeninger.org>
> >> > >> > > wrote:
> >> > >> > > >
> >> > >> > > >> That sounds like an interesting way of addressing the
> problem,
> >> > can
> >> > >> > > >> continue further discussions on the JIRA
> >> > >> > > >>
> >> > >> > > >>
> >> > >> > > >>
> >> > >> > > >> On Wed, Mar 9, 2016 at 2:59 PM, Guozhang Wang <
> >> > wangg...@gmail.com>
> >> > >> > > wrote:
> >> > >> > > >> > Cody:
> >> > >> > > >> >
> >> > >> > > >> > More specifically, you do not need the "listTopics"
> function
> >> if
> >> > >> you
> >> > >> > > >> already
> >> > >> > > >> > know your subscribed topics, just use "partitionsFor" is
> >> > >> sufficient.
> >> > >> > > >> >
> >> > >> > > >> > About the fix, I'm thinking of adding two more options in
> the
> >> > >> > > >> > auto.offset.rest, say namely "earliest-on-start" and
> >> > >> > > "latest-on-start",
> >> > >> > > >> > which sets the reset position ONLY at starting up. The
> reason
> >> > is
> >> > >> > that
> >> > >> > > >> the
> >> > >> > > >> > seekToXX was actually not designed to do such
> initialization
> >> > but
> >> > >> for
> >> > >> > > >> > calling during the lifetime of the consumer, and we'd
> better
> >> > >> provide
> >> > >> > > the
> >> > >> > > >> > right solution to do so.
> >> > >> > > >> >
> >> > >> > > >> > I can file the JIRA right away and start further
> discussions
> >> > >> there.
> >> > >> > > But
> >> > >> > > >> let
> >> > >> > > >> > me know if you have any other ideas.
> >> > >> > > >> >
> >> > >> > > >> > Guozhang
> >> > >> > > >> >
> >> > >> > > >> > On Wed, Mar 9, 2016 at 12:25 PM, Cody Koeninger <
> >> > >> c...@koeninger.org
> >> > >> > >
> >> > >> > > >> wrote:
> >> > >> > > >> >
> >> > >> > > >> >> Yeah, I think I understood what you were saying. What
> I'm
> >> > saying
> >> > >> > is
> >> > >> > > >> >> that if there were a way to just fetch metadata without
> >> doing
> >> > the
> >> > >> > > rest
> >> > >> > > >> >> of the work poll() does, it wouldn't be necessary. I
> guess
> >> I
> >> > can
> >> > >> > do
> >> > >> > > >> >> listTopics to get all metadata for all topics and then
> parse
> >> > it.
> >> > >> > > >> >>
> >> > >> > > >> >> Regarding running a single instance, that is the case for
> >> what
> >> > >> I'm
> >> > >> > > >> >> talking about.
> >> > >> > > >> >>
> >> > >> > > >> >> On Wed, Mar 9, 2016 at 2:02 PM, Guozhang Wang <
> >> > >> wangg...@gmail.com>
> >> > >> > > >> wrote:
> >> > >> > > >> >> > Cody,
> >> > >> > > >> >> >
> >> > >> > > >> >> > What I meant for a special case of `seekToXX` is that,
> >> today
> >> > >> when
> >> > >> > > the
> >> > >> > > >> >> > function is called with no partition parameters. It
> will
> >> > try to
> >> > >> > > >> execute
> >> > >> > > >> >> the
> >> > >> > > >> >> > logic on all "assigned" partitions for the consumer.
> And
> >> > once
> >> > >> > that
> >> > >> > > is
> >> > >> > > >> >> done,
> >> > >> > > >> >> > the subsequent poll() will not throw the exception
> since
> >> it
> >> > >> knows
> >> > >> > > >> those
> >> > >> > > >> >> > partitions needs to reset offsets.
> >> > >> > > >> >> >
> >> > >> > > >> >> > However for your case, there is no assigned partitions
> >> yet,
> >> > and
> >> > >> > > hence
> >> > >> > > >> >> > `seekToXX` will not take effects on any partitions. The
> >> > >> > assignment
> >> > >> > > is
> >> > >> > > >> >> > wrapped in the poll() call as you mentioned. And one
> way
> >> to
> >> > >> solve
> >> > >> > > it
> >> > >> > > >> is
> >> > >> > > >> >> to
> >> > >> > > >> >> > let the `seekToXX()` with no parameters do the
> >> coordination
> >> > and
> >> > >> > get
> >> > >> > > >> the
> >> > >> > > >> >> > assigned partitions if there are any subscribed
> topics, so
> >> > that
> >> > >> > the
> >> > >> > > >> >> > subsequent poll() will know those partitions need
> >> resetting
> >> > >> > > offsets.
