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Posted to dev@kafka.apache.org by Jason Gustafson <ja...@confluent.io> on 2018/05/02 20:55:26 UTC
Re: [DISCUSSION] KIP-266: Add TimeoutException to KafkaConsumer#position()
I think John's proposal look reasonable to me. My only doubt is about use
cases for the new `awaitAssignmentMetadata` API. I think the basic idea is
that we want a way to block until we have joined the consumer group, but we
do not want to await fetched data. Maybe another way to accomplish this
would be to add a `PollOptions` argument which specified the condition we
are awaiting? It's a little weird that we'd have two separate APIs where
the group membership can change. I know this functionality can be helpful
in testing, but we should probably spend some more time understanding and
motivating the general use cases.
Since we're leaving around the old poll() with its current behavior for
now, I wonder if we could leave this as potential future work?
Other than that, I have a few minor suggestions and I'm happy with the KIP:
1. Can we use Duration across the board for all of these APIs?
2. Can we cover the following blocking APIs with in this KIP:
`partitionsFor`, `listTopics`, `offsetsForTimes`, `beginningOffsets`,
`endOffsets`?
3. Perhaps we can add a `close(Duration)` and deprecate the one accepting
`TimeUnit`?
4. Seems we don't really need `ClientTimeoutException` since we already
have `TimeoutException`?
Thanks,
Jason
On Wed, Apr 25, 2018 at 2:14 PM, Guozhang Wang <wa...@gmail.com> wrote:
> Previously there are some debates on whether we should add this nonblocking
> behavior via a config v.s. via overloaded functions. To make progress on
> this discussion we need to first figure that part out. I'm in favor of the
> current approach of overloaded functions over the config since if we are
> going to have multiple configs other than a single one to control timeout
> semantics it may be even confusing: take our producer side configs for an
> example, right now we have "request.timeout.ms" and "max.block.ms" and we
> are proposing to add another one in KIP-91. But I'd also like to hear from
> people who's in favor of the configs.
>
>
> Guozhang
>
>
> On Wed, Apr 25, 2018 at 1:39 PM, John Roesler <jo...@confluent.io> wrote:
>
> > Re Ted's last comment, that style of async API requires some thread to
> > actually drive the request/response cycle and invoke the callback when
> it's
> > complete. Right now, this happens in the caller's thread as a side-effect
> > of calling poll(). But that clearly won't work for poll() itself!
> >
> > In the future, I think we'd like to add a background thread to drive the
> > request/response loops, and then make all these methods return
> > Future<Whatever>.
> >
> > But we don't need to bite that off right now.
> >
> > The "async" model I'm proposing is really just a generalization of the
> one
> > that poll already partially implements: when you call poll, it fires off
> > any requests it needs to make and checks if any responses are ready. If
> so,
> > it returns them. If not, it returns empty. When you call poll() again, it
> > again checks on the responses from last time, and so forth.
> >
> > But that model currently only applies to the "fetch" part of poll. I'm
> > proposing that we extend it to the "metadata update" part of poll as
> well.
> >
> > However, as previously discussed, doing this in place would break the
> > semantics of poll that folks currently rely on, so I propose to add new
> > methods and deprecate the existing poll method. Here's what I'm thinking:
> > https://github.com/apache/kafka/pull/4855 . In the discussion on that
> PR,
> > I've described in greater detail how the async+blocking semantics work.
> >
> > I'll update KIP-266 with this interface for poll().
> >
> > It would be great to get this discussion moving again so we can get these
> > changes into 2.0. What does everyone think about this?
> >
> > Thanks,
> > -John
> >
> > On Thu, Apr 19, 2018 at 5:12 PM, John Roesler <jo...@confluent.io> wrote:
> >
> > > Thanks for the tip, Ted!
> > >
> > > On Thu, Apr 19, 2018 at 12:12 PM, Ted Yu <yu...@gmail.com> wrote:
> > >
> > >> John:
> > >> In case you want to pursue async poll, it seems (by looking at current
> > >> API)
> > >> that introducing PollCallback follows existing pattern(s).
> > >>
> > >> e.g. KafkaConsumer#commitAsync(OffsetCommitCallback)
> > >>
> > >> FYI
> > >>
> > >> On Thu, Apr 19, 2018 at 10:08 AM, John Roesler <jo...@confluent.io>
> > wrote:
> > >>
> > >> > Hi Richard,
> > >> >
> > >> > Thanks for the invitation! I do think it would be safer to
> introduce a
> > >> new
> > >> > poll
> > >> > method than to change the semantics of the old one. I've been
> mulling
> > >> about
> > >> > whether the new one could still have (slightly different) async
> > >> semantics
> > >> > with
> > >> > a timeout of 0. If possible, I'd like to avoid introducing another
> new
> > >> > "asyncPoll".
> > >> >
> > >> > I'm planning to run some experiments and dig into the
> implementation a
> > >> bit
> > >> > more before solidifying the proposal. I'll update the KIP as you
> > >> suggest at
> > >> > that point,
> > >> > and then can call for another round of reviews and voting.
> > >> >
> > >> > Thanks,
> > >> > -John
> > >> >
> > >> > On Tue, Apr 17, 2018 at 4:53 PM, Richard Yu <
> > yohan.richard.yu@gmail.com
> > >> >
> > >> > wrote:
> > >> >
> > >> > > Hi John,
> > >> > >
> > >> > > Do you have a preference for fixing the poll() method (e.g. using
> > >> > asyncPoll
> > >> > > or just sticking with the current method but with an extra timeout
> > >> > > parameter) ? I think your current proposition for KIP-288 is
> better
> > >> than
> > >> > > what I have on my side. If you think there is something that you
> > want
> > >> to
> > >> > > add, you could go ahead and change KIP-266 to your liking. Just to
> > >> note
> > >> > > that it would be preferable that if one of us modifies this KIP,
> it
> > >> would
> > >> > > be best to mention your change on this thread to let each other
> know
> > >> > (makes
> > >> > > it easier to coordinate progress).
> > >> > >
> > >> > > Thanks,
> > >> > > Richard
> > >> > >
> > >> > > On Tue, Apr 17, 2018 at 2:07 PM, John Roesler <jo...@confluent.io>
> > >> wrote:
> > >> > >
> > >> > > > Ok, I'll close the discussion on KIP-288 and mark it discarded.
> > >> > > >
> > >> > > > We can solidify the design for poll in KIP-266, and once it's
> > >> approved,
> > >> > > > I'll coordinate with Qiang Zhao on the PR for the poll part of
> the
> > >> > work.
> > >> > > > Once that is merged, you'll have a clean slate for the rest of
> the
> > >> > work.
> > >> > > >
> > >> > > > On Tue, Apr 17, 2018 at 3:39 PM, Richard Yu <
> > >> > yohan.richard.yu@gmail.com>
> > >> > > > wrote:
> > >> > > >
> > >> > > > > Hi John,
> > >> > > > >
> > >> > > > > I think that you could finish your PR that corresponds with
> > >> KIP-288
> > >> > and
> > >> > > > > merge it. I can finish my side of the work afterwards.
> > >> > > > >
> > >> > > > > On another note, adding an asynchronized version of poll()
> would
> > >> make
> > >> > > > > sense, particularily since the current version of Kafka does
> not
> > >> > > support
> > >> > > > > it.
> > >> > > > >
> > >> > > > > Thanks
> > >> > > > > Richar
> > >> > > > >
> > >> > > > > On Tue, Apr 17, 2018 at 12:30 PM, John Roesler <
> > john@confluent.io
> > >> >
> > >> > > > wrote:
> > >> > > > >
> > >> > > > > > Cross-pollinating from some discussion we've had on KIP-288,
> > >> > > > > >
> > >> > > > > > I think there's a good reason that poll() takes a timeout
> when
> > >> none
> > >> > > of
> > >> > > > > the
> > >> > > > > > other methods do, and it's relevant to this discussion. The
> > >> timeout
> > >> > > in
> > >> > > > > > poll() is effectively implementing a long-poll API (on the
> > >> client
> > >> > > side,
> > >> > > > > so
> > >> > > > > > it's not really long-poll, but the programmer-facing
> behavior
> > is
> > >> > the
> > >> > > > > same).
> > >> > > > > > The timeout isn't really bounding the execution time of the
> > >> method,
> > >> > > but
> > >> > > > > > instead giving a max time that callers are willing to wait
> > >> around
> > >> > and
> > >> > > > see
> > >> > > > > > if any results show up.
> > >> > > > > >
> > >> > > > > > If I understand the code sufficiently, it would be perfectly
> > >> > > reasonable
> > >> > > > > for
> > >> > > > > > a caller to use a timeout of 0 to implement async poll, it
> > would
> > >> > just
> > >> > > > > mean
> > >> > > > > > that KafkaConsumer would just check on each call if there's
> a
> > >> > > response
> > >> > > > > > ready and if not, fire off a new request without waiting
> for a
> > >> > > > response.
> > >> > > > > >
> > >> > > > > > As such, it seems inappropriate to throw a
> > >> ClientTimeoutException
> > >> > > from
> > >> > > > > > poll(), except possibly if the initial phase of ensuring an
> > >> > > assignment
> > >> > > > > > times out. We wouldn't want the method contract to be
> > "returns a
> > >> > > > > non-empty
> > >> > > > > > collection or throws a ClientTimeoutException"
> > >> > > > > >
> > >> > > > > > Now, I'm wondering if we should actually consider one of my
> > >> > rejected
> > >> > > > > > alternatives, to treat the "operation timeout" as a separate
> > >> > > parameter
> > >> > > > > from
> > >> > > > > > the "long-poll time". Or maybe adding an "asyncPoll(timeout,
> > >> time
> > >> > > > unit)"
> > >> > > > > > that only uses the timeout to bound metadata updates and
> > >> otherwise
> > >> > > > > behaves
> > >> > > > > > like the current "poll(0)".
> > >> > > > > >
> > >> > > > > > Thanks,
> > >> > > > > > -John
> > >> > > > > >
> > >> > > > > > On Tue, Apr 17, 2018 at 2:05 PM, John Roesler <
> > >> john@confluent.io>
> > >> > > > wrote:
> > >> > > > > >
> > >> > > > > > > Hey Richard,
> > >> > > > > > >
> > >> > > > > > > As you noticed, the newly introduced KIP-288 overlaps with
> > >> this
> > >> > > one.
> > >> > > > > > Sorry
> > >> > > > > > > for stepping on your toes... How would you like to
> proceed?
> > >> I'm
> > >> > > happy
> > >> > > > > to
> > >> > > > > > > "close" KIP-288 in deference to this KIP.
> > >> > > > > > >
> > >> > > > > > > With respect to poll(), reading this discussion gave me a
> > new
> > >> > idea
> > >> > > > for
> > >> > > > > > > providing a non-breaking update path... What if we
> > introduce a
> > >> > new
> > >> > > > > > variant
> > >> > > > > > > 'poll(long timeout, TimeUnit unit)' that displays the new,
> > >> > desired
> > >> > > > > > > behavior, and just leave the old method alone?
> > >> > > > > > >
> > >> > > > > > > Thanks,
> > >> > > > > > > -John
> > >> > > > > > >
> > >> > > > > > > On Tue, Apr 17, 2018 at 12:09 PM, Richard Yu <
> > >> > > > > yohan.richard.yu@gmail.com
> > >> > > > > > >
> > >> > > > > > > wrote:
> > >> > > > > > >
> > >> > > > > > >> Hi all,
> > >> > > > > > >>
> > >> > > > > > >> If possible, would a committer please review?
> > >> > > > > > >>
> > >> > > > > > >> Thanks
> > >> > > > > > >>
> > >> > > > > > >> On Sun, Apr 1, 2018 at 7:24 PM, Richard Yu <
> > >> > > > > yohan.richard.yu@gmail.com>
> > >> > > > > > >> wrote:
> > >> > > > > > >>
> > >> > > > > > >> > Hi Guozhang,
> > >> > > > > > >> >
> > >> > > > > > >> > I have clarified the KIP a bit to account for Becket's
> > >> > > suggestion
> > >> > > > on
> > >> > > > > > >> > ClientTimeoutException.
> > >> > > > > > >> > About adding an extra config, you were right about my
> > >> > > intentions.
> > >> > > > I
> > >> > > > > am
> > >> > > > > > >> > just wondering if the config
> > >> > > > > > >> > should be included, since Ismael seems to favor an
> extra
> > >> > > > > > configuration,
> > >> > > > > > >> >
> > >> > > > > > >> > Thanks,
> > >> > > > > > >> > Richard
> > >> > > > > > >> >
> > >> > > > > > >> > On Sun, Apr 1, 2018 at 5:35 PM, Guozhang Wang <
> > >> > > wangguoz@gmail.com
> > >> > > > >
> > >> > > > > > >> wrote:
> > >> > > > > > >> >
> > >> > > > > > >> >> Hi Richard,
> > >> > > > > > >> >>
> > >> > > > > > >> >> Regarding the streams side changes, we plan to
> > incorporate
> > >> > with
> > >> > > > the
> > >> > > > > > new
> > >> > > > > > >> >> APIs once the KIP is done, which is only internal code
> > >> > changes
> > >> > > > and
> > >> > > > > > >> hence
> > >> > > > > > >> >> do
> > >> > > > > > >> >> not need to include in the KIP.
> > >> > > > > > >> >>
> > >> > > > > > >> >> Could you update the KIP because it has been quite
> > >> obsoleted
> > >> > > from
> > >> > > > > the
> > >> > > > > > >> >> discussed topics, and I'm a bit loosing track on what
> is
> > >> your
> > >> > > > final
> > >> > > > > > >> >> proposal right now. For example, I'm not completely
> > >> following
> > >> > > > your
> > >> > > > > > >> >> "compromise
> > >> > > > > > >> >> of sorts": are you suggesting that we still add
> > >> overloading
> > >> > > > > functions
> > >> > > > > > >> and
> > >> > > > > > >> >> add a config that will be applied to all overload
> > >> functions
> > >> > > > without
> > >> > > > > > the
> > >> > > > > > >> >> timeout, while for other overloaded functions with the
> > >> > timeout
> > >> > > > > value
> > >> > > > > > >> the
> > >> > > > > > >> >> config will be ignored?
> > >> > > > > > >> >>
> > >> > > > > > >> >>
> > >> > > > > > >> >> Guozhang
> > >> > > > > > >> >>
> > >> > > > > > >> >> On Fri, Mar 30, 2018 at 8:36 PM, Richard Yu <
> > >> > > > > > >> yohan.richard.yu@gmail.com>
> > >> > > > > > >> >> wrote:
> > >> > > > > > >> >>
> > >> > > > > > >> >> > On a side note, I have noticed that the several
> other
> > >> > methods
> > >> > > > in
> > >> > > > > > >> classes
> > >> > > > > > >> >> > such as StoreChangeLogReader in Streams calls
> > position()
> > >> > > which
> > >> > > > > > causes
> > >> > > > > > >> >> tests
> > >> > > > > > >> >> > to hang. It might be out of the scope of the KIP,
> but
> > >> > should
> > >> > > I
> > >> > > > > also
> > >> > > > > > >> >> change
> > >> > > > > > >> >> > the methods which use position() as a callback to at
> > the
> > >> > very
> > >> > > > > least
> > >> > > > > > >> >> prevent
> > >> > > > > > >> >> > the tests from hanging? This issue might be out of
> the
> > >> KIP,
> > >> > > > but I
> > >> > > > > > >> >> prefer it
> > >> > > > > > >> >> > if we could at least make my PR pass the Jenkins
> Q&A.
> > >> > > > > > >> >> >
> > >> > > > > > >> >> > Thanks
> > >> > > > > > >> >> >
> > >> > > > > > >> >> > On Fri, Mar 30, 2018 at 8:24 PM, Richard Yu <
> > >> > > > > > >> yohan.richard.yu@gmail.com
> > >> > > > > > >> >> >
> > >> > > > > > >> >> > wrote:
> > >> > > > > > >> >> >
> > >> > > > > > >> >> > > Thanks for the review Becket.
> > >> > > > > > >> >> > >
> > >> > > > > > >> >> > > About the methods beginningOffsets(),
> endOffsets(),
> > >> ...:
> > >> > > > > > >> >> > > I took a look through the code of KafkaConsumer,
> but
> > >> > after
> > >> > > > > > looking
> > >> > > > > > >> >> > through
> > >> > > > > > >> >> > > the offsetsByTimes() method
> > >> > > > > > >> >> > > and its callbacks in Fetcher, I think these
> methods
> > >> > already
> > >> > > > > block
> > >> > > > > > >> for
> > >> > > > > > >> >> a
> > >> > > > > > >> >> > > set period of time. I know that there
> > >> > > > > > >> >> > > is a chance that the offsets methods in
> > KafkaConsumer
> > >> > might
> > >> > > > be
> > >> > > > > > like
> > >> > > > > > >> >> poll
> > >> > > > > > >> >> > > (that is one section of the method
> > >> > > > > > >> >> > > honors the timeout while another --
> > >> updateFetchPositions
> > >> > --
> > >> > > > > does
> > >> > > > > > >> not).
> > >> > > > > > >> >> > > However, I don't think that this is the
> > >> > > > > > >> >> > > case with offsetsByTimes since the callbacks that
> I
> > >> > checked
> > >> > > > > does
> > >> > > > > > >> not
> > >> > > > > > >> >> seem
> > >> > > > > > >> >> > > to hang.
> > >> > > > > > >> >> > >
> > >> > > > > > >> >> > > The clarity of the exception message is a
> problem. I
> > >> > > thought
> > >> > > > > your
> > >> > > > > > >> >> > > suggestion there was reasonable. I included
> > >> > > > > > >> >> > > it in the KIP.
> > >> > > > > > >> >> > >
> > >> > > > > > >> >> > > And on another note, I have noticed that several
> > >> people
> > >> > has
> > >> > > > > > voiced
> > >> > > > > > >> the
> > >> > > > > > >> >> > > opinion that adding a config might
> > >> > > > > > >> >> > > be advisable in relation to adding an extra
> > >> parameter. I
> > >> > > > think
> > >> > > > > > >> that we
> > >> > > > > > >> >> > can
> > >> > > > > > >> >> > > have a compromise of sorts: some
> > >> > > > > > >> >> > > methods in KafkaConsumer are relatively similar --
> > for
> > >> > > > example,
> > >> > > > > > >> >> > position()
> > >> > > > > > >> >> > > and committed() both call
> > >> > > > > > >> >> > > updateFetchPositions(). I think that we could use
> > the
> > >> > same
> > >> > > > > config
> > >> > > > > > >> for
> > >> > > > > > >> >> > > these method as a default timeout if
> > >> > > > > > >> >> > > the user does not provide one. On the other hand,
> if
> > >> they
> > >> > > > wish
> > >> > > > > to
> > >> > > > > > >> >> specify
> > >> > > > > > >> >> > > a longer or shorter blocking time,
> > >> > > > > > >> >> > > they have the option of changing the timeout. (I
> > >> included
> > >> > > the
> > >> > > > > > >> config
> > >> > > > > > >> >> as
> > >> > > > > > >> >> > an
> > >> > > > > > >> >> > > alternative in the KIP) WDYT?
> > >> > > > > > >> >> > >
> > >> > > > > > >> >> > > Thanks,
> > >> > > > > > >> >> > > Richard
> > >> > > > > > >> >> > >
> > >> > > > > > >> >> > >
> > >> > > > > > >> >> > > On Fri, Mar 30, 2018 at 1:26 AM, Becket Qin <
> > >> > > > > > becket.qin@gmail.com>
> > >> > > > > > >> >> > wrote:
> > >> > > > > > >> >> > >
> > >> > > > > > >> >> > >> Glad to see the KIP, Richard. This has been a
> > really
> > >> > long
> > >> > > > > > pending
> > >> > > > > > >> >> issue.
> > >> > > > > > >> >> > >>
> > >> > > > > > >> >> > >> The original arguments from Jay for using config,
> > >> such
> > >> > as
> > >> > > > > > >> >> max.block.ms,
> > >> > > > > > >> >> > >> instead of using timeout parameters was that
> people
> > >> will
> > >> > > > > always
> > >> > > > > > >> hard
> > >> > > > > > >> >> > code
> > >> > > > > > >> >> > >> the timeout, and the hard coded timeout is rarely
> > >> > correct
> > >> > > > > > because
> > >> > > > > > >> it
> > >> > > > > > >> >> has
> > >> > > > > > >> >> > >> to
> > >> > > > > > >> >> > >> consider different scenarios. For example, users
> > may
> > >> > > receive
> > >> > > > > > >> timeout
> > >> > > > > > >> >> > >> exception when the group coordinator moves.
> Having
> > a
> > >> > > > > > configuration
> > >> > > > > > >> >> with
> > >> > > > > > >> >> > >> some reasonable default value will make users'
> life
> > >> > > easier.
> > >> > > > > > >> >> > >>
> > >> > > > > > >> >> > >> That said, in practice, it seems more useful to
> > have
> > >> > > timeout
> > >> > > > > > >> >> parameters.
> > >> > > > > > >> >> > >> We
> > >> > > > > > >> >> > >> have seen some library, using the consumers
> > >> internally,
> > >> > > > needs
> > >> > > > > to
> > >> > > > > > >> >> provide
> > >> > > > > > >> >> > >> an
> > >> > > > > > >> >> > >> external flexible timeout interface. Also, user
> can
> > >> > easily
> > >> > > > > hard
> > >> > > > > > >> code
> > >> > > > > > >> >> a
> > >> > > > > > >> >> > >> value to get the same as a config based solution.
> > >> > > > > > >> >> > >>
> > >> > > > > > >> >> > >> The KIP looks good overall. A few comments:
> > >> > > > > > >> >> > >>
> > >> > > > > > >> >> > >> 1. There are a few other blocking methods that
> are
> > >> not
> > >> > > > > included,
> > >> > > > > > >> e.g.
> > >> > > > > > >> >> > >> offsetsForTimes(), beginningOffsets(),
> > endOffsets().
> > >> Is
> > >> > > > there
> > >> > > > > > any
> > >> > > > > > >> >> > reason?
> > >> > > > > > >> >> > >>
> > >> > > > > > >> >> > >> 2. I am wondering can we take the KIP as a chance
> > to
> > >> > clean
> > >> > > > up
> > >> > > > > > our
> > >> > > > > > >> >> > timeout
> > >> > > > > > >> >> > >> exception(s)? More specifically, instead of
> reusing
> > >> > > > > > >> TimeoutException,
> > >> > > > > > >> >> > can
> > >> > > > > > >> >> > >> we introduce a new ClientTimeoutException with
> > >> different
> > >> > > > > causes,
> > >> > > > > > >> e.g.
> > >> > > > > > >> >> > >> UnknownTopicOrPartition, RequestTimeout,
> > >> > > LeaderNotAvailable,
> > >> > > > > > etc.
> > >> > > > > > >> >> > >> As of now, the TimeoutException is used in the
> > >> following
> > >> > > > three
> > >> > > > > > >> cases:
> > >> > > > > > >> >> > >>
> > >> > > > > > >> >> > >> 1. TimeoutException is a subclass of
> > ApiException
> > >> > which
> > >> > > > > > >> indicates
> > >> > > > > > >> >> the
> > >> > > > > > >> >> > >> exception was returned by the broker. The
> > >> > > > TimeoutException
> > >> > > > > > was
> > >> > > > > > >> >> > >> initially
> > >> > > > > > >> >> > >> returned by the leaders when replication was
> not
> > >> done
> > >> > > > > within
> > >> > > > > > >> the
> > >> > > > > > >> >> > >> specified
> > >> > > > > > >> >> > >> timeout in the ProduceRequest. It has an error
> > >> code
> > >> > of
> > >> > > 7,
> > >> > > > > > >> which is
> > >> > > > > > >> >> > >> returned
> > >> > > > > > >> >> > >> by the broker.
> > >> > > > > > >> >> > >> 2. When we migrate to Java clients, in Errors
> > >> > > definition,
> > >> > > > > we
> > >> > > > > > >> >> extended
> > >> > > > > > >> >> > >> it
> > >> > > > > > >> >> > >> to indicate request timeout, i.e. a request
> was
> > >> sent
> > >> > > but
> > >> > > > > the
> > >> > > > > > >> >> response
> > >> > > > > > >> >> > >> was
> > >> > > > > > >> >> > >> not received before timeout. In this case, the
> > >> > clients
> > >> > > > did
> > >> > > > > > not
> > >> > > > > > >> >> have a
> > >> > > > > > >> >> > >> return code from the broker.
> > >> > > > > > >> >> > >> 3. Later at some point, we started to use the
> > >> > > > > > TimeoutException
> > >> > > > > > >> for
> > >> > > > > > >> >> > >> clients method call timeout. It is neither
> > >> related to
> > >> > > any
> > >> > > > > > >> broker
> > >> > > > > > >> >> > >> returned
> > >> > > > > > >> >> > >> error code, nor to request timeout on the
> wire.
> > >> > > > > > >> >> > >>
> > >> > > > > > >> >> > >> Due to the various interpretations, users can
> > easily
> > >> be
> > >> > > > > > confused.
> > >> > > > > > >> As
> > >> > > > > > >> >> an
> > >> > > > > > >> >> > >> example, when a timeout is thrown with "Failed to
> > >> > refresh
> > >> > > > > > metadata
> > >> > > > > > >> >> in X
> > >> > > > > > >> >> > >> ms", it is hard to tell what exactly happened.
> > Since
> > >> we
> > >> > > are
> > >> > > > > > >> changing
> > >> > > > > > >> >> the
> > >> > > > > > >> >> > >> API here, it would be good to avoid introducing
> > more
> > >> > > > ambiguity
> > >> > > > > > and
> > >> > > > > > >> >> see
> > >> > > > > > >> >> > >> whether this can be improved. It would be at
> least
> > >> one
> > >> > > step
> > >> > > > > > >> forward
> > >> > > > > > >> >> to
> > >> > > > > > >> >> > >> remove the usage of case 3.
> > >> > > > > > >> >> > >>
> > >> > > > > > >> >> > >> Thanks,
> > >> > > > > > >> >> > >>
> > >> > > > > > >> >> > >> Jiangjie (Becket) Qin
> > >> > > > > > >> >> > >>
> > >> > > > > > >> >> > >>
> > >> > > > > > >> >> > >>
> > >> > > > > > >> >> > >>
> > >> > > > > > >> >> > >> On Mon, Mar 26, 2018 at 5:50 PM, Guozhang Wang <
> > >> > > > > > >> wangguoz@gmail.com>
> > >> > > > > > >> >> > >> wrote:
> > >> > > > > > >> >> > >>
> > >> > > > > > >> >> > >> > @Richard: TimeoutException inherits from
> > >> > > > RetriableException
> > >> > > > > > >> which
> > >> > > > > > >> >> > >> inherits
> > >> > > > > > >> >> > >> > from ApiException. So users should explicitly
> try
> > >> to
> > >> > > > capture
> > >> > > > > > >> >> > >> > RetriableException in their code and handle the
> > >> > > exception.
> > >> > > > > > >> >> > >> >
> > >> > > > > > >> >> > >> > @Isamel, Ewen: I'm trying to push progress
> > forward
> > >> on
> > >> > > this
> > >> > > > > > one,
> > >> > > > > > >> >> are we
> > >> > > > > > >> >> > >> now
> > >> > > > > > >> >> > >> > on the same page for using function parameters
> > than
> > >> > > > configs?
> > >> > > > > > >> >> > >> >
> > >> > > > > > >> >> > >> >
> > >> > > > > > >> >> > >> > Guozhang
> > >> > > > > > >> >> > >> >
> > >> > > > > > >> >> > >> >
> > >> > > > > > >> >> > >> > On Fri, Mar 23, 2018 at 4:42 PM, Ismael Juma <
> > >> > > > > > ismael@juma.me.uk
> > >> > > > > > >> >
> > >> > > > > > >> >> > wrote:
> > >> > > > > > >> >> > >> >
> > >> > > > > > >> >> > >> > > Hi Ewen,
> > >> > > > > > >> >> > >> > >
> > >> > > > > > >> >> > >> > > Yeah, I mentioned KAFKA-2391 where some of
> this
> > >> was
> > >> > > > > > discussed.
> > >> > > > > > >> >> Jay
> > >> > > > > > >> >> > was
> > >> > > > > > >> >> > >> > > against having timeouts in the methods at the
> > >> time.
> > >> > > > > However,
> > >> > > > > > >> as
> > >> > > > > > >> >> > Jason
> > >> > > > > > >> >> > >> > said
> > >> > > > > > >> >> > >> > > offline, we did end up with a timeout
> parameter
> > >> in
> > >> > > > `poll`.
> > >> > > > > > >> >> > >> > >
> > >> > > > > > >> >> > >> > > Ismael
> > >> > > > > > >> >> > >> > >
> > >> > > > > > >> >> > >> > > On Fri, Mar 23, 2018 at 4:26 PM, Ewen
> > >> > > Cheslack-Postava <
> > >> > > > > > >> >> > >> > ewen@confluent.io>
> > >> > > > > > >> >> > >> > > wrote:
> > >> > > > > > >> >> > >> > >
> > >> > > > > > >> >> > >> > > > Regarding the flexibility question, has
> > someone
> > >> > > tried
> > >> > > > to
> > >> > > > > > >> dig up
> > >> > > > > > >> >> > the
> > >> > > > > > >> >> > >> > > > discussion of the new consumer APIs when
> they
> > >> were
> > >> > > > being
> > >> > > > > > >> >> written?
> > >> > > > > > >> >> > I
> > >> > > > > > >> >> > >> > > vaguely
> > >> > > > > > >> >> > >> > > > recall these exact questions about using
> APIs
> > >> vs
> > >> > > > configs
> > >> > > > > > and
> > >> > > > > > >> >> > >> > flexibility
> > >> > > > > > >> >> > >> > > vs
> > >> > > > > > >> >> > >> > > > bloating the API surface area having
> already
> > >> been
> > >> > > > > > discussed.
> > >> > > > > > >> >> (Not
> > >> > > > > > >> >> > >> that
> > >> > > > > > >> >> > >> > we
> > >> > > > > > >> >> > >> > > > shouldn't revisit, just that it might also
> > be a
> > >> > > faster
> > >> > > > > way
> > >> > > > > > >> to
> > >> > > > > > >> >> get
> > >> > > > > > >> >> > >> to a
> > >> > > > > > >> >> > >> > > full
> > >> > > > > > >> >> > >> > > > understanding of the options, concerns, and
> > >> > > > tradeoffs).
> > >> > > > > > >> >> > >> > > >
> > >> > > > > > >> >> > >> > > > -Ewen
> > >> > > > > > >> >> > >> > > >
> > >> > > > > > >> >> > >> > > > On Thu, Mar 22, 2018 at 7:19 AM, Richard
> Yu <
> > >> > > > > > >> >> > >> > yohan.richard.yu@gmail.com>
> > >> > > > > > >> >> > >> > > > wrote:
> > >> > > > > > >> >> > >> > > >
> > >> > > > > > >> >> > >> > > > > I do have one question though: in the
> > current
> > >> > KIP,
> > >> > > > > > >> throwing
> > >> > > > > > >> >> > >> > > > > TimeoutException to mark
> > >> > > > > > >> >> > >> > > > > that time limit is exceeded is applied to
> > all
> > >> > new
> > >> > > > > > methods
> > >> > > > > > >> >> > >> introduced
> > >> > > > > > >> >> > >> > in
> > >> > > > > > >> >> > >> > > > > this proposal.
> > >> > > > > > >> >> > >> > > > > However, how would users respond when a
> > >> > > > > TimeoutException
> > >> > > > > > >> >> (since
> > >> > > > > > >> >> > >> it is
> > >> > > > > > >> >> > >> > > > > considered
> > >> > > > > > >> >> > >> > > > > a RuntimeException)?
> > >> > > > > > >> >> > >> > > > >
> > >> > > > > > >> >> > >> > > > > Thanks,
> > >> > > > > > >> >> > >> > > > > Richard
> > >> > > > > > >> >> > >> > > > >
> > >> > > > > > >> >> > >> > > > >
> > >> > > > > > >> >> > >> > > > >
> > >> > > > > > >> >> > >> > > > > On Mon, Mar 19, 2018 at 6:10 PM, Richard
> > Yu <
> > >> > > > > > >> >> > >> > > yohan.richard.yu@gmail.com>
> > >> > > > > > >> >> > >> > > > > wrote:
> > >> > > > > > >> >> > >> > > > >
> > >> > > > > > >> >> > >> > > > > > Hi Ismael,
> > >> > > > > > >> >> > >> > > > > >
> > >> > > > > > >> >> > >> > > > > > You have a great point. Since most of
> the
> > >> > > methods
> > >> > > > in
> > >> > > > > > >> this
> > >> > > > > > >> >> KIP
> > >> > > > > > >> >> > >> have
> > >> > > > > > >> >> > >> > > > > similar
> > >> > > > > > >> >> > >> > > > > > callbacks (position() and committed()
> > both
> > >> use
> > >> > > > > > >> >> > >> > > fetchCommittedOffsets(),
> > >> > > > > > >> >> > >> > > > > > and
> > >> > > > > > >> >> > >> > > > > > commitSync() is similar to position(),
> > >> except
> > >> > > just
> > >> > > > > > >> updating
> > >> > > > > > >> >> > >> > offsets),
> > >> > > > > > >> >> > >> > > > the
> > >> > > > > > >> >> > >> > > > > > amount of time
> > >> > > > > > >> >> > >> > > > > > they block should be also about equal.
> > >> > > > > > >> >> > >> > > > > >
> > >> > > > > > >> >> > >> > > > > > However, I think that we need to take
> > into
> > >> > > > account a
> > >> > > > > > >> >> couple of
> > >> > > > > > >> >> > >> > > things.
> > >> > > > > > >> >> > >> > > > > For
> > >> > > > > > >> >> > >> > > > > > starters,
> > >> > > > > > >> >> > >> > > > > > if the new methods were all reliant on
> > one
> > >> > > config,
> > >> > > > > > >> there is
> > >> > > > > > >> >> > >> > > likelihood
> > >> > > > > > >> >> > >> > > > > > that the
> > >> > > > > > >> >> > >> > > > > > shortcomings for this approach would be
> > >> > similar
> > >> > > to
> > >> > > > > > what
> > >> > > > > > >> we
> > >> > > > > > >> >> > >> faced if
> > >> > > > > > >> >> > >> > > we
> > >> > > > > > >> >> > >> > > > > let
> > >> > > > > > >> >> > >> > > > > > request.timeout.ms control all method
> > >> > timeouts.
> > >> > > > In
> > >> > > > > > >> >> > comparison,
> > >> > > > > > >> >> > >> > > adding
> > >> > > > > > >> >> > >> > > > > > overloads
> > >> > > > > > >> >> > >> > > > > > does not have this problem.
> > >> > > > > > >> >> > >> > > > > >
> > >> > > > > > >> >> > >> > > > > > If you have further thoughts, please
> let
> > me
> > >> > > know.
> > >> > > > > > >> >> > >> > > > > >
> > >> > > > > > >> >> > >> > > > > > Richard
> > >> > > > > > >> >> > >> > > > > >
> > >> > > > > > >> >> > >> > > > > >
> > >> > > > > > >> >> > >> > > > > > On Mon, Mar 19, 2018 at 5:12 PM, Ismael
> > >> Juma <
> > >> > > > > > >> >> > ismael@juma.me.uk
> > >> > > > > > >> >> > >> >
> > >> > > > > > >> >> > >> > > > wrote:
> > >> > > > > > >> >> > >> > > > > >
> > >> > > > > > >> >> > >> > > > > >> Hi,
> > >> > > > > > >> >> > >> > > > > >>
> > >> > > > > > >> >> > >> > > > > >> An option that is not currently
> covered
> > in
> > >> > the
> > >> > > > KIP
> > >> > > > > is
> > >> > > > > > >> to
> > >> > > > > > >> >> > have a
> > >> > > > > > >> >> > >> > > > separate
> > >> > > > > > >> >> > >> > > > > >> config max.block.ms, which is similar
> > to
> > >> the
> > >> > > > > > producer
> > >> > > > > > >> >> config
> > >> > > > > > >> >> > >> with
> > >> > > > > > >> >> > >> > > the
> > >> > > > > > >> >> > >> > > > > >> same
> > >> > > > > > >> >> > >> > > > > >> name. This came up during the
> KAFKA-2391
> > >> > > > > discussion.
> > >> > > > > > I
> > >> > > > > > >> >> think
> > >> > > > > > >> >> > >> it's
> > >> > > > > > >> >> > >> > > > clear
> > >> > > > > > >> >> > >> > > > > >> that we can't rely on
> > request.timeout.ms,
> > >> so
> > >> > > the
> > >> > > > > > >> >> decision is
> > >> > > > > > >> >> > >> > > between
> > >> > > > > > >> >> > >> > > > > >> adding
> > >> > > > > > >> >> > >> > > > > >> overloads or adding a new config.