> >> > >> > > >> Does
> >> > >> > > >> >> > that make sense?
> >> > >> > > >> >> >
> >> > >> > > >> >> > As for now another way I can think of is to get the
> >> > partition
> >> > >> > info
> >> > >> > > >> >> > beforehand and call `seekToBeginning` on all
> partitions.
> >> But
> >> > >> that
> >> > >> > > >> only
> >> > >> > > >> >> > works if the consumer knows it is going to get all the
> >> > >> partitions
> >> > >> > > >> >> assigned
> >> > >> > > >> >> > to itself (i.e. you are only running a single
> instance).
> >> > >> > > >> >> >
> >> > >> > > >> >> > Guozhang
> >> > >> > > >> >> >
> >> > >> > > >> >> >
> >> > >> > > >> >> > On Wed, Mar 9, 2016 at 6:22 AM, Cody Koeninger <
> >> > >> > c...@koeninger.org
> >> > >> > > >
> >> > >> > > >> >> wrote:
> >> > >> > > >> >> >
> >> > >> > > >> >> >> Another unfortunate thing about
> ConsumerRebalanceListener
> >> > is
> >> > >> > that
> >> > >> > > in
> >> > >> > > >> >> >> order to do meaningful work in the callback, you need
> a
> >> > >> > reference
> >> > >> > > to
> >> > >> > > >> >> >> the consumer that called it. But that reference isn't
> >> > >> provided
> >> > >> > to
> >> > >> > > >> the
> >> > >> > > >> >> >> callback, which means the listener implementation
> needs
> >> to
> >> > >> hold
> >> > >> > a
> >> > >> > > >> >> >> reference to the consumer. Seems like this makes it
> >> > >> > unnecessarily
> >> > >> > > >> >> >> awkward to serialize or provide a 0 arg constructor
> for
> >> the
> >> > >> > > >> listener.
> >> > >> > > >> >> >>
> >> > >> > > >> >> >> On Wed, Mar 9, 2016 at 7:28 AM, Cody Koeninger <
> >> > >> > > c...@koeninger.org>
> >> > >> > > >> >> wrote:
> >> > >> > > >> >> >> > I thought about ConsumerRebalanceListener, but
> seeking
> >> to
> >> > >> the
> >> > >> > > >> >> >> > beginning any time there's a rebalance for whatever
> >> > reason
> >> > >> is
> >> > >> > > not
> >> > >> > > >> >> >> > necessarily the same thing as seeking to the
> beginning
> >> > >> before
> >> > >> > > >> first
> >> > >> > > >> >> >> > starting the consumer.
> >> > >> > > >> >> >> >
> >> > >> > > >> >> >> > On Wed, Mar 9, 2016 at 2:24 AM, Kamal C <
> >> > >> > kamaltar...@gmail.com>
> >> > >> > > >> >> wrote:
> >> > >> > > >> >> >> >> Cody,
> >> > >> > > >> >> >> >>
> >> > >> > > >> >> >> >> Use ConsumerRebalanceListener to achieve that,
> >> > >> > > >> >> >> >>
> >> > >> > > >> >> >> >> ConsumerRebalanceListener listener = new
> >> > >> > > >> ConsumerRebalanceListener()
> >> > >> > > >> >> {
> >> > >> > > >> >> >> >>
> >> > >> > > >> >> >> >> @Override
> >> > >> > > >> >> >> >> public void
> >> > >> > > >> >> onPartitionsRevoked(Collection<TopicPartition>
> >> > >> > > >> >> >> >> partitions) {
> >> > >> > > >> >> >> >> }
> >> > >> > > >> >> >> >>
> >> > >> > > >> >> >> >> @Override
> >> > >> > > >> >> >> >> public void
> >> > >> > > >> >> onPartitionsAssigned(Collection<TopicPartition>
> >> > >> > > >> >> >> >> partitions) {
> >> > >> > > >> >> >> >>
> >> > >> > consumer.seekToBeginning(partitions.toArray(new
> >> > >> > > >> >> >> >> TopicPartition[0]));
> >> > >> > > >> >> >> >> }
> >> > >> > > >> >> >> >> };
> >> > >> > > >> >> >> >>
> >> > >> > > >> >> >> >> consumer.subscribe(topics, listener);
> >> > >> > > >> >> >> >>
> >> > >> > > >> >> >> >> On Wed, Mar 9, 2016 at 12:05 PM, Cody Koeninger <
> >> > >> > > >> c...@koeninger.org>
> >> > >> > > >> >> >> wrote:
> >> > >> > > >> >> >> >>
> >> > >> > > >> >> >> >>> That suggestion doesn't work, for pretty much the
> >> same
> >> > >> > reason
> >> > >> > > -
> >> > >> > > >> at
> >> > >> > > >> >> the
> >> > >> > > >> >> >> >>> time poll is first called, there is no reset
> policy
> >> > and no
> >> > >> > > >> committed
> >> > >> > > >> >> >> >>> offset, so NoOffsetForPartitionException is thrown
> >> > >> > > >> >> >> >>>
> >> > >> > > >> >> >> >>> I feel like the underlying problem isn't so much
> that
> >> > >> > > seekToEnd
> >> > >> > > >> >> needs
> >> > >> > > >> >> >> >>> special case behavior. It's more that topic
> >> metadata
> >> > >> > > fetches,
> >> > >> > > >> >> >> >>> consumer position fetches, and message fetches are
> >> all
> >> > >> > lumped
> >> > >> > > >> >> together
> >> > >> > > >> >> >> >>> under a single poll() call, with no way to do them
> >> > >> > > individually
> >> > >> > > >> if
> >> > >> > > >> >> >> >>> necessary.
> >> > >> > > >> >> >> >>>
> >> > >> > > >> >> >> >>> What does "work" in this situation is to just
> catch
> >> the
> >> > >> > > >> exception
> >> > >> > > >> >> >> >>> (which leaves the consumer in a state where topics
> >> are
> >> > >> > > >> assigned) and
> >> > >> > > >> >> >> >>> then seek. But that is not exactly an elegant
> >> > interface.
> >> > >> > > >> >> >> >>>
> >> > >> > > >> >> >> >>> consumer.subscribe(topics)
> >> > >> > > >> >> >> >>> try {
> >> > >> > > >> >> >> >>> consumer.poll(0)
> >> > >> > > >> >> >> >>> } catch {
> >> > >> > > >> >> >> >>> case x: Throwable =>
> >> > >> > > >> >> >> >>> }
> >> > >> > > >> >> >> >>> consumer.seekToBeginning()
> >> > >> > > >> >> >> >>> consumer.poll(0)
> >> > >> > > >> >> >> >>>
> >> > >> > > >> >> >> >>>
> >> > >> > > >> >> >> >>>
> >> > >> > > >> >> >> >>>
> >> > >> > > >> >> >> >>> On Tue, Mar 8, 2016 at 11:22 PM, Guozhang Wang <
> >> > >> > > >> wangg...@gmail.com>
> >> > >> > > >> >> >> wrote:
> >> > >> > > >> >> >> >>> > Hi Cody,
> >> > >> > > >> >> >> >>> >
> >> > >> > > >> >> >> >>> > The problem with that code is in
> >> `seekToBeginning()`
> >> > >> > > followed
> >> > >> > > >> by
> >> > >> > > >> >> >> >>> > `subscribe(topic)`.
> >> > >> > > >> >> >> >>> >
> >> > >> > > >> >> >> >>> > Since `subscribe` call is lazy evaluated, by the
> >> time
> >> > >> > > >> >> >> `seekToBeginning()`
> >> > >> > > >> >> >> >>> > is called no partition is assigned yet, and
> hence
> >> it
> >> > is
> >> > >> > > >> >> effectively
> >> > >> > > >> >> >> an
> >> > >> > > >> >> >> >>> > no-op.
> >> > >> > > >> >> >> >>> >
> >> > >> > > >> >> >> >>> > Try
> >> > >> > > >> >> >> >>> >
> >> > >> > > >> >> >> >>> > consumer.subscribe(topics)
> >> > >> > > >> >> >> >>> > consumer.poll(0); // get assigned
> partitions
> >> > >> > > >> >> >> >>> > consumer.seekToBeginning()
> >> > >> > > >> >> >> >>> > consumer.poll(0)
> >> > >> > > >> >> >> >>> >
> >> > >> > > >> >> >> >>> > to see if that works.