> People
> > >> > seemed
> > >> > > > to
> > >> > > > > be
> > >> > > > > > >> >> leaning
> > >> > > > > > >> >> > >> > > towards
> > >> > > > > > >> >> > >> > > > > the
> > >> > > > > > >> >> > >> > > > > >> latter in KAFKA-2391, but Jason makes
> a
> > >> good
> > >> > > > point
> > >> > > > > > that
> > >> > > > > > >> >> the
> > >> > > > > > >> >> > >> > > overloads
> > >> > > > > > >> >> > >> > > > > are
> > >> > > > > > >> >> > >> > > > > >> more flexible. A couple of questions
> > from
> > >> me:
> > >> > > > > > >> >> > >> > > > > >>
> > >> > > > > > >> >> > >> > > > > >> 1. Do we need the additional
> > flexibility?
> > >> > > > > > >> >> > >> > > > > >> 2. If we do, do we need it for every
> > >> blocking
> > >> > > > > method?
> > >> > > > > > >> >> > >> > > > > >>
> > >> > > > > > >> >> > >> > > > > >> Ismael
> > >> > > > > > >> >> > >> > > > > >>
> > >> > > > > > >> >> > >> > > > > >> On Mon, Mar 19, 2018 at 5:03 PM,
> Richard
> > >> Yu <
> > >> > > > > > >> >> > >> > > > yohan.richard.yu@gmail.com
> > >> > > > > > >> >> > >> > > > > >
> > >> > > > > > >> >> > >> > > > > >> wrote:
> > >> > > > > > >> >> > >> > > > > >>
> > >> > > > > > >> >> > >> > > > > >> > Hi Guozhang,
> > >> > > > > > >> >> > >> > > > > >> >
> > >> > > > > > >> >> > >> > > > > >> > I made some clarifications to
> KIP-266,
> > >> > > namely:
> > >> > > > > > >> >> > >> > > > > >> > 1. Stated more specifically that
> > >> commitSync
> > >> > > > will
> > >> > > > > > >> accept
> > >> > > > > > >> >> > user
> > >> > > > > > >> >> > >> > > input.
> > >> > > > > > >> >> > >> > > > > >> > 2. fetchCommittedOffsets(): Made its
> > >> role
> > >> > in
> > >> > > > > > blocking
> > >> > > > > > >> >> more
> > >> > > > > > >> >> > >> clear
> > >> > > > > > >> >> > >> > > to
> > >> > > > > > >> >> > >> > > > > the
> > >> > > > > > >> >> > >> > > > > >> > reader.
> > >> > > > > > >> >> > >> > > > > >> > 3. Sketched what would happen when
> > time
> > >> > limit
> > >> > > > is
> > >> > > > > > >> >> exceeded.
> > >> > > > > > >> >> > >> > > > > >> >
> > >> > > > > > >> >> > >> > > > > >> > These changes should make the KIP
> > >> easier to
> > >> > > > > > >> understand.
> > >> > > > > > >> >> > >> > > > > >> >
> > >> > > > > > >> >> > >> > > > > >> > Cheers,
> > >> > > > > > >> >> > >> > > > > >> > Richard
> > >> > > > > > >> >> > >> > > > > >> >
> > >> > > > > > >> >> > >> > > > > >> > On Mon, Mar 19, 2018 at 9:33 AM,
> > >> Guozhang
> > >> > > Wang
> > >> > > > <
> > >> > > > > > >> >> > >> > > wangguoz@gmail.com>
> > >> > > > > > >> >> > >> > > > > >> wrote:
> > >> > > > > > >> >> > >> > > > > >> >
> > >> > > > > > >> >> > >> > > > > >> > > Hi Richard,
> > >> > > > > > >> >> > >> > > > > >> > >
> > >> > > > > > >> >> > >> > > > > >> > > I made a pass over the KIP again,
> > some
> > >> > more
> > >> > > > > > >> >> > clarifications
> > >> > > > > > >> >> > >> /
> > >> > > > > > >> >> > >> > > > > comments:
> > >> > > > > > >> >> > >> > > > > >> > >
> > >> > > > > > >> >> > >> > > > > >> > > 1. seek() call itself is not
> > blocking,
> > >> > only
> > >> > > > the
> > >> > > > > > >> >> following
> > >> > > > > > >> >> > >> > poll()
> > >> > > > > > >> >> > >> > > > > call
> > >> > > > > > >> >> > >> > > > > >> may
> > >> > > > > > >> >> > >> > > > > >> > > be blocking as the actually
> metadata
> > >> rq
> > >> > > will
> > >> > > > > > >> happen.
> > >> > > > > > >> >> > >> > > > > >> > >
> > >> > > > > > >> >> > >> > > > > >> > > 2. I saw you did not include
> > >> > > > > > >> Consumer.partitionFor(),
> > >> > > > > > >> >> > >> > > > > >> > > Consumer.OffsetAndTimestamp() and
> > >> > > > > > >> >> Consumer.listTopics()
> > >> > > > > > >> >> > in
> > >> > > > > > >> >> > >> > your
> > >> > > > > > >> >> > >> > > > KIP.
> > >> > > > > > >> >> > >> > > > > >> > After
> > >> > > > > > >> >> > >> > > > > >> > > a second thought, I think this may
> > be
> > >> a
> > >> > > > better
> > >> > > > > > >> idea to
> > >> > > > > > >> >> > not
> > >> > > > > > >> >> > >> > > tackle
> > >> > > > > > >> >> > >> > > > > >> them in
> > >> > > > > > >> >> > >> > > > > >> > > the same KIP, and probably we
> should
> > >> > > consider
> > >> > > > > > >> whether
> > >> > > > > > >> >> we
> > >> > > > > > >> >> > >> would
> > >> > > > > > >> >> > >> > > > > change
> > >> > > > > > >> >> > >> > > > > >> the
> > >> > > > > > >> >> > >> > > > > >> > > behavior or not in another
> > discussion.
> > >> > So I
> > >> > > > > agree
> > >> > > > > > >> to
> > >> > > > > > >> >> not
> > >> > > > > > >> >> > >> > include
> > >> > > > > > >> >> > >> > > > > them.
> > >> > > > > > >> >> > >> > > > > >> > >
> > >> > > > > > >> >> > >> > > > > >> > > 3. In your wiki you mentioned
> > "Another
> > >> > > change
> > >> > > > > > >> shall be
> > >> > > > > > >> >> > >> made to
> > >> > > > > > >> >> > >> > > > > >> > > KafkaConsumer#poll(), due to its
> > call
> > >> to
> > >> > > > > > >> >> > >> > updateFetchPositions()
> > >> > > > > > >> >> > >> > > > > which
> > >> > > > > > >> >> > >> > > > > >> > > blocks indefinitely." This part
> may
> > a
> > >> bit
> > >> > > > > obscure
> > >> > > > > > >> to
> > >> > > > > > >> >> most
> > >> > > > > > >> >> > >> > > readers
> > >> > > > > > >> >> > >> > > > > >> who's
> > >> > > > > > >> >> > >> > > > > >> > not
> > >> > > > > > >> >> > >> > > > > >> > > familiar with the KafkaConsumer
> > >> > internals,
> > >> > > > > could
> > >> > > > > > >> you
> > >> > > > > > >> >> > please
> > >> > > > > > >> >> > >> > add
> > >> > > > > > >> >> > >> > > > more
> > >> > > > > > >> >> > >> > > > > >> > > elaborations. More specifically, I
> > >> think
> > >> > > the
> > >> > > > > root
> > >> > > > > > >> >> causes
> > >> > > > > > >> >> > of
> > >> > > > > > >> >> > >> > the
> > >> > > > > > >> >> > >> > > > > public
> > >> > > > > > >> >> > >> > > > > >> > APIs
> > >> > > > > > >> >> > >> > > > > >> > > mentioned are a bit different
> while
> > >> the
> > >> > > KIP's
> > >> > > > > > >> >> explanation
> > >> > > > > > >> >> > >> > sounds
> > >> > > > > > >> >> > >> > > > > like
> > >> > > > > > >> >> > >> > > > > >> > they
> > >> > > > > > >> >> > >> > > > > >> > > are due to the same reason:
> > >> > > > > > >> >> > >> > > > > >> > >
> > >> > > > > > >> >> > >> > > > > >> > > 3.1 fetchCommittedOffsets(): this
> > >> > internal
> > >> > > > call
> > >> > > > > > >> will
> > >> > > > > > >> >> > block
> > >> > > > > > >> >> > >> > > forever
> > >> > > > > > >> >> > >> > > > > if
> > >> > > > > > >> >> > >> > > > > >> the
> > >> > > > > > >> >> > >> > > > > >> > > committed offsets cannot be
> fetched
> > >> > > > > successfully
> > >> > > > > > >> and
> > >> > > > > > >> >> > affect
> > >> > > > > > >> >> > >> > > > > position()
> > >> > > > > > >> >> > >> > > > > >> > and
> > >> > > > > > >> >> > >> > > > > >> > > committed(). We need to break out
> of
> > >> its
> > >> > > > > internal
> > >> > > > > > >> >> while
> > >> > > > > > >> >> > >> loop.
> > >> > > > > > >> >> > >> > > > > >> > > 3.2 position() itself will while
> > loop
> > >> > when
> > >> > > > > > offsets
> > >> > > > > > >> >> cannot
> > >> > > > > > >> >> > >> be
> > >> > > > > > >> >> > >> > > > > >> retrieved in
> > >> > > > > > >> >> > >> > > > > >> > > the underlying async call. We need
> > to
> > >> > break
> > >> > > > out
> > >> > > > > > >> this
> > >> > > > > > >> >> > while
> > >> > > > > > >> >> > >> > loop.
> > >> > > > > > >> >> > >> > > > > >> > > 3.3 commitSync() passed
> > >> Long.MAX_VALUE as
> > >> > > the
> > >> > > > > > >> timeout
> > >> > > > > > >> >> > >> value,
> > >> > > > > > >> >> > >> > we
> > >> > > > > > >> >> > >> > > > > should
> > >> > > > > > >> >> > >> > > > > >> > take
> > >> > > > > > >> >> > >> > > > > >> > > the user specified timeouts when
> > >> > > applicable.
> > >> > > > > > >> >> > >> > > > > >> > >
> > >> > > > > > >> >> > >> > > > > >> > >
> > >> > > > > > >> >> > >> > > > > >> > >
> > >> > > > > > >> >> > >> > > > > >> > > Guozhang
> > >> > > > > > >> >> > >> > > > > >> > >
> > >> > > > > > >> >> > >> > > > > >> > > On Sat, Mar 17, 2018 at 4:44 PM,
> > >> Richard
> > >> > > Yu <
> > >> > > > > > >> >> > >> > > > > >> yohan.richard.yu@gmail.com>
> > >> > > > > > >> >> > >> > > > > >> > > wrote:
> > >> > > > > > >> >> > >> > > > > >> > >
> > >> > > > > > >> >> > >> > > > > >> > > > Actually, what I said above is
> > >> > > inaccurate.
> > >> > > > In
> > >> > > > > > >> >> > >> > > > > >> > > > testSeekAndCommitWithBrokerFai
> > >> lures,
> > >> > > > > > >> >> > >> > TestUtils.waitUntilTrue
> > >> > > > > > >> >> > >> > > > > >> blocks,
> > >> > > > > > >> >> > >> > > > > >> > not
> > >> > > > > > >> >> > >> > > > > >> > > > seek.
> > >> > > > > > >> >> > >> > > > > >> > > > My assumption is that seek did
> not
> > >> > update
> > >> > > > > > >> >> correctly. I
> > >> > > > > > >> >> > >> will
> > >> > > > > > >> >> > >> > be
> > >> > > > > > >> >> > >> > > > > >> digging
> > >> > > > > > >> >> > >> > > > > >> > > > further into this.
> > >> > > > > > >> >> > >> > > > > >> > > >
> > >> > > > > > >> >> > >> > > > > >> > > >
> > >> > > > > > >> >> > >> > > > > >> > > >
> > >> > > > > > >> >> > >> > > > > >> > > > On Sat, Mar 17, 2018 at 4:16 PM,
> > >> > Richard
> > >> > > > Yu <
> > >> > > > > > >> >> > >> > > > > >> > yohan.richard.yu@gmail.com>
> > >> > > > > > >> >> > >> > > > > >> > > > wrote:
> > >> > > > > > >> >> > >> > > > > >> > > >
> > >> > > > > > >> >> > >> > > > > >> > > > > One more thing: when looking
> > >> through
> > >> > > > > tests, I
> > >> > > > > > >> have
> > >> > > > > > >> >> > >> > realized
> > >> > > > > > >> >> > >> > > > that
> > >> > > > > > >> >> > >> > > > > >> > seek()
> > >> > > > > > >> >> > >> > > > > >> > > > > methods can potentially block
> > >> > > > indefinitely.
> > >> > > > > > As
> > >> > > > > > >> you
> > >> > > > > > >> >> > well
> > >> > > > > > >> >> > >> > > know,
> > >> > > > > > >> >> > >> > > > > >> seek()
> > >> > > > > > >> >> > >> > > > > >> > is
> > >> > > > > > >> >> > >> > > > > >> > > > > called when pollOnce() or
> > >> position()
> > >> > is
> > >> > > > > > active.
> > >> > > > > > >> >> Thus,
> > >> > > > > > >> >> > >> if
> > >> > > > > > >> >> > >> > > > > >> position()
> > >> > > > > > >> >> > >> > > > > >> > > > blocks
> > >> > > > > > >> >> > >> > > > > >> > > > > indefinitely, then so would
> > >> seek().
> > >> > > > Should
> > >> > > > > > >> >> bounding
> > >> > > > > > >> >> > >> seek()
> > >> > > > > > >> >> > >> > > > also
> > >> > > > > > >> >> > >> > > > > be
> > >> > > > > > >> >> > >> > > > > >> > > > included
> > >> > > > > > >> >> > >> > > > > >> > > > > in this KIP?
> > >> > > > > > >> >> > >> > > > > >> > > > >
> > >> > > > > > >> >> > >> > > > > >> > > > > Thanks, Richard
> > >> > > > > > >> >> > >> > > > > >> > > > >
> > >> > > > > > >> >> > >> > > > > >> > > > > On Sat, Mar 17, 2018 at 1:16
> PM,
> > >> > > Richard
> > >> > > > > Yu <
> > >> > > > > > >> >> > >> > > > > >> > > yohan.richard.yu@gmail.com>
> > >> > > > > > >> >> > >> > > > > >> > > > > wrote:
> > >> > > > > > >> >> > >> > > > > >> > > > >
> > >> > > > > > >> >> > >> > > > > >> > > > >> Thanks for the advice, Jason
> > >> > > > > > >> >> > >> > > > > >> > > > >>
> > >> > > > > > >> >> > >> > > > > >> > > > >> I have modified KIP-266 to
> > >> include
> > >> > the
> > >> > > > > java
> > >> > > > > > >> doc
> > >> > > > > > >> >> for
> > >> > > > > > >> >> > >> > > > committed()
> > >> > > > > > >> >> > >> > > > > >> and
> > >> > > > > > >> >> > >> > > > > >> > > > other
> > >> > > > > > >> >> > >> > > > > >> > > > >> blocking methods, and I also
> > >> > > > > > >> >> > >> > > > > >> > > > >> mentioned poll() which will
> > also
> > >> be
> > >> > > > > bounded.
> > >> > > > > > >> Let
> > >> > > > > > >> >> me
> > >> > > > > > >> >> > >> know
> > >> > > > > > >> >> > >> > if
> > >> > > > > > >> >> > >> > > > > >> there is
> > >> > > > > > >> >> > >> > > > > >> > > > >> anything else. :)
> > >> > > > > > >> >> > >> > > > > >> > > > >>
> > >> > > > > > >> >> > >> > > > > >> > > > >> Sincerely, Richard
> > >> > > > > > >> >> > >> > > > > >> > > > >>
> > >> > > > > > >> >> > >> > > > > >> > > > >>
> > >> > > > > > >> >> > >> > > > > >> > > > >>
> > >> > > > > > >> >> > >> > > > > >> > > > >>
> > >> > > > > > >> >> > >> > > > > >> > > > >>
> > >> > > > > > >> >> > >> > > > > >> > > > >> On Sat, Mar 17, 2018 at 12:00
> > PM,
> > >> > > Jason
> > >> > > > > > >> >> Gustafson <
> > >> > > > > > >> >> > >> > > > > >> > jason@confluent.io
> > >> > > > > > >> >> > >> > > > > >> > > >
> > >> > > > > > >> >> > >> > > > > >> > > > >> wrote:
> > >> > > > > > >> >> > >> > > > > >> > > > >>
> > >> > > > > > >> >> > >> > > > > >> > > > >>> Hi Richard,
> > >> > > > > > >> >> > >> > > > > >> > > > >>>
> > >> > > > > > >> >> > >> > > > > >> > > > >>> Thanks for the updates. I'm
> > >> really
> > >> > > glad
> > >> > > > > you
> > >> > > > > > >> >> picked
> > >> > > > > > >> >> > >> this
> > >> > > > > > >> >> > >> > > up.
> > >> > > > > > >> >> > >> > > > A
> > >> > > > > > >> >> > >> > > > > >> > couple
> > >> > > > > > >> >> > >> > > > > >> > > > >>> minor
> > >> > > > > > >> >> > >> > > > > >> > > > >>> comments:
> > >> > > > > > >> >> > >> > > > > >> > > > >>>
> > >> > > > > > >> >> > >> > > > > >> > > > >>> 1. Can you list the full set
> > of
> > >> new
> > >> > > > APIs
> > >> > > > > > >> >> explicitly
> > >> > > > > > >> >> > >> in
> > >> > > > > > >> >> > >> > the
> > >> > > > > > >> >> > >> > > > > KIP?
> > >> > > > > > >> >> > >> > > > > >> > > > >>> Currently I
> > >> > > > > > >> >> > >> > > > > >> > > > >>> only see the javadoc for
> > >> > > `position()`.
> > >> > > > > > >> >> > >> > > > > >> > > > >>>
> > >> > > > > > >> >> > >> > > > > >> > > > >>> 2. We should consider adding
> > >> > > `TimeUnit`
> > >> > > > > to
> > >> > > > > > >> the
> > >> > > > > > >> >> new
> > >> > > > > > >> >> > >> > methods
> > >> > > > > > >> >> > >> > > > to
> > >> > > > > > >> >> > >> > > > > >> avoid
> > >> > > > > > >> >> > >> > > > > >> > > > unit
> > >> > > > > > >> >> > >> > > > > >> > > > >>> confusion. I know it's
> > >> inconsistent
> > >> > > > with
> > >> > > > > > the
> > >> > > > > > >> >> poll()
> > >> > > > > > >> >> > >> API,
> > >> > > > > > >> >> > >> > > > but I
> > >> > > > > > >> >> > >> > > > > >> > think
> > >> > > > > > >> >> > >> > > > > >> > > it
> > >> > > > > > >> >> > >> > > > > >> > > > >>> was
> > >> > > > > > >> >> > >> > > > > >> > > > >>> probably a mistake not to
> > >> include
> > >> > it
> > >> > > > > there,
> > >> > > > > > >> so
> > >> > > > > > >> >> > better
> > >> > > > > > >> >> > >> > not
> > >> > > > > > >> >> > >> > > to
> > >> > > > > > >> >> > >> > > > > >> double
> > >> > > > > > >> >> > >> > > > > >> > > > down
> > >> > > > > > >> >> > >> > > > > >> > > > >>> on
> > >> > > > > > >> >> > >> > > > > >> > > > >>> that mistake. And note that
> we
> > >> do
> > >> > > > already
> > >> > > > > > >> have
> > >> > > > > > >> >> > >> > > `close(long,
> > >> > > > > > >> >> > >> > > > > >> > > TimeUnit)`.
> > >> > > > > > >> >> > >> > > > > >> > > > >>>
> > >> > > > > > >> >> > >> > > > > >> > > > >>> Other than that, I think the
> > >> > current
> > >> > > > KIP
> > >> > > > > > >> seems
> > >> > > > > > >> >> > >> > reasonable.
> > >> > > > > > >> >> > >> > > > > >> > > > >>>
> > >> > > > > > >> >> > >> > > > > >> > > > >>> Thanks,
> > >> > > > > > >> >> > >> > > > > >> > > > >>> Jason
> > >> > > > > > >> >> > >> > > > > >> > > > >>>
> > >> > > > > > >> >> > >> > > > > >> > > > >>> On Wed, Mar 14, 2018 at 5:00
> > PM,
> > >> > > > Richard
> > >> > > > > > Yu <
> > >> > > > > > >> >> > >> > > > > >> > > > yohan.richard.yu@gmail.com>
> > >> > > > > > >> >> > >> > > > > >> > > > >>> wrote:
> > >> > > > > > >> >> > >> > > > > >> > > > >>>
> > >> > > > > > >> >> > >> > > > > >> > > > >>> > Note to all: I have
> included
> > >> > > bounding
> > >> > > > > > >> >> > commitSync()
> > >> > > > > > >> >> > >> and
> > >> > > > > > >> >> > >> > > > > >> > committed()
> > >> > > > > > >> >> > >> > > > > >> > > in
> > >> > > > > > >> >> > >> > > > > >> > > > >>> this
> > >> > > > > > >> >> > >> > > > > >> > > > >>> > KIP.
> > >> > > > > > >> >> > >> > > > > >> > > > >>> >
> > >> > > > > > >> >> > >> > > > > >> > > > >>> > On Sun, Mar 11, 2018 at
> 5:05
> > >> PM,
> > >> > > > > Richard
> > >> > > > > > >> Yu <
> > >> > > > > > >> >> > >> > > > > >> > > > >>> yohan.richard.yu@gmail.com>
> > >> > > > > > >> >> > >> > > > > >> > > > >>> > wrote:
> > >> > > > > > >> >> > >> > > > > >> > > > >>> >
> > >> > > > > > >> >> > >> > > > > >> > > > >>> > > Hi all,
> > >> > > > > > >> >> > >> > > > > >> > > > >>> > >
> > >> > > > > > >> >> > >> > > > > >> > > > >>> > > I updated the KIP where
> > >> > > overloading
> > >> > > > > > >> >> position()
> > >> > > > > > >> >> > is
> > >> > > > > > >> >> > >> > now
> > >> > > > > > >> >> > >> > > > the
> > >> > > > > > >> >> > >> > > > > >> > favored
> > >> > > > > > >> >> > >> > > > > >> > > > >>> > approach.
> > >> > > > > > >> >> > >> > > > > >> > > > >>> > > Bounding position()
> using
> > >> > > > > > >> requestTimeoutMs
> > >> > > > > > >> >> has
> > >> > > > > > >> >> > >> been
> > >> > > > > > >> >> > >> > > > listed
> > >> > > > > > >> >> > >> > > > > >> as
> > >> > > > > > >> >> > >> > > > > >> > > > >>> rejected.
> > >> > > > > > >> >> > >> > > > > >> > > > >>> > >
> > >> > > > > > >> >> > >> > > > > >> > > > >>> > > Any thoughts?
> > >> > > > > > >> >> > >> > > > > >> > > > >>> > >
> > >> > > > > > >> >> > >> > > > > >> > > > >>> > > On Tue, Mar 6, 2018 at
> > 6:00
> > >> PM,
> > >> > > > > > Guozhang
> > >> > > > > > >> >> Wang <
> > >> > > > > > >> >> > >> > > > > >> > > wangguoz@gmail.com>
> > >> > > > > > >> >> > >> > > > > >> > > > >>> > wrote:
> > >> > > > > > >> >> > >> > > > > >> > > > >>> > >
> > >> > > > > > >> >> > >> > > > > >> > > > >>> > >> I agree that adding the
> > >> > > overloads
> > >> > > > is
> > >> > > > > > >> most
> > >> > > > > > >> >> > >> flexible.
> > >> > > > > > >> >> > >> > > But
> > >> > > > > > >> >> > >> > > > > >> going
> > >> > > > > > >> >> > >> > > > > >> > > for
> > >> > > > > > >> >> > >> > > > > >> > > > >>> that
> > >> > > > > > >> >> > >> > > > > >> > > > >>> > >> direction we'd do that
> > for
> > >> all
> > >> > > the
> > >> > > > > > >> blocking
> > >> > > > > > >> >> > call
> > >> > > > > > >> >> > >> > that
> > >> > > > > > >> >> > >> > > > > I've
> > >> > > > > > >> >> > >> > > > > >> > > listed
> > >> > > > > > >> >> > >> > > > > >> > > > >>> above,
> > >> > > > > > >> >> > >> > > > > >> > > > >>> > >> with this timeout value
> > >> > covering
> > >> > > > the
> > >> > > > > > >> >> > end-to-end
> > >> > > > > > >> >> > >> > > waiting
> > >> > > > > > >> >> > >> > > > > >> time.
> > >> > > > > > >> >> > >> > > > > >> > > > >>> > >>
> > >> > > > > > >> >> > >> > > > > >> > > > >>> > >>
> > >> > > > > > >> >> > >> > > > > >> > > > >>> > >> Guozhang
> > >> > > > > > >> >> > >> > > > > >> > > > >>> > >>
> > >> > > > > > >> >> > >> > > > > >> > > > >>> > >> On Tue, Mar 6, 2018 at
> > >> 10:02
> > >> > AM,
> > >> > > > Ted
> > >> > > > > > Yu
> > >> > > > > > >> <
> > >> > > > > > >> >> > >> > > > > >> yuzhihong@gmail.com>
> > >> > > > > > >> >> > >> > > > > >> > > > >>> wrote:
> > >> > > > > > >> >> > >> > > > > >> > > > >>> > >>
> > >> > > > > > >> >> > >> > > > > >> > > > >>> > >> > bq. The most flexible
> > >> option
> > >> > > is
> > >> > > > to
> > >> > > > > > add
> > >> > > > > > >> >> > >> overloads
> > >> > > > > > >> >> > >> > to
> > >> > > > > > >> >> > >> > > > the
> > >> > > > > > >> >> > >> > > > > >> > > consumer
> > >> > > > > > >> >> > >> > > > > >> > > > >>> > >> >
> > >> > > > > > >> >> > >> > > > > >> > > > >>> > >> > This option is
> > flexible.
> > >> > > > > > >> >> > >> > > > > >> > > > >>> > >> >
> > >> > > > > > >> >> > >> > > > > >> > > > >>> > >> > Looking at the tail
> of
> > >> > > > > SPARK-18057,
> > >> > > > > > >> Spark
> > >> > > > > > >> >> > dev
> > >> > > > > > >> >> > >> > > voiced
> > >> > > > > > >> >> > >> > > > > the
> > >> > > > > > >> >> > >> > > > > >> > same
> > >> > > > > > >> >> > >> > > > > >> > > > >>> choice.
> > >> > > > > > >> >> > >> > > > > >> > > > >>> > >> >
> > >> > > > > > >> >> > >> > > > > >> > > > >>> > >> > +1 for adding
> overload
> > >> with
> > >> > > > > timeout
> > >> > > > > > >> >> > parameter.
> > >> > > > > > >> >> > >> > > > > >> > > > >>> > >> >
> > >> > > > > > >> >> > >> > > > > >> > > > >>> > >> > Cheers
> > >> > > > > > >> >> > >> > > > > >> > > > >>> > >> >
> > >> > > > > > >> >> > >> > > > > >> > > > >>> > >> > On Mon, Mar 5, 2018
> at
> > >> 2:42
> > >> > > PM,
> > >> > > > > > Jason
> > >> > > > > > >> >> > >> Gustafson <
> > >> > > > > > >> >> > >> > > > > >> > > > >>> jason@confluent.io>
> > >> > > > > > >> >> > >> > > > > >> > > > >>> > >> > wrote:
> > >> > > > > > >> >> > >> > > > > >> > > > >>> > >> >
> > >> > > > > > >> >> > >> > > > > >> > > > >>> > >> > > @Guozhang I
> probably
> > >> have
> > >> > > > > > suggested
> > >> > > > > > >> all
> > >> > > > > > >> >> > >> options
> > >> > > > > > >> >> > >> > > at
> > >> > > > > > >> >> > >> > > > > some
> > >> > > > > > >> >> > >> > > > > >> > > point
> > >> > > > > > >> >> > >> > > > > >> > > > or
> > >> > > > > > >> >> > >> > > > > >> > > > >>> > >> another,
> > >> > > > > > >> >> > >> > > > > >> > > > >>> > >> > > including most
> > >> recently,
> > >> > the
> > >> > > > > > current
> > >> > > > > > >> >> KIP!
> > >> > > > > > >> >> > I
> > >> > > > > > >> >> > >> was
> > >> > > > > > >> >> > >> > > > > >> thinking
> > >> > > > > > >> >> > >> > > > > >> > > that
> > >> > > > > > >> >> > >> > > > > >> > > > >>> > >> practically
> > >> > > > > > >> >> > >> > > > > >> > > > >>> > >> > > speaking, the
> request
> > >> > > timeout
> > >> > > > > > >> defines
> > >> > > > > > >> >> how
> > >> > > > > > >> >> > >> long
> > >> > > > > > >> >> > >> > > the
> > >> > > > > > >> >> > >> > > > > >> user is
> > >> > > > > > >> >> > >> > > > > >> > > > >>> willing
> > >> > > > > > >> >> > >> > > > > >> > > > >>> > to
> > >> > > > > > >> >> > >> > > > > >> > > > >>> > >> > wait
> > >> > > > > > >> >> > >> > > > > >> > > > >>> > >> > > for a response. The
> > >> > consumer
> > >> > > > > > doesn't
> > >> > > > > > >> >> > really
> > >> > > > > > >> >> > >> > have
> > >> > > > > > >> >> > >> > > a
> > >> > > > > > >> >> > >> > > > > >> complex
> > >> > > > > > >> >> > >> > > > > >> > > > send
> > >> > > > > > >> >> > >> > > > > >> > > > >>> > >> process
> > >> > > > > > >> >> > >> > > > > >> > > > >>> > >> > > like the producer
> for
> > >> any
> > >> > of
> > >> > > > > these
> > >> > > > > > >> >> APIs,
> > >> > > > > > >> >> > so
> > >> > > > > > >> >> > >> I
> > >> > > > > > >> >> > >> > > > wasn't
> > >> > > > > > >> >> > >> > > > > >> sure
> > >> > > > > > >> >> > >> > > > > >> > > how
> > >> > > > > > >> >> > >> > > > > >> > > > >>> much
> > >> > > > > > >> >> > >> > > > > >> > > > >>> > >> > benefit
> > >> > > > > > >> >> > >> > > > > >> > > > >>> > >> > > there would be from
> > >> having
> > >> > > > more
> > >> > > > > > >> >> granular
> > >> > > > > > >> >> > >> > control
> > >> > > > > > >> >> > >> > > > over
> > >> > > > > > >> >> > >> > > > > >> > > timeouts
> > >> > > > > > >> >> > >> > > > > >> > > > >>> (in
> > >> > > > > > >> >> > >> > > > > >> > > > >>> > the
> > >> > > > > > >> >> > >> > > > > >> > > > >>> > >> > end,
> > >> > > > > > >> >> > >> > > > > >> > > > >>> > >> > > KIP-91 just adds a
> > >> single
> > >> > > > > timeout
> > >> > > > > > to
> > >> > > > > > >> >> > control
> > >> > > > > > >> >> > >> > the
> > >> > > > > > >> >> > >> > > > > whole
> > >> > > > > > >> >> > >> > > > > >> > > send).
> > >> > > > > > >> >> > >> > > > > >> > > > >>> That
> > >> > > > > > >> >> > >> > > > > >> > > > >>> > >> said,
> > >> > > > > > >> >> > >> > > > > >> > > > >>> > >> > it
> > >> > > > > > >> >> > >> > > > > >> > > > >>> > >> > > might indeed be
> > better
> > >> to
> > >> > > > avoid
> > >> > > > > > >> >> > overloading
> > >> > > > > > >> >> > >> the
> > >> > > > > > >> >> > >> > > > > config
> > >> > > > > > >> >> > >> > > > > >> as
> > >> > > > > > >> >> > >> > > > > >> > > you
> > >> > > > > > >> >> > >> > > > > >> > > > >>> > suggest
> > >> > > > > > >> >> > >> > > > > >> > > > >>> > >> > since
> > >> > > > > > >> >> > >> > > > > >> > > > >>> > >> > > at least it avoids
> > >> > > > inconsistency
> > >> > > > > > >> with
> > >> > > > > > >> >> the
> > >> > > > > > >> >> > >> > > > producer's
> > >> > > > > > >> >> > >> > > > > >> > usage.
> > >> > > > > > >> >> > >> > > > > >> > > > >>> > >> > >
> > >> > > > > > >> >> > >> > > > > >> > > > >>> > >> > > The most flexible
> > >> option
> > >> > is
> > >> > > to
> > >> > > > > add
> > >> > > > > > >> >> > >> overloads to
> > >> > > > > > >> >> > >> > > the
> > >> > > > > > >> >> > >> > > > > >> > consumer
> > >> > > > > > >> >> > >> > > > > >> > > > so
> > >> > > > > > >> >> > >> > > > > >> > > > >>> that
> > >> > > > > > >> >> > >> > > > > >> > > > >>> > >> > users
> > >> > > > > > >> >> > >> > > > > >> > > > >>> > >> > > can pass the
> timeout
> > >> > > directly.
> > >> > > > > I'm
> > >> > > > > > >> not
> > >> > > > > > >> >> > sure
> > >> > > > > > >> >> > >> if
> > >> > > > > > >> >> > >> > > that
> > >> > > > > > >> >> > >> > > > > is
> > >> > > > > > >> >> > >> > > > > >> > more
> > >> > > > > > >> >> > >> > > > > >> > > or
> > >> > > > > > >> >> > >> > > > > >> > > > >>> less
> > >> > > > > > >> >> > >> > > > > >> > > > >>> > >> > > annoying than a new
> > >> > config,
> > >> > > > but
> > >> > > > > > I've
> > >> > > > > > >> >> found
> > >> > > > > > >> >> > >> > config
> > >> > > > > > >> >> > >> > > > > >> > timeouts a
> > >> > > > > > >> >> > >> > > > > >> > > > >>> little
> > >> > > > > > >> >> > >> > > > > >> > > > >>> > >> > > constraining in
> > >> practice.
> > >> > > For
> > >> > > > > > >> example,
> > >> > > > > > >> >> I
> > >> > > > > > >> >> > >> could
> > >> > > > > > >> >> > >> > > > > imagine
> > >> > > > > > >> >> > >> > > > > >> > users
> > >> > > > > > >> >> > >> > > > > >> > > > >>> wanting
> > >> > > > > > >> >> > >> > > > > >> > > > >>> > >> to
> > >> > > > > > >> >> > >> > > > > >> > > > >>> > >> > > wait longer for an
> > >> offset
> > >> > > > commit
> > >> > > > > > >> >> operation
> > >> > > > > > >> >> > >> > than a
> > >> > > > > > >> >> > >> > > > > >> position
> > >> > > > > > >> >> > >> > > > > >> > > > >>> lookup;
> > >> > > > > > >> >> > >> > > > > >> > > > >>> > if
> > >> > > > > > >> >> > >> > > > > >> > > > >>> > >> the
> > >> > > > > > >> >> > >> > > > > >> > > > >>> > >> > > latter isn't
> timely,
> > >> users
> > >> > > can
> > >> > > > > > just
> > >> > > > > > >> >> pause
> > >> > > > > > >> >> > >> the
> > >> > > > > > >> >> > >> > > > > partition
> > >> > > > > > >> >> > >> > > > > >> > and
> > >> > > > > > >> >> > >> > > > > >> > > > >>> continue
> > >> > > > > > >> >> > >> > > > > >> > > > >>> > >> > > fetching on others.
> > If
> > >> you
> > >> > > > > cannot
> > >> > > > > > >> >> commit
> > >> > > > > > >> >> > >> > offsets,
> > >> > > > > > >> >> > >> > > > > >> however,
> > >> > > > > > >> >> > >> > > > > >> > > it
> > >> > > > > > >> >> > >> > > > > >> > > > >>> might
> > >> > > > > > >> >> > >> > > > > >> > > > >>> > be
> > >> > > > > > >> >> > >> > > > > >> > > > >>> > >> > > safer for an
> > >> application
> > >> > to
> > >> > > > wait
> > >> > > > > > >> >> > >> availability
> > >> > > > > > >> >> > >> > of
> > >> > > > > > >> >> > >> > > > the
> > >> > > > > > >> >> > >> > > > > >> > > > coordinator
> > >> > > > > > >> >> > >> > > > > >> > > > >>> > than
> > >> > > > > > >> >> > >> > > > > >> > > > >>> > >> > > continuing.