> >> > >> > > >> >> >> >>> >
> >> > >> > > >> >> >> >>> > I think it is a valid issue that can be fixed in
> >> the
> >> > new
> >> > >> > > >> consumer
> >> > >> > > >> >> >> that,
> >> > >> > > >> >> >> >>> > upon calling seekToEnd/Beginning with no
> parameter,
> >> > >> while
> >> > >> > no
> >> > >> > > >> >> >> assigned is
> >> > >> > > >> >> >> >>> > done yet, do the coordination behind the scene;
> it
> >> > will
> >> > >> > > though
> >> > >> > > >> >> >> change the
> >> > >> > > >> >> >> >>> > behavior of the functions as they are no longer
> >> > always
> >> > >> > > lazily
> >> > >> > > >> >> >> evaluated.
> >> > >> > > >> >> >> >>> >
> >> > >> > > >> >> >> >>> >
> >> > >> > > >> >> >> >>> > Guozhang
> >> > >> > > >> >> >> >>> >
> >> > >> > > >> >> >> >>> >
> >> > >> > > >> >> >> >>> > On Tue, Mar 8, 2016 at 2:08 PM, Cody Koeninger <
> >> > >> > > >> >> c...@koeninger.org>
> >> > >> > > >> >> >> >>> wrote:
> >> > >> > > >> >> >> >>> >
> >> > >> > > >> >> >> >>> >> Using the 0.9 consumer, I would like to start
> >> > consuming
> >> > >> > at
> >> > >> > > >> the
> >> > >> > > >> >> >> >>> >> beginning or end, without specifying
> >> > auto.offset.reset.
> >> > >> > > >> >> >> >>> >>
> >> > >> > > >> >> >> >>> >> This does not seem to be possible:
> >> > >> > > >> >> >> >>> >>
> >> > >> > > >> >> >> >>> >> val kafkaParams = Map[String, Object](
> >> > >> > > >> >> >> >>> >> "bootstrap.servers" ->
> >> > >> > > conf.getString("kafka.brokers"),
> >> > >> > > >> >> >> >>> >> "key.deserializer" ->
> >> > >> classOf[StringDeserializer],
> >> > >> > > >> >> >> >>> >> "value.deserializer" ->
> >> > >> > classOf[StringDeserializer],
> >> > >> > > >> >> >> >>> >> "group.id" -> "example",
> >> > >> > > >> >> >> >>> >> "auto.offset.reset" -> "none"
> >> > >> > > >> >> >> >>> >> ).asJava
> >> > >> > > >> >> >> >>> >> val topics =
> >> > >> > > >> >> >>
> conf.getString("kafka.topics").split(",").toList.asJava
> >> > >> > > >> >> >> >>> >> val consumer = new KafkaConsumer[String,
> >> > >> > > >> String](kafkaParams)
> >> > >> > > >> >> >> >>> >> consumer.subscribe(topics)
> >> > >> > > >> >> >> >>> >> consumer.seekToBeginning()
> >> > >> > > >> >> >> >>> >> consumer.poll(0)
> >> > >> > > >> >> >> >>> >>
> >> > >> > > >> >> >> >>> >>
> >> > >> > > >> >> >> >>> >> Results in:
> >> > >> > > >> >> >> >>> >>
> >> > >> > > >> >> >> >>> >> Exception in thread "main"
> >> > >> > > >> >> >> >>> >>
> >> > >> > > >>
> >> org.apache.kafka.clients.consumer.NoOffsetForPartitionException:
> >> > >> > > >> >> >> >>> >> Undefined offset with no reset policy for
> >> partition:
> >> > >> > > >> testtwo-4
> >> > >> > > >> >> >> >>> >> at
> >> > >> > > >> >> >> >>> >>
> >> > >> > > >> >> >> >>>
> >> > >> > > >> >> >>
> >> > >> > > >> >>
> >> > >> > > >>
> >> > >> > >
> >> > >> >
> >> > >>
> >> >
> >>
> org.apache.kafka.clients.consumer.internals.Fetcher.resetOffset(Fetcher.java:288)
> >> > >> > > >> >> >> >>> >> at