> > >> > > > > > >> >> > >> > > > > >> > > > >>> > >> > >
> > >> > > > > > >> >> > >> > > > > >> > > > >>> > >> > > -Jason
> > >> > > > > > >> >> > >> > > > > >> > > > >>> > >> > >
> > >> > > > > > >> >> > >> > > > > >> > > > >>> > >> > > On Sun, Mar 4, 2018
> > at
> > >> > 10:14
> > >> > > > PM,
> > >> > > > > > >> >> Guozhang
> > >> > > > > > >> >> > >> Wang
> > >> > > > > > >> >> > >> > <
> > >> > > > > > >> >> > >> > > > > >> > > > >>> wangguoz@gmail.com>
> > >> > > > > > >> >> > >> > > > > >> > > > >>> > >> > wrote:
> > >> > > > > > >> >> > >> > > > > >> > > > >>> > >> > >
> > >> > > > > > >> >> > >> > > > > >> > > > >>> > >> > > > Hello Richard,
> > >> > > > > > >> >> > >> > > > > >> > > > >>> > >> > > >
> > >> > > > > > >> >> > >> > > > > >> > > > >>> > >> > > > Thanks for the
> > >> proposed
> > >> > > > KIP. I
> > >> > > > > > >> have a
> > >> > > > > > >> >> > >> couple
> > >> > > > > > >> >> > >> > of
> > >> > > > > > >> >> > >> > > > > >> general
> > >> > > > > > >> >> > >> > > > > >> > > > >>> comments:
> > >> > > > > > >> >> > >> > > > > >> > > > >>> > >> > > >
> > >> > > > > > >> >> > >> > > > > >> > > > >>> > >> > > > 1. I'm not sure
> if
> > >> > > > > piggy-backing
> > >> > > > > > >> the
> > >> > > > > > >> >> > >> timeout
> > >> > > > > > >> >> > >> > > > > >> exception
> > >> > > > > > >> >> > >> > > > > >> > on
> > >> > > > > > >> >> > >> > > > > >> > > > the
> > >> > > > > > >> >> > >> > > > > >> > > > >>> > >> > > > existing
> > >> > requestTimeoutMs
> > >> > > > > > >> configured
> > >> > > > > > >> >> in
> > >> > > > > > >> >> > "
> > >> > > > > > >> >> > >> > > > > >> > > request.timeout.ms
> > >> > > > > > >> >> > >> > > > > >> > > > "
> > >> > > > > > >> >> > >> > > > > >> > > > >>> is a
> > >> > > > > > >> >> > >> > > > > >> > > > >>> > >> good
> > >> > > > > > >> >> > >> > > > > >> > > > >>> > >> > > > idea
> > >> > > > > > >> >> > >> > > > > >> > > > >>> > >> > > > since a) it is a
> > >> general
> > >> > > > > config
> > >> > > > > > >> that
> > >> > > > > > >> >> > >> applies
> > >> > > > > > >> >> > >> > > for
> > >> > > > > > >> >> > >> > > > > all
> > >> > > > > > >> >> > >> > > > > >> > types
> > >> > > > > > >> >> > >> > > > > >> > > > of
> > >> > > > > > >> >> > >> > > > > >> > > > >>> > >> requests,
> > >> > > > > > >> >> > >> > > > > >> > > > >>> > >> > > and
> > >> > > > > > >> >> > >> > > > > >> > > > >>> > >> > > > 2) using it to
> > cover
> > >> all
> > >> > > the
> > >> > > > > > >> phases
> > >> > > > > > >> >> of
> > >> > > > > > >> >> > an
> > >> > > > > > >> >> > >> API
> > >> > > > > > >> >> > >> > > > call,
> > >> > > > > > >> >> > >> > > > > >> > > > including
> > >> > > > > > >> >> > >> > > > > >> > > > >>> > >> network
> > >> > > > > > >> >> > >> > > > > >> > > > >>> > >> > > round
> > >> > > > > > >> >> > >> > > > > >> > > > >>> > >> > > > trip and
> potential
> > >> > > metadata
> > >> > > > > > >> refresh
> > >> > > > > > >> >> is
> > >> > > > > > >> >> > >> shown
> > >> > > > > > >> >> > >> > to
> > >> > > > > > >> >> > >> > > > not
> > >> > > > > > >> >> > >> > > > > >> be a
> > >> > > > > > >> >> > >> > > > > >> > > > good
> > >> > > > > > >> >> > >> > > > > >> > > > >>> > idea,
> > >> > > > > > >> >> > >> > > > > >> > > > >>> > >> as
> > >> > > > > > >> >> > >> > > > > >> > > > >>> > >> > > > illustrated in
> > >> KIP-91:
> > >> > > > > > >> >> > >> > > > > >> > > > >>> > >> > > >
> > >> > > > > > >> >> > >> > > > > >> > > > >>> > >> > > >
> > >> > > > > https://cwiki.apache.org/confl
> > >> > > > > > >> >> > >> > > > > >> uence/display/KAFKA/KIP-
> > >> > > > > > >> >> > >> > > > > >> > > > >>> > >> > > >
> > >> > 91+Provide+Intuitive+User+
> > >> > > > > > >> >> > >> > > > Timeouts+in+The+Producer
> > >> > > > > > >> >> > >> > > > > >> > > > >>> > >> > > >
> > >> > > > > > >> >> > >> > > > > >> > > > >>> > >> > > > In fact, I think
> in
> > >> > > > KAFKA-4879
> > >> > > > > > >> which
> > >> > > > > > >> >> is
> > >> > > > > > >> >> > >> aimed
> > >> > > > > > >> >> > >> > > for
> > >> > > > > > >> >> > >> > > > > the
> > >> > > > > > >> >> > >> > > > > >> > same
> > >> > > > > > >> >> > >> > > > > >> > > > >>> issue
> > >> > > > > > >> >> > >> > > > > >> > > > >>> > as
> > >> > > > > > >> >> > >> > > > > >> > > > >>> > >> > > > KAFKA-6608,
> > >> > > > > > >> >> > >> > > > > >> > > > >>> > >> > > > Jason has
> suggested
> > >> we
> > >> > > use a
> > >> > > > > new
> > >> > > > > > >> >> config
> > >> > > > > > >> >> > >> for
> > >> > > > > > >> >> > >> > the
> > >> > > > > > >> >> > >> > > > > API.
> > >> > > > > > >> >> > >> > > > > >> > Maybe
> > >> > > > > > >> >> > >> > > > > >> > > > >>> this
> > >> > > > > > >> >> > >> > > > > >> > > > >>> > >> would
> > >> > > > > > >> >> > >> > > > > >> > > > >>> > >> > be
> > >> > > > > > >> >> > >> > > > > >> > > > >>> > >> > > a
> > >> > > > > > >> >> > >> > > > > >> > > > >>> > >> > > > more intuitive
> > manner
> > >> > than
> > >> > > > > > reusing
> > >> > > > > > >> >> the
> > >> > > > > > >> >> > >> > > > > >> > request.timeout.ms
> > >> > > > > > >> >> > >> > > > > >> > > > >>> config.
> > >> > > > > > >> >> > >> > > > > >> > > > >>> > >> > > >
> > >> > > > > > >> >> > >> > > > > >> > > > >>> > >> > > >
> > >> > > > > > >> >> > >> > > > > >> > > > >>> > >> > > > 2. Besides the
> > >> > > > > > Consumer.position()
> > >> > > > > > >> >> call,
> > >> > > > > > >> >> > >> > there
> > >> > > > > > >> >> > >> > > > are
> > >> > > > > > >> >> > >> > > > > a
> > >> > > > > > >> >> > >> > > > > >> > > couple
> > >> > > > > > >> >> > >> > > > > >> > > > of
> > >> > > > > > >> >> > >> > > > > >> > > > >>> > more
> > >> > > > > > >> >> > >> > > > > >> > > > >>> > >> > > > blocking calls
> > today
> > >> > that
> > >> > > > > could
> > >> > > > > > >> >> result
> > >> > > > > > >> >> > in
> > >> > > > > > >> >> > >> > > > infinite
> > >> > > > > > >> >> > >> > > > > >> > > blocking:
> > >> > > > > > >> >> > >> > > > > >> > > > >>> > >> > > >
> > Consumer.commitSync()
> > >> > and
> > >> > > > > > >> >> > >> > Consumer.committed(),
> > >> > > > > > >> >> > >> > > > > >> should
> > >> > > > > > >> >> > >> > > > > >> > > they
> > >> > > > > > >> >> > >> > > > > >> > > > be
> > >> > > > > > >> >> > >> > > > > >> > > > >>> > >> > considered
> > >> > > > > > >> >> > >> > > > > >> > > > >>> > >> > > > in this KIP as
> > well?
> > >> > > > > > >> >> > >> > > > > >> > > > >>> > >> > > >
> > >> > > > > > >> >> > >> > > > > >> > > > >>> > >> > > > 3. There are a
> few
> > >> other
> > >> > > > APIs
> > >> > > > > > that
> > >> > > > > > >> >> are
> > >> > > > > > >> >> > >> today
> > >> > > > > > >> >> > >> > > > > relying
> > >> > > > > > >> >> > >> > > > > >> on
> > >> > > > > > >> >> > >> > > > > >> > > > >>> > >> > > request.timeout.ms
> > >> > > > > > >> >> > >> > > > > >> > > > >>> > >> > > > already for
> > breaking
> > >> the
> > >> > > > > > infinite
> > >> > > > > > >> >> > >> blocking,
> > >> > > > > > >> >> > >> > > > namely
> > >> > > > > > >> >> > >> > > > > >> > > > >>> > >> > >
> > >> Consumer.partitionFor(),
> > >> > > > > > >> >> > >> > > > > >> > > > >>> > >> > > >
> > >> > > > Consumer.OffsetAndTimestamp()
> > >> > > > > > and
> > >> > > > > > >> >> > >> > > > > >> Consumer.listTopics(),
> > >> > > > > > >> >> > >> > > > > >> > > if
> > >> > > > > > >> >> > >> > > > > >> > > > >>> we are
> > >> > > > > > >> >> > >> > > > > >> > > > >>> > >> > making
> > >> > > > > > >> >> > >> > > > > >> > > > >>> > >> > > > the other
> blocking
> > >> calls
> > >> > > to
> > >> > > > be
> > >> > > > > > >> >> relying a
> > >> > > > > > >> >> > >> new
> > >> > > > > > >> >> > >> > > > config
> > >> > > > > > >> >> > >> > > > > >> as
> > >> > > > > > >> >> > >> > > > > >> > > > >>> suggested
> > >> > > > > > >> >> > >> > > > > >> > > > >>> > in
> > >> > > > > > >> >> > >> > > > > >> > > > >>> > >> 1)
> > >> > > > > > >> >> > >> > > > > >> > > > >>> > >> > > > above, should we
> > also
> > >> > > change
> > >> > > > > the
> > >> > > > > > >> >> > >> semantics of
> > >> > > > > > >> >> > >> > > > these
> > >> > > > > > >> >> > >> > > > > >> API
> > >> > > > > > >> >> > >> > > > > >> > > > >>> functions
> > >> > > > > > >> >> > >> > > > > >> > > > >>> > >> for
> > >> > > > > > >> >> > >> > > > > >> > > > >>> > >> > > > consistency?
> > >> > > > > > >> >> > >> > > > > >> > > > >>> > >> > > >
> > >> > > > > > >> >> > >> > > > > >> > > > >>> > >> > > >
> > >> > > > > > >> >> > >> > > > > >> > > > >>> > >> > > > Guozhang
> > >> > > > > > >> >> > >> > > > > >> > > > >>> > >> > > >
> > >> > > > > > >> >> > >> > > > > >> > > > >>> > >> > > >
> > >> > > > > > >> >> > >> > > > > >> > > > >>> > >> > > >
> > >> > > > > > >> >> > >> > > > > >> > > > >>> > >> > > >
> > >> > > > > > >> >> > >> > > > > >> > > > >>> > >> > > > On Sun, Mar 4,
> 2018
> > >> at
> > >> > > 11:13
> > >> > > > > AM,
> > >> > > > > > >> >> Richard
> > >> > > > > > >> >> > >> Yu <
> > >> > > > > > >> >> > >> > > > > >> > > > >>> > >> >
> > >> yohan.richard.yu@gmail.com>
> > >> > > > > > >> >> > >> > > > > >> > > > >>> > >> > > > wrote:
> > >> > > > > > >> >> > >> > > > > >> > > > >>> > >> > > >
> > >> > > > > > >> >> > >> > > > > >> > > > >>> > >> > > > > Hi all,
> > >> > > > > > >> >> > >> > > > > >> > > > >>> > >> > > > >
> > >> > > > > > >> >> > >> > > > > >> > > > >>> > >> > > > > I would like to
> > >> > discuss
> > >> > > a
> > >> > > > > > >> potential
> > >> > > > > > >> >> > >> change
> > >> > > > > > >> >> > >> > > > which
> > >> > > > > > >> >> > >> > > > > >> would
> > >> > > > > > >> >> > >> > > > > >> > > be
> > >> > > > > > >> >> > >> > > > > >> > > > >>> made
> > >> > > > > > >> >> > >> > > > > >> > > > >>> > to
> > >> > > > > > >> >> > >> > > > > >> > > > >>> > >> > > > > KafkaConsumer:
> > >> > > > > > >> >> > >> > > > > >> > > > >>> > >> > > > >
> > >> > > https://cwiki.apache.org/
> > >> > > > > > >> >> > >> > > > > confluence/pages/viewpage
> > >> > > > > > >> >> > >> > > > > >> .
> > >> > > > > > >> >> > >> > > > > >> > > > >>> > >> > > >
> > >> action?pageId=75974886
> > >> > > > > > >> >> > >> > > > > >> > > > >>> > >> > > > >
> > >> > > > > > >> >> > >> > > > > >> > > > >>> > >> > > > > Thanks,
> > >> > > > > > >> >> > >> > > > > >> > > > >>> > >> > > > > Richard Yu
> > >> > > > > > >> >> > >> > > > > >> > > > >>> > >> > > > >
> > >> > > > > > >> >> > >> > > > > >> > > > >>> > >> > > >
> > >> > > > > > >> >> > >> > > > > >> > > > >>> > >> > > >
> > >> > > > > > >> >> > >> > > > > >> > > > >>> > >> > > >
> > >> > > > > > >> >> > >> > > > > >> > > > >>> > >> > > > --
> > >> > > > > > >> >> > >> > > > > >> > > > >>> > >> > > > -- Guozhang
> > >> > > > > > >> >> > >> > > > > >> > > > >>> > >> > > >
> > >> > > > > > >> >> > >> > > > > >> > > > >>> > >> > >
> > >> > > > > > >> >> > >> > > > > >> > > > >>> > >> >
> > >> > > > > > >> >> > >> > > > > >> > > > >>> > >>
> > >> > > > > > >> >> > >> > > > > >> > > > >>> > >>
> > >> > > > > > >> >> > >> > > > > >> > > > >>> > >>
> > >> > > > > > >> >> > >> > > > > >> > > > >>> > >> --
> > >> > > > > > >> >> > >> > > > > >> > > > >>> > >> -- Guozhang
> > >> > > > > > >> >> > >> > > > > >> > > > >>> > >>
> > >> > > > > > >> >> > >> > > > > >> > > > >>> > >
> > >> > > > > > >> >> > >> > > > > >> > > > >>> > >
> > >> > > > > > >> >> > >> > > > > >> > > > >>> >
> > >> > > > > > >> >> > >> > > > > >> > > > >>>
> > >> > > > > > >> >> > >> > > > > >> > > > >>
> > >> > > > > > >> >> > >> > > > > >> > > > >>
> > >> > > > > > >> >> > >> > > > > >> > > > >
> > >> > > > > > >> >> > >> > > > > >> > > >
> > >> > > > > > >> >> > >> > > > > >> > >
> > >> > > > > > >> >> > >> > > > > >> > >
> > >> > > > > > >> >> > >> > > > > >> > >
> > >> > > > > > >> >> > >> > > > > >> > > --
> > >> > > > > > >> >> > >> > > > > >> > > -- Guozhang
> > >> > > > > > >> >> > >> > > > > >> > >
> > >> > > > > > >> >> > >> > > > > >> >
> > >> > > > > > >> >> > >> > > > > >>
> > >> > > > > > >> >> > >> > > > > >
> > >> > > > > > >> >> > >> > > > > >
> > >> > > > > > >> >> > >> > > > >
> > >> > > > > > >> >> > >> > > >
> > >> > > > > > >> >> > >> > >
> > >> > > > > > >> >> > >> >
> > >> > > > > > >> >> > >> >
> > >> > > > > > >> >> > >> >
> > >> > > > > > >> >> > >> > --
> > >> > > > > > >> >> > >> > -- Guozhang
> > >> > > > > > >> >> > >> >
> > >> > > > > > >> >> > >>
> > >> > > > > > >> >> > >
> > >> > > > > > >> >> > >
> > >> > > > > > >> >> >
> > >> > > > > > >> >>
> > >> > > > > > >> >>
> > >> > > > > > >> >>
> > >> > > > > > >> >> --
> > >> > > > > > >> >> -- Guozhang
> > >> > > > > > >> >>
> > >> > > > > > >> >
> > >> > > > > > >> >
> > >> > > > > > >>
> > >> > > > > > >
> > >> > > > > > >
> > >> > > > > >
> > >> > > > >
> > >> > > >
> > >> > >
> > >> >
> > >>
> > >
> > >
> >
>
>
>
> --
> -- Guozhang
>
Re: [DISCUSSION] KIP-266: Add TimeoutException to
KafkaConsumer#position()
Posted by Colin McCabe <cm...@apache.org>.
On Wed, May 2, 2018, at 14:54, John Roesler wrote:
> Thanks Jason,
>
> I did find some production use cases "on the internet" that use poll(0)
> *just* to join the group initially and ignore the response. I suppose the
> assumption is that it'll be empty on the very first call to poll with
> timeout=0. In my opinion, this usage is unsafe, since there's a declared
> return value. I proposed the method to give these use cases a safe
> alternative.
>
> Of course, there's another safe alternative: just don't ignore the response.
>
> I'd agree with the decision to just deprecate the old poll(long) and add
> only a new poll(Duration). It should be obvious that there's no
> non-deprecated way to do what the code I found is doing, so those
> developers will either alter their code to handle the response or they will
> come back and ask us for the awaitAssignmentMetadata method.
>
> Better to present a simpler api and wait for a reason to make it more
> complicated.
>
> I'm fine with suggestions 1,2, and 3. Unless Richard objects super fast,
> I'll update the KIP momentarily.
>
> Regarding the ClientTimeoutException, this was introduced earlier in this
> discussion when Becket pointed out that the TimeoutException is a subclass
> of ApiException, and therefore implies that a call to the broker timed out.
Hmm. AdminClient uses TimeoutException for timeouts that don't occur on the broker. For example, if we fail to get cluster metadata within the given request timeout, the request gets a TimeoutException.
BrokerNotAvailableException is another ApiException that is thrown on the client side rather than the broker side. For example, if you attempt to call alterReplicaLogDirs and specify a broker that can't be found in the cluster metadata, AdminClient will fail with BrokerNotAvailableException. This exception does not come from the broker (there is no broker to talk to, in this case).
In general, I interpret ApiExceptions to be exceptions that users should be able to handle when calling a Kafka API.
I don't think they always have to come from a broker.
Colin
>
> Reconsidering this point, I found the javadoc on ApiException to be a
> little ambiguous. All it says is that "any API exception that is part of
> the public protocol should be a subclass of this class...". It's not clear
> to me whether this is the broker's API/protocol or more generally *any*
> API/protocol. So we'd have to bring the lawyers in, but I think we can just
> say it's the latter and keep the old exception.
>
> I'm not sure if it's an important distiction to users whether their request
> timed out as a broker side timeout, an HTTP timeout, or a client-side
> timeout. In any case, they'd want to retry for a while and then fail if
> they can't get their request through.
>
> Plus RetryableException also inherits from ApiException, and that one is
> ubiquitous. Adding a new exception would require users to catch both
> RetriableException and ClientTimeoutException, which seems odd since the
> latter is retriable.
>
> All in all, I'm now in favor of sticking with the current TimeoutException.
> If there's some higher-level problem with the ApiException being used this
> way, I think it should be addressed holistically in a separate KIP.
>
> So, I'll go ahead and switch the KIP back to TimeoutException, unless
> Becket wants to argue (harder) in favor of the ClientTimeoutException.
>
> Thanks,
> -John
>
>
> On Wed, May 2, 2018 at 3:55 PM, Jason Gustafson <ja...@confluent.io> wrote:
>
> > I think John's proposal look reasonable to me. My only doubt is about use
> > cases for the new `awaitAssignmentMetadata` API. I think the basic idea is
> > that we want a way to block until we have joined the consumer group, but we
> > do not want to await fetched data. Maybe another way to accomplish this
> > would be to add a `PollOptions` argument which specified the condition we
> > are awaiting? It's a little weird that we'd have two separate APIs where
> > the group membership can change. I know this functionality can be helpful
> > in testing, but we should probably spend some more time understanding and
> > motivating the general use cases.
> >
> > Since we're leaving around the old poll() with its current behavior for
> > now, I wonder if we could leave this as potential future work?
> >
> > Other than that, I have a few minor suggestions and I'm happy with the KIP:
> >
> > 1. Can we use Duration across the board for all of these APIs?
> > 2. Can we cover the following blocking APIs with in this KIP:
> > `partitionsFor`, `listTopics`, `offsetsForTimes`, `beginningOffsets`,
> > `endOffsets`?
> > 3. Perhaps we can add a `close(Duration)` and deprecate the one accepting
> > `TimeUnit`?
> > 4. Seems we don't really need `ClientTimeoutException` since we already
> > have `TimeoutException`?
> >
> > Thanks,
> > Jason
> >
> >
> >
> > On Wed, Apr 25, 2018 at 2:14 PM, Guozhang Wang <wa...@gmail.com> wrote:
> >
> > > Previously there are some debates on whether we should add this
> > nonblocking
> > > behavior via a config v.s. via overloaded functions. To make progress on
> > > this discussion we need to first figure that part out. I'm in favor of
> > the
> > > current approach of overloaded functions over the config since if we are
> > > going to have multiple configs other than a single one to control timeout
> > > semantics it may be even confusing: take our producer side configs for an
> > > example, right now we have "request.timeout.ms" and "max.block.ms" and
> > we
> > > are proposing to add another one in KIP-91. But I'd also like to hear
> > from
> > > people who's in favor of the configs.
> > >
> > >
> > > Guozhang
> > >
> > >
> > > On Wed, Apr 25, 2018 at 1:39 PM, John Roesler <jo...@confluent.io> wrote:
> > >
> > > > Re Ted's last comment, that style of async API requires some thread to
> > > > actually drive the request/response cycle and invoke the callback when
> > > it's
> > > > complete. Right now, this happens in the caller's thread as a
> > side-effect
> > > > of calling poll(). But that clearly won't work for poll() itself!
> > > >
> > > > In the future, I think we'd like to add a background thread to drive
> > the
> > > > request/response loops, and then make all these methods return
> > > > Future<Whatever>.
> > > >
> > > > But we don't need to bite that off right now.
> > > >
> > > > The "async" model I'm proposing is really just a generalization of the
> > > one
> > > > that poll already partially implements: when you call poll, it fires
> > off
> > > > any requests it needs to make and checks if any responses are ready. If
> > > so,
> > > > it returns them. If not, it returns empty. When you call poll() again,
> > it
> > > > again checks on the responses from last time, and so forth.
> > > >
> > > > But that model currently only applies to the "fetch" part of poll. I'm
> > > > proposing that we extend it to the "metadata update" part of poll as
> > > well.
> > > >
> > > > However, as previously discussed, doing this in place would break the
> > > > semantics of poll that folks currently rely on, so I propose to add new
> > > > methods and deprecate the existing poll method. Here's what I'm
> > thinking:
> > > > https://github.com/apache/kafka/pull/4855 . In the discussion on that
> > > PR,
> > > > I've described in greater detail how the async+blocking semantics work.
> > > >
> > > > I'll update KIP-266 with this interface for poll().
> > > >
> > > > It would be great to get this discussion moving again so we can get
> > these
> > > > changes into 2.0. What does everyone think about this?
> > > >
> > > > Thanks,
> > > > -John
> > > >
> > > > On Thu, Apr 19, 2018 at 5:12 PM, John Roesler <jo...@confluent.io>
> > wrote:
> > > >
> > > > > Thanks for the tip, Ted!
> > > > >
> > > > > On Thu, Apr 19, 2018 at 12:12 PM, Ted Yu <yu...@gmail.com>
> > wrote:
> > > > >
> > > > >> John:
> > > > >> In case you want to pursue async poll, it seems (by looking at
> > current
> > > > >> API)
> > > > >> that introducing PollCallback follows existing pattern(s).
> > > > >>
> > > > >> e.g. KafkaConsumer#commitAsync(OffsetCommitCallback)
> > > > >>
> > > > >> FYI
> > > > >>
> > > > >> On Thu, Apr 19, 2018 at 10:08 AM, John Roesler <jo...@confluent.io>
> > > > wrote:
> > > > >>
> > > > >> > Hi Richard,
> > > > >> >
> > > > >> > Thanks for the invitation! I do think it would be safer to
> > > introduce a
> > > > >> new
> > > > >> > poll
> > > > >> > method than to change the semantics of the old one. I've been
> > > mulling
> > > > >> about
> > > > >> > whether the new one could still have (slightly different) async
> > > > >> semantics
> > > > >> > with
> > > > >> > a timeout of 0. If possible, I'd like to avoid introducing another
> > > new
> > > > >> > "asyncPoll".
> > > > >> >
> > > > >> > I'm planning to run some experiments and dig into the
> > > implementation a
> > > > >> bit
> > > > >> > more before solidifying the proposal. I'll update the KIP as you
> > > > >> suggest at
> > > > >> > that point,
> > > > >> > and then can call for another round of reviews and voting.
> > > > >> >
> > > > >> > Thanks,
> > > > >> > -John
> > > > >> >
> > > > >> > On Tue, Apr 17, 2018 at 4:53 PM, Richard Yu <
> > > > yohan.richard.yu@gmail.com
> > > > >> >
> > > > >> > wrote:
> > > > >> >
> > > > >> > > Hi John,
> > > > >> > >
> > > > >> > > Do you have a preference for fixing the poll() method (e.g.
> > using
> > > > >> > asyncPoll
> > > > >> > > or just sticking with the current method but with an extra
> > timeout
> > > > >> > > parameter) ? I think your current proposition for KIP-288 is
> > > better
> > > > >> than
> > > > >> > > what I have on my side. If you think there is something that you
> > > > want
> > > > >> to
> > > > >> > > add, you could go ahead and change KIP-266 to your liking. Just
> > to
> > > > >> note
> > > > >> > > that it would be preferable that if one of us modifies this KIP,
> > > it
> > > > >> would
> > > > >> > > be best to mention your change on this thread to let each other
> > > know
> > > > >> > (makes
> > > > >> > > it easier to coordinate progress).
> > > > >> > >
> > > > >> > > Thanks,
> > > > >> > > Richard
> > > > >> > >
> > > > >> > > On Tue, Apr 17, 2018 at 2:07 PM, John Roesler <
> > john@confluent.io>
> > > > >> wrote:
> > > > >> > >
> > > > >> > > > Ok, I'll close the discussion on KIP-288 and mark it
> > discarded.
> > > > >> > > >
> > > > >> > > > We can solidify the design for poll in KIP-266, and once it's
> > > > >> approved,
> > > > >> > > > I'll coordinate with Qiang Zhao on the PR for the poll part of
> > > the
> > > > >> > work.
> > > > >> > > > Once that is merged, you'll have a clean slate for the rest of
> > > the
> > > > >> > work.
> > > > >> > > >
> > > > >> > > > On Tue, Apr 17, 2018 at 3:39 PM, Richard Yu <
> > > > >> > yohan.richard.yu@gmail.com>
> > > > >> > > > wrote:
> > > > >> > > >
> > > > >> > > > > Hi John,
> > > > >> > > > >
> > > > >> > > > > I think that you could finish your PR that corresponds with
> > > > >> KIP-288
> > > > >> > and
> > > > >> > > > > merge it. I can finish my side of the work afterwards.
> > > > >> > > > >
> > > > >> > > > > On another note, adding an asynchronized version of poll()
> > > would
> > > > >> make
> > > > >> > > > > sense, particularily since the current version of Kafka does
> > > not
> > > > >> > > support
> > > > >> > > > > it.
> > > > >> > > > >
> > > > >> > > > > Thanks
> > > > >> > > > > Richar
> > > > >> > > > >
> > > > >> > > > > On Tue, Apr 17, 2018 at 12:30 PM, John Roesler <
> > > > john@confluent.io
> > > > >> >
> > > > >> > > > wrote:
> > > > >> > > > >
> > > > >> > > > > > Cross-pollinating from some discussion we've had on
> > KIP-288,
> > > > >> > > > > >
> > > > >> > > > > > I think there's a good reason that poll() takes a timeout
> > > when
> > > > >> none
> > > > >> > > of
> > > > >> > > > > the
> > > > >> > > > > > other methods do, and it's relevant to this discussion.
> > The
> > > > >> timeout
> > > > >> > > in
> > > > >> > > > > > poll() is effectively implementing a long-poll API (on the
> > > > >> client
> > > > >> > > side,
> > > > >> > > > > so
> > > > >> > > > > > it's not really long-poll, but the programmer-facing
> > > behavior
> > > > is
> > > > >> > the
> > > > >> > > > > same).
> > > > >> > > > > > The timeout isn't really bounding the execution time of
> > the
> > > > >> method,
> > > > >> > > but
> > > > >> > > > > > instead giving a max time that callers are willing to wait
> > > > >> around
> > > > >> > and
> > > > >> > > > see
> > > > >> > > > > > if any results show up.
> > > > >> > > > > >
> > > > >> > > > > > If I understand the code sufficiently, it would be
> > perfectly
> > > > >> > > reasonable
> > > > >> > > > > for
> > > > >> > > > > > a caller to use a timeout of 0 to implement async poll, it
> > > > would
> > > > >> > just
> > > > >> > > > > mean
> > > > >> > > > > > that KafkaConsumer would just check on each call if
> > there's
> > > a
> > > > >> > > response
> > > > >> > > > > > ready and if not, fire off a new request without waiting
> > > for a
> > > > >> > > > response.
> > > > >> > > > > >
> > > > >> > > > > > As such, it seems inappropriate to throw a
> > > > >> ClientTimeoutException
> > > > >> > > from
> > > > >> > > > > > poll(), except possibly if the initial phase of ensuring
> > an
> > > > >> > > assignment
> > > > >> > > > > > times out. We wouldn't want the method contract to be
> > > > "returns a
> > > > >> > > > > non-empty
> > > > >> > > > > > collection or throws a ClientTimeoutException"
> > > > >> > > > > >
> > > > >> > > > > > Now, I'm wondering if we should actually consider one of
> > my
> > > > >> > rejected
> > > > >> > > > > > alternatives, to treat the "operation timeout" as a
> > separate
> > > > >> > > parameter
> > > > >> > > > > from
> > > > >> > > > > > the "long-poll time". Or maybe adding an
> > "asyncPoll(timeout,
> > > > >> time
> > > > >> > > > unit)"
> > > > >> > > > > > that only uses the timeout to bound metadata updates and
> > > > >> otherwise
> > > > >> > > > > behaves
> > > > >> > > > > > like the current "poll(0)".
> > > > >> > > > > >
> > > > >> > > > > > Thanks,
> > > > >> > > > > > -John
> > > > >> > > > > >
> > > > >> > > > > > On Tue, Apr 17, 2018 at 2:05 PM, John Roesler <
> > > > >> john@confluent.io>
> > > > >> > > > wrote:
> > > > >> > > > > >
> > > > >> > > > > > > Hey Richard,
> > > > >> > > > > > >
> > > > >> > > > > > > As you noticed, the newly introduced KIP-288 overlaps
> > with
> > > > >> this
> > > > >> > > one.
> > > > >> > > > > > Sorry
> > > > >> > > > > > > for stepping on your toes... How would you like to
> > > proceed?
> > > > >> I'm
> > > > >> > > happy
> > > > >> > > > > to
> > > > >> > > > > > > "close" KIP-288 in deference to this KIP.
> > > > >> > > > > > >
> > > > >> > > > > > > With respect to poll(), reading this discussion gave me
> > a
> > > > new
> > > > >> > idea
> > > > >> > > > for
> > > > >> > > > > > > providing a non-breaking update path... What if we
> > > > introduce a
> > > > >> > new
> > > > >> > > > > > variant
> > > > >> > > > > > > 'poll(long timeout, TimeUnit unit)' that displays the
> > new,
> > > > >> > desired
> > > > >> > > > > > > behavior, and just leave the old method alone?
> > > > >> > > > > > >
> > > > >> > > > > > > Thanks,
> > > > >> > > > > > > -John
> > > > >> > > > > > >
> > > > >> > > > > > > On Tue, Apr 17, 2018 at 12:09 PM, Richard Yu <
> > > > >> > > > > yohan.richard.yu@gmail.com
> > > > >> > > > > > >
> > > > >> > > > > > > wrote:
> > > > >> > > > > > >
> > > > >> > > > > > >> Hi all,
> > > > >> > > > > > >>
> > > > >> > > > > > >> If possible, would a committer please review?
> > > > >> > > > > > >>
> > > > >> > > > > > >> Thanks
> > > > >> > > > > > >>
> > > > >> > > > > > >> On Sun, Apr 1, 2018 at 7:24 PM, Richard Yu <
> > > > >> > > > > yohan.richard.yu@gmail.com>
> > > > >> > > > > > >> wrote:
> > > > >> > > > > > >>
> > > > >> > > > > > >> > Hi Guozhang,
> > > > >> > > > > > >> >
> > > > >> > > > > > >> > I have clarified the KIP a bit to account for
> > Becket's
> > > > >> > > suggestion
> > > > >> > > > on
> > > > >> > > > > > >> > ClientTimeoutException.
> > > > >> > > > > > >> > About adding an extra config, you were right about my
> > > > >> > > intentions.
> > > > >> > > > I
> > > > >> > > > > am
> > > > >> > > > > > >> > just wondering if the config
> > > > >> > > > > > >> > should be included, since Ismael seems to favor an
> > > extra
> > > > >> > > > > > configuration,
> > > > >> > > > > > >> >
> > > > >> > > > > > >> > Thanks,
> > > > >> > > > > > >> > Richard
> > > > >> > > > > > >> >
> > > > >> > > > > > >> > On Sun, Apr 1, 2018 at 5:35 PM, Guozhang Wang <
> > > > >> > > wangguoz@gmail.com
> > > > >> > > > >
> > > > >> > > > > > >> wrote:
> > > > >> > > > > > >> >
> > > > >> > > > > > >> >> Hi Richard,
> > > > >> > > > > > >> >>
> > > > >> > > > > > >> >> Regarding the streams side changes, we plan to
> > > > incorporate
> > > > >> > with
> > > > >> > > > the
> > > > >> > > > > > new
> > > > >> > > > > > >> >> APIs once the KIP is done, which is only internal
> > code
> > > > >> > changes
> > > > >> > > > and
> > > > >> > > > > > >> hence
> > > > >> > > > > > >> >> do
> > > > >> > > > > > >> >> not need to include in the KIP.
> > > > >> > > > > > >> >>
> > > > >> > > > > > >> >> Could you update the KIP because it has been quite
> > > > >> obsoleted
> > > > >> > > from
> > > > >> > > > > the
> > > > >> > > > > > >> >> discussed topics, and I'm a bit loosing track on
> > what
> > > is
> > > > >> your
> > > > >> > > > final
> > > > >> > > > > > >> >> proposal right now. For example, I'm not completely
> > > > >> following
> > > > >> > > > your
> > > > >> > > > > > >> >> "compromise
> > > > >> > > > > > >> >> of sorts": are you suggesting that we still add
> > > > >> overloading
> > > > >> > > > > functions
> > > > >> > > > > > >> and
> > > > >> > > > > > >> >> add a config that will be applied to all overload
> > > > >> functions
> > > > >> > > > without
> > > > >> > > > > > the
> > > > >> > > > > > >> >> timeout, while for other overloaded functions with
> > the
> > > > >> > timeout
> > > > >> > > > > value
> > > > >> > > > > > >> the
> > > > >> > > > > > >> >> config will be ignored?
> > > > >> > > > > > >> >>
> > > > >> > > > > > >> >>
> > > > >> > > > > > >> >> Guozhang
> > > > >> > > > > > >> >>
> > > > >> > > > > > >> >> On Fri, Mar 30, 2018 at 8:36 PM, Richard Yu <
> > > > >> > > > > > >> yohan.richard.yu@gmail.com>
> > > > >> > > > > > >> >> wrote:
> > > > >> > > > > > >> >>
> > > > >> > > > > > >> >> > On a side note, I have noticed that the several
> > > other
> > > > >> > methods
> > > > >> > > > in
> > > > >> > > > > > >> classes
> > > > >> > > > > > >> >> > such as StoreChangeLogReader in Streams calls
> > > > position()
> > > > >> > > which
> > > > >> > > > > > causes
> > > > >> > > > > > >> >> tests
> > > > >> > > > > > >> >> > to hang. It might be out of the scope of the KIP,
> > > but
> > > > >> > should
> > > > >> > > I
> > > > >> > > > > also
> > > > >> > > > > > >> >> change
> > > > >> > > > > > >> >> > the methods which use position() as a callback to
> > at
> > > > the
> > > > >> > very
> > > > >> > > > > least
> > > > >> > > > > > >> >> prevent
> > > > >> > > > > > >> >> > the tests from hanging? This issue might be out of
> > > the
> > > > >> KIP,
> > > > >> > > > but I
> > > > >> > > > > > >> >> prefer it
> > > > >> > > > > > >> >> > if we could at least make my PR pass the Jenkins
> > > Q&A.
> > > > >> > > > > > >> >> >
> > > > >> > > > > > >> >> > Thanks
> > > > >> > > > > > >> >> >
> > > > >> > > > > > >> >> > On Fri, Mar 30, 2018 at 8:24 PM, Richard Yu <
> > > > >> > > > > > >> yohan.richard.yu@gmail.com
> > > > >> > > > > > >> >> >
> > > > >> > > > > > >> >> > wrote:
> > > > >> > > > > > >> >> >
> > > > >> > > > > > >> >> > > Thanks for the review Becket.
> > > > >> > > > > > >> >> > >
> > > > >> > > > > > >> >> > > About the methods beginningOffsets(),
> > > endOffsets(),
> > > > >> ...:
> > > > >> > > > > > >> >> > > I took a look through the code of KafkaConsumer,
> > > but
> > > > >> > after
> > > > >> > > > > > looking
> > > > >> > > > > > >> >> > through
> > > > >> > > > > > >> >> > > the offsetsByTimes() method
> > > > >> > > > > > >> >> > > and its callbacks in Fetcher, I think these
> > > methods
> > > > >> > already
> > > > >> > > > > block
> > > > >> > > > > > >> for
> > > > >> > > > > > >> >> a
> > > > >> > > > > > >> >> > > set period of time. I know that there
> > > > >> > > > > > >> >> > > is a chance that the offsets methods in
> > > > KafkaConsumer
> > > > >> > might
> > > > >> > > > be
> > > > >> > > > > > like
> > > > >> > > > > > >> >> poll
> > > > >> > > > > > >> >> > > (that is one section of the method
> > > > >> > > > > > >> >> > > honors the timeout while another --
> > > > >> updateFetchPositions
> > > > >> > --
> > > > >> > > > > does
> > > > >> > > > > > >> not).
> > > > >> > > > > > >> >> > > However, I don't think that this is the
> > > > >> > > > > > >> >> > > case with offsetsByTimes since the callbacks
> > that
> > > I
> > > > >> > checked
> > > > >> > > > > does
> > > > >> > > > > > >> not
> > > > >> > > > > > >> >> seem
> > > > >> > > > > > >> >> > > to hang.
> > > > >> > > > > > >> >> > >
> > > > >> > > > > > >> >> > > The clarity of the exception message is a
> > > problem. I
> > > > >> > > thought
> > > > >> > > > > your
> > > > >> > > > > > >> >> > > suggestion there was reasonable. I included
> > > > >> > > > > > >> >> > > it in the KIP.
> > > > >> > > > > > >> >> > >
> > > > >> > > > > > >> >> > > And on another note, I have noticed that several
> > > > >> people
> > > > >> > has
> > > > >> > > > > > voiced
> > > > >> > > > > > >> the
> > > > >> > > > > > >> >> > > opinion that adding a config might
> > > > >> > > > > > >> >> > > be advisable in relation to adding an extra
> > > > >> parameter. I
> > > > >> > > > think
> > > > >> > > > > > >> that we
> > > > >> > > > > > >> >> > can
> > > > >> > > > > > >> >> > > have a compromise of sorts: some
> > > > >> > > > > > >> >> > > methods in KafkaConsumer are relatively similar
> > --
> > > > for
> > > > >> > > > example,
> > > > >> > > > > > >> >> > position()
> > > > >> > > > > > >> >> > > and committed() both call
> > > > >> > > > > > >> >> > > updateFetchPositions(). I think that we could
> > use
> > > > the
> > > > >> > same
> > > > >> > > > > config
> > > > >> > > > > > >> for
> > > > >> > > > > > >> >> > > these method as a default timeout if
> > > > >> > > > > > >> >> > > the user does not provide one. On the other
> > hand,
> > > if
> > > > >> they
> > > > >> > > > wish
> > > > >> > > > > to
> > > > >> > > > > > >> >> specify
> > > > >> > > > > > >> >> > > a longer or shorter blocking time,
> > > > >> > > > > > >> >> > > they have the option of changing the timeout. (I
> > > > >> included
> > > > >> > > the
> > > > >> > > > > > >> config
> > > > >> > > > > > >> >> as
> > > > >> > > > > > >> >> > an
> > > > >> > > > > > >> >> > > alternative in the KIP) WDYT?
> > > > >> > > > > > >> >> > >
> > > > >> > > > > > >> >> > > Thanks,
> > > > >> > > > > > >> >> > > Richard
> > > > >> > > > > > >> >> > >
> > > > >> > > > > > >> >> > >
> > > > >> > > > > > >> >> > > On Fri, Mar 30, 2018 at 1:26 AM, Becket Qin <
> > > > >> > > > > > becket.qin@gmail.com>
> > > > >> > > > > > >> >> > wrote:
> > > > >> > > > > > >> >> > >
> > > > >> > > > > > >> >> > >> Glad to see the KIP, Richard. This has been a
> > > > really
> > > > >> > long
> > > > >> > > > > > pending
> > > > >> > > > > > >> >> issue.
> > > > >> > > > > > >> >> > >>
> > > > >> > > > > > >> >> > >> The original arguments from Jay for using
> > config,
> > > > >> such
> > > > >> > as
> > > > >> > > > > > >> >> max.block.ms,
> > > > >> > > > > > >> >> > >> instead of using timeout parameters was that
> > > people
> > > > >> will
> > > > >> > > > > always
> > > > >> > > > > > >> hard
> > > > >> > > > > > >> >> > code
> > > > >> > > > > > >> >> > >> the timeout, and the hard coded timeout is
> > rarely
> > > > >> > correct
> > > > >> > > > > > because
> > > > >> > > > > > >> it
> > > > >> > > > > > >> >> has
> > > > >> > > > > > >> >> > >> to
> > > > >> > > > > > >> >> > >> consider different scenarios. For example,
> > users
> > > > may
> > > > >> > > receive
> > > > >> > > > > > >> timeout
> > > > >> > > > > > >> >> > >> exception when the group coordinator moves.
> > > Having
> > > > a
> > > > >> > > > > > configuration
> > > > >> > > > > > >> >> with
> > > > >> > > > > > >> >> > >> some reasonable default value will make users'
> > > life
> > > > >> > > easier.
> > > > >> > > > > > >> >> > >>
> > > > >> > > > > > >> >> > >> That said, in practice, it seems more useful to
> > > > have
> > > > >> > > timeout
> > > > >> > > > > > >> >> parameters.
> > > > >> > > > > > >> >> > >> We
> > > > >> > > > > > >> >> > >> have seen some library, using the consumers
> > > > >> internally,
> > > > >> > > > needs
> > > > >> > > > > to
> > > > >> > > > > > >> >> provide
> > > > >> > > > > > >> >> > >> an
> > > > >> > > > > > >> >> > >> external flexible timeout interface. Also, user
> > > can
> > > > >> > easily
> > > > >> > > > > hard
> > > > >> > > > > > >> code
> > > > >> > > > > > >> >> a
> > > > >> > > > > > >> >> > >> value to get the same as a config based
> > solution.
> > > > >> > > > > > >> >> > >>
> > > > >> > > > > > >> >> > >> The KIP looks good overall. A few comments:
> > > > >> > > > > > >> >> > >>
> > > > >> > > > > > >> >> > >> 1. There are a few other blocking methods that
> > > are
> > > > >> not
> > > > >> > > > > included,
> > > > >> > > > > > >> e.g.
> > > > >> > > > > > >> >> > >> offsetsForTimes(), beginningOffsets(),
> > > > endOffsets().
> > > > >> Is
> > > > >> > > > there
> > > > >> > > > > > any
> > > > >> > > > > > >> >> > reason?
> > > > >> > > > > > >> >> > >>
> > > > >> > > > > > >> >> > >> 2. I am wondering can we take the KIP as a
> > chance
> > > > to
> > > > >> > clean
> > > > >> > > > up
> > > > >> > > > > > our
> > > > >> > > > > > >> >> > timeout
> > > > >> > > > > > >> >> > >> exception(s)? More specifically, instead of
> > > reusing
> > > > >> > > > > > >> TimeoutException,
> > > > >> > > > > > >> >> > can
> > > > >> > > > > > >> >> > >> we introduce a new ClientTimeoutException with
> > > > >> different
> > > > >> > > > > causes,
> > > > >> > > > > > >> e.g.
> > > > >> > > > > > >> >> > >> UnknownTopicOrPartition, RequestTimeout,
> > > > >> > > LeaderNotAvailable,
> > > > >> > > > > > etc.
> > > > >> > > > > > >> >> > >> As of now, the TimeoutException is used in the
> > > > >> following
> > > > >> > > > three
> > > > >> > > > > > >> cases:
> > > > >> > > > > > >> >> > >>
> > > > >> > > > > > >> >> > >> 1. TimeoutException is a subclass of
> > > > ApiException
> > > > >> > which
> > > > >> > > > > > >> indicates
> > > > >> > > > > > >> >> the
> > > > >> > > > > > >> >> > >> exception was returned by the broker. The
> > > > >> > > > TimeoutException
> > > > >> > > > > > was
> > > > >> > > > > > >> >> > >> initially
> > > > >> > > > > > >> >> > >> returned by the leaders when replication was
> > > not
> > > > >> done
> > > > >> > > > > within
> > > > >> > > > > > >> the
> > > > >> > > > > > >> >> > >> specified
> > > > >> > > > > > >> >> > >> timeout in the ProduceRequest. It has an
> > error
> > > > >> code
> > > > >> > of
> > > > >> > > 7,
> > > > >> > > > > > >> which is
> > > > >> > > > > > >> >> > >> returned
> > > > >> > > > > > >> >> > >> by the broker.
> > > > >> > > > > > >> >> > >> 2. When we migrate to Java clients, in
> > Errors
> > > > >> > > definition,
> > > > >> > > > > we
> > > > >> > > > > > >> >> extended
> > > > >> > > > > > >> >> > >> it
> > > > >> > > > > > >> >> > >> to indicate request timeout, i.e. a request
> > > was
> > > > >> sent
> > > > >> > > but
> > > > >> > > > > the
> > > > >> > > > > > >> >> response
> > > > >> > > > > > >> >> > >> was
> > > > >> > > > > > >> >> > >> not received before timeout. In this case,
> > the
> > > > >> > clients
> > > > >> > > > did
> > > > >> > > > > > not
> > > > >> > > > > > >> >> have a
> > > > >> > > > > > >> >> > >> return code from the broker.
> > > > >> > > > > > >> >> > >> 3. Later at some point, we started to use
> > the
> > > > >> > > > > > TimeoutException
> > > > >> > > > > > >> for
> > > > >> > > > > > >> >> > >> clients method call timeout. It is neither
> > > > >> related to
> > > > >> > > any
> > > > >> > > > > > >> broker
> > > > >> > > > > > >> >> > >> returned
> > > > >> > > > > > >> >> > >> error code, nor to request timeout on the
> > > wire.
> > > > >> > > > > > >> >> > >>
> > > > >> > > > > > >> >> > >> Due to the various interpretations, users can
> > > > easily
> > > > >> be
> > > > >> > > > > > confused.
> > > > >> > > > > > >> As
> > > > >> > > > > > >> >> an
> > > > >> > > > > > >> >> > >> example, when a timeout is thrown with "Failed
> > to
> > > > >> > refresh
> > > > >> > > > > > metadata
> > > > >> > > > > > >> >> in X
> > > > >> > > > > > >> >> > >> ms", it is hard to tell what exactly happened.
> > > > Since
> > > > >> we
> > > > >> > > are
> > > > >> > > > > > >> changing
> > > > >> > > > > > >> >> the
> > > > >> > > > > > >> >> > >> API here, it would be good to avoid introducing
> > > > more
> > > > >> > > > ambiguity
> > > > >> > > > > > and
> > > > >> > > > > > >> >> see
> > > > >> > > > > > >> >> > >> whether this can be improved. It would be at
> > > least
> > > > >> one
> > > > >> > > step
> > > > >> > > > > > >> forward
> > > > >> > > > > > >> >> to
> > > > >> > > > > > >> >> > >> remove the usage of case 3.
> > > > >> > > > > > >> >> > >>
> > > > >> > > > > > >> >> > >> Thanks,
> > > > >> > > > > > >> >> > >>
> > > > >> > > > > > >> >> > >> Jiangjie (Becket) Qin
> > > > >> > > > > > >> >> > >>
> > > > >> > > > > > >> >> > >>
> > > > >> > > > > > >> >> > >>
> > > > >> > > > > > >> >> > >>
> > > > >> > > > > > >> >> > >> On Mon, Mar 26, 2018 at 5:50 PM, Guozhang Wang
> > <
> > > > >> > > > > > >> wangguoz@gmail.com>
> > > > >> > > > > > >> >> > >> wrote:
> > > > >> > > > > > >> >> > >>
> > > > >> > > > > > >> >> > >> > @Richard: TimeoutException inherits from
> > > > >> > > > RetriableException
> > > > >> > > > > > >> which
> > > > >> > > > > > >> >> > >> inherits
> > > > >> > > > > > >> >> > >> > from ApiException. So users should explicitly
> > > try
> > > > >> to
> > > > >> > > > capture
> > > > >> > > > > > >> >> > >> > RetriableException in their code and handle
> > the
> > > > >> > > exception.
> > > > >> > > > > > >> >> > >> >
> > > > >> > > > > > >> >> > >> > @Isamel, Ewen: I'm trying to push progress
> > > > forward
> > > > >> on
> > > > >> > > this
> > > > >> > > > > > one,
> > > > >> > > > > > >> >> are we
> > > > >> > > > > > >> >> > >> now
> > > > >> > > > > > >> >> > >> > on the same page for using function
> > parameters
> > > > than
> > > > >> > > > configs?
> > > > >> > > > > > >> >> > >> >
> > > > >> > > > > > >> >> > >> >
> > > > >> > > > > > >> >> > >> > Guozhang
> > > > >> > > > > > >> >> > >> >
> > > > >> > > > > > >> >> > >> >
> > > > >> > > > > > >> >> > >> > On Fri, Mar 23, 2018 at 4:42 PM, Ismael Juma
> > <
> > > > >> > > > > > ismael@juma.me.uk
> > > > >> > > > > > >> >
> > > > >> > > > > > >> >> > wrote:
> > > > >> > > > > > >> >> > >> >
> > > > >> > > > > > >> >> > >> > > Hi Ewen,
> > > > >> > > > > > >> >> > >> > >
> > > > >> > > > > > >> >> > >> > > Yeah, I mentioned KAFKA-2391 where some of
> > > this
> > > > >> was
> > > > >> > > > > > discussed.
> > > > >> > > > > > >> >> Jay
> > > > >> > > > > > >> >> > was
> > > > >> > > > > > >> >> > >> > > against having timeouts in the methods at
> > the
> > > > >> time.
> > > > >> > > > > However,
> > > > >> > > > > > >> as
> > > > >> > > > > > >> >> > Jason
> > > > >> > > > > > >> >> > >> > said
> > > > >> > > > > > >> >> > >> > > offline, we did end up with a timeout
> > > parameter
> > > > >> in
> > > > >> > > > `poll`.
> > > > >> > > > > > >> >> > >> > >
> > > > >> > > > > > >> >> > >> > > Ismael
> > > > >> > > > > > >> >> > >> > >
> > > > >> > > > > > >> >> > >> > > On Fri, Mar 23, 2018 at 4:26 PM, Ewen
> > > > >> > > Cheslack-Postava <
> > > > >> > > > > > >> >> > >> > ewen@confluent.io>
> > > > >> > > > > > >> >> > >> > > wrote:
> > > > >> > > > > > >> >> > >> > >
> > > > >> > > > > > >> >> > >> > > > Regarding the flexibility question, has
> > > > someone
> > > > >> > > tried
> > > > >> > > > to
> > > > >> > > > > > >> dig up
> > > > >> > > > > > >> >> > the
> > > > >> > > > > > >> >> > >> > > > discussion of the new consumer APIs when
> > > they
> > > > >> were
> > > > >> > > > being
> > > > >> > > > > > >> >> written?
> > > > >> > > > > > >> >> > I
> > > > >> > > > > > >> >> > >> > > vaguely
> > > > >> > > > > > >> >> > >> > > > recall these exact questions about using
> > > APIs
> > > > >> vs
> > > > >> > > > configs
> > > > >> > > > > > and
> > > > >> > > > > > >> >> > >> > flexibility
> > > > >> > > > > > >> >> > >> > > vs
> > > > >> > > > > > >> >> > >> > > > bloating the API surface area having
> > > already
> > > > >> been
> > > > >> > > > > > discussed.
> > > > >> > > > > > >> >> (Not
> > > > >> > > > > > >> >> > >> that
> > > > >> > > > > > >> >> > >> > we
> > > > >> > > > > > >> >> > >> > > > shouldn't revisit, just that it might
> > also
> > > > be a
> > > > >> > > faster
> > > > >> > > > > way
> > > > >> > > > > > >> to
> > > > >> > > > > > >> >> get
> > > > >> > > > > > >> >> > >> to a
> > > > >> > > > > > >> >> > >> > > full
> > > > >> > > > > > >> >> > >> > > > understanding of the options, concerns,
> > and
> > > > >> > > > tradeoffs).
> > > > >> > > > > > >> >> > >> > > >
> > > > >> > > > > > >> >> > >> > > > -Ewen
> > > > >> > > > > > >> >> > >> > > >
> > > > >> > > > > > >> >> > >> > > > On Thu, Mar 22, 2018 at 7:19 AM, Richard
> > > Yu <
> > > > >> > > > > > >> >> > >> > yohan.richard.yu@gmail.com>
> > > > >> > > > > > >> >> > >> > > > wrote:
> > > > >> > > > > > >> >> > >> > > >
> > > > >> > > > > > >> >> > >> > > > > I do have one question though: in the
> > > > current
> > > > >> > KIP,
> > > > >> > > > > > >> throwing
> > > > >> > > > > > >> >> > >> > > > > TimeoutException to mark
> > > > >> > > > > > >> >> > >> > > > > that time limit is exceeded is applied
> > to
> > > > all
> > > > >> > new
> > > > >> > > > > > methods
> > > > >> > > > > > >> >> > >> introduced
> > > > >> > > > > > >> >> > >> > in
> > > > >> > > > > > >> >> > >> > > > > this proposal.
> > > > >> > > > > > >> >> > >> > > > > However, how would users respond when a
> > > > >> > > > > TimeoutException
> > > > >> > > > > > >> >> (since
> > > > >> > > > > > >> >> > >> it is
> > > > >> > > > > > >> >> > >> > > > > considered
> > > > >> > > > > > >> >> > >> > > > > a RuntimeException)?
> > > > >> > > > > > >> >> > >> > > > >
> > > > >> > > > > > >> >> > >> > > > > Thanks,
> > > > >> > > > > > >> >> > >> > > > > Richard
> > > > >> > > > > > >> >> > >> > > > >
> > > > >> > > > > > >> >> > >> > > > >
> > > > >> > > > > > >> >> > >> > > > >
> > > > >> > > > > > >> >> > >> > > > > On Mon, Mar 19, 2018 at 6:10 PM,
> > Richard
> > > > Yu <
> > > > >> > > > > > >> >> > >> > > yohan.richard.yu@gmail.com>
> > > > >> > > > > > >> >> > >> > > > > wrote:
> > > > >> > > > > > >> >> > >> > > > >
> > > > >> > > > > > >> >> > >> > > > > > Hi Ismael,
> > > > >> > > > > > >> >> > >> > > > > >
> > > > >> > > > > > >> >> > >> > > > > > You have a great point. Since most of
> > > the
> > > > >> > > methods
> > > > >> > > > in
> > > > >> > > > > > >> this
> > > > >> > > > > > >> >> KIP
> > > > >> > > > > > >> >> > >> have
> > > > >> > > > > > >> >> > >> > > > > similar
> > > > >> > > > > > >> >> > >> > > > > > callbacks (position() and committed()
> > > > both
> > > > >> use
> > > > >> > > > > > >> >> > >> > > fetchCommittedOffsets(),
> > > > >> > > > > > >> >> > >> > > > > > and
> > > > >> > > > > > >> >> > >> > > > > > commitSync() is similar to
> > position(),
> > > > >> except
> > > > >> > > just
> > > > >> > > > > > >> updating
> > > > >> > > > > > >> >> > >> > offsets),
> > > > >> > > > > > >> >> > >> > > > the
> > > > >> > > > > > >> >> > >> > > > > > amount of time
> > > > >> > > > > > >> >> > >> > > > > > they block should be also about
> > equal.
> > > > >> > > > > > >> >> > >> > > > > >
> > > > >> > > > > > >> >> > >> > > > > > However, I think that we need to take
> > > > into
> > > > >> > > > account a
> > > > >> > > > > > >> >> couple of
> > > > >> > > > > > >> >> > >> > > things.
> > > > >> > > > > > >> >> > >> > > > > For
> > > > >> > > > > > >> >> > >> > > > > > starters,
> > > > >> > > > > > >> >> > >> > > > > > if the new methods were all reliant
> > on
> > > > one
> > > > >> > > config,
> > > > >> > > > > > >> there is
> > > > >> > > > > > >> >> > >> > > likelihood
> > > > >> > > > > > >> >> > >> > > > > > that the
> > > > >> > > > > > >> >> > >> > > > > > shortcomings for this approach would
> > be
> > > > >> > similar
> > > > >> > > to
> > > > >> > > > > > what
> > > > >> > > > > > >> we
> > > > >> > > > > > >> >> > >> faced if
> > > > >> > > > > > >> >> > >> > > we
> > > > >> > > > > > >> >> > >> > > > > let
> > > > >> > > > > > >> >> > >> > > > > > request.timeout.ms control all
> > method
> > > > >> > timeouts.
> > > > >> > > > In
> > > > >> > > > > > >> >> > comparison,
> > > > >> > > > > > >> >> > >> > > adding
> > > > >> > > > > > >> >> > >> > > > > > overloads
> > > > >> > > > > > >> >> > >> > > > > > does not have this problem.
> > > > >> > > > > > >> >> > >> > > > > >
> > > > >> > > > > > >> >> > >> > > > > > If you have further thoughts, please
> > > let
> > > > me
> > > > >> > > know.
> > > > >> > > > > > >> >> > >> > > > > >
> > > > >> > > > > > >> >> > >> > > > > > Richard
> > > > >> > > > > > >> >> > >> > > > > >
> > > > >> > > > > > >> >> > >> > > > > >
> > > > >> > > > > > >> >> > >> > > > > > On Mon, Mar 19, 2018 at 5:12 PM,
> > Ismael
> > > > >> Juma <
> > > > >> > > > > > >> >> > ismael@juma.me.uk
> > > > >> > > > > > >> >> > >> >
> > > > >> > > > > > >> >> > >> > > > wrote:
> > > > >> > > > > > >> >> > >> > > > > >
> > > > >> > > > > > >> >> > >> > > > > >> Hi,
> > > > >> > > > > > >> >> > >> > > > > >>
> > > > >> > > > > > >> >> > >> > > > > >> An option that is not currently
> > > covered
> > > > in
> > > > >> > the
> > > > >> > > > KIP
> > > > >> > > > > is
> > > > >> > > > > > >> to
> > > > >> > > > > > >> >> > have a
> > > > >> > > > > > >> >> > >> > > > separate
> > > > >> > > > > > >> >> > >> > > > > >> config max.block.ms, which is
> > similar
> > > > to
> > > > >> the
> > > > >> > > > > > producer
> > > > >> > > > > > >> >> config
> > > > >> > > > > > >> >> > >> with
> > > > >> > > > > > >> >> > >> > > the
> > > > >> > > > > > >> >> > >> > > > > >> same
> > > > >> > > > > > >> >> > >> > > > > >> name. This came up during the
> > > KAFKA-2391
> > > > >> > > > > discussion.
> > > > >> > > > > > I
> > > > >> > > > > > >> >> think
> > > > >> > > > > > >> >> > >> it's
> > > > >> > > > > > >> >> > >> > > > clear
> > > > >> > > > > > >> >> > >> > > > > >> that we can't rely on
> > > > request.timeout.ms,
> > > > >> so
> > > > >> > > the
> > > > >> > > > > > >> >> decision is
> > > > >> > > > > > >> >> > >> > > between
> > > > >> > > > > > >> >> > >> > > > > >> adding
> > > > >> > > > > > >> >> > >> > > > > >> overloads or adding a new config.
> > > People
> > > > >> > seemed
> > > > >> > > > to
> > > > >> > > > > be
> > > > >> > > > > > >> >> leaning
> > > > >> > > > > > >> >> > >> > > towards
> > > > >> > > > > > >> >> > >> > > > > the
> > > > >> > > > > > >> >> > >> > > > > >> latter in KAFKA-2391, but Jason
> > makes
> > > a
> > > > >> good
> > > > >> > > > point
> > > > >> > > > > > that
> > > > >> > > > > > >> >> the
> > > > >> > > > > > >> >> > >> > > overloads
> > > > >> > > > > > >> >> > >> > > > > are
> > > > >> > > > > > >> >> > >> > > > > >> more flexible. A couple of questions
> > > > from
> > > > >> me:
> > > > >> > > > > > >> >> > >> > > > > >>
> > > > >> > > > > > >> >> > >> > > > > >> 1. Do we need the additional
> > > > flexibility?
> > > > >> > > > > > >> >> > >> > > > > >> 2. If we do, do we need it for every
> > > > >> blocking
> > > > >> > > > > method?
> > > > >> > > > > > >> >> > >> > > > > >>
> > > > >> > > > > > >> >> > >> > > > > >> Ismael
> > > > >> > > > > > >> >> > >> > > > > >>
> > > > >> > > > > > >> >> > >> > > > > >> On Mon, Mar 19, 2018 at 5:03 PM,
> > > Richard
> > > > >> Yu <
> > > > >> > > > > > >> >> > >> > > > yohan.richard.yu@gmail.com
> > > > >> > > > > > >> >> > >> > > > > >
> > > > >> > > > > > >> >> > >> > > > > >> wrote:
> > > > >> > > > > > >> >> > >> > > > > >>
> > > > >> > > > > > >> >> > >> > > > > >> > Hi Guozhang,
> > > > >> > > > > > >> >> > >> > > > > >> >
> > > > >> > > > > > >> >> > >> > > > > >> > I made some clarifications to
> > > KIP-266,
> > > > >> > > namely:
> > > > >> > > > > > >> >> > >> > > > > >> > 1. Stated more specifically that
> > > > >> commitSync
> > > > >> > > > will
> > > > >> > > > > > >> accept
> > > > >> > > > > > >> >> > user
> > > > >> > > > > > >> >> > >> > > input.
> > > > >> > > > > > >> >> > >> > > > > >> > 2. fetchCommittedOffsets(): Made
> > its
> > > > >> role
> > > > >> > in
> > > > >> > > > > > blocking
> > > > >> > > > > > >> >> more
> > > > >> > > > > > >> >> > >> clear
> > > > >> > > > > > >> >> > >> > > to
> > > > >> > > > > > >> >> > >> > > > > the
> > > > >> > > > > > >> >> > >> > > > > >> > reader.
> > > > >> > > > > > >> >> > >> > > > > >> > 3. Sketched what would happen when
> > > > time
> > > > >> > limit
> > > > >> > > > is
> > > > >> > > > > > >> >> exceeded.
> > > > >> > > > > > >> >> > >> > > > > >> >
> > > > >> > > > > > >> >> > >> > > > > >> > These changes should make the KIP
> > > > >> easier to
> > > > >> > > > > > >> understand.
> > > > >> > > > > > >> >> > >> > > > > >> >
> > > > >> > > > > > >> >> > >> > > > > >> > Cheers,
> > > > >> > > > > > >> >> > >> > > > > >> > Richard
> > > > >> > > > > > >> >> > >> > > > > >> >
> > > > >> > > > > > >> >> > >> > > > > >> > On Mon, Mar 19, 2018 at 9:33 AM,
> > > > >> Guozhang
> > > > >> > > Wang
> > > > >> > > > <
> > > > >> > > > > > >> >> > >> > > wangguoz@gmail.com>
> > > > >> > > > > > >> >> > >> > > > > >> wrote:
> > > > >> > > > > > >> >> > >> > > > > >> >
> > > > >> > > > > > >> >> > >> > > > > >> > > Hi Richard,
> > > > >> > > > > > >> >> > >> > > > > >> > >
> > > > >> > > > > > >> >> > >> > > > > >> > > I made a pass over the KIP
> > again,
> > > > some
> > > > >> > more
> > > > >> > > > > > >> >> > clarifications
> > > > >> > > > > > >> >> > >> /
> > > > >> > > > > > >> >> > >> > > > > comments:
> > > > >> > > > > > >> >> > >> > > > > >> > >
> > > > >> > > > > > >> >> > >> > > > > >> > > 1. seek() call itself is not
> > > > blocking,
> > > > >> > only
> > > > >> > > > the
> > > > >> > > > > > >> >> following
> > > > >> > > > > > >> >> > >> > poll()
> > > > >> > > > > > >> >> > >> > > > > call
> > > > >> > > > > > >> >> > >> > > > > >> may
> > > > >> > > > > > >> >> > >> > > > > >> > > be blocking as the actually
> > > metadata
> > > > >> rq
> > > > >> > > will
> > > > >> > > > > > >> happen.
> > > > >> > > > > > >> >> > >> > > > > >> > >
> > > > >> > > > > > >> >> > >> > > > > >> > > 2. I saw you did not include
> > > > >> > > > > > >> Consumer.partitionFor(),
> > > > >> > > > > > >> >> > >> > > > > >> > > Consumer.OffsetAndTimestamp()
> > and
> > > > >> > > > > > >> >> Consumer.listTopics()
> > > > >> > > > > > >> >> > in
> > > > >> > > > > > >> >> > >> > your
> > > > >> > > > > > >> >> > >> > > > KIP.
> > > > >> > > > > > >> >> > >> > > > > >> > After
> > > > >> > > > > > >> >> > >> > > > > >> > > a second thought, I think this
> > may
> > > > be
> > > > >> a
> > > > >> > > > better
> > > > >> > > > > > >> idea to
> > > > >> > > > > > >> >> > not
> > > > >> > > > > > >> >> > >> > > tackle
> > > > >> > > > > > >> >> > >> > > > > >> them in
> > > > >> > > > > > >> >> > >> > > > > >> > > the same KIP, and probably we
> > > should
> > > > >> > > consider
> > > > >> > > > > > >> whether
> > > > >> > > > > > >> >> we
> > > > >> > > > > > >> >> > >> would
> > > > >> > > > > > >> >> > >> > > > > change
> > > > >> > > > > > >> >> > >> > > > > >> the
> > > > >> > > > > > >> >> > >> > > > > >> > > behavior or not in another
> > > > discussion.
> > > > >> > So I
> > > > >> > > > > agree
> > > > >> > > > > > >> to
> > > > >> > > > > > >> >> not
> > > > >> > > > > > >> >> > >> > include
> > > > >> > > > > > >> >> > >> > > > > them.
> > > > >> > > > > > >> >> > >> > > > > >> > >
> > > > >> > > > > > >> >> > >> > > > > >> > > 3. In your wiki you mentioned
> > > > "Another
> > > > >> > > change
> > > > >> > > > > > >> shall be
> > > > >> > > > > > >> >> > >> made to
> > > > >> > > > > > >> >> > >> > > > > >> > > KafkaConsumer#poll(), due to its
> > > > call
> > > > >> to
> > > > >> > > > > > >> >> > >> > updateFetchPositions()
> > > > >> > > > > > >> >> > >> > > > > which
> > > > >> > > > > > >> >> > >> > > > > >> > > blocks indefinitely." This part
> > > may
> > > > a
> > > > >> bit
> > > > >> > > > > obscure
> > > > >> > > > > > >> to
> > > > >> > > > > > >> >> most
> > > > >> > > > > > >> >> > >> > > readers
> > > > >> > > > > > >> >> > >> > > > > >> who's
> > > > >> > > > > > >> >> > >> > > > > >> > not
> > > > >> > > > > > >> >> > >> > > > > >> > > familiar with the KafkaConsumer
> > > > >> > internals,
> > > > >> > > > > could
> > > > >> > > > > > >> you
> > > > >> > > > > > >> >> > please
> > > > >> > > > > > >> >> > >> > add
> > > > >> > > > > > >> >> > >> > > > more
> > > > >> > > > > > >> >> > >> > > > > >> > > elaborations. More
> > specifically, I
> > > > >> think
> > > > >> > > the
> > > > >> > > > > root
> > > > >> > > > > > >> >> causes
> > > > >> > > > > > >> >> > of
> > > > >> > > > > > >> >> > >> > the
> > > > >> > > > > > >> >> > >> > > > > public
> > > > >> > > > > > >> >> > >> > > > > >> > APIs
> > > > >> > > > > > >> >> > >> > > > > >> > > mentioned are a bit different
> > > while
> > > > >> the
> > > > >> > > KIP's
> > > > >> > > > > > >> >> explanation
> > > > >> > > > > > >> >> > >> > sounds
> > > > >> > > > > > >> >> > >> > > > > like
> > > > >> > > > > > >> >> > >> > > > > >> > they
> > > > >> > > > > > >> >> > >> > > > > >> > > are due to the same reason:
> > > > >> > > > > > >> >> > >> > > > > >> > >
> > > > >> > > > > > >> >> > >> > > > > >> > > 3.1 fetchCommittedOffsets():
> > this
> > > > >> > internal
> > > > >> > > > call
> > > > >> > > > > > >> will
> > > > >> > > > > > >> >> > block
> > > > >> > > > > > >> >> > >> > > forever
> > > > >> > > > > > >> >> > >> > > > > if
> > > > >> > > > > > >> >> > >> > > > > >> the
> > > > >> > > > > > >> >> > >> > > > > >> > > committed offsets cannot be
> > > fetched
> > > > >> > > > > successfully
> > > > >> > > > > > >> and
> > > > >> > > > > > >> >> > affect
> > > > >> > > > > > >> >> > >> > > > > position()
> > > > >> > > > > > >> >> > >> > > > > >> > and
> > > > >> > > > > > >> >> > >> > > > > >> > > committed(). We need to break
> > out
> > > of
> > > > >> its
> > > > >> > > > > internal
> > > > >> > > > > > >> >> while
> > > > >> > > > > > >> >> > >> loop.
> > > > >> > > > > > >> >> > >> > > > > >> > > 3.2 position() itself will while
> > > > loop
> > > > >> > when
> > > > >> > > > > > offsets
> > > > >> > > > > > >> >> cannot
> > > > >> > > > > > >> >> > >> be
> > > > >> > > > > > >> >> > >> > > > > >> retrieved in
> > > > >> > > > > > >> >> > >> > > > > >> > > the underlying async call. We
> > need
> > > > to
> > > > >> > break
> > > > >> > > > out
> > > > >> > > > > > >> this
> > > > >> > > > > > >> >> > while
> > > > >> > > > > > >> >> > >> > loop.
> > > > >> > > > > > >> >> > >> > > > > >> > > 3.3 commitSync() passed
> > > > >> Long.MAX_VALUE as
> > > > >> > > the
> > > > >> > > > > > >> timeout
> > > > >> > > > > > >> >> > >> value,
> > > > >> > > > > > >> >> > >> > we
> > > > >> > > > > > >> >> > >> > > > > should
> > > > >> > > > > > >> >> > >> > > > > >> > take
> > > > >> > > > > > >> >> > >> > > > > >> > > the user specified timeouts when
> > > > >> > > applicable.
> > > > >> > > > > > >> >> > >> > > > > >> > >
> > > > >> > > > > > >> >> > >> > > > > >> > >
> > > > >> > > > > > >> >> > >> > > > > >> > >
> > > > >> > > > > > >> >> > >> > > > > >> > > Guozhang
> > > > >> > > > > > >> >> > >> > > > > >> > >
> > > > >> > > > > > >> >> > >> > > > > >> > > On Sat, Mar 17, 2018 at 4:44 PM,
> > > > >> Richard
> > > > >> > > Yu <
> > > > >> > > > > > >> >> > >> > > > > >> yohan.richard.yu@gmail.com>
> > > > >> > > > > > >> >> > >> > > > > >> > > wrote:
> > > > >> > > > > > >> >> > >> > > > > >> > >
> > > > >> > > > > > >> >> > >> > > > > >> > > > Actually, what I said above is
> > > > >> > > inaccurate.
> > > > >> > > > In
> > > > >> > > > > > >> >> > >> > > > > >> > > > testSeekAndCommitWithBrokerFai
> > > > >> lures,
> > > > >> > > > > > >> >> > >> > TestUtils.waitUntilTrue
> > > > >> > > > > > >> >> > >> > > > > >> blocks,
> > > > >> > > > > > >> >> > >> > > > > >> > not
> > > > >> > > > > > >> >> > >> > > > > >> > > > seek.
> > > > >> > > > > > >> >> > >> > > > > >> > > > My assumption is that seek did
> > > not
> > > > >> > update
> > > > >> > > > > > >> >> correctly. I
> > > > >> > > > > > >> >> > >> will
> > > > >> > > > > > >> >> > >> > be
> > > > >> > > > > > >> >> > >> > > > > >> digging
> > > > >> > > > > > >> >> > >> > > > > >> > > > further into this.