> >> > >> > > >> >> >> >>> >>
> >> > >> > > >> >> >> >>>
> >> > >> > > >> >> >>
> >> > >> > > >> >>
> >> > >> > > >>
> >> > >> > >
> >> > >> >
> >> > >>
> >> >
> >>
> org.apache.kafka.clients.consumer.internals.Fetcher.updateFetchPositions(Fetcher.java:167)
> >> > >> > > >> >> >> >>> >> at
> >> > >> > > >> >> >> >>> >>
> >> > >> > > >> >> >> >>>
> >> > >> > > >> >> >>
> >> > >> > > >> >>
> >> > >> > > >>
> >> > >> > >
> >> > >> >
> >> > >>
> >> >
> >>
> org.apache.kafka.clients.consumer.KafkaConsumer.updateFetchPositions(KafkaConsumer.java:1302)
> >> > >> > > >> >> >> >>> >> at
> >> > >> > > >> >> >> >>> >>
> >> > >> > > >> >> >> >>>
> >> > >> > > >> >> >>
> >> > >> > > >> >>
> >> > >> > > >>
> >> > >> > >
> >> > >> >
> >> > >>
> >> >
> >>
> org.apache.kafka.clients.consumer.KafkaConsumer.pollOnce(KafkaConsumer.java:895)
> >> > >> > > >> >> >> >>> >> at
> >> > >> > > >> >> >> >>> >>
> >> > >> > > >> >> >> >>>
> >> > >> > > >> >> >>
> >> > >> > > >> >>
> >> > >> > > >>
> >> > >> > >
> >> > >> >
> >> > >>
> >> >
> >>
> org.apache.kafka.clients.consumer.KafkaConsumer.poll(KafkaConsumer.java:853)
> >> > >> > > >> >> >> >>> >> at
> >> > >> > > >> >> >>
> >> > example.BasicKafkaConsumer$.main(BasicKafkaConsumer.scala:25)
> >> > >> > > >> >> >> >>> >>
> >> > >> > > >> >> >> >>> >>
> >> > >> > > >> >> >> >>> >> I'm assuming this is because, at the time
> >> > >> > seekToBeginning()
> >> > >> > > >> is
> >> > >> > > >> >> >> called,
> >> > >> > > >> >> >> >>> >> subscriptions.assignedPartitions isn't
> populated.
> >> > But
> >> > >> > > >> polling in
> >> > >> > > >> >> >> >>> >> order to assign topicpartitions results in an
> >> error,
> >> > >> > which
> >> > >> > > >> >> creates a
> >> > >> > > >> >> >> >>> >> chicken-or-the-egg situation.
> >> > >> > > >> >> >> >>> >>
> >> > >> > > >> >> >> >>> >> I don't want to set auto.offset.reset, because
> I
> >> > want a
> >> > >> > > hard
> >> > >> > > >> >> error
> >> > >> > > >> >> >> if
> >> > >> > > >> >> >> >>> >> the offsets are out of range at any other time
> >> > during
> >> > >> > > >> >> consumption.
> >> > >> > > >> >> >> >>> >>
> >> > >> > > >> >> >> >>> >
> >> > >> > > >> >> >> >>> >
> >> > >> > > >> >> >> >>> >
> >> > >> > > >> >> >> >>> > --
> >> > >> > > >> >> >> >>> > -- Guozhang
> >> > >> > > >> >> >> >>>
> >> > >> > > >> >> >>
> >> > >> > > >> >> >
> >> > >> > > >> >> >
> >> > >> > > >> >> >
> >> > >> > > >> >> > --
> >> > >> > > >> >> > -- Guozhang
> >> > >> > > >> >>
> >> > >> > > >> >
> >> > >> > > >> >
> >> > >> > > >> >
> >> > >> > > >> > --
> >> > >> > > >> > -- Guozhang
> >> > >> > > >>
> >> > >> > > >
> >> > >> > > >
> >> > >> > > >
> >> > >> > > > --
> >> > >> > > > -- Guozhang
> >> > >> > > >
> >> > >> > >
> >> > >> > >
> >> > >> > >
> >> > >> > > --
> >> > >> > > -- Guozhang
> >> > >> > >
> >> > >> >
> >> > >>
> >> > >>
> >> > >>
> >> > >> --
> >> > >> -- Guozhang
> >> > >>
> >> >
> >>
> >
> >
> >
> > --
> > -- Guozhang
>
--
-- Guozhang