> > > > >> > > > > > >> >> > >> > > > > >> > > >
> > > > >> > > > > > >> >> > >> > > > > >> > > >
> > > > >> > > > > > >> >> > >> > > > > >> > > >
> > > > >> > > > > > >> >> > >> > > > > >> > > > On Sat, Mar 17, 2018 at 4:16
> > PM,
> > > > >> > Richard
> > > > >> > > > Yu <
> > > > >> > > > > > >> >> > >> > > > > >> > yohan.richard.yu@gmail.com>
> > > > >> > > > > > >> >> > >> > > > > >> > > > wrote:
> > > > >> > > > > > >> >> > >> > > > > >> > > >
> > > > >> > > > > > >> >> > >> > > > > >> > > > > One more thing: when looking
> > > > >> through
> > > > >> > > > > tests, I
> > > > >> > > > > > >> have
> > > > >> > > > > > >> >> > >> > realized
> > > > >> > > > > > >> >> > >> > > > that
> > > > >> > > > > > >> >> > >> > > > > >> > seek()
> > > > >> > > > > > >> >> > >> > > > > >> > > > > methods can potentially
> > block
> > > > >> > > > indefinitely.
> > > > >> > > > > > As
> > > > >> > > > > > >> you
> > > > >> > > > > > >> >> > well
> > > > >> > > > > > >> >> > >> > > know,
> > > > >> > > > > > >> >> > >> > > > > >> seek()
> > > > >> > > > > > >> >> > >> > > > > >> > is
> > > > >> > > > > > >> >> > >> > > > > >> > > > > called when pollOnce() or
> > > > >> position()
> > > > >> > is
> > > > >> > > > > > active.
> > > > >> > > > > > >> >> Thus,
> > > > >> > > > > > >> >> > >> if
> > > > >> > > > > > >> >> > >> > > > > >> position()
> > > > >> > > > > > >> >> > >> > > > > >> > > > blocks
> > > > >> > > > > > >> >> > >> > > > > >> > > > > indefinitely, then so would
> > > > >> seek().
> > > > >> > > > Should
> > > > >> > > > > > >> >> bounding
> > > > >> > > > > > >> >> > >> seek()
> > > > >> > > > > > >> >> > >> > > > also
> > > > >> > > > > > >> >> > >> > > > > be
> > > > >> > > > > > >> >> > >> > > > > >> > > > included
> > > > >> > > > > > >> >> > >> > > > > >> > > > > in this KIP?
> > > > >> > > > > > >> >> > >> > > > > >> > > > >
> > > > >> > > > > > >> >> > >> > > > > >> > > > > Thanks, Richard
> > > > >> > > > > > >> >> > >> > > > > >> > > > >
> > > > >> > > > > > >> >> > >> > > > > >> > > > > On Sat, Mar 17, 2018 at 1:16
> > > PM,
> > > > >> > > Richard
> > > > >> > > > > Yu <
> > > > >> > > > > > >> >> > >> > > > > >> > > yohan.richard.yu@gmail.com>
> > > > >> > > > > > >> >> > >> > > > > >> > > > > wrote:
> > > > >> > > > > > >> >> > >> > > > > >> > > > >
> > > > >> > > > > > >> >> > >> > > > > >> > > > >> Thanks for the advice,
> > Jason
> > > > >> > > > > > >> >> > >> > > > > >> > > > >>
> > > > >> > > > > > >> >> > >> > > > > >> > > > >> I have modified KIP-266 to
> > > > >> include
> > > > >> > the
> > > > >> > > > > java
> > > > >> > > > > > >> doc
> > > > >> > > > > > >> >> for
> > > > >> > > > > > >> >> > >> > > > committed()
> > > > >> > > > > > >> >> > >> > > > > >> and
> > > > >> > > > > > >> >> > >> > > > > >> > > > other
> > > > >> > > > > > >> >> > >> > > > > >> > > > >> blocking methods, and I
> > also
> > > > >> > > > > > >> >> > >> > > > > >> > > > >> mentioned poll() which will
> > > > also
> > > > >> be
> > > > >> > > > > bounded.
> > > > >> > > > > > >> Let
> > > > >> > > > > > >> >> me
> > > > >> > > > > > >> >> > >> know
> > > > >> > > > > > >> >> > >> > if
> > > > >> > > > > > >> >> > >> > > > > >> there is
> > > > >> > > > > > >> >> > >> > > > > >> > > > >> anything else. :)
> > > > >> > > > > > >> >> > >> > > > > >> > > > >>
> > > > >> > > > > > >> >> > >> > > > > >> > > > >> Sincerely, Richard
> > > > >> > > > > > >> >> > >> > > > > >> > > > >>
> > > > >> > > > > > >> >> > >> > > > > >> > > > >>
> > > > >> > > > > > >> >> > >> > > > > >> > > > >>
> > > > >> > > > > > >> >> > >> > > > > >> > > > >>
> > > > >> > > > > > >> >> > >> > > > > >> > > > >>
> > > > >> > > > > > >> >> > >> > > > > >> > > > >> On Sat, Mar 17, 2018 at
> > 12:00
> > > > PM,
> > > > >> > > Jason
> > > > >> > > > > > >> >> Gustafson <
> > > > >> > > > > > >> >> > >> > > > > >> > jason@confluent.io
> > > > >> > > > > > >> >> > >> > > > > >> > > >
> > > > >> > > > > > >> >> > >> > > > > >> > > > >> wrote:
> > > > >> > > > > > >> >> > >> > > > > >> > > > >>
> > > > >> > > > > > >> >> > >> > > > > >> > > > >>> Hi Richard,
> > > > >> > > > > > >> >> > >> > > > > >> > > > >>>
> > > > >> > > > > > >> >> > >> > > > > >> > > > >>> Thanks for the updates.
> > I'm
> > > > >> really
> > > > >> > > glad
> > > > >> > > > > you
> > > > >> > > > > > >> >> picked
> > > > >> > > > > > >> >> > >> this
> > > > >> > > > > > >> >> > >> > > up.
> > > > >> > > > > > >> >> > >> > > > A
> > > > >> > > > > > >> >> > >> > > > > >> > couple
> > > > >> > > > > > >> >> > >> > > > > >> > > > >>> minor
> > > > >> > > > > > >> >> > >> > > > > >> > > > >>> comments:
> > > > >> > > > > > >> >> > >> > > > > >> > > > >>>
> > > > >> > > > > > >> >> > >> > > > > >> > > > >>> 1. Can you list the full
> > set
> > > > of
> > > > >> new
> > > > >> > > > APIs
> > > > >> > > > > > >> >> explicitly
> > > > >> > > > > > >> >> > >> in
> > > > >> > > > > > >> >> > >> > the
> > > > >> > > > > > >> >> > >> > > > > KIP?
> > > > >> > > > > > >> >> > >> > > > > >> > > > >>> Currently I
> > > > >> > > > > > >> >> > >> > > > > >> > > > >>> only see the javadoc for
> > > > >> > > `position()`.
> > > > >> > > > > > >> >> > >> > > > > >> > > > >>>
> > > > >> > > > > > >> >> > >> > > > > >> > > > >>> 2. We should consider
> > adding
> > > > >> > > `TimeUnit`
> > > > >> > > > > to
> > > > >> > > > > > >> the
> > > > >> > > > > > >> >> new
> > > > >> > > > > > >> >> > >> > methods
> > > > >> > > > > > >> >> > >> > > > to
> > > > >> > > > > > >> >> > >> > > > > >> avoid
> > > > >> > > > > > >> >> > >> > > > > >> > > > unit
> > > > >> > > > > > >> >> > >> > > > > >> > > > >>> confusion. I know it's
> > > > >> inconsistent
> > > > >> > > > with
> > > > >> > > > > > the
> > > > >> > > > > > >> >> poll()
> > > > >> > > > > > >> >> > >> API,
> > > > >> > > > > > >> >> > >> > > > but I
> > > > >> > > > > > >> >> > >> > > > > >> > think
> > > > >> > > > > > >> >> > >> > > > > >> > > it
> > > > >> > > > > > >> >> > >> > > > > >> > > > >>> was
> > > > >> > > > > > >> >> > >> > > > > >> > > > >>> probably a mistake not to
> > > > >> include
> > > > >> > it
> > > > >> > > > > there,
> > > > >> > > > > > >> so
> > > > >> > > > > > >> >> > better
> > > > >> > > > > > >> >> > >> > not
> > > > >> > > > > > >> >> > >> > > to
> > > > >> > > > > > >> >> > >> > > > > >> double
> > > > >> > > > > > >> >> > >> > > > > >> > > > down
> > > > >> > > > > > >> >> > >> > > > > >> > > > >>> on
> > > > >> > > > > > >> >> > >> > > > > >> > > > >>> that mistake. And note
> > that
> > > we
> > > > >> do
> > > > >> > > > already
> > > > >> > > > > > >> have
> > > > >> > > > > > >> >> > >> > > `close(long,
> > > > >> > > > > > >> >> > >> > > > > >> > > TimeUnit)`.
> > > > >> > > > > > >> >> > >> > > > > >> > > > >>>
> > > > >> > > > > > >> >> > >> > > > > >> > > > >>> Other than that, I think
> > the
> > > > >> > current
> > > > >> > > > KIP
> > > > >> > > > > > >> seems
> > > > >> > > > > > >> >> > >> > reasonable.
> > > > >> > > > > > >> >> > >> > > > > >> > > > >>>
> > > > >> > > > > > >> >> > >> > > > > >> > > > >>> Thanks,
> > > > >> > > > > > >> >> > >> > > > > >> > > > >>> Jason
> > > > >> > > > > > >> >> > >> > > > > >> > > > >>>
> > > > >> > > > > > >> >> > >> > > > > >> > > > >>> On Wed, Mar 14, 2018 at
> > 5:00
> > > > PM,
> > > > >> > > > Richard
> > > > >> > > > > > Yu <
> > > > >> > > > > > >> >> > >> > > > > >> > > > yohan.richard.yu@gmail.com>
> > > > >> > > > > > >> >> > >> > > > > >> > > > >>> wrote:
> > > > >> > > > > > >> >> > >> > > > > >> > > > >>>
> > > > >> > > > > > >> >> > >> > > > > >> > > > >>> > Note to all: I have
> > > included
> > > > >> > > bounding
> > > > >> > > > > > >> >> > commitSync()
> > > > >> > > > > > >> >> > >> and
> > > > >> > > > > > >> >> > >> > > > > >> > committed()
> > > > >> > > > > > >> >> > >> > > > > >> > > in
> > > > >> > > > > > >> >> > >> > > > > >> > > > >>> this
> > > > >> > > > > > >> >> > >> > > > > >> > > > >>> > KIP.
> > > > >> > > > > > >> >> > >> > > > > >> > > > >>> >
> > > > >> > > > > > >> >> > >> > > > > >> > > > >>> > On Sun, Mar 11, 2018 at
> > > 5:05
> > > > >> PM,
> > > > >> > > > > Richard
> > > > >> > > > > > >> Yu <
> > > > >> > > > > > >> >> > >> > > > > >> > > > >>>
> > yohan.richard.yu@gmail.com>
> > > > >> > > > > > >> >> > >> > > > > >> > > > >>> > wrote:
> > > > >> > > > > > >> >> > >> > > > > >> > > > >>> >
> > > > >> > > > > > >> >> > >> > > > > >> > > > >>> > > Hi all,
> > > > >> > > > > > >> >> > >> > > > > >> > > > >>> > >
> > > > >> > > > > > >> >> > >> > > > > >> > > > >>> > > I updated the KIP
> > where
> > > > >> > > overloading
> > > > >> > > > > > >> >> position()
> > > > >> > > > > > >> >> > is
> > > > >> > > > > > >> >> > >> > now
> > > > >> > > > > > >> >> > >> > > > the
> > > > >> > > > > > >> >> > >> > > > > >> > favored
> > > > >> > > > > > >> >> > >> > > > > >> > > > >>> > approach.
> > > > >> > > > > > >> >> > >> > > > > >> > > > >>> > > Bounding position()
> > > using
> > > > >> > > > > > >> requestTimeoutMs
> > > > >> > > > > > >> >> has
> > > > >> > > > > > >> >> > >> been
> > > > >> > > > > > >> >> > >> > > > listed
> > > > >> > > > > > >> >> > >> > > > > >> as
> > > > >> > > > > > >> >> > >> > > > > >> > > > >>> rejected.
> > > > >> > > > > > >> >> > >> > > > > >> > > > >>> > >
> > > > >> > > > > > >> >> > >> > > > > >> > > > >>> > > Any thoughts?
> > > > >> > > > > > >> >> > >> > > > > >> > > > >>> > >
> > > > >> > > > > > >> >> > >> > > > > >> > > > >>> > > On Tue, Mar 6, 2018 at
> > > > 6:00
> > > > >> PM,
> > > > >> > > > > > Guozhang
> > > > >> > > > > > >> >> Wang <
> > > > >> > > > > > >> >> > >> > > > > >> > > wangguoz@gmail.com>
> > > > >> > > > > > >> >> > >> > > > > >> > > > >>> > wrote:
> > > > >> > > > > > >> >> > >> > > > > >> > > > >>> > >
> > > > >> > > > > > >> >> > >> > > > > >> > > > >>> > >> I agree that adding
> > the
> > > > >> > > overloads
> > > > >> > > > is
> > > > >> > > > > > >> most
> > > > >> > > > > > >> >> > >> flexible.
> > > > >> > > > > > >> >> > >> > > But
> > > > >> > > > > > >> >> > >> > > > > >> going
> > > > >> > > > > > >> >> > >> > > > > >> > > for
> > > > >> > > > > > >> >> > >> > > > > >> > > > >>> that
> > > > >> > > > > > >> >> > >> > > > > >> > > > >>> > >> direction we'd do
> > that
> > > > for
> > > > >> all
> > > > >> > > the
> > > > >> > > > > > >> blocking
> > > > >> > > > > > >> >> > call
> > > > >> > > > > > >> >> > >> > that
> > > > >> > > > > > >> >> > >> > > > > I've
> > > > >> > > > > > >> >> > >> > > > > >> > > listed
> > > > >> > > > > > >> >> > >> > > > > >> > > > >>> above,
> > > > >> > > > > > >> >> > >> > > > > >> > > > >>> > >> with this timeout
> > value
> > > > >> > covering
> > > > >> > > > the
> > > > >> > > > > > >> >> > end-to-end
> > > > >> > > > > > >> >> > >> > > waiting
> > > > >> > > > > > >> >> > >> > > > > >> time.
> > > > >> > > > > > >> >> > >> > > > > >> > > > >>> > >>
> > > > >> > > > > > >> >> > >> > > > > >> > > > >>> > >>
> > > > >> > > > > > >> >> > >> > > > > >> > > > >>> > >> Guozhang
> > > > >> > > > > > >> >> > >> > > > > >> > > > >>> > >>
> > > > >> > > > > > >> >> > >> > > > > >> > > > >>> > >> On Tue, Mar 6, 2018
> > at
> > > > >> 10:02
> > > > >> > AM,
> > > > >> > > > Ted
> > > > >> > > > > > Yu
> > > > >> > > > > > >> <
> > > > >> > > > > > >> >> > >> > > > > >> yuzhihong@gmail.com>
> > > > >> > > > > > >> >> > >> > > > > >> > > > >>> wrote:
> > > > >> > > > > > >> >> > >> > > > > >> > > > >>> > >>
> > > > >> > > > > > >> >> > >> > > > > >> > > > >>> > >> > bq. The most
> > flexible
> > > > >> option
> > > > >> > > is
> > > > >> > > > to
> > > > >> > > > > > add
> > > > >> > > > > > >> >> > >> overloads
> > > > >> > > > > > >> >> > >> > to
> > > > >> > > > > > >> >> > >> > > > the
> > > > >> > > > > > >> >> > >> > > > > >> > > consumer
> > > > >> > > > > > >> >> > >> > > > > >> > > > >>> > >> >
> > > > >> > > > > > >> >> > >> > > > > >> > > > >>> > >> > This option is
> > > > flexible.
> > > > >> > > > > > >> >> > >> > > > > >> > > > >>> > >> >
> > > > >> > > > > > >> >> > >> > > > > >> > > > >>> > >> > Looking at the tail
> > > of
> > > > >> > > > > SPARK-18057,
> > > > >> > > > > > >> Spark
> > > > >> > > > > > >> >> > dev
> > > > >> > > > > > >> >> > >> > > voiced
> > > > >> > > > > > >> >> > >> > > > > the
> > > > >> > > > > > >> >> > >> > > > > >> > same
> > > > >> > > > > > >> >> > >> > > > > >> > > > >>> choice.
> > > > >> > > > > > >> >> > >> > > > > >> > > > >>> > >> >
> > > > >> > > > > > >> >> > >> > > > > >> > > > >>> > >> > +1 for adding
> > > overload
> > > > >> with
> > > > >> > > > > timeout
> > > > >> > > > > > >> >> > parameter.
> > > > >> > > > > > >> >> > >> > > > > >> > > > >>> > >> >
> > > > >> > > > > > >> >> > >> > > > > >> > > > >>> > >> > Cheers
> > > > >> > > > > > >> >> > >> > > > > >> > > > >>> > >> >
> > > > >> > > > > > >> >> > >> > > > > >> > > > >>> > >> > On Mon, Mar 5, 2018
> > > at
> > > > >> 2:42
> > > > >> > > PM,
> > > > >> > > > > > Jason
> > > > >> > > > > > >> >> > >> Gustafson <
> > > > >> > > > > > >> >> > >> > > > > >> > > > >>> jason@confluent.io>
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> > > > >> > > > > > >> >> > >> > > > > >> > > it
> > > > >> > > > > > >> >> > >> > > > > >> > > > >>> might
> > > > >> > > > > > >> >> > >> > > > > >> > > > >>> > be
> > > > >> > > > > > >> >> > >> > > > > >> > > > >>> > >> > > safer for an
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> > > > >> > > > > > >> >> > >> > > > > >> > > > coordinator
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> > 2018
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> > > > >> > 10:14
> > > > >> > > > PM,
> > > > >> > > > > > >> >> Guozhang
> > > > >> > > > > > >> >> > >> Wang
> > > > >> > > > > > >> >> > >> > <
> > > > >> > > > > > >> >> > >> > > > > >> > > > >>> wangguoz@gmail.com>
> > > > >> > > > > > >> >> > >> > > > > >> > > > >>> > >> > wrote:
> > > > >> > > > > > >> >> > >> > > > > >> > > > >>> > >> > >
> > > > >> > > > > > >> >> > >> > > > > >> > > > >>> > >> > > > Hello Richard,
> > > > >> > > > > > >> >> > >> > > > > >> > > > >>> > >> > > >
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> > > > >> proposed
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> > > > >> > > > > > >> >> > >> > > > > >> general
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> > > potential
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> > > > >> > > > > > >> >> > >> > > > > >> > > > >>> > >> > > >
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> > > 2018
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> > > > >> > > 11:13
> > > > >> > > > > AM,
> > > > >> > > > > > >> >> Richard
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> > > > >> > > > > > >> >> > >> > > > > >> > > > >>> > >> >
> > > > >> yohan.richard.yu@gmail.com>
> > > > >> > > > > > >> >> > >> > > > > >> > > > >>> > >> > > > wrote:
> > > > >> > > > > > >> >> > >> > > > > >> > > > >>> > >> > > >
> > > > >> > > > > > >> >> > >> > > > > >> > > > >>> > >> > > > > Hi all,
> > > > >> > > > > > >> >> > >> > > > > >> > > > >>> > >> > > > >
> > > > >> > > > > > >> >> > >> > > > > >> > > > >>> > >> > > > > I would like
> > to
> > > > >> > discuss
> > > > >> > > a
> > > > >> > > > > > >> potential
> > > > >> > > > > > >> >> > >> change
> > > > >> > > > > > >> >> > >> > > > which
> > > > >> > > > > > >> >> > >> > > > > >> would
> > > > >> > > > > > >> >> > >> > > > > >> > > be
> > > > >> > > > > > >> >> > >> > > > > >> > > > >>> made
> > > > >> > > > > > >> >> > >> > > > > >> > > > >>> > to
> > > > >> > > > > > >> >> > >> > > > > >> > > > >>> > >> > > > >
> > KafkaConsumer:
> > > > >> > > > > > >> >> > >> > > > > >> > > > >>> > >> > > > >
> > > > >> > > https://cwiki.apache.org/
> > > > >> > > > > > >> >> > >> > > > > confluence/pages/viewpage
> > > > >> > > > > > >> >> > >> > > > > >> .
> > > > >> > > > > > >> >> > >> > > > > >> > > > >>> > >> > > >
> > > > >> action?pageId=75974886
> > > > >> > > > > > >> >> > >> > > > > >> > > > >>> > >> > > > >
> > > > >> > > > > > >> >> > >> > > > > >> > > > >>> > >> > > > > Thanks,
> > > > >> > > > > > >> >> > >> > > > > >> > > > >>> > >> > > > > Richard Yu
> > > > >> > > > > > >> >> > >> > > > > >> > > > >>> > >> > > > >
> > > > >> > > > > > >> >> > >> > > > > >> > > > >>> > >> > > >
> > > > >> > > > > > >> >> > >> > > > > >> > > > >>> > >> > > >
> > > > >> > > > > > >> >> > >> > > > > >> > > > >>> > >> > > >
> > > > >> > > > > > >> >> > >> > > > > >> > > > >>> > >> > > > --
> > > > >> > > > > > >> >> > >> > > > > >> > > > >>> > >> > > > -- Guozhang
> > > > >> > > > > > >> >> > >> > > > > >> > > > >>> > >> > > >
> > > > >> > > > > > >> >> > >> > > > > >> > > > >>> > >> > >
> > > > >> > > > > > >> >> > >> > > > > >> > > > >>> > >> >
> > > > >> > > > > > >> >> > >> > > > > >> > > > >>> > >>
> > > > >> > > > > > >> >> > >> > > > > >> > > > >>> > >>
> > > > >> > > > > > >> >> > >> > > > > >> > > > >>> > >>
> > > > >> > > > > > >> >> > >> > > > > >> > > > >>> > >> --
> > > > >> > > > > > >> >> > >> > > > > >> > > > >>> > >> -- Guozhang
> > > > >> > > > > > >> >> > >> > > > > >> > > > >>> > >>
> > > > >> > > > > > >> >> > >> > > > > >> > > > >>> > >
> > > > >> > > > > > >> >> > >> > > > > >> > > > >>> > >
> > > > >> > > > > > >> >> > >> > > > > >> > > > >>> >
> > > > >> > > > > > >> >> > >> > > > > >> > > > >>>
> > > > >> > > > > > >> >> > >> > > > > >> > > > >>
> > > > >> > > > > > >> >> > >> > > > > >> > > > >>
> > > > >> > > > > > >> >> > >> > > > > >> > > > >
> > > > >> > > > > > >> >> > >> > > > > >> > > >
> > > > >> > > > > > >> >> > >> > > > > >> > >
> > > > >> > > > > > >> >> > >> > > > > >> > >
> > > > >> > > > > > >> >> > >> > > > > >> > >
> > > > >> > > > > > >> >> > >> > > > > >> > > --
> > > > >> > > > > > >> >> > >> > > > > >> > > -- Guozhang
> > > > >> > > > > > >> >> > >> > > > > >> > >
> > > > >> > > > > > >> >> > >> > > > > >> >
> > > > >> > > > > > >> >> > >> > > > > >>
> > > > >> > > > > > >> >> > >> > > > > >
> > > > >> > > > > > >> >> > >> > > > > >
> > > > >> > > > > > >> >> > >> > > > >
> > > > >> > > > > > >> >> > >> > > >
> > > > >> > > > > > >> >> > >> > >
> > > > >> > > > > > >> >> > >> >
> > > > >> > > > > > >> >> > >> >
> > > > >> > > > > > >> >> > >> >
> > > > >> > > > > > >> >> > >> > --
> > > > >> > > > > > >> >> > >> > -- Guozhang
> > > > >> > > > > > >> >> > >> >
> > > > >> > > > > > >> >> > >>
> > > > >> > > > > > >> >> > >
> > > > >> > > > > > >> >> > >
> > > > >> > > > > > >> >> >
> > > > >> > > > > > >> >>
> > > > >> > > > > > >> >>
> > > > >> > > > > > >> >>
> > > > >> > > > > > >> >> --
> > > > >> > > > > > >> >> -- Guozhang
> > > > >> > > > > > >> >>
> > > > >> > > > > > >> >
> > > > >> > > > > > >> >
> > > > >> > > > > > >>
> > > > >> > > > > > >
> > > > >> > > > > > >
> > > > >> > > > > >
> > > > >> > > > >
> > > > >> > > >
> > > > >> > >
> > > > >> >
> > > > >>
> > > > >
> > > > >
> > > >
> > >
> > >
> > >
> > > --
> > > -- Guozhang
> > >
> >
Re: [DISCUSSION] KIP-266: Add TimeoutException to KafkaConsumer#position()
Posted by John Roesler <jo...@confluent.io>.
Hey Richard,
I've updated the KIP with the changes discussed here. If you're happy with
the state of it, I think that we're probably ready to call for a vote.
However, I'm about to take a week off for vacation. Do you mind sending the
[VOTE] message and managing the vote thread?
Obviously, you can count me as a non-binding +1.
Thanks,
-John
On Wed, May 2, 2018 at 8:08 PM, Jason Gustafson <ja...@confluent.io> wrote:
> Hey John,
>
> Yeah, I appreciate Becket's point. We do tend to abuse the initial intent
> of ApiException. It's just that it can be awkward to come up with another
> name when the ApiException already has a reasonable and appropriate name
> for the user API. `ClientTimeoutException` is a perfect example of this
> awkwardness. In practice I don't think the convention has provided much
> benefit. I looked around the code and saw only a handful of cases where we
> were checking ApiException directly, and it was just to determine the log
> level of a message. I think I'd probably take the more concise name, even
> if it's a slight abuse of the convention. We use it in similar scenarios in
> the producer, for what it's worth.
>
> -Jason
>
>
> On Wed, May 2, 2018 at 3:26 PM, Richard Yu <yo...@gmail.com>
> wrote:
>
> > Hi John,
> >
> > I don't have any objections to this KIP change. Please go ahead.
> >
> > Thanks,
> > Richard
> >
> > On Wed, May 2, 2018 at 2:54 PM, John Roesler <jo...@confluent.io> wrote:
> >
> > > Thanks Jason,
> > >
> > > I did find some production use cases "on the internet" that use poll(0)
> > > *just* to join the group initially and ignore the response. I suppose
> the
> > > assumption is that it'll be empty on the very first call to poll with
> > > timeout=0. In my opinion, this usage is unsafe, since there's a
> declared
> > > return value. I proposed the method to give these use cases a safe
> > > alternative.
> > >
> > > Of course, there's another safe alternative: just don't ignore the
> > > response.
> > >
> > > I'd agree with the decision to just deprecate the old poll(long) and
> add
> > > only a new poll(Duration). It should be obvious that there's no
> > > non-deprecated way to do what the code I found is doing, so those
> > > developers will either alter their code to handle the response or they
> > will
> > > come back and ask us for the awaitAssignmentMetadata method.
> > >
> > > Better to present a simpler api and wait for a reason to make it more
> > > complicated.
> > >
> > > I'm fine with suggestions 1,2, and 3. Unless Richard objects super
> fast,
> > > I'll update the KIP momentarily.
> > >
> > > Regarding the ClientTimeoutException, this was introduced earlier in
> this
> > > discussion when Becket pointed out that the TimeoutException is a
> > subclass
> > > of ApiException, and therefore implies that a call to the broker timed
> > out.
> > >
> > > Reconsidering this point, I found the javadoc on ApiException to be a
> > > little ambiguous. All it says is that "any API exception that is part
> of
> > > the public protocol should be a subclass of this class...". It's not
> > clear
> > > to me whether this is the broker's API/protocol or more generally *any*
> > > API/protocol. So we'd have to bring the lawyers in, but I think we can
> > just
> > > say it's the latter and keep the old exception.
> > >
> > > I'm not sure if it's an important distiction to users whether their
> > request
> > > timed out as a broker side timeout, an HTTP timeout, or a client-side
> > > timeout. In any case, they'd want to retry for a while and then fail if
> > > they can't get their request through.
> > >
> > > Plus RetryableException also inherits from ApiException, and that one
> is
> > > ubiquitous. Adding a new exception would require users to catch both
> > > RetriableException and ClientTimeoutException, which seems odd since
> the
> > > latter is retriable.
> > >
> > > All in all, I'm now in favor of sticking with the current
> > TimeoutException.
> > > If there's some higher-level problem with the ApiException being used
> > this
> > > way, I think it should be addressed holistically in a separate KIP.
> > >
> > > So, I'll go ahead and switch the KIP back to TimeoutException, unless
> > > Becket wants to argue (harder) in favor of the ClientTimeoutException.
> > >
> > > Thanks,
> > > -John
> > >
> > >
> > > On Wed, May 2, 2018 at 3:55 PM, Jason Gustafson <ja...@confluent.io>
> > > wrote:
> > >
> > > > I think John's proposal look reasonable to me. My only doubt is about
> > use
> > > > cases for the new `awaitAssignmentMetadata` API. I think the basic
> idea
> > > is
> > > > that we want a way to block until we have joined the consumer group,
> > but
> > > we
> > > > do not want to await fetched data. Maybe another way to accomplish
> this
> > > > would be to add a `PollOptions` argument which specified the
> condition
> > we
> > > > are awaiting? It's a little weird that we'd have two separate APIs
> > where
> > > > the group membership can change. I know this functionality can be
> > helpful
> > > > in testing, but we should probably spend some more time understanding
> > and
> > > > motivating the general use cases.
> > > >
> > > > Since we're leaving around the old poll() with its current behavior
> for
> > > > now, I wonder if we could leave this as potential future work?
> > > >
> > > > Other than that, I have a few minor suggestions and I'm happy with
> the
> > > KIP:
> > > >
> > > > 1. Can we use Duration across the board for all of these APIs?
> > > > 2. Can we cover the following blocking APIs with in this KIP:
> > > > `partitionsFor`, `listTopics`, `offsetsForTimes`, `beginningOffsets`,
> > > > `endOffsets`?
> > > > 3. Perhaps we can add a `close(Duration)` and deprecate the one
> > accepting
> > > > `TimeUnit`?
> > > > 4. Seems we don't really need `ClientTimeoutException` since we
> already
> > > > have `TimeoutException`?
> > > >
> > > > Thanks,
> > > > Jason
> > > >
> > > >
> > > >
> > > > On Wed, Apr 25, 2018 at 2:14 PM, Guozhang Wang <wa...@gmail.com>
> > > wrote:
> > > >
> > > > > Previously there are some debates on whether we should add this
> > > > nonblocking
> > > > > behavior via a config v.s. via overloaded functions. To make
> progress
> > > on
> > > > > this discussion we need to first figure that part out. I'm in favor
> > of
> > > > the
> > > > > current approach of overloaded functions over the config since if
> we
> > > are
> > > > > going to have multiple configs other than a single one to control
> > > timeout
> > > > > semantics it may be even confusing: take our producer side configs
> > for
> > > an
> > > > > example, right now we have "request.timeout.ms" and "max.block.ms"
> > and
> > > > we
> > > > > are proposing to add another one in KIP-91. But I'd also like to
> hear
> > > > from
> > > > > people who's in favor of the configs.
> > > > >
> > > > >
> > > > > Guozhang
> > > > >
> > > > >
> > > > > On Wed, Apr 25, 2018 at 1:39 PM, John Roesler <jo...@confluent.io>
> > > wrote:
> > > > >
> > > > > > Re Ted's last comment, that style of async API requires some
> thread
> > > to
> > > > > > actually drive the request/response cycle and invoke the callback
> > > when
> > > > > it's
> > > > > > complete. Right now, this happens in the caller's thread as a
> > > > side-effect
> > > > > > of calling poll(). But that clearly won't work for poll() itself!
> > > > > >
> > > > > > In the future, I think we'd like to add a background thread to
> > drive
> > > > the
> > > > > > request/response loops, and then make all these methods return
> > > > > > Future<Whatever>.
> > > > > >
> > > > > > But we don't need to bite that off right now.
> > > > > >
> > > > > > The "async" model I'm proposing is really just a generalization
> of
> > > the
> > > > > one
> > > > > > that poll already partially implements: when you call poll, it
> > fires
> > > > off
> > > > > > any requests it needs to make and checks if any responses are
> > ready.
> > > If
> > > > > so,
> > > > > > it returns them. If not, it returns empty. When you call poll()
> > > again,
> > > > it
> > > > > > again checks on the responses from last time, and so forth.
> > > > > >
> > > > > > But that model currently only applies to the "fetch" part of
> poll.
> > > I'm
> > > > > > proposing that we extend it to the "metadata update" part of poll
> > as
> > > > > well.
> > > > > >
> > > > > > However, as previously discussed, doing this in place would break
> > the
> > > > > > semantics of poll that folks currently rely on, so I propose to
> add
> > > new
> > > > > > methods and deprecate the existing poll method. Here's what I'm
> > > > thinking:
> > > > > > https://github.com/apache/kafka/pull/4855 . In the discussion on
> > > that
> > > > > PR,
> > > > > > I've described in greater detail how the async+blocking semantics
> > > work.
> > > > > >
> > > > > > I'll update KIP-266 with this interface for poll().
> > > > > >
> > > > > > It would be great to get this discussion moving again so we can
> get
> > > > these
> > > > > > changes into 2.0. What does everyone think about this?
> > > > > >
> > > > > > Thanks,
> > > > > > -John
> > > > > >
> > > > > > On Thu, Apr 19, 2018 at 5:12 PM, John Roesler <john@confluent.io
> >
> > > > wrote:
> > > > > >
> > > > > > > Thanks for the tip, Ted!
> > > > > > >
> > > > > > > On Thu, Apr 19, 2018 at 12:12 PM, Ted Yu <yu...@gmail.com>
> > > > wrote:
> > > > > > >
> > > > > > >> John:
> > > > > > >> In case you want to pursue async poll, it seems (by looking at
> > > > current
> > > > > > >> API)
> > > > > > >> that introducing PollCallback follows existing pattern(s).
> > > > > > >>
> > > > > > >> e.g. KafkaConsumer#commitAsync(OffsetCommitCallback)
> > > > > > >>
> > > > > > >> FYI
> > > > > > >>
> > > > > > >> On Thu, Apr 19, 2018 at 10:08 AM, John Roesler <
> > john@confluent.io
> > > >
> > > > > > wrote:
> > > > > > >>
> > > > > > >> > Hi Richard,
> > > > > > >> >
> > > > > > >> > Thanks for the invitation! I do think it would be safer to
> > > > > introduce a
> > > > > > >> new
> > > > > > >> > poll
> > > > > > >> > method than to change the semantics of the old one. I've
> been
> > > > > mulling
> > > > > > >> about
> > > > > > >> > whether the new one could still have (slightly different)
> > async
> > > > > > >> semantics
> > > > > > >> > with
> > > > > > >> > a timeout of 0. If possible, I'd like to avoid introducing
> > > another
> > > > > new
> > > > > > >> > "asyncPoll".
> > > > > > >> >
> > > > > > >> > I'm planning to run some experiments and dig into the
> > > > > implementation a
> > > > > > >> bit
> > > > > > >> > more before solidifying the proposal. I'll update the KIP as
> > you
> > > > > > >> suggest at
> > > > > > >> > that point,
> > > > > > >> > and then can call for another round of reviews and voting.
> > > > > > >> >
> > > > > > >> > Thanks,
> > > > > > >> > -John
> > > > > > >> >
> > > > > > >> > On Tue, Apr 17, 2018 at 4:53 PM, Richard Yu <
> > > > > > yohan.richard.yu@gmail.com
> > > > > > >> >
> > > > > > >> > wrote:
> > > > > > >> >
> > > > > > >> > > Hi John,
> > > > > > >> > >
> > > > > > >> > > Do you have a preference for fixing the poll() method
> (e.g.
> > > > using
> > > > > > >> > asyncPoll
> > > > > > >> > > or just sticking with the current method but with an extra
> > > > timeout
> > > > > > >> > > parameter) ? I think your current proposition for KIP-288
> is
> > > > > better
> > > > > > >> than
> > > > > > >> > > what I have on my side. If you think there is something
> that
> > > you
> > > > > > want
> > > > > > >> to
> > > > > > >> > > add, you could go ahead and change KIP-266 to your liking.
> > > Just
> > > > to
> > > > > > >> note
> > > > > > >> > > that it would be preferable that if one of us modifies
> this
> > > KIP,
> > > > > it
> > > > > > >> would
> > > > > > >> > > be best to mention your change on this thread to let each
> > > other
> > > > > know
> > > > > > >> > (makes
> > > > > > >> > > it easier to coordinate progress).
> > > > > > >> > >
> > > > > > >> > > Thanks,
> > > > > > >> > > Richard
> > > > > > >> > >
> > > > > > >> > > On Tue, Apr 17, 2018 at 2:07 PM, John Roesler <
> > > > john@confluent.io>
> > > > > > >> wrote:
> > > > > > >> > >
> > > > > > >> > > > Ok, I'll close the discussion on KIP-288 and mark it
> > > > discarded.
> > > > > > >> > > >
> > > > > > >> > > > We can solidify the design for poll in KIP-266, and once
> > > it's
> > > > > > >> approved,
> > > > > > >> > > > I'll coordinate with Qiang Zhao on the PR for the poll
> > part
> > > of
> > > > > the
> > > > > > >> > work.
> > > > > > >> > > > Once that is merged, you'll have a clean slate for the
> > rest
> > > of
> > > > > the
> > > > > > >> > work.
> > > > > > >> > > >
> > > > > > >> > > > On Tue, Apr 17, 2018 at 3:39 PM, Richard Yu <
> > > > > > >> > yohan.richard.yu@gmail.com>
> > > > > > >> > > > wrote:
> > > > > > >> > > >
> > > > > > >> > > > > Hi John,
> > > > > > >> > > > >
> > > > > > >> > > > > I think that you could finish your PR that corresponds
> > > with
> > > > > > >> KIP-288
> > > > > > >> > and
> > > > > > >> > > > > merge it. I can finish my side of the work afterwards.
> > > > > > >> > > > >
> > > > > > >> > > > > On another note, adding an asynchronized version of
> > poll()
> > > > > would
> > > > > > >> make
> > > > > > >> > > > > sense, particularily since the current version of
> Kafka
> > > does
> > > > > not
> > > > > > >> > > support
> > > > > > >> > > > > it.
> > > > > > >> > > > >
> > > > > > >> > > > > Thanks
> > > > > > >> > > > > Richar
> > > > > > >> > > > >
> > > > > > >> > > > > On Tue, Apr 17, 2018 at 12:30 PM, John Roesler <
> > > > > > john@confluent.io
> > > > > > >> >
> > > > > > >> > > > wrote:
> > > > > > >> > > > >
> > > > > > >> > > > > > Cross-pollinating from some discussion we've had on
> > > > KIP-288,
> > > > > > >> > > > > >
> > > > > > >> > > > > > I think there's a good reason that poll() takes a
> > > timeout
> > > > > when
> > > > > > >> none
> > > > > > >> > > of
> > > > > > >> > > > > the
> > > > > > >> > > > > > other methods do, and it's relevant to this
> > discussion.
> > > > The
> > > > > > >> timeout
> > > > > > >> > > in
> > > > > > >> > > > > > poll() is effectively implementing a long-poll API
> (on
> > > the
> > > > > > >> client
> > > > > > >> > > side,
> > > > > > >> > > > > so
> > > > > > >> > > > > > it's not really long-poll, but the programmer-facing
> > > > > behavior
> > > > > > is
> > > > > > >> > the
> > > > > > >> > > > > same).
> > > > > > >> > > > > > The timeout isn't really bounding the execution time
> > of
> > > > the
> > > > > > >> method,
> > > > > > >> > > but
> > > > > > >> > > > > > instead giving a max time that callers are willing
> to
> > > wait
> > > > > > >> around
> > > > > > >> > and
> > > > > > >> > > > see
> > > > > > >> > > > > > if any results show up.
> > > > > > >> > > > > >
> > > > > > >> > > > > > If I understand the code sufficiently, it would be
> > > > perfectly
> > > > > > >> > > reasonable
> > > > > > >> > > > > for
> > > > > > >> > > > > > a caller to use a timeout of 0 to implement async
> > poll,
> > > it
> > > > > > would
> > > > > > >> > just
> > > > > > >> > > > > mean
> > > > > > >> > > > > > that KafkaConsumer would just check on each call if
> > > > there's
> > > > > a
> > > > > > >> > > response
> > > > > > >> > > > > > ready and if not, fire off a new request without
> > waiting
> > > > > for a
> > > > > > >> > > > response.
> > > > > > >> > > > > >
> > > > > > >> > > > > > As such, it seems inappropriate to throw a
> > > > > > >> ClientTimeoutException
> > > > > > >> > > from
> > > > > > >> > > > > > poll(), except possibly if the initial phase of
> > ensuring
> > > > an
> > > > > > >> > > assignment
> > > > > > >> > > > > > times out. We wouldn't want the method contract to
> be
> > > > > > "returns a
> > > > > > >> > > > > non-empty
> > > > > > >> > > > > > collection or throws a ClientTimeoutException"
> > > > > > >> > > > > >
> > > > > > >> > > > > > Now, I'm wondering if we should actually consider
> one
> > of
> > > > my
> > > > > > >> > rejected
> > > > > > >> > > > > > alternatives, to treat the "operation timeout" as a
> > > > separate
> > > > > > >> > > parameter
> > > > > > >> > > > > from
> > > > > > >> > > > > > the "long-poll time". Or maybe adding an
> > > > "asyncPoll(timeout,
> > > > > > >> time
> > > > > > >> > > > unit)"
> > > > > > >> > > > > > that only uses the timeout to bound metadata updates
> > and
> > > > > > >> otherwise
> > > > > > >> > > > > behaves
> > > > > > >> > > > > > like the current "poll(0)".
> > > > > > >> > > > > >
> > > > > > >> > > > > > Thanks,
> > > > > > >> > > > > > -John
> > > > > > >> > > > > >
> > > > > > >> > > > > > On Tue, Apr 17, 2018 at 2:05 PM, John Roesler <
> > > > > > >> john@confluent.io>
> > > > > > >> > > > wrote:
> > > > > > >> > > > > >
> > > > > > >> > > > > > > Hey Richard,
> > > > > > >> > > > > > >
> > > > > > >> > > > > > > As you noticed, the newly introduced KIP-288
> > overlaps
> > > > with
> > > > > > >> this
> > > > > > >> > > one.
> > > > > > >> > > > > > Sorry
> > > > > > >> > > > > > > for stepping on your toes... How would you like to
> > > > > proceed?
> > > > > > >> I'm
> > > > > > >> > > happy
> > > > > > >> > > > > to
> > > > > > >> > > > > > > "close" KIP-288 in deference to this KIP.
> > > > > > >> > > > > > >
> > > > > > >> > > > > > > With respect to poll(), reading this discussion
> gave
> > > me
> > > > a
> > > > > > new
> > > > > > >> > idea
> > > > > > >> > > > for
> > > > > > >> > > > > > > providing a non-breaking update path... What if we
> > > > > > introduce a
> > > > > > >> > new
> > > > > > >> > > > > > variant
> > > > > > >> > > > > > > 'poll(long timeout, TimeUnit unit)' that displays
> > the
> > > > new,
> > > > > > >> > desired
> > > > > > >> > > > > > > behavior, and just leave the old method alone?
> > > > > > >> > > > > > >
> > > > > > >> > > > > > > Thanks,
> > > > > > >> > > > > > > -John
> > > > > > >> > > > > > >
> > > > > > >> > > > > > > On Tue, Apr 17, 2018 at 12:09 PM, Richard Yu <
> > > > > > >> > > > > yohan.richard.yu@gmail.com
> > > > > > >> > > > > > >
> > > > > > >> > > > > > > wrote:
> > > > > > >> > > > > > >
> > > > > > >> > > > > > >> Hi all,
> > > > > > >> > > > > > >>
> > > > > > >> > > > > > >> If possible, would a committer please review?
> > > > > > >> > > > > > >>
> > > > > > >> > > > > > >> Thanks
> > > > > > >> > > > > > >>
> > > > > > >> > > > > > >> On Sun, Apr 1, 2018 at 7:24 PM, Richard Yu <
> > > > > > >> > > > > yohan.richard.yu@gmail.com>
> > > > > > >> > > > > > >> wrote:
> > > > > > >> > > > > > >>
> > > > > > >> > > > > > >> > Hi Guozhang,
> > > > > > >> > > > > > >> >
> > > > > > >> > > > > > >> > I have clarified the KIP a bit to account for
> > > > Becket's
> > > > > > >> > > suggestion
> > > > > > >> > > > on
> > > > > > >> > > > > > >> > ClientTimeoutException.
> > > > > > >> > > > > > >> > About adding an extra config, you were right
> > about
> > > my
> > > > > > >> > > intentions.
> > > > > > >> > > > I
> > > > > > >> > > > > am
> > > > > > >> > > > > > >> > just wondering if the config
> > > > > > >> > > > > > >> > should be included, since Ismael seems to favor
> > an
> > > > > extra
> > > > > > >> > > > > > configuration,
> > > > > > >> > > > > > >> >
> > > > > > >> > > > > > >> > Thanks,
> > > > > > >> > > > > > >> > Richard
> > > > > > >> > > > > > >> >
> > > > > > >> > > > > > >> > On Sun, Apr 1, 2018 at 5:35 PM, Guozhang Wang <
> > > > > > >> > > wangguoz@gmail.com
> > > > > > >> > > > >
> > > > > > >> > > > > > >> wrote:
> > > > > > >> > > > > > >> >
> > > > > > >> > > > > > >> >> Hi Richard,
> > > > > > >> > > > > > >> >>
> > > > > > >> > > > > > >> >> Regarding the streams side changes, we plan to
> > > > > > incorporate
> > > > > > >> > with
> > > > > > >> > > > the
> > > > > > >> > > > > > new
> > > > > > >> > > > > > >> >> APIs once the KIP is done, which is only
> > internal
> > > > code
> > > > > > >> > changes
> > > > > > >> > > > and
> > > > > > >> > > > > > >> hence
> > > > > > >> > > > > > >> >> do
> > > > > > >> > > > > > >> >> not need to include in the KIP.
> > > > > > >> > > > > > >> >>
> > > > > > >> > > > > > >> >> Could you update the KIP because it has been
> > quite
> > > > > > >> obsoleted
> > > > > > >> > > from
> > > > > > >> > > > > the
> > > > > > >> > > > > > >> >> discussed topics, and I'm a bit loosing track
> on
> > > > what
> > > > > is
> > > > > > >> your
> > > > > > >> > > > final
> > > > > > >> > > > > > >> >> proposal right now. For example, I'm not
> > > completely
> > > > > > >> following
> > > > > > >> > > > your
> > > > > > >> > > > > > >> >> "compromise
> > > > > > >> > > > > > >> >> of sorts": are you suggesting that we still
> add
> > > > > > >> overloading
> > > > > > >> > > > > functions
> > > > > > >> > > > > > >> and
> > > > > > >> > > > > > >> >> add a config that will be applied to all
> > overload
> > > > > > >> functions
> > > > > > >> > > > without
> > > > > > >> > > > > > the
> > > > > > >> > > > > > >> >> timeout, while for other overloaded functions
> > with
> > > > the
> > > > > > >> > timeout
> > > > > > >> > > > > value
> > > > > > >> > > > > > >> the
> > > > > > >> > > > > > >> >> config will be ignored?
> > > > > > >> > > > > > >> >>
> > > > > > >> > > > > > >> >>
> > > > > > >> > > > > > >> >> Guozhang
> > > > > > >> > > > > > >> >>
> > > > > > >> > > > > > >> >> On Fri, Mar 30, 2018 at 8:36 PM, Richard Yu <
> > > > > > >> > > > > > >> yohan.richard.yu@gmail.com>
> > > > > > >> > > > > > >> >> wrote:
> > > > > > >> > > > > > >> >>
> > > > > > >> > > > > > >> >> > On a side note, I have noticed that the
> > several
> > > > > other
> > > > > > >> > methods
> > > > > > >> > > > in
> > > > > > >> > > > > > >> classes
> > > > > > >> > > > > > >> >> > such as StoreChangeLogReader in Streams
> calls
> > > > > > position()
> > > > > > >> > > which
> > > > > > >> > > > > > causes
> > > > > > >> > > > > > >> >> tests
> > > > > > >> > > > > > >> >> > to hang. It might be out of the scope of the
> > > KIP,
> > > > > but
> > > > > > >> > should
> > > > > > >> > > I
> > > > > > >> > > > > also
> > > > > > >> > > > > > >> >> change
> > > > > > >> > > > > > >> >> > the methods which use position() as a
> callback
> > > to
> > > > at
> > > > > > the
> > > > > > >> > very
> > > > > > >> > > > > least
> > > > > > >> > > > > > >> >> prevent
> > > > > > >> > > > > > >> >> > the tests from hanging? This issue might be
> > out
> > > of
> > > > > the
> > > > > > >> KIP,
> > > > > > >> > > > but I
> > > > > > >> > > > > > >> >> prefer it
> > > > > > >> > > > > > >> >> > if we could at least make my PR pass the
> > Jenkins
> > > > > Q&A.
> > > > > > >> > > > > > >> >> >
> > > > > > >> > > > > > >> >> > Thanks
> > > > > > >> > > > > > >> >> >
> > > > > > >> > > > > > >> >> > On Fri, Mar 30, 2018 at 8:24 PM, Richard Yu
> <
> > > > > > >> > > > > > >> yohan.richard.yu@gmail.com
> > > > > > >> > > > > > >> >> >
> > > > > > >> > > > > > >> >> > wrote:
> > > > > > >> > > > > > >> >> >
> > > > > > >> > > > > > >> >> > > Thanks for the review Becket.
> > > > > > >> > > > > > >> >> > >
> > > > > > >> > > > > > >> >> > > About the methods beginningOffsets(),
> > > > > endOffsets(),
> > > > > > >> ...:
> > > > > > >> > > > > > >> >> > > I took a look through the code of
> > > KafkaConsumer,
> > > > > but
> > > > > > >> > after
> > > > > > >> > > > > > looking
> > > > > > >> > > > > > >> >> > through
> > > > > > >> > > > > > >> >> > > the offsetsByTimes() method
> > > > > > >> > > > > > >> >> > > and its callbacks in Fetcher, I think
> these
> > > > > methods
> > > > > > >> > already
> > > > > > >> > > > > block
> > > > > > >> > > > > > >> for
> > > > > > >> > > > > > >> >> a
> > > > > > >> > > > > > >> >> > > set period of time. I know that there
> > > > > > >> > > > > > >> >> > > is a chance that the offsets methods in
> > > > > > KafkaConsumer
> > > > > > >> > might
> > > > > > >> > > > be
> > > > > > >> > > > > > like
> > > > > > >> > > > > > >> >> poll
> > > > > > >> > > > > > >> >> > > (that is one section of the method
> > > > > > >> > > > > > >> >> > > honors the timeout while another --
> > > > > > >> updateFetchPositions
> > > > > > >> > --
> > > > > > >> > > > > does
> > > > > > >> > > > > > >> not).
> > > > > > >> > > > > > >> >> > > However, I don't think that this is the
> > > > > > >> > > > > > >> >> > > case with offsetsByTimes since the
> callbacks
> > > > that
> > > > > I
> > > > > > >> > checked
> > > > > > >> > > > > does
> > > > > > >> > > > > > >> not
> > > > > > >> > > > > > >> >> seem
> > > > > > >> > > > > > >> >> > > to hang.
> > > > > > >> > > > > > >> >> > >
> > > > > > >> > > > > > >> >> > > The clarity of the exception message is a
> > > > > problem. I
> > > > > > >> > > thought
> > > > > > >> > > > > your
> > > > > > >> > > > > > >> >> > > suggestion there was reasonable. I
> included
> > > > > > >> > > > > > >> >> > > it in the KIP.
> > > > > > >> > > > > > >> >> > >
> > > > > > >> > > > > > >> >> > > And on another note, I have noticed that
> > > several
> > > > > > >> people
> > > > > > >> > has
> > > > > > >> > > > > > voiced
> > > > > > >> > > > > > >> the
> > > > > > >> > > > > > >> >> > > opinion that adding a config might
> > > > > > >> > > > > > >> >> > > be advisable in relation to adding an
> extra
> > > > > > >> parameter. I
> > > > > > >> > > > think
> > > > > > >> > > > > > >> that we
> > > > > > >> > > > > > >> >> > can
> > > > > > >> > > > > > >> >> > > have a compromise of sorts: some
> > > > > > >> > > > > > >> >> > > methods in KafkaConsumer are relatively
> > > similar
> > > > --
> > > > > > for
> > > > > > >> > > > example,
> > > > > > >> > > > > > >> >> > position()
> > > > > > >> > > > > > >> >> > > and committed() both call
> > > > > > >> > > > > > >> >> > > updateFetchPositions(). I think that we
> > could
> > > > use
> > > > > > the
> > > > > > >> > same
> > > > > > >> > > > > config
> > > > > > >> > > > > > >> for
> > > > > > >> > > > > > >> >> > > these method as a default timeout if
> > > > > > >> > > > > > >> >> > > the user does not provide one. On the
> other
> > > > hand,
> > > > > if
> > > > > > >> they
> > > > > > >> > > > wish
> > > > > > >> > > > > to
> > > > > > >> > > > > > >> >> specify
> > > > > > >> > > > > > >> >> > > a longer or shorter blocking time,
> > > > > > >> > > > > > >> >> > > they have the option of changing the
> > timeout.
> > > (I
> > > > > > >> included
> > > > > > >> > > the
> > > > > > >> > > > > > >> config
> > > > > > >> > > > > > >> >> as
> > > > > > >> > > > > > >> >> > an
> > > > > > >> > > > > > >> >> > > alternative in the KIP) WDYT?
> > > > > > >> > > > > > >> >> > >
> > > > > > >> > > > > > >> >> > > Thanks,
> > > > > > >> > > > > > >> >> > > Richard
> > > > > > >> > > > > > >> >> > >
> > > > > > >> > > > > > >> >> > >
> > > > > > >> > > > > > >> >> > > On Fri, Mar 30, 2018 at 1:26 AM, Becket
> Qin
> > <
> > > > > > >> > > > > > becket.qin@gmail.com>
> > > > > > >> > > > > > >> >> > wrote:
> > > > > > >> > > > > > >> >> > >
> > > > > > >> > > > > > >> >> > >> Glad to see the KIP, Richard. This has
> > been a
> > > > > > really
> > > > > > >> > long
> > > > > > >> > > > > > pending
> > > > > > >> > > > > > >> >> issue.
> > > > > > >> > > > > > >> >> > >>
> > > > > > >> > > > > > >> >> > >> The original arguments from Jay for using
> > > > config,
> > > > > > >> such
> > > > > > >> > as
> > > > > > >> > > > > > >> >> max.block.ms,
> > > > > > >> > > > > > >> >> > >> instead of using timeout parameters was
> > that
> > > > > people
> > > > > > >> will
> > > > > > >> > > > > always
> > > > > > >> > > > > > >> hard
> > > > > > >> > > > > > >> >> > code
> > > > > > >> > > > > > >> >> > >> the timeout, and the hard coded timeout
> is
> > > > rarely
> > > > > > >> > correct
> > > > > > >> > > > > > because
> > > > > > >> > > > > > >> it
> > > > > > >> > > > > > >> >> has
> > > > > > >> > > > > > >> >> > >> to
> > > > > > >> > > > > > >> >> > >> consider different scenarios. For
> example,
> > > > users
> > > > > > may
> > > > > > >> > > receive
> > > > > > >> > > > > > >> timeout
> > > > > > >> > > > > > >> >> > >> exception when the group coordinator
> moves.
> > > > > Having
> > > > > > a
> > > > > > >> > > > > > configuration
> > > > > > >> > > > > > >> >> with
> > > > > > >> > > > > > >> >> > >> some reasonable default value will make
> > > users'
> > > > > life
> > > > > > >> > > easier.
> > > > > > >> > > > > > >> >> > >>
> > > > > > >> > > > > > >> >> > >> That said, in practice, it seems more
> > useful
> > > to
> > > > > > have
> > > > > > >> > > timeout
> > > > > > >> > > > > > >> >> parameters.
> > > > > > >> > > > > > >> >> > >> We
> > > > > > >> > > > > > >> >> > >> have seen some library, using the
> consumers
> > > > > > >> internally,
> > > > > > >> > > > needs
> > > > > > >> > > > > to
> > > > > > >> > > > > > >> >> provide
> > > > > > >> > > > > > >> >> > >> an
> > > > > > >> > > > > > >> >> > >> external flexible timeout interface.
> Also,
> > > user
> > > > > can
> > > > > > >> > easily
> > > > > > >> > > > > hard
> > > > > > >> > > > > > >> code
> > > > > > >> > > > > > >> >> a
> > > > > > >> > > > > > >> >> > >> value to get the same as a config based
> > > > solution.
> > > > > > >> > > > > > >> >> > >>
> > > > > > >> > > > > > >> >> > >> The KIP looks good overall. A few
> comments:
> > > > > > >> > > > > > >> >> > >>
> > > > > > >> > > > > > >> >> > >> 1. There are a few other blocking methods
> > > that
> > > > > are
> > > > > > >> not
> > > > > > >> > > > > included,
> > > > > > >> > > > > > >> e.g.
> > > > > > >> > > > > > >> >> > >> offsetsForTimes(), beginningOffsets(),
> > > > > > endOffsets().
> > > > > > >> Is
> > > > > > >> > > > there
> > > > > > >> > > > > > any
> > > > > > >> > > > > > >> >> > reason?
> > > > > > >> > > > > > >> >> > >>
> > > > > > >> > > > > > >> >> > >> 2. I am wondering can we take the KIP as
> a
> > > > chance
> > > > > > to
> > > > > > >> > clean
> > > > > > >> > > > up
> > > > > > >> > > > > > our
> > > > > > >> > > > > > >> >> > timeout
> > > > > > >> > > > > > >> >> > >> exception(s)? More specifically, instead
> of
> > > > > reusing
> > > > > > >> > > > > > >> TimeoutException,
> > > > > > >> > > > > > >> >> > can
> > > > > > >> > > > > > >> >> > >> we introduce a new ClientTimeoutException
> > > with
> > > > > > >> different
> > > > > > >> > > > > causes,
> > > > > > >> > > > > > >> e.g.
> > > > > > >> > > > > > >> >> > >> UnknownTopicOrPartition, RequestTimeout,
> > > > > > >> > > LeaderNotAvailable,
> > > > > > >> > > > > > etc.
> > > > > > >> > > > > > >> >> > >> As of now, the TimeoutException is used
> in
> > > the
> > > > > > >> following
> > > > > > >> > > > three
> > > > > > >> > > > > > >> cases:
> > > > > > >> > > > > > >> >> > >>
> > > > > > >> > > > > > >> >> > >> 1. TimeoutException is a subclass of
> > > > > > ApiException
> > > > > > >> > which
> > > > > > >> > > > > > >> indicates
> > > > > > >> > > > > > >> >> the
> > > > > > >> > > > > > >> >> > >> exception was returned by the broker.
> > The
> > > > > > >> > > > TimeoutException
> > > > > > >> > > > > > was
> > > > > > >> > > > > > >> >> > >> initially
> > > > > > >> > > > > > >> >> > >> returned by the leaders when
> replication
> > > was
> > > > > not
> > > > > > >> done
> > > > > > >> > > > > within
> > > > > > >> > > > > > >> the
> > > > > > >> > > > > > >> >> > >> specified
> > > > > > >> > > > > > >> >> > >> timeout in the ProduceRequest. It has
> an
> > > > error
> > > > > > >> code
> > > > > > >> > of
> > > > > > >> > > 7,
> > > > > > >> > > > > > >> which is
> > > > > > >> > > > > > >> >> > >> returned
> > > > > > >> > > > > > >> >> > >> by the broker.
> > > > > > >> > > > > > >> >> > >> 2. When we migrate to Java clients, in
> > > > Errors
> > > > > > >> > > definition,
> > > > > > >> > > > > we
> > > > > > >> > > > > > >> >> extended
> > > > > > >> > > > > > >> >> > >> it
> > > > > > >> > > > > > >> >> > >> to indicate request timeout, i.e. a
> > > request
> > > > > was
> > > > > > >> sent
> > > > > > >> > > but
> > > > > > >> > > > > the
> > > > > > >> > > > > > >> >> response
> > > > > > >> > > > > > >> >> > >> was
> > > > > > >> > > > > > >> >> > >> not received before timeout. In this
> > case,
> > > > the
> > > > > > >> > clients
> > > > > > >> > > > did
> > > > > > >> > > > > > not
> > > > > > >> > > > > > >> >> have a
> > > > > > >> > > > > > >> >> > >> return code from the broker.
> > > > > > >> > > > > > >> >> > >> 3. Later at some point, we started to
> > use
> > > > the
> > > > > > >> > > > > > TimeoutException
> > > > > > >> > > > > > >> for
> > > > > > >> > > > > > >> >> > >> clients method call timeout. It is
> > neither
> > > > > > >> related to
> > > > > > >> > > any
> > > > > > >> > > > > > >> broker
> > > > > > >> > > > > > >> >> > >> returned
> > > > > > >> > > > > > >> >> > >> error code, nor to request timeout on
> > the
> > > > > wire.
> > > > > > >> > > > > > >> >> > >>
> > > > > > >> > > > > > >> >> > >> Due to the various interpretations, users
> > can
> > > > > > easily
> > > > > > >> be
> > > > > > >> > > > > > confused.
> > > > > > >> > > > > > >> As
> > > > > > >> > > > > > >> >> an
> > > > > > >> > > > > > >> >> > >> example, when a timeout is thrown with
> > > "Failed
> > > > to
> > > > > > >> > refresh
> > > > > > >> > > > > > metadata
> > > > > > >> > > > > > >> >> in X
> > > > > > >> > > > > > >> >> > >> ms", it is hard to tell what exactly
> > > happened.
> > > > > > Since
> > > > > > >> we
> > > > > > >> > > are
> > > > > > >> > > > > > >> changing
> > > > > > >> > > > > > >> >> the
> > > > > > >> > > > > > >> >> > >> API here, it would be good to avoid
> > > introducing
> > > > > > more
> > > > > > >> > > > ambiguity
> > > > > > >> > > > > > and
> > > > > > >> > > > > > >> >> see
> > > > > > >> > > > > > >> >> > >> whether this can be improved. It would be
> > at
> > > > > least
> > > > > > >> one
> > > > > > >> > > step
> > > > > > >> > > > > > >> forward
> > > > > > >> > > > > > >> >> to
> > > > > > >> > > > > > >> >> > >> remove the usage of case 3.
> > > > > > >> > > > > > >> >> > >>
> > > > > > >> > > > > > >> >> > >> Thanks,
> > > > > > >> > > > > > >> >> > >>
> > > > > > >> > > > > > >> >> > >> Jiangjie (Becket) Qin
> > > > > > >> > > > > > >> >> > >>
> > > > > > >> > > > > > >> >> > >>
> > > > > > >> > > > > > >> >> > >>
> > > > > > >> > > > > > >> >> > >>
> > > > > > >> > > > > > >> >> > >> On Mon, Mar 26, 2018 at 5:50 PM, Guozhang
> > > Wang
> > > > <
> > > > > > >> > > > > > >> wangguoz@gmail.com>
> > > > > > >> > > > > > >> >> > >> wrote:
> > > > > > >> > > > > > >> >> > >>
> > > > > > >> > > > > > >> >> > >> > @Richard: TimeoutException inherits
> from
> > > > > > >> > > > RetriableException
> > > > > > >> > > > > > >> which
> > > > > > >> > > > > > >> >> > >> inherits
> > > > > > >> > > > > > >> >> > >> > from ApiException. So users should
> > > explicitly
> > > > > try
> > > > > > >> to
> > > > > > >> > > > capture
> > > > > > >> > > > > > >> >> > >> > RetriableException in their code and
> > handle
> > > > the
> > > > > > >> > > exception.
> > > > > > >> > > > > > >> >> > >> >
> > > > > > >> > > > > > >> >> > >> > @Isamel, Ewen: I'm trying to push
> > progress
> > > > > > forward
> > > > > > >> on
> > > > > > >> > > this
> > > > > > >> > > > > > one,
> > > > > > >> > > > > > >> >> are we
> > > > > > >> > > > > > >> >> > >> now
> > > > > > >> > > > > > >> >> > >> > on the same page for using function
> > > > parameters
> > > > > > than
> > > > > > >> > > > configs?
> > > > > > >> > > > > > >> >> > >> >
> > > > > > >> > > > > > >> >> > >> >
> > > > > > >> > > > > > >> >> > >> > Guozhang
> > > > > > >> > > > > > >> >> > >> >
> > > > > > >> > > > > > >> >> > >> >
> > > > > > >> > > > > > >> >> > >> > On Fri, Mar 23, 2018 at 4:42 PM, Ismael
> > > Juma
> > > > <
> > > > > > >> > > > > > ismael@juma.me.uk
> > > > > > >> > > > > > >> >
> > > > > > >> > > > > > >> >> > wrote:
> > > > > > >> > > > > > >> >> > >> >
> > > > > > >> > > > > > >> >> > >> > > Hi Ewen,
> > > > > > >> > > > > > >> >> > >> > >
> > > > > > >> > > > > > >> >> > >> > > Yeah, I mentioned KAFKA-2391 where
> some
> > > of
> > > > > this
> > > > > > >> was
> > > > > > >> > > > > > discussed.
> > > > > > >> > > > > > >> >> Jay
> > > > > > >> > > > > > >> >> > was
> > > > > > >> > > > > > >> >> > >> > > against having timeouts in the
> methods
> > at
> > > > the
> > > > > > >> time.
> > > > > > >> > > > > However,
> > > > > > >> > > > > > >> as
> > > > > > >> > > > > > >> >> > Jason
> > > > > > >> > > > > > >> >> > >> > said
> > > > > > >> > > > > > >> >> > >> > > offline, we did end up with a timeout
> > > > > parameter
> > > > > > >> in
> > > > > > >> > > > `poll`.
> > > > > > >> > > > > > >> >> > >> > >
> > > > > > >> > > > > > >> >> > >> > > Ismael
> > > > > > >> > > > > > >> >> > >> > >
> > > > > > >> > > > > > >> >> > >> > > On Fri, Mar 23, 2018 at 4:26 PM, Ewen
> > > > > > >> > > Cheslack-Postava <
> > > > > > >> > > > > > >> >> > >> > ewen@confluent.io>
> > > > > > >> > > > > > >> >> > >> > > wrote:
> > > > > > >> > > > > > >> >> > >> > >
> > > > > > >> > > > > > >> >> > >> > > > Regarding the flexibility question,
> > has
> > > > > > someone
> > > > > > >> > > tried
> > > > > > >> > > > to
> > > > > > >> > > > > > >> dig up
> > > > > > >> > > > > > >> >> > the
> > > > > > >> > > > > > >> >> > >> > > > discussion of the new consumer APIs
> > > when
> > > > > they
> > > > > > >> were
> > > > > > >> > > > being
> > > > > > >> > > > > > >> >> written?
> > > > > > >> > > > > > >> >> > I
> > > > > > >> > > > > > >> >> > >> > > vaguely
> > > > > > >> > > > > > >> >> > >> > > > recall these exact questions about
> > > using
> > > > > APIs
> > > > > > >> vs
> > > > > > >> > > > configs
> > > > > > >> > > > > > and
> > > > > > >> > > > > > >> >> > >> > flexibility
> > > > > > >> > > > > > >> >> > >> > > vs
> > > > > > >> > > > > > >> >> > >> > > > bloating the API surface area
> having
> > > > > already
> > > > > > >> been
> > > > > > >> > > > > > discussed.
> > > > > > >> > > > > > >> >> (Not
> > > > > > >> > > > > > >> >> > >> that
> > > > > > >> > > > > > >> >> > >> > we
> > > > > > >> > > > > > >> >> > >> > > > shouldn't revisit, just that it
> might
> > > > also
> > > > > > be a
> > > > > > >> > > faster
> > > > > > >> > > > > way
> > > > > > >> > > > > > >> to
> > > > > > >> > > > > > >> >> get
> > > > > > >> > > > > > >> >> > >> to a
> > > > > > >> > > > > > >> >> > >> > > full
> > > > > > >> > > > > > >> >> > >> > > > understanding of the options,
> > concerns,
> > > > and
> > > > > > >> > > > tradeoffs).
> > > > > > >> > > > > > >> >> > >> > > >
> > > > > > >> > > > > > >> >> > >> > > > -Ewen
> > > > > > >> > > > > > >> >> > >> > > >
> > > > > > >> > > > > > >> >> > >> > > > On Thu, Mar 22, 2018 at 7:19 AM,
> > > Richard
> > > > > Yu <
> > > > > > >> > > > > > >> >> > >> > yohan.richard.yu@gmail.com>
> > > > > > >> > > > > > >> >> > >> > > > wrote:
> > > > > > >> > > > > > >> >> > >> > > >
> > > > > > >> > > > > > >> >> > >> > > > > I do have one question though: in
> > the
> > > > > > current
> > > > > > >> > KIP,
> > > > > > >> > > > > > >> throwing
> > > > > > >> > > > > > >> >> > >> > > > > TimeoutException to mark
> > > > > > >> > > > > > >> >> > >> > > > > that time limit is exceeded is
> > > applied
> > > > to
> > > > > > all
> > > > > > >> > new
> > > > > > >> > > > > > methods
> > > > > > >> > > > > > >> >> > >> introduced
> > > > > > >> > > > > > >> >> > >> > in
> > > > > > >> > > > > > >> >> > >> > > > > this proposal.
> > > > > > >> > > > > > >> >> > >> > > > > However, how would users respond
> > > when a
> > > > > > >> > > > > TimeoutException
> > > > > > >> > > > > > >> >> (since
> > > > > > >> > > > > > >> >> > >> it is
> > > > > > >> > > > > > >> >> > >> > > > > considered
> > > > > > >> > > > > > >> >> > >> > > > > a RuntimeException)?
> > > > > > >> > > > > > >> >> > >> > > > >
> > > > > > >> > > > > > >> >> > >> > > > > Thanks,
> > > > > > >> > > > > > >> >> > >> > > > > Richard
> > > > > > >> > > > > > >> >> > >> > > > >
> > > > > > >> > > > > > >> >> > >> > > > >
> > > > > > >> > > > > > >> >> > >> > > > >
> > > > > > >> > > > > > >> >> > >> > > > > On Mon, Mar 19, 2018 at 6:10 PM,
> > > > Richard
> > > > > > Yu <
> > > > > > >> > > > > > >> >> > >> > > yohan.richard.yu@gmail.com>
> > > > > > >> > > > > > >> >> > >> > > > > wrote:
> > > > > > >> > > > > > >> >> > >> > > > >
> > > > > > >> > > > > > >> >> > >> > > > > > Hi Ismael,
> > > > > > >> > > > > > >> >> > >> > > > > >
> > > > > > >> > > > > > >> >> > >> > > > > > You have a great point. Since
> > most
> > > of
> > > > > the
> > > > > > >> > > methods
> > > > > > >> > > > in
> > > > > > >> > > > > > >> this
> > > > > > >> > > > > > >> >> KIP
> > > > > > >> > > > > > >> >> > >> have
> > > > > > >> > > > > > >> >> > >> > > > > similar
> > > > > > >> > > > > > >> >> > >> > > > > > callbacks (position() and
> > > committed()
> > > > > > both
> > > > > > >> use
> > > > > > >> > > > > > >> >> > >> > > fetchCommittedOffsets(),
> > > > > > >> > > > > > >> >> > >> > > > > > and
> > > > > > >> > > > > > >> >> > >> > > > > > commitSync() is similar to
> > > > position(),
> > > > > > >> except
> > > > > > >> > > just
> > > > > > >> > > > > > >> updating
> > > > > > >> > > > > > >> >> > >> > offsets),
> > > > > > >> > > > > > >> >> > >> > > > the
> > > > > > >> > > > > > >> >> > >> > > > > > amount of time
> > > > > > >> > > > > > >> >> > >> > > > > > they block should be also about
> > > > equal.
> > > > > > >> > > > > > >> >> > >> > > > > >
> > > > > > >> > > > > > >> >> > >> > > > > > However, I think that we need
> to
> > > take
> > > > > > into
> > > > > > >> > > > account a
> > > > > > >> > > > > > >> >> couple of
> > > > > > >> > > > > > >> >> > >> > > things.
> > > > > > >> > > > > > >> >> > >> > > > > For
> > > > > > >> > > > > > >> >> > >> > > > > > starters,
> > > > > > >> > > > > > >> >> > >> > > > > > if the new methods were all
> > reliant
> > > > on
> > > > > > one
> > > > > > >> > > config,
> > > > > > >> > > > > > >> there is
> > > > > > >> > > > > > >> >> > >> > > likelihood
> > > > > > >> > > > > > >> >> > >> > > > > > that the
> > > > > > >> > > > > > >> >> > >> > > > > > shortcomings for this approach
> > > would
> > > > be
> > > > > > >> > similar
> > > > > > >> > > to
> > > > > > >> > > > > > what
> > > > > > >> > > > > > >> we
> > > > > > >> > > > > > >> >> > >> faced if
> > > > > > >> > > > > > >> >> > >> > > we
> > > > > > >> > > > > > >> >> > >> > > > > let
> > > > > > >> > > > > > >> >> > >> > > > > > request.timeout.ms control all
> > > > method
> > > > > > >> > timeouts.
> > > > > > >> > > > In
> > > > > > >> > > > > > >> >> > comparison,
> > > > > > >> > > > > > >> >> > >> > > adding
> > > > > > >> > > > > > >> >> > >> > > > > > overloads
> > > > > > >> > > > > > >> >> > >> > > > > > does not have this problem.
> > > > > > >> > > > > > >> >> > >> > > > > >
> > > > > > >> > > > > > >> >> > >> > > > > > If you have further thoughts,
> > > please
> > > > > let
> > > > > > me
> > > > > > >> > > know.
> > > > > > >> > > > > > >> >> > >> > > > > >
> > > > > > >> > > > > > >> >> > >> > > > > > Richard
> > > > > > >> > > > > > >> >> > >> > > > > >
> > > > > > >> > > > > > >> >> > >> > > > > >
> > > > > > >> > > > > > >> >> > >> > > > > > On Mon, Mar 19, 2018 at 5:12
> PM,
> > > > Ismael
> > > > > > >> Juma <
> > > > > > >> > > > > > >> >> > ismael@juma.me.uk
> > > > > > >> > > > > > >> >> > >> >
> > > > > > >> > > > > > >> >> > >> > > > wrote:
> > > > > > >> > > > > > >> >> > >> > > > > >
> > > > > > >> > > > > > >> >> > >> > > > > >> Hi,
> > > > > > >> > > > > > >> >> > >> > > > > >>
> > > > > > >> > > > > > >> >> > >> > > > > >> An option that is not
> currently
> > > > > covered
> > > > > > in
> > > > > > >> > the
> > > > > > >> > > > KIP
> > > > > > >> > > > > is
> > > > > > >> > > > > > >> to
> > > > > > >> > > > > > >> >> > have a
> > > > > > >> > > > > > >> >> > >> > > > separate
> > > > > > >> > > > > > >> >> > >> > > > > >> config max.block.ms, which is
> > > > similar
> > > > > > to
> > > > > > >> the
> > > > > > >> > > > > > producer
> > > > > > >> > > > > > >> >> config
> > > > > > >> > > > > > >> >> > >> with
> > > > > > >> > > > > > >> >> > >> > > the
> > > > > > >> > > > > > >> >> > >> > > > > >> same
> > > > > > >> > > > > > >> >> > >> > > > > >> name. This came up during the
> > > > > KAFKA-2391
> > > > > > >> > > > > discussion.
> > > > > > >> > > > > > I
> > > > > > >> > > > > > >> >> think
> > > > > > >> > > > > > >> >> > >> it's
> > > > > > >> > > > > > >> >> > >> > > > clear
> > > > > > >> > > > > > >> >> > >> > > > > >> that we can't rely on
> > > > > > request.timeout.ms,
> > > > > > >> so
> > > > > > >> > > the
> > > > > > >> > > > > > >> >> decision is
> > > > > > >> > > > > > >> >> > >> > > between
> > > > > > >> > > > > > >> >> > >> > > > > >> adding
> > > > > > >> > > > > > >> >> > >> > > > > >> overloads or adding a new
> > config.
> > > > > People
> > > > > > >> > seemed
> > > > > > >> > > > to
> > > > > > >> > > > > be
> > > > > > >> > > > > > >> >> leaning
> > > > > > >> > > > > > >> >> > >> > > towards
> > > > > > >> > > > > > >> >> > >> > > > > the
> > > > > > >> > > > > > >> >> > >> > > > > >> latter in KAFKA-2391, but
> Jason
> > > > makes
> > > > > a
> > > > > > >> good
> > > > > > >> > > > point
> > > > > > >> > > > > > that
> > > > > > >> > > > > > >> >> the
> > > > > > >> > > > > > >> >> > >> > > overloads
> > > > > > >> > > > > > >> >> > >> > > > > are
> > > > > > >> > > > > > >> >> > >> > > > > >> more flexible. A couple of
> > > questions
> > > > > > from
> > > > > > >> me:
> > > > > > >> > > > > > >> >> > >> > > > > >>
> > > > > > >> > > > > > >> >> > >> > > > > >> 1. Do we need the additional
> > > > > > flexibility?
> > > > > > >> > > > > > >> >> > >> > > > > >> 2. If we do, do we need it for
> > > every
> > > > > > >> blocking
> > > > > > >> > > > > method?
> > > > > > >> > > > > > >> >> > >> > > > > >>
> > > > > > >> > > > > > >> >> > >> > > > > >> Ismael
> > > > > > >> > > > > > >> >> > >> > > > > >>
> > > > > > >> > > > > > >> >> > >> > > > > >> On Mon, Mar 19, 2018 at 5:03
> PM,
> > > > > Richard
> > > > > > >> Yu <
> > > > > > >> > > > > > >> >> > >> > > > yohan.richard.yu@gmail.com
> > > > > > >> > > > > > >> >> > >> > > > > >
> > > > > > >> > > > > > >> >> > >> > > > > >> wrote:
> > > > > > >> > > > > > >> >> > >> > > > > >>
> > > > > > >> > > > > > >> >> > >> > > > > >> > Hi Guozhang,
> > > > > > >> > > > > > >> >> > >> > > > > >> >
> > > > > > >> > > > > > >> >> > >> > > > > >> > I made some clarifications
> to
> > > > > KIP-266,
> > > > > > >> > > namely:
> > > > > > >> > > > > > >> >> > >> > > > > >> > 1. Stated more specifically
> > that
> > > > > > >> commitSync
> > > > > > >> > > > will
> > > > > > >> > > > > > >> accept
> > > > > > >> > > > > > >> >> > user
> > > > > > >> > > > > > >> >> > >> > > input.
> > > > > > >> > > > > > >> >> > >> > > > > >> > 2. fetchCommittedOffsets():
> > Made
> > > > its
> > > > > > >> role
> > > > > > >> > in
> > > > > > >> > > > > > blocking
> > > > > > >> > > > > > >> >> more
> > > > > > >> > > > > > >> >> > >> clear
> > > > > > >> > > > > > >> >> > >> > > to
> > > > > > >> > > > > > >> >> > >> > > > > the
> > > > > > >> > > > > > >> >> > >> > > > > >> > reader.
> > > > > > >> > > > > > >> >> > >> > > > > >> > 3. Sketched what would
> happen
> > > when
> > > > > > time
> > > > > > >> > limit
> > > > > > >> > > > is
> > > > > > >> > > > > > >> >> exceeded.
> > > > > > >> > > > > > >> >> > >> > > > > >> >
> > > > > > >> > > > > > >> >> > >> > > > > >> > These changes should make
> the
> > > KIP
> > > > > > >> easier to
> > > > > > >> > > > > > >> understand.
> > > > > > >> > > > > > >> >> > >> > > > > >> >
> > > > > > >> > > > > > >> >> > >> > > > > >> > Cheers,
> > > > > > >> > > > > > >> >> > >> > > > > >> > Richard
> > > > > > >> > > > > > >> >> > >> > > > > >> >
> > > > > > >> > > > > > >> >> > >> > > > > >> > On Mon, Mar 19, 2018 at 9:33
> > AM,
> > > > > > >> Guozhang
> > > > > > >> > > Wang
> > > > > > >> > > > <
> > > > > > >> > > > > > >> >> > >> > > wangguoz@gmail.com>
> > > > > > >> > > > > > >> >> > >> > > > > >> wrote:
> > > > > > >> > > > > > >> >> > >> > > > > >> >
> > > > > > >> > > > > > >> >> > >> > > > > >> > > Hi Richard,
> > > > > > >> > > > > > >> >> > >> > > > > >> > >
> > > > > > >> > > > > > >> >> > >> > > > > >> > > I made a pass over the KIP
> > > > again,
> > > > > > some
> > > > > > >> > more
> > > > > > >> > > > > > >> >> > clarifications
> > > > > > >> > > > > > >> >> > >> /
> > > > > > >> > > > > > >> >> > >> > > > > comments:
> > > > > > >> > > > > > >> >> > >> > > > > >> > >
> > > > > > >> > > > > > >> >> > >> > > > > >> > > 1. seek() call itself is
> not
> > > > > > blocking,
> > > > > > >> > only
> > > > > > >> > > > the
> > > > > > >> > > > > > >> >> following
> > > > > > >> > > > > > >> >> > >> > poll()
> > > > > > >> > > > > > >> >> > >> > > > > call
> > > > > > >> > > > > > >> >> > >> > > > > >> may
> > > > > > >> > > > > > >> >> > >> > > > > >> > > be blocking as the
> actually
> > > > > metadata
> > > > > > >> rq
> > > > > > >> > > will
> > > > > > >> > > > > > >> happen.
> > > > > > >> > > > > > >> >> > >> > > > > >> > >
> > > > > > >> > > > > > >> >> > >> > > > > >> > > 2. I saw you did not
> include
> > > > > > >> > > > > > >> Consumer.partitionFor(),
> > > > > > >> > > > > > >> >> > >> > > > > >> > >
> > Consumer.OffsetAndTimestamp()
> > > > and
> > > > > > >> > > > > > >> >> Consumer.listTopics()
> > > > > > >> > > > > > >> >> > in
> > > > > > >> > > > > > >> >> > >> > your
> > > > > > >> > > > > > >> >> > >> > > > KIP.
> > > > > > >> > > > > > >> >> > >> > > > > >> > After
> > > > > > >> > > > > > >> >> > >> > > > > >> > > a second thought, I think
> > this
> > > > may
> > > > > > be
> > > > > > >> a
> > > > > > >> > > > better
> > > > > > >> > > > > > >> idea to
> > > > > > >> > > > > > >> >> > not
> > > > > > >> > > > > > >> >> > >> > > tackle
> > > > > > >> > > > > > >> >> > >> > > > > >> them in
> > > > > > >> > > > > > >> >> > >> > > > > >> > > the same KIP, and probably
> > we
> > > > > should
> > > > > > >> > > consider
> > > > > > >> > > > > > >> whether
> > > > > > >> > > > > > >> >> we
> > > > > > >> > > > > > >> >> > >> would
> > > > > > >> > > > > > >> >> > >> > > > > change
> > > > > > >> > > > > > >> >> > >> > > > > >> the
> > > > > > >> > > > > > >> >> > >> > > > > >> > > behavior or not in another
> > > > > > discussion.
> > > > > > >> > So I
> > > > > > >> > > > > agree
> > > > > > >> > > > > > >> to
> > > > > > >> > > > > > >> >> not
> > > > > > >> > > > > > >> >> > >> > include
> > > > > > >> > > > > > >> >> > >> > > > > them.
> > > > > > >> > > > > > >> >> > >> > > > > >> > >
> > > > > > >> > > > > > >> >> > >> > > > > >> > > 3. In your wiki you
> > mentioned
> > > > > > "Another
> > > > > > >> > > change
> > > > > > >> > > > > > >> shall be
> > > > > > >> > > > > > >> >> > >> made to
> > > > > > >> > > > > > >> >> > >> > > > > >> > > KafkaConsumer#poll(), due
> to
> > > its
> > > > > > call
> > > > > > >> to
> > > > > > >> > > > > > >> >> > >> > updateFetchPositions()
> > > > > > >> > > > > > >> >> > >> > > > > which
> > > > > > >> > > > > > >> >> > >> > > > > >> > > blocks indefinitely." This
> > > part
> > > > > may
> > > > > > a
> > > > > > >> bit
> > > > > > >> > > > > obscure
> > > > > > >> > > > > > >> to
> > > > > > >> > > > > > >> >> most
> > > > > > >> > > > > > >> >> > >> > > readers
> > > > > > >> > > > > > >> >> > >> > > > > >> who's
> > > > > > >> > > > > > >> >> > >> > > > > >> > not
> > > > > > >> > > > > > >> >> > >> > > > > >> > > familiar with the
> > > KafkaConsumer
> > > > > > >> > internals,
> > > > > > >> > > > > could
> > > > > > >> > > > > > >> you
> > > > > > >> > > > > > >> >> > please
> > > > > > >> > > > > > >> >> > >> > add
> > > > > > >> > > > > > >> >> > >> > > > more
> > > > > > >> > > > > > >> >> > >> > > > > >> > > elaborations. More
> > > > specifically, I
> > > > > > >> think
> > > > > > >> > > the
> > > > > > >> > > > > root
> > > > > > >> > > > > > >> >> causes
> > > > > > >> > > > > > >> >> > of
> > > > > > >> > > > > > >> >> > >> > the
> > > > > > >> > > > > > >> >> > >> > > > > public
> > > > > > >> > > > > > >> >> > >> > > > > >> > APIs
> > > > > > >> > > > > > >> >> > >> > > > > >> > > mentioned are a bit
> > different
> > > > > while
> > > > > > >> the
> > > > > > >> > > KIP's
> > > > > > >> > > > > > >> >> explanation
> > > > > > >> > > > > > >> >> > >> > sounds
> > > > > > >> > > > > > >> >> > >> > > > > like
> > > > > > >> > > > > > >> >> > >> > > > > >> > they
> > > > > > >> > > > > > >> >> > >> > > > > >> > > are due to the same
> reason:
> > > > > > >> > > > > > >> >> > >> > > > > >> > >
> > > > > > >> > > > > > >> >> > >> > > > > >> > > 3.1
> fetchCommittedOffsets():
> > > > this
> > > > > > >> > internal
> > > > > > >> > > > call
> > > > > > >> > > > > > >> will
> > > > > > >> > > > > > >> >> > block
> > > > > > >> > > > > > >> >> > >> > > forever
> > > > > > >> > > > > > >> >> > >> > > > > if
> > > > > > >> > > > > > >> >> > >> > > > > >> the
> > > > > > >> > > > > > >> >> > >> > > > > >> > > committed offsets cannot
> be
> > > > > fetched
> > > > > > >> > > > > successfully
> > > > > > >> > > > > > >> and
> > > > > > >> > > > > > >> >> > affect
> > > > > > >> > > > > > >> >> > >> > > > > position()
> > > > > > >> > > > > > >> >> > >> > > > > >> > and
> > > > > > >> > > > > > >> >> > >> > > > > >> > > committed(). We need to
> > break
> > > > out
> > > > > of
> > > > > > >> its
> > > > > > >> > > > > internal
> > > > > > >> > > > > > >> >> while
> > > > > > >> > > > > > >> >> > >> loop.
> > > > > > >> > > > > > >> >> > >> > > > > >> > > 3.2 position() itself will
> > > while
> > > > > > loop
> > > > > > >> > when
> > > > > > >> > > > > > offsets
> > > > > > >> > > > > > >> >> cannot
> > > > > > >> > > > > > >> >> > >> be
> > > > > > >> > > > > > >> >> > >> > > > > >> retrieved in
> > > > > > >> > > > > > >> >> > >> > > > > >> > > the underlying async call.
> > We
> > > > need
> > > > > > to
> > > > > > >> > break
> > > > > > >> > > > out
> > > > > > >> > > > > > >> this
> > > > > > >> > > > > > >> >> > while
> > > > > > >> > > > > > >> >> > >> > loop.
> > > > > > >> > > > > > >> >> > >> > > > > >> > > 3.3 commitSync() passed
> > > > > > >> Long.MAX_VALUE as
> > > > > > >> > > the
> > > > > > >> > > > > > >> timeout
> > > > > > >> > > > > > >> >> > >> value,
> > > > > > >> > > > > > >> >> > >> > we
> > > > > > >> > > > > > >> >> > >> > > > > should
> > > > > > >> > > > > > >> >> > >> > > > > >> > take
> > > > > > >> > > > > > >> >> > >> > > > > >> > > the user specified
> timeouts
> > > when
> > > > > > >> > > applicable.
> > > > > > >> > > > > > >> >> > >> > > > > >> > >
> > > > > > >> > > > > > >> >> > >> > > > > >> > >
> > > > > > >> > > > > > >> >> > >> > > > > >> > >
> > > > > > >> > > > > > >> >> > >> > > > > >> > > Guozhang
> > > > > > >> > > > > > >> >> > >> > > > > >> > >
> > > > > > >> > > > > > >> >> > >> > > > > >> > > On Sat, Mar 17, 2018 at
> 4:44
> > > PM,
> > > > > > >> Richard
> > > > > > >> > > Yu <
> > > > > > >> > > > > > >> >> > >> > > > > >> yohan.richard.yu@gmail.com>
> > > > > > >> > > > > > >> >> > >> > > > > >> > > wrote:
> > > > > > >> > > > > > >> >> > >> > > > > >> > >
> > > > > > >> > > > > > >> >> > >> > > > > >> > > > Actually, what I said
> > above
> > > is
> > > > > > >> > > inaccurate.
> > > > > > >> > > > In
> > > > > > >> > > > > > >> >> > >> > > > > >> > > >
> > > testSeekAndCommitWithBrokerFai
> > > > > > >> lures,
> > > > > > >> > > > > > >> >> > >> > TestUtils.waitUntilTrue
> > > > > > >> > > > > > >> >> > >> > > > > >> blocks,
> > > > > > >> > > > > > >> >> > >> > > > > >> > not
> > > > > > >> > > > > > >> >> > >> > > > > >> > > > seek.
> > > > > > >> > > > > > >> >> > >> > > > > >> > > > My assumption is that
> seek
> > > did
> > > > > not
> > > > > > >> > update
> > > > > > >> > > > > > >> >> correctly. I
> > > > > > >> > > > > > >> >> > >> will
> > > > > > >> > > > > > >> >> > >> > be
> > > > > > >> > > > > > >> >> > >> > > > > >> digging
> > > > > > >> > > > > > >> >> > >> > > > > >> > > > further into this.
> > > > > > >> > > > > > >> >> > >> > > > > >> > > >
> > > > > > >> > > > > > >> >> > >> > > > > >> > > >
> > > > > > >> > > > > > >> >> > >> > > > > >> > > >
> > > > > > >> > > > > > >> >> > >> > > > > >> > > > On Sat, Mar 17, 2018 at
> > 4:16
> > > > PM,
> > > > > > >> > Richard
> > > > > > >> > > > Yu <
> > > > > > >> > > > > > >> >> > >> > > > > >> > yohan.richard.yu@gmail.com>
> > > > > > >> > > > > > >> >> > >> > > > > >> > > > wrote:
> > > > > > >> > > > > > >> >> > >> > > > > >> > > >
> > > > > > >> > > > > > >> >> > >> > > > > >> > > > > One more thing: when
> > > looking
> > > > > > >> through
> > > > > > >> > > > > tests, I
> > > > > > >> > > > > > >> have
> > > > > > >> > > > > > >> >> > >> > realized
> > > > > > >> > > > > > >> >> > >> > > > that
> > > > > > >> > > > > > >> >> > >> > > > > >> > seek()
> > > > > > >> > > > > > >> >> > >> > > > > >> > > > > methods can
> potentially
> > > > block
> > > > > > >> > > > indefinitely.
> > > > > > >> > > > > > As
> > > > > > >> > > > > > >> you
> > > > > > >> > > > > > >> >> > well
> > > > > > >> > > > > > >> >> > >> > > know,
> > > > > > >> > > > > > >> >> > >> > > > > >> seek()
> > > > > > >> > > > > > >> >> > >> > > > > >> > is
> > > > > > >> > > > > > >> >> > >> > > > > >> > > > > called when pollOnce()
> > or
> > > > > > >> position()
> > > > > > >> > is
> > > > > > >> > > > > > active.
> > > > > > >> > > > > > >> >> Thus,
> > > > > > >> > > > > > >> >> > >> if
> > > > > > >> > > > > > >> >> > >> > > > > >> position()
> > > > > > >> > > > > > >> >> > >> > > > > >> > > > blocks
> > > > > > >> > > > > > >> >> > >> > > > > >> > > > > indefinitely, then so
> > > would
> > > > > > >> seek().
> > > > > > >> > > > Should
> > > > > > >> > > > > > >> >> bounding
> > > > > > >> > > > > > >> >> > >> seek()
> > > > > > >> > > > > > >> >> > >> > > > also
> > > > > > >> > > > > > >> >> > >> > > > > be
> > > > > > >> > > > > > >> >> > >> > > > > >> > > > included
> > > > > > >> > > > > > >> >> > >> > > > > >> > > > > in this KIP?
> > > > > > >> > > > > > >> >> > >> > > > > >> > > > >
> > > > > > >> > > > > > >> >> > >> > > > > >> > > > > Thanks, Richard
> > > > > > >> > > > > > >> >> > >> > > > > >> > > > >
> > > > > > >> > > > > > >> >> > >> > > > > >> > > > > On Sat, Mar 17, 2018
> at
> > > 1:16
> > > > > PM,
> > > > > > >> > > Richard
> > > > > > >> > > > > Yu <
> > > > > > >> > > > > > >> >> > >> > > > > >> > >
> yohan.richard.yu@gmail.com>
> > > > > > >> > > > > > >> >> > >> > > > > >> > > > > wrote:
> > > > > > >> > > > > > >> >> > >> > > > > >> > > > >
> > > > > > >> > > > > > >> >> > >> > > > > >> > > > >> Thanks for the
> advice,
> > > > Jason
> > > > > > >> > > > > > >> >> > >> > > > > >> > > > >>
> > > > > > >> > > > > > >> >> > >> > > > > >> > > > >> I have modified
> KIP-266
> > > to
> > > > > > >> include
> > > > > > >> > the
> > > > > > >> > > > > java
> > > > > > >> > > > > > >> doc
> > > > > > >> > > > > > >> >> for
> > > > > > >> > > > > > >> >> > >> > > > committed()
> > > > > > >> > > > > > >> >> > >> > > > > >> and
> > > > > > >> > > > > > >> >> > >> > > > > >> > > > other
> > > > > > >> > > > > > >> >> > >> > > > > >> > > > >> blocking methods,
> and I
> > > > also
> > > > > > >> > > > > > >> >> > >> > > > > >> > > > >> mentioned poll()
> which
> > > will
> > > > > > also
> > > > > > >> be
> > > > > > >> > > > > bounded.
> > > > > > >> > > > > > >> Let
> > > > > > >> > > > > > >> >> me
> > > > > > >> > > > > > >> >> > >> know
> > > > > > >> > > > > > >> >> > >> > if
> > > > > > >> > > > > > >> >> > >> > > > > >> there is
> > > > > > >> > > > > > >> >> > >> > > > > >> > > > >> anything else. :)
> > > > > > >> > > > > > >> >> > >> > > > > >> > > > >>
> > > > > > >> > > > > > >> >> > >> > > > > >> > > > >> Sincerely, Richard
> > > > > > >> > > > > > >> >> > >> > > > > >> > > > >>
> > > > > > >> > > > > > >> >> > >> > > > > >> > > > >>
> > > > > > >> > > > > > >> >> > >> > > > > >> > > > >>
> > > > > > >> > > > > > >> >> > >> > > > > >> > > > >>
> > > > > > >> > > > > > >> >> > >> > > > > >> > > > >>
> > > > > > >> > > > > > >> >> > >> > > > > >> > > > >> On Sat, Mar 17, 2018
> at
> > > > 12:00
> > > > > > PM,
> > > > > > >> > > Jason
> > > > > > >> > > > > > >> >> Gustafson <
> > > > > > >> > > > > > >> >> > >> > > > > >> > jason@confluent.io
> > > > > > >> > > > > > >> >> > >> > > > > >> > > >
> > > > > > >> > > > > > >> >> > >> > > > > >> > > > >> wrote:
> > > > > > >> > > > > > >> >> > >> > > > > >> > > > >>
> > > > > > >> > > > > > >> >> > >> > > > > >> > > > >>> Hi Richard,
> > > > > > >> > > > > > >> >> > >> > > > > >> > > > >>>
> > > > > > >> > > > > > >> >> > >> > > > > >> > > > >>> Thanks for the
> > updates.
> > > > I'm
> > > > > > >> really
> > > > > > >> > > glad
> > > > > > >> > > > > you
> > > > > > >> > > > > > >> >> picked
> > > > > > >> > > > > > >> >> > >> this
> > > > > > >> > > > > > >> >> > >> > > up.
> > > > > > >> > > > > > >> >> > >> > > > A
> > > > > > >> > > > > > >> >> > >> > > > > >> > couple
> > > > > > >> > > > > > >> >> > >> > > > > >> > > > >>> minor
> > > > > > >> > > > > > >> >> > >> > > > > >> > > > >>> comments:
> > > > > > >> > > > > > >> >> > >> > > > > >> > > > >>>
> > > > > > >> > > > > > >> >> > >> > > > > >> > > > >>> 1. Can you list the
> > full
> > > > set
> > > > > > of
> > > > > > >> new
> > > > > > >> > > > APIs
> > > > > > >> > > > > > >> >> explicitly
> > > > > > >> > > > > > >> >> > >> in
> > > > > > >> > > > > > >> >> > >> > the
> > > > > > >> > > > > > >> >> > >> > > > > KIP?
> > > > > > >> > > > > > >> >> > >> > > > > >> > > > >>> Currently I
> > > > > > >> > > > > > >> >> > >> > > > > >> > > > >>> only see the javadoc
> > for
> > > > > > >> > > `position()`.
> > > > > > >> > > > > > >> >> > >> > > > > >> > > > >>>
> > > > > > >> > > > > > >> >> > >> > > > > >> > > > >>> 2. We should
> consider
> > > > adding
> > > > > > >> > > `TimeUnit`
> > > > > > >> > > > > to
> > > > > > >> > > > > > >> the
> > > > > > >> > > > > > >> >> new
> > > > > > >> > > > > > >> >> > >> > methods
> > > > > > >> > > > > > >> >> > >> > > > to
> > > > > > >> > > > > > >> >> > >> > > > > >> avoid
> > > > > > >> > > > > > >> >> > >> > > > > >> > > > unit
> > > > > > >> > > > > > >> >> > >> > > > > >> > > > >>> confusion. I know
> it's
> > > > > > >> inconsistent
> > > > > > >> > > > with
> > > > > > >> > > > > > the
> > > > > > >> > > > > > >> >> poll()
> > > > > > >> > > > > > >> >> > >> API,
> > > > > > >> > > > > > >> >> > >> > > > but I
> > > > > > >> > > > > > >> >> > >> > > > > >> > think
> > > > > > >> > > > > > >> >> > >> > > > > >> > > it
> > > > > > >> > > > > > >> >> > >> > > > > >> > > > >>> was
> > > > > > >> > > > > > >> >> > >> > > > > >> > > > >>> probably a mistake
> not
> > > to
> > > > > > >> include
> > > > > > >> > it
> > > > > > >> > > > > there,
> > > > > > >> > > > > > >> so
> > > > > > >> > > > > > >> >> > better
> > > > > > >> > > > > > >> >> > >> > not
> > > > > > >> > > > > > >> >> > >> > > to
> > > > > > >> > > > > > >> >> > >> > > > > >> double
> > > > > > >> > > > > > >> >> > >> > > > > >> > > > down
> > > > > > >> > > > > > >> >> > >> > > > > >> > > > >>> on
> > > > > > >> > > > > > >> >> > >> > > > > >> > > > >>> that mistake. And
> note
> > > > that
> > > > > we
> > > > > > >> do
> > > > > > >> > > > already
> > > > > > >> > > > > > >> have
> > > > > > >> > > > > > >> >> > >> > > `close(long,
> > > > > > >> > > > > > >> >> > >> > > > > >> > > TimeUnit)`.
> > > > > > >> > > > > > >> >> > >> > > > > >> > > > >>>
> > > > > > >> > > > > > >> >> > >> > > > > >> > > > >>> Other than that, I
> > think
> > > > the
> > > > > > >> > current
> > > > > > >> > > > KIP
> > > > > > >> > > > > > >> seems
> > > > > > >> > > > > > >> >> > >> > reasonable.
> > > > > > >> > > > > > >> >> > >> > > > > >> > > > >>>
> > > > > > >> > > > > > >> >> > >> > > > > >> > > > >>> Thanks,
> > > > > > >> > > > > > >> >> > >> > > > > >> > > > >>> Jason
> > > > > > >> > > > > > >> >> > >> > > > > >> > > > >>>
> > > > > > >> > > > > > >> >> > >> > > > > >> > > > >>> On Wed, Mar 14, 2018
> > at
> > > > 5:00
> > > > > > PM,
> > > > > > >> > > > Richard
> > > > > > >> > > > > > Yu <
> > > > > > >> > > > > > >> >> > >> > > > > >> > > >
> > yohan.richard.yu@gmail.com>
> > > > > > >> > > > > > >> >> > >> > > > > >> > > > >>> wrote:
> > > > > > >> > > > > > >> >> > >> > > > > >> > > > >>>
> > > > > > >> > > > > > >> >> > >> > > > > >> > > > >>> > Note to all: I
> have
> > > > > included
> > > > > > >> > > bounding
> > > > > > >> > > > > > >> >> > commitSync()
> > > > > > >> > > > > > >> >> > >> and
> > > > > > >> > > > > > >> >> > >> > > > > >> > committed()
> > > > > > >> > > > > > >> >> > >> > > > > >> > > in
> > > > > > >> > > > > > >> >> > >> > > > > >> > > > >>> this
> > > > > > >> > > > > > >> >> > >> > > > > >> > > > >>> > KIP.
> > > > > > >> > > > > > >> >> > >> > > > > >> > > > >>> >
> > > > > > >> > > > > > >> >> > >> > > > > >> > > > >>> > On Sun, Mar 11,
> 2018
> > > at
> > > > > 5:05
> > > > > > >> PM,
> > > > > > >> > > > > Richard
> > > > > > >> > > > > > >> Yu <
> > > > > > >> > > > > > >> >> > >> > > > > >> > > > >>>
> > > > yohan.richard.yu@gmail.com>
> > > > > > >> > > > > > >> >> > >> > > > > >> > > > >>> > wrote:
> > > > > > >> > > > > > >> >> > >> > > > > >> > > > >>> >
> > > > > > >> > > > > > >> >> > >> > > > > >> > > > >>> > > Hi all,
> > > > > > >> > > > > > >> >> > >> > > > > >> > > > >>> > >
> > > > > > >> > > > > > >> >> > >> > > > > >> > > > >>> > > I updated the
> KIP
> > > > where
> > > > > > >> > > overloading
> > > > > > >> > > > > > >> >> position()
> > > > > > >> > > > > > >> >> > is
> > > > > > >> > > > > > >> >> > >> > now
> > > > > > >> > > > > > >> >> > >> > > > the
> > > > > > >> > > > > > >> >> > >> > > > > >> > favored
> > > > > > >> > > > > > >> >> > >> > > > > >> > > > >>> > approach.
> > > > > > >> > > > > > >> >> > >> > > > > >> > > > >>> > > Bounding
> > position()
> > > > > using
> > > > > > >> > > > > > >> requestTimeoutMs
> > > > > > >> > > > > > >> >> has
> > > > > > >> > > > > > >> >> > >> been
> > > > > > >> > > > > > >> >> > >> > > > listed
> > > > > > >> > > > > > >> >> > >> > > > > >> as
> > > > > > >> > > > > > >> >> > >> > > > > >> > > > >>> rejected.
> > > > > > >> > > > > > >> >> > >> > > > > >> > > > >>> > >
> > > > > > >> > > > > > >> >> > >> > > > > >> > > > >>> > > Any thoughts?
> > > > > > >> > > > > > >> >> > >> > > > > >> > > > >>> > >
> > > > > > >> > > > > > >> >> > >> > > > > >> > > > >>> > > On Tue, Mar 6,
> > 2018
> > > at
> > > > > > 6:00
> > > > > > >> PM,
> > > > > > >> > > > > > Guozhang
> > > > > > >> > > > > > >> >> Wang <
> > > > > > >> > > > > > >> >> > >> > > > > >> > > wangguoz@gmail.com>
> > > > > > >> > > > > > >> >> > >> > > > > >> > > > >>> > wrote:
> > > > > > >> > > > > > >> >> > >> > > > > >> > > > >>> > >
> > > > > > >> > > > > > >> >> > >> > > > > >> > > > >>> > >> I agree that
> > adding
> > > > the
> > > > > > >> > > overloads
> > > > > > >> > > > is
> > > > > > >> > > > > > >> most
> > > > > > >> > > > > > >> >> > >> flexible.
> > > > > > >> > > > > > >> >> > >> > > But
> > > > > > >> > > > > > >> >> > >> > > > > >> going
> > > > > > >> > > > > > >> >> > >> > > > > >> > > for
> > > > > > >> > > > > > >> >> > >> > > > > >> > > > >>> that
> > > > > > >> > > > > > >> >> > >> > > > > >> > > > >>> > >> direction we'd
> do
> > > > that
> > > > > > for
> > > > > > >> all
> > > > > > >> > > the
> > > > > > >> > > > > > >> blocking
> > > > > > >> > > > > > >> >> > call
> > > > > > >> > > > > > >> >> > >> > that
> > > > > > >> > > > > > >> >> > >> > > > > I've
> > > > > > >> > > > > > >> >> > >> > > > > >> > > listed
> > > > > > >> > > > > > >> >> > >> > > > > >> > > > >>> above,
> > > > > > >> > > > > > >> >> > >> > > > > >> > > > >>> > >> with this
> timeout
> > > > value
> > > > > > >> > covering
> > > > > > >> > > > the
> > > > > > >> > > > > > >> >> > end-to-end
> > > > > > >> > > > > > >> >> > >> > > waiting
> > > > > > >> > > > > > >> >> > >> > > > > >> time.
> > > > > > >> > > > > > >> >> > >> > > > > >> > > > >>> > >>
> > > > > > >> > > > > > >> >> > >> > > > > >> > > > >>> > >>
> > > > > > >> > > > > > >> >> > >> > > > > >> > > > >>> > >> Guozhang
> > > > > > >> > > > > > >> >> > >> > > > > >> > > > >>> > >>
> > > > > > >> > > > > > >> >> > >> > > > > >> > > > >>> > >> On Tue, Mar 6,
> > 2018
> > > > at
> > > > > > >> 10:02
> > > > > > >> > AM,
> > > > > > >> > > > Ted
> > > > > > >> > > > > > Yu
> > > > > > >> > > > > > >> <
> > > > > > >> > > > > > >> >> > >> > > > > >> yuzhihong@gmail.com>
> > > > > > >> > > > > > >> >> > >> > > > > >> > > > >>> wrote:
> > > > > > >> > > > > > >> >> > >> > > > > >> > > > >>> > >>
> > > > > > >> > > > > > >> >> > >> > > > > >> > > > >>> > >> > bq. The most
> > > > flexible
> > > > > > >> option
> > > > > > >> > > is
> > > > > > >> > > > to
> > > > > > >> > > > > > add
> > > > > > >> > > > > > >> >> > >> overloads
> > > > > > >> > > > > > >> >> > >> > to
> > > > > > >> > > > > > >> >> > >> > > > the
> > > > > > >> > > > > > >> >> > >> > > > > >> > > consumer
> > > > > > >> > > > > > >> >> > >> > > > > >> > > > >>> > >> >
> > > > > > >> > > > > > >> >> > >> > > > > >> > > > >>> > >> > This option
> is
> > > > > > flexible.
> > > > > > >> > > > > > >> >> > >> > > > > >> > > > >>> > >> >
> > > > > > >> > > > > > >> >> > >> > > > > >> > > > >>> > >> > Looking at
> the
> > > tail
> > > > > of
> > > > > > >> > > > > SPARK-18057,
> > > > > > >> > > > > > >> Spark
> > > > > > >> > > > > > >> >> > dev
> > > > > > >> > > > > > >> >> > >> > > voiced
> > > > > > >> > > > > > >> >> > >> > > > > the
> > > > > > >> > > > > > >> >> > >> > > > > >> > same
> > > > > > >> > > > > > >> >> > >> > > > > >> > > > >>> choice.
> > > > > > >> > > > > > >> >> > >> > > > > >> > > > >>> > >> >
> > > > > > >> > > > > > >> >> > >> > > > > >> > > > >>> > >> > +1 for adding
> > > > > overload
> > > > > > >> with
> > > > > > >> > > > > timeout
> > > > > > >> > > > > > >> >> > parameter.
> > > > > > >> > > > > > >> >> > >> > > > > >> > > > >>> > >> >
> > > > > > >> > > > > > >> >> > >> > > > > >> > > > >>> > >> > Cheers
> > > > > > >> > > > > > >> >> > >> > > > > >> > > > >>> > >> >
> > > > > > >> > > > > > >> >> > >> > > > > >> > > > >>> > >> > On Mon, Mar
> 5,
> > > 2018
> > > > > at
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> > > > > > >> > > > > > >> >> > >> > > > > >> > > > >>> we are
> > > > > > >> > > > > > >> >> > >> > > > > >> > > > >>> > >> > making
> > > > > > >> > > > > > >> >> > >> > > > > >> > > > >>> > >> > > > the other
> > > > > blocking
> > > > > > >> calls
> > > > > > >> > > to
> > > > > > >> > > > be
> > > > > > >> > > > > > >> >> relying a
> > > > > > >> > > > > > >> >> > >> new
> > > > > > >> > > > > > >> >> > >> > > > config
> > > > > > >> > > > > > >> >> > >> > > > > >> as
> > > > > > >> > > > > > >> >> > >> > > > > >> > > > >>> suggested
> > > > > > >> > > > > > >> >> > >> > > > > >> > > > >>> > in
> > > > > > >> > > > > > >> >> > >> > > > > >> > > > >>> > >> 1)
> > > > > > >> > > > > > >> >> > >> > > > > >> > > > >>> > >> > > > above,
> > should
> > > > we
> > > > > > also
> > > > > > >> > > change
> > > > > > >> > > > > the
> > > > > > >> > > > > > >> >> > >> semantics of
> > > > > > >> > > > > > >> >> > >> > > > these
> > > > > > >> > > > > > >> >> > >> > > > > >> API
> > > > > > >> > > > > > >> >> > >> > > > > >> > > > >>> functions
> > > > > > >> > > > > > >> >> > >> > > > > >> > > > >>> > >> for
> > > > > > >> > > > > > >> >> > >> > > > > >> > > > >>> > >> > > >
> > consistency?
> > > > > > >> > > > > > >> >> > >> > > > > >> > > > >>> > >> > > >
> > > > > > >> > > > > > >> >> > >> > > > > >> > > > >>> > >> > > >
> > > > > > >> > > > > > >> >> > >> > > > > >> > > > >>> > >> > > > Guozhang
> > > > > > >> > > > > > >> >> > >> > > > > >> > > > >>> > >> > > >
> > > > > > >> > > > > > >> >> > >> > > > > >> > > > >>> > >> > > >
> > > > > > >> > > > > > >> >> > >> > > > > >> > > > >>> > >> > > >
> > > > > > >> > > > > > >> >> > >> > > > > >> > > > >>> > >> > > >
> > > > > > >> > > > > > >> >> > >> > > > > >> > > > >>> > >> > > > On Sun,
> Mar
> > > 4,
> > > > > 2018
> > > > > > >> at
> > > > > > >> > > 11:13
> > > > > > >> > > > > AM,
> > > > > > >> > > > > > >> >> Richard
> > > > > > >> > > > > > >> >> > >> Yu <
> > > > > > >> > > > > > >> >> > >> > > > > >> > > > >>> > >> >
> > > > > > >> yohan.richard.yu@gmail.com>
> > > > > > >> > > > > > >> >> > >> > > > > >> > > > >>> > >> > > > wrote:
> > > > > > >> > > > > > >> >> > >> > > > > >> > > > >>> > >> > > >
> > > > > > >> > > > > > >> >> > >> > > > > >> > > > >>> > >> > > > > Hi all,
> > > > > > >> > > > > > >> >> > >> > > > > >> > > > >>> > >> > > > >
> > > > > > >> > > > > > >> >> > >> > > > > >> > > > >>> > >> > > > > I would
> > > like
> > > > to
> > > > > > >> > discuss
> > > > > > >> > > a
> > > > > > >> > > > > > >> potential
> > > > > > >> > > > > > >> >> > >> change
> > > > > > >> > > > > > >> >> > >> > > > which
> > > > > > >> > > > > > >> >> > >> > > > > >> would
> > > > > > >> > > > > > >> >> > >> > > > > >> > > be
> > > > > > >> > > > > > >> >> > >> > > > > >> > > > >>> made
> > > > > > >> > > > > > >> >> > >> > > > > >> > > > >>> > to
> > > > > > >> > > > > > >> >> > >> > > > > >> > > > >>> > >> > > > >
> > > > KafkaConsumer:
> > > > > > >> > > > > > >> >> > >> > > > > >> > > > >>> > >> > > > >
> > > > > > >> > > https://cwiki.apache.org/
> > > > > > >> > > > > > >> >> > >> > > > > confluence/pages/viewpage
> > > > > > >> > > > > > >> >> > >> > > > > >> .
> > > > > > >> > > > > > >> >> > >> > > > > >> > > > >>> > >> > > >
> > > > > > >> action?pageId=75974886
> > > > > > >> > > > > > >> >> > >> > > > > >> > > > >>> > >> > > > >
> > > > > > >> > > > > > >> >> > >> > > > > >> > > > >>> > >> > > > > Thanks,
> > > > > > >> > > > > > >> >> > >> > > > > >> > > > >>> > >> > > > > Richard
> > Yu
> > > > > > >> > > > > > >> >> > >> > > > > >> > > > >>> > >> > > > >
> > > > > > >> > > > > > >> >> > >> > > > > >> > > > >>> > >> > > >
> > > > > > >> > > > > > >> >> > >> > > > > >> > > > >>> > >> > > >
> > > > > > >> > > > > > >> >> > >> > > > > >> > > > >>> > >> > > >
> > > > > > >> > > > > > >> >> > >> > > > > >> > > > >>> > >> > > > --
> > > > > > >> > > > > > >> >> > >> > > > > >> > > > >>> > >> > > > --
> Guozhang
> > > > > > >> > > > > > >> >> > >> > > > > >> > > > >>> > >> > > >
> > > > > > >> > > > > > >> >> > >> > > > > >> > > > >>> > >> > >
> > > > > > >> > > > > > >> >> > >> > > > > >> > > > >>> > >> >
> > > > > > >> > > > > > >> >> > >> > > > > >> > > > >>> > >>
> > > > > > >> > > > > > >> >> > >> > > > > >> > > > >>> > >>
> > > > > > >> > > > > > >> >> > >> > > > > >> > > > >>> > >>
> > > > > > >> > > > > > >> >> > >> > > > > >> > > > >>> > >> --
> > > > > > >> > > > > > >> >> > >> > > > > >> > > > >>> > >> -- Guozhang
> > > > > > >> > > > > > >> >> > >> > > > > >> > > > >>> > >>
> > > > > > >> > > > > > >> >> > >> > > > > >> > > > >>> > >
> > > > > > >> > > > > > >> >> > >> > > > > >> > > > >>> > >
> > > > > > >> > > > > > >> >> > >> > > > > >> > > > >>> >
> > > > > > >> > > > > > >> >> > >> > > > > >> > > > >>>
> > > > > > >> > > > > > >> >> > >> > > > > >> > > > >>
> > > > > > >> > > > > > >> >> > >> > > > > >> > > > >>
> > > > > > >> > > > > > >> >> > >> > > > > >> > > > >
> > > > > > >> > > > > > >> >> > >> > > > > >> > > >
> > > > > > >> > > > > > >> >> > >> > > > > >> > >
> > > > > > >> > > > > > >> >> > >> > > > > >> > >
> > > > > > >> > > > > > >> >> > >> > > > > >> > >
> > > > > > >> > > > > > >> >> > >> > > > > >> > > --
> > > > > > >> > > > > > >> >> > >> > > > > >> > > -- Guozhang
> > > > > > >> > > > > > >> >> > >> > > > > >> > >
> > > > > > >> > > > > > >> >> > >> > > > > >> >
> > > > > > >> > > > > > >> >> > >> > > > > >>
> > > > > > >> > > > > > >> >> > >> > > > > >
> > > > > > >> > > > > > >> >> > >> > > > > >
> > > > > > >> > > > > > >> >> > >> > > > >
> > > > > > >> > > > > > >> >> > >> > > >
> > > > > > >> > > > > > >> >> > >> > >
> > > > > > >> > > > > > >> >> > >> >
> > > > > > >> > > > > > >> >> > >> >
> > > > > > >> > > > > > >> >> > >> >
> > > > > > >> > > > > > >> >> > >> > --
> > > > > > >> > > > > > >> >> > >> > -- Guozhang
> > > > > > >> > > > > > >> >> > >> >
> > > > > > >> > > > > > >> >> > >>
> > > > > > >> > > > > > >> >> > >
> > > > > > >> > > > > > >> >> > >
> > > > > > >> > > > > > >> >> >
> > > > > > >> > > > > > >> >>
> > > > > > >> > > > > > >> >>
> > > > > > >> > > > > > >> >>
> > > > > > >> > > > > > >> >> --
> > > > > > >> > > > > > >> >> -- Guozhang
> > > > > > >> > > > > > >> >>
> > > > > > >> > > > > > >> >
> > > > > > >> > > > > > >> >
> > > > > > >> > > > > > >>
> > > > > > >> > > > > > >
> > > > > > >> > > > > > >
> > > > > > >> > > > > >
> > > > > > >> > > > >
> > > > > > >> > > >
> > > > > > >> > >
> > > > > > >> >
> > > > > > >>
> > > > > > >
> > > > > > >
> > > > > >
> > > > >
> > > > >
> > > > >
> > > > > --
> > > > > -- Guozhang
> > > > >
> > > >
> > >
> >
>
Re: [DISCUSSION] KIP-266: Add TimeoutException to KafkaConsumer#position()
Posted by Jason Gustafson <ja...@confluent.io>.
Hey John,
Yeah, I appreciate Becket's point. We do tend to abuse the initial intent
of ApiException. It's just that it can be awkward to come up with another
name when the ApiException already has a reasonable and appropriate name
for the user API. `ClientTimeoutException` is a perfect example of this
awkwardness. In practice I don't think the convention has provided much
benefit. I looked around the code and saw only a handful of cases where we
were checking ApiException directly, and it was just to determine the log
level of a message. I think I'd probably take the more concise name, even
if it's a slight abuse of the convention. We use it in similar scenarios in
the producer, for what it's worth.
-Jason
On Wed, May 2, 2018 at 3:26 PM, Richard Yu <yo...@gmail.com>
wrote:
> Hi John,
>
> I don't have any objections to this KIP change. Please go ahead.
>
> Thanks,
> Richard
>
> On Wed, May 2, 2018 at 2:54 PM, John Roesler <jo...@confluent.io> wrote:
>
> > Thanks Jason,
> >
> > I did find some production use cases "on the internet" that use poll(0)
> > *just* to join the group initially and ignore the response. I suppose the
> > assumption is that it'll be empty on the very first call to poll with
> > timeout=0. In my opinion, this usage is unsafe, since there's a declared
> > return value. I proposed the method to give these use cases a safe
> > alternative.
> >
> > Of course, there's another safe alternative: just don't ignore the
> > response.
> >
> > I'd agree with the decision to just deprecate the old poll(long) and add
> > only a new poll(Duration). It should be obvious that there's no
> > non-deprecated way to do what the code I found is doing, so those
> > developers will either alter their code to handle the response or they
> will
> > come back and ask us for the awaitAssignmentMetadata method.
> >
> > Better to present a simpler api and wait for a reason to make it more
> > complicated.
> >
> > I'm fine with suggestions 1,2, and 3. Unless Richard objects super fast,
> > I'll update the KIP momentarily.
> >
> > Regarding the ClientTimeoutException, this was introduced earlier in this
> > discussion when Becket pointed out that the TimeoutException is a
> subclass
> > of ApiException, and therefore implies that a call to the broker timed
> out.
> >
> > Reconsidering this point, I found the javadoc on ApiException to be a
> > little ambiguous. All it says is that "any API exception that is part of
> > the public protocol should be a subclass of this class...". It's not
> clear
> > to me whether this is the broker's API/protocol or more generally *any*
> > API/protocol. So we'd have to bring the lawyers in, but I think we can
> just
> > say it's the latter and keep the old exception.
> >
> > I'm not sure if it's an important distiction to users whether their
> request
> > timed out as a broker side timeout, an HTTP timeout, or a client-side
> > timeout. In any case, they'd want to retry for a while and then fail if
> > they can't get their request through.
> >
> > Plus RetryableException also inherits from ApiException, and that one is
> > ubiquitous. Adding a new exception would require users to catch both
> > RetriableException and ClientTimeoutException, which seems odd since the
> > latter is retriable.
> >
> > All in all, I'm now in favor of sticking with the current
> TimeoutException.
> > If there's some higher-level problem with the ApiException being used
> this
> > way, I think it should be addressed holistically in a separate KIP.
> >
> > So, I'll go ahead and switch the KIP back to TimeoutException, unless
> > Becket wants to argue (harder) in favor of the ClientTimeoutException.
> >
> > Thanks,
> > -John
> >
> >
> > On Wed, May 2, 2018 at 3:55 PM, Jason Gustafson <ja...@confluent.io>
> > wrote:
> >
> > > I think John's proposal look reasonable to me. My only doubt is about
> use
> > > cases for the new `awaitAssignmentMetadata` API. I think the basic idea
> > is
> > > that we want a way to block until we have joined the consumer group,
> but
> > we
> > > do not want to await fetched data. Maybe another way to accomplish this
> > > would be to add a `PollOptions` argument which specified the condition
> we
> > > are awaiting? It's a little weird that we'd have two separate APIs
> where
> > > the group membership can change. I know this functionality can be
> helpful
> > > in testing, but we should probably spend some more time understanding
> and
> > > motivating the general use cases.
> > >
> > > Since we're leaving around the old poll() with its current behavior for
> > > now, I wonder if we could leave this as potential future work?
> > >
> > > Other than that, I have a few minor suggestions and I'm happy with the
> > KIP:
> > >
> > > 1. Can we use Duration across the board for all of these APIs?
> > > 2. Can we cover the following blocking APIs with in this KIP:
> > > `partitionsFor`, `listTopics`, `offsetsForTimes`, `beginningOffsets`,
> > > `endOffsets`?
> > > 3. Perhaps we can add a `close(Duration)` and deprecate the one
> accepting
> > > `TimeUnit`?
> > > 4. Seems we don't really need `ClientTimeoutException` since we already
> > > have `TimeoutException`?
> > >
> > > Thanks,
> > > Jason
> > >
> > >
> > >
> > > On Wed, Apr 25, 2018 at 2:14 PM, Guozhang Wang <wa...@gmail.com>
> > wrote:
> > >
> > > > Previously there are some debates on whether we should add this
> > > nonblocking
> > > > behavior via a config v.s. via overloaded functions. To make progress
> > on
> > > > this discussion we need to first figure that part out. I'm in favor
> of
> > > the
> > > > current approach of overloaded functions over the config since if we
> > are
> > > > going to have multiple configs other than a single one to control
> > timeout
> > > > semantics it may be even confusing: take our producer side configs
> for
> > an
> > > > example, right now we have "request.timeout.ms" and "max.block.ms"
> and
> > > we
> > > > are proposing to add another one in KIP-91. But I'd also like to hear
> > > from
> > > > people who's in favor of the configs.
> > > >
> > > >
> > > > Guozhang
> > > >
> > > >
> > > > On Wed, Apr 25, 2018 at 1:39 PM, John Roesler <jo...@confluent.io>
> > wrote:
> > > >
> > > > > Re Ted's last comment, that style of async API requires some thread
> > to
> > > > > actually drive the request/response cycle and invoke the callback
> > when
> > > > it's
> > > > > complete. Right now, this happens in the caller's thread as a
> > > side-effect
> > > > > of calling poll(). But that clearly won't work for poll() itself!
> > > > >
> > > > > In the future, I think we'd like to add a background thread to
> drive
> > > the
> > > > > request/response loops, and then make all these methods return
> > > > > Future<Whatever>.
> > > > >
> > > > > But we don't need to bite that off right now.
> > > > >
> > > > > The "async" model I'm proposing is really just a generalization of
> > the
> > > > one
> > > > > that poll already partially implements: when you call poll, it
> fires
> > > off
> > > > > any requests it needs to make and checks if any responses are
> ready.
> > If
> > > > so,
> > > > > it returns them. If not, it returns empty. When you call poll()
> > again,
> > > it
> > > > > again checks on the responses from last time, and so forth.
> > > > >
> > > > > But that model currently only applies to the "fetch" part of poll.
> > I'm
> > > > > proposing that we extend it to the "metadata update" part of poll
> as
> > > > well.
> > > > >
> > > > > However, as previously discussed, doing this in place would break
> the
> > > > > semantics of poll that folks currently rely on, so I propose to add
> > new
> > > > > methods and deprecate the existing poll method. Here's what I'm
> > > thinking:
> > > > > https://github.com/apache/kafka/pull/4855 . In the discussion on
> > that
> > > > PR,
> > > > > I've described in greater detail how the async+blocking semantics
> > work.
> > > > >
> > > > > I'll update KIP-266 with this interface for poll().
> > > > >
> > > > > It would be great to get this discussion moving again so we can get
> > > these
> > > > > changes into 2.0. What does everyone think about this?
> > > > >
> > > > > Thanks,
> > > > > -John
> > > > >
> > > > > On Thu, Apr 19, 2018 at 5:12 PM, John Roesler <jo...@confluent.io>
> > > wrote:
> > > > >
> > > > > > Thanks for the tip, Ted!
> > > > > >
> > > > > > On Thu, Apr 19, 2018 at 12:12 PM, Ted Yu <yu...@gmail.com>
> > > wrote:
> > > > > >
> > > > > >> John:
> > > > > >> In case you want to pursue async poll, it seems (by looking at
> > > current
> > > > > >> API)
> > > > > >> that introducing PollCallback follows existing pattern(s).
> > > > > >>
> > > > > >> e.g. KafkaConsumer#commitAsync(OffsetCommitCallback)
> > > > > >>
> > > > > >> FYI
> > > > > >>
> > > > > >> On Thu, Apr 19, 2018 at 10:08 AM, John Roesler <
> john@confluent.io
> > >
> > > > > wrote:
> > > > > >>
> > > > > >> > Hi Richard,
> > > > > >> >
> > > > > >> > Thanks for the invitation! I do think it would be safer to
> > > > introduce a
> > > > > >> new
> > > > > >> > poll
> > > > > >> > method than to change the semantics of the old one. I've been
> > > > mulling
> > > > > >> about
> > > > > >> > whether the new one could still have (slightly different)
> async
> > > > > >> semantics
> > > > > >> > with
> > > > > >> > a timeout of 0. If possible, I'd like to avoid introducing
> > another
> > > > new
> > > > > >> > "asyncPoll".
> > > > > >> >
> > > > > >> > I'm planning to run some experiments and dig into the
> > > > implementation a
> > > > > >> bit
> > > > > >> > more before solidifying the proposal. I'll update the KIP as
> you
> > > > > >> suggest at
> > > > > >> > that point,
> > > > > >> > and then can call for another round of reviews and voting.
> > > > > >> >
> > > > > >> > Thanks,
> > > > > >> > -John
> > > > > >> >
> > > > > >> > On Tue, Apr 17, 2018 at 4:53 PM, Richard Yu <
> > > > > yohan.richard.yu@gmail.com
> > > > > >> >
> > > > > >> > wrote:
> > > > > >> >
> > > > > >> > > Hi John,
> > > > > >> > >
> > > > > >> > > Do you have a preference for fixing the poll() method (e.g.
> > > using
> > > > > >> > asyncPoll
> > > > > >> > > or just sticking with the current method but with an extra
> > > timeout
> > > > > >> > > parameter) ? I think your current proposition for KIP-288 is
> > > > better
> > > > > >> than
> > > > > >> > > what I have on my side. If you think there is something that
> > you
> > > > > want
> > > > > >> to
> > > > > >> > > add, you could go ahead and change KIP-266 to your liking.
> > Just
> > > to
> > > > > >> note
> > > > > >> > > that it would be preferable that if one of us modifies this
> > KIP,
> > > > it
> > > > > >> would
> > > > > >> > > be best to mention your change on this thread to let each
> > other
> > > > know
> > > > > >> > (makes
> > > > > >> > > it easier to coordinate progress).
> > > > > >> > >
> > > > > >> > > Thanks,
> > > > > >> > > Richard
> > > > > >> > >
> > > > > >> > > On Tue, Apr 17, 2018 at 2:07 PM, John Roesler <
> > > john@confluent.io>
> > > > > >> wrote:
> > > > > >> > >
> > > > > >> > > > Ok, I'll close the discussion on KIP-288 and mark it
> > > discarded.
> > > > > >> > > >
> > > > > >> > > > We can solidify the design for poll in KIP-266, and once
> > it's
> > > > > >> approved,
> > > > > >> > > > I'll coordinate with Qiang Zhao on the PR for the poll
> part
> > of
> > > > the
> > > > > >> > work.
> > > > > >> > > > Once that is merged, you'll have a clean slate for the
> rest
> > of
> > > > the
> > > > > >> > work.
> > > > > >> > > >
> > > > > >> > > > On Tue, Apr 17, 2018 at 3:39 PM, Richard Yu <
> > > > > >> > yohan.richard.yu@gmail.com>
> > > > > >> > > > wrote:
> > > > > >> > > >
> > > > > >> > > > > Hi John,
> > > > > >> > > > >
> > > > > >> > > > > I think that you could finish your PR that corresponds
> > with
> > > > > >> KIP-288
> > > > > >> > and
> > > > > >> > > > > merge it. I can finish my side of the work afterwards.
> > > > > >> > > > >
> > > > > >> > > > > On another note, adding an asynchronized version of
> poll()
> > > > would
> > > > > >> make
> > > > > >> > > > > sense, particularily since the current version of Kafka
> > does
> > > > not
> > > > > >> > > support
> > > > > >> > > > > it.
> > > > > >> > > > >
> > > > > >> > > > > Thanks
> > > > > >> > > > > Richar
> > > > > >> > > > >
> > > > > >> > > > > On Tue, Apr 17, 2018 at 12:30 PM, John Roesler <
> > > > > john@confluent.io
> > > > > >> >
> > > > > >> > > > wrote:
> > > > > >> > > > >
> > > > > >> > > > > > Cross-pollinating from some discussion we've had on
> > > KIP-288,
> > > > > >> > > > > >
> > > > > >> > > > > > I think there's a good reason that poll() takes a
> > timeout
> > > > when
> > > > > >> none
> > > > > >> > > of
> > > > > >> > > > > the
> > > > > >> > > > > > other methods do, and it's relevant to this
> discussion.
> > > The
> > > > > >> timeout
> > > > > >> > > in
> > > > > >> > > > > > poll() is effectively implementing a long-poll API (on
> > the
> > > > > >> client
> > > > > >> > > side,
> > > > > >> > > > > so
> > > > > >> > > > > > it's not really long-poll, but the programmer-facing
> > > > behavior
> > > > > is
> > > > > >> > the
> > > > > >> > > > > same).
> > > > > >> > > > > > The timeout isn't really bounding the execution time
> of
> > > the
> > > > > >> method,
> > > > > >> > > but
> > > > > >> > > > > > instead giving a max time that callers are willing to
> > wait
> > > > > >> around
> > > > > >> > and
> > > > > >> > > > see
> > > > > >> > > > > > if any results show up.
> > > > > >> > > > > >
> > > > > >> > > > > > If I understand the code sufficiently, it would be
> > > perfectly
> > > > > >> > > reasonable
> > > > > >> > > > > for
> > > > > >> > > > > > a caller to use a timeout of 0 to implement async
> poll,
> > it
> > > > > would
> > > > > >> > just
> > > > > >> > > > > mean
> > > > > >> > > > > > that KafkaConsumer would just check on each call if
> > > there's
> > > > a
> > > > > >> > > response
> > > > > >> > > > > > ready and if not, fire off a new request without
> waiting
> > > > for a
> > > > > >> > > > response.
> > > > > >> > > > > >
> > > > > >> > > > > > As such, it seems inappropriate to throw a
> > > > > >> ClientTimeoutException
> > > > > >> > > from
> > > > > >> > > > > > poll(), except possibly if the initial phase of
> ensuring
> > > an
> > > > > >> > > assignment
> > > > > >> > > > > > times out. We wouldn't want the method contract to be
> > > > > "returns a
> > > > > >> > > > > non-empty
> > > > > >> > > > > > collection or throws a ClientTimeoutException"
> > > > > >> > > > > >
> > > > > >> > > > > > Now, I'm wondering if we should actually consider one
> of
> > > my
> > > > > >> > rejected
> > > > > >> > > > > > alternatives, to treat the "operation timeout" as a
> > > separate
> > > > > >> > > parameter
> > > > > >> > > > > from
> > > > > >> > > > > > the "long-poll time". Or maybe adding an
> > > "asyncPoll(timeout,
> > > > > >> time
> > > > > >> > > > unit)"
> > > > > >> > > > > > that only uses the timeout to bound metadata updates
> and
> > > > > >> otherwise
> > > > > >> > > > > behaves
> > > > > >> > > > > > like the current "poll(0)".
> > > > > >> > > > > >
> > > > > >> > > > > > Thanks,
> > > > > >> > > > > > -John
> > > > > >> > > > > >
> > > > > >> > > > > > On Tue, Apr 17, 2018 at 2:05 PM, John Roesler <
> > > > > >> john@confluent.io>
> > > > > >> > > > wrote:
> > > > > >> > > > > >
> > > > > >> > > > > > > Hey Richard,
> > > > > >> > > > > > >
> > > > > >> > > > > > > As you noticed, the newly introduced KIP-288
> overlaps
> > > with
> > > > > >> this
> > > > > >> > > one.
> > > > > >> > > > > > Sorry
> > > > > >> > > > > > > for stepping on your toes... How would you like to
> > > > proceed?
> > > > > >> I'm
> > > > > >> > > happy
> > > > > >> > > > > to
> > > > > >> > > > > > > "close" KIP-288 in deference to this KIP.
> > > > > >> > > > > > >
> > > > > >> > > > > > > With respect to poll(), reading this discussion gave
> > me
> > > a
> > > > > new
> > > > > >> > idea
> > > > > >> > > > for
> > > > > >> > > > > > > providing a non-breaking update path... What if we
> > > > > introduce a
> > > > > >> > new
> > > > > >> > > > > > variant
> > > > > >> > > > > > > 'poll(long timeout, TimeUnit unit)' that displays
> the
> > > new,
> > > > > >> > desired
> > > > > >> > > > > > > behavior, and just leave the old method alone?
> > > > > >> > > > > > >
> > > > > >> > > > > > > Thanks,
> > > > > >> > > > > > > -John
> > > > > >> > > > > > >
> > > > > >> > > > > > > On Tue, Apr 17, 2018 at 12:09 PM, Richard Yu <
> > > > > >> > > > > yohan.richard.yu@gmail.com
> > > > > >> > > > > > >
> > > > > >> > > > > > > wrote:
> > > > > >> > > > > > >
> > > > > >> > > > > > >> Hi all,
> > > > > >> > > > > > >>
> > > > > >> > > > > > >> If possible, would a committer please review?
> > > > > >> > > > > > >>
> > > > > >> > > > > > >> Thanks
> > > > > >> > > > > > >>
> > > > > >> > > > > > >> On Sun, Apr 1, 2018 at 7:24 PM, Richard Yu <
> > > > > >> > > > > yohan.richard.yu@gmail.com>
> > > > > >> > > > > > >> wrote:
> > > > > >> > > > > > >>
> > > > > >> > > > > > >> > Hi Guozhang,
> > > > > >> > > > > > >> >
> > > > > >> > > > > > >> > I have clarified the KIP a bit to account for
> > > Becket's
> > > > > >> > > suggestion
> > > > > >> > > > on
> > > > > >> > > > > > >> > ClientTimeoutException.
> > > > > >> > > > > > >> > About adding an extra config, you were right
> about
> > my
> > > > > >> > > intentions.
> > > > > >> > > > I
> > > > > >> > > > > am
> > > > > >> > > > > > >> > just wondering if the config
> > > > > >> > > > > > >> > should be included, since Ismael seems to favor
> an
> > > > extra
> > > > > >> > > > > > configuration,
> > > > > >> > > > > > >> >
> > > > > >> > > > > > >> > Thanks,
> > > > > >> > > > > > >> > Richard
> > > > > >> > > > > > >> >
> > > > > >> > > > > > >> > On Sun, Apr 1, 2018 at 5:35 PM, Guozhang Wang <
> > > > > >> > > wangguoz@gmail.com
> > > > > >> > > > >
> > > > > >> > > > > > >> wrote:
> > > > > >> > > > > > >> >
> > > > > >> > > > > > >> >> Hi Richard,
> > > > > >> > > > > > >> >>
> > > > > >> > > > > > >> >> Regarding the streams side changes, we plan to
> > > > > incorporate
> > > > > >> > with
> > > > > >> > > > the
> > > > > >> > > > > > new
> > > > > >> > > > > > >> >> APIs once the KIP is done, which is only
> internal
> > > code
> > > > > >> > changes
> > > > > >> > > > and
> > > > > >> > > > > > >> hence
> > > > > >> > > > > > >> >> do
> > > > > >> > > > > > >> >> not need to include in the KIP.
> > > > > >> > > > > > >> >>
> > > > > >> > > > > > >> >> Could you update the KIP because it has been
> quite
> > > > > >> obsoleted
> > > > > >> > > from
> > > > > >> > > > > the
> > > > > >> > > > > > >> >> discussed topics, and I'm a bit loosing track on
> > > what
> > > > is
> > > > > >> your
> > > > > >> > > > final
> > > > > >> > > > > > >> >> proposal right now. For example, I'm not
> > completely
> > > > > >> following
> > > > > >> > > > your
> > > > > >> > > > > > >> >> "compromise
> > > > > >> > > > > > >> >> of sorts": are you suggesting that we still add
> > > > > >> overloading
> > > > > >> > > > > functions
> > > > > >> > > > > > >> and
> > > > > >> > > > > > >> >> add a config that will be applied to all
> overload
> > > > > >> functions
> > > > > >> > > > without
> > > > > >> > > > > > the
> > > > > >> > > > > > >> >> timeout, while for other overloaded functions
> with
> > > the
> > > > > >> > timeout
> > > > > >> > > > > value
> > > > > >> > > > > > >> the
> > > > > >> > > > > > >> >> config will be ignored?
> > > > > >> > > > > > >> >>
> > > > > >> > > > > > >> >>
> > > > > >> > > > > > >> >> Guozhang
> > > > > >> > > > > > >> >>
> > > > > >> > > > > > >> >> On Fri, Mar 30, 2018 at 8:36 PM, Richard Yu <
> > > > > >> > > > > > >> yohan.richard.yu@gmail.com>
> > > > > >> > > > > > >> >> wrote:
> > > > > >> > > > > > >> >>
> > > > > >> > > > > > >> >> > On a side note, I have noticed that the
> several
> > > > other
> > > > > >> > methods
> > > > > >> > > > in
> > > > > >> > > > > > >> classes
> > > > > >> > > > > > >> >> > such as StoreChangeLogReader in Streams calls
> > > > > position()
> > > > > >> > > which
> > > > > >> > > > > > causes
> > > > > >> > > > > > >> >> tests
> > > > > >> > > > > > >> >> > to hang. It might be out of the scope of the
> > KIP,
> > > > but
> > > > > >> > should
> > > > > >> > > I
> > > > > >> > > > > also
> > > > > >> > > > > > >> >> change
> > > > > >> > > > > > >> >> > the methods which use position() as a callback
> > to
> > > at
> > > > > the
> > > > > >> > very
> > > > > >> > > > > least
> > > > > >> > > > > > >> >> prevent
> > > > > >> > > > > > >> >> > the tests from hanging? This issue might be
> out
> > of
> > > > the
> > > > > >> KIP,
> > > > > >> > > > but I
> > > > > >> > > > > > >> >> prefer it
> > > > > >> > > > > > >> >> > if we could at least make my PR pass the
> Jenkins
> > > > Q&A.
> > > > > >> > > > > > >> >> >
> > > > > >> > > > > > >> >> > Thanks
> > > > > >> > > > > > >> >> >
> > > > > >> > > > > > >> >> > On Fri, Mar 30, 2018 at 8:24 PM, Richard Yu <
> > > > > >> > > > > > >> yohan.richard.yu@gmail.com
> > > > > >> > > > > > >> >> >
> > > > > >> > > > > > >> >> > wrote:
> > > > > >> > > > > > >> >> >
> > > > > >> > > > > > >> >> > > Thanks for the review Becket.
> > > > > >> > > > > > >> >> > >
> > > > > >> > > > > > >> >> > > About the methods beginningOffsets(),
> > > > endOffsets(),
> > > > > >> ...:
> > > > > >> > > > > > >> >> > > I took a look through the code of
> > KafkaConsumer,
> > > > but
> > > > > >> > after
> > > > > >> > > > > > looking
> > > > > >> > > > > > >> >> > through
> > > > > >> > > > > > >> >> > > the offsetsByTimes() method
> > > > > >> > > > > > >> >> > > and its callbacks in Fetcher, I think these
> > > > methods
> > > > > >> > already
> > > > > >> > > > > block
> > > > > >> > > > > > >> for
> > > > > >> > > > > > >> >> a
> > > > > >> > > > > > >> >> > > set period of time. I know that there
> > > > > >> > > > > > >> >> > > is a chance that the offsets methods in
> > > > > KafkaConsumer
> > > > > >> > might
> > > > > >> > > > be
> > > > > >> > > > > > like
> > > > > >> > > > > > >> >> poll
> > > > > >> > > > > > >> >> > > (that is one section of the method
> > > > > >> > > > > > >> >> > > honors the timeout while another --
> > > > > >> updateFetchPositions
> > > > > >> > --
> > > > > >> > > > > does
> > > > > >> > > > > > >> not).
> > > > > >> > > > > > >> >> > > However, I don't think that this is the
> > > > > >> > > > > > >> >> > > case with offsetsByTimes since the callbacks
> > > that
> > > > I
> > > > > >> > checked
> > > > > >> > > > > does
> > > > > >> > > > > > >> not
> > > > > >> > > > > > >> >> seem
> > > > > >> > > > > > >> >> > > to hang.
> > > > > >> > > > > > >> >> > >
> > > > > >> > > > > > >> >> > > The clarity of the exception message is a
> > > > problem. I
> > > > > >> > > thought
> > > > > >> > > > > your
> > > > > >> > > > > > >> >> > > suggestion there was reasonable. I included
> > > > > >> > > > > > >> >> > > it in the KIP.
> > > > > >> > > > > > >> >> > >
> > > > > >> > > > > > >> >> > > And on another note, I have noticed that
> > several
> > > > > >> people
> > > > > >> > has
> > > > > >> > > > > > voiced
> > > > > >> > > > > > >> the
> > > > > >> > > > > > >> >> > > opinion that adding a config might
> > > > > >> > > > > > >> >> > > be advisable in relation to adding an extra
> > > > > >> parameter. I
> > > > > >> > > > think
> > > > > >> > > > > > >> that we
> > > > > >> > > > > > >> >> > can
> > > > > >> > > > > > >> >> > > have a compromise of sorts: some
> > > > > >> > > > > > >> >> > > methods in KafkaConsumer are relatively
> > similar
> > > --
> > > > > for
> > > > > >> > > > example,
> > > > > >> > > > > > >> >> > position()
> > > > > >> > > > > > >> >> > > and committed() both call
> > > > > >> > > > > > >> >> > > updateFetchPositions(). I think that we
> could
> > > use
> > > > > the
> > > > > >> > same
> > > > > >> > > > > config
> > > > > >> > > > > > >> for
> > > > > >> > > > > > >> >> > > these method as a default timeout if
> > > > > >> > > > > > >> >> > > the user does not provide one. On the other
> > > hand,
> > > > if
> > > > > >> they
> > > > > >> > > > wish
> > > > > >> > > > > to
> > > > > >> > > > > > >> >> specify
> > > > > >> > > > > > >> >> > > a longer or shorter blocking time,
> > > > > >> > > > > > >> >> > > they have the option of changing the
> timeout.
> > (I
> > > > > >> included
> > > > > >> > > the
> > > > > >> > > > > > >> config
> > > > > >> > > > > > >> >> as
> > > > > >> > > > > > >> >> > an
> > > > > >> > > > > > >> >> > > alternative in the KIP) WDYT?
> > > > > >> > > > > > >> >> > >
> > > > > >> > > > > > >> >> > > Thanks,
> > > > > >> > > > > > >> >> > > Richard
> > > > > >> > > > > > >> >> > >
> > > > > >> > > > > > >> >> > >
> > > > > >> > > > > > >> >> > > On Fri, Mar 30, 2018 at 1:26 AM, Becket Qin
> <
> > > > > >> > > > > > becket.qin@gmail.com>
> > > > > >> > > > > > >> >> > wrote:
> > > > > >> > > > > > >> >> > >
> > > > > >> > > > > > >> >> > >> Glad to see the KIP, Richard. This has
> been a
> > > > > really
> > > > > >> > long
> > > > > >> > > > > > pending
> > > > > >> > > > > > >> >> issue.
> > > > > >> > > > > > >> >> > >>
> > > > > >> > > > > > >> >> > >> The original arguments from Jay for using
> > > config,
> > > > > >> such
> > > > > >> > as
> > > > > >> > > > > > >> >> max.block.ms,
> > > > > >> > > > > > >> >> > >> instead of using timeout parameters was
> that
> > > > people
> > > > > >> will
> > > > > >> > > > > always
> > > > > >> > > > > > >> hard
> > > > > >> > > > > > >> >> > code
> > > > > >> > > > > > >> >> > >> the timeout, and the hard coded timeout is
> > > rarely
> > > > > >> > correct
> > > > > >> > > > > > because
> > > > > >> > > > > > >> it
> > > > > >> > > > > > >> >> has
> > > > > >> > > > > > >> >> > >> to
> > > > > >> > > > > > >> >> > >> consider different scenarios. For example,
> > > users
> > > > > may
> > > > > >> > > receive
> > > > > >> > > > > > >> timeout
> > > > > >> > > > > > >> >> > >> exception when the group coordinator moves.
> > > > Having
> > > > > a
> > > > > >> > > > > > configuration
> > > > > >> > > > > > >> >> with
> > > > > >> > > > > > >> >> > >> some reasonable default value will make
> > users'
> > > > life
> > > > > >> > > easier.
> > > > > >> > > > > > >> >> > >>
> > > > > >> > > > > > >> >> > >> That said, in practice, it seems more
> useful
> > to
> > > > > have
> > > > > >> > > timeout
> > > > > >> > > > > > >> >> parameters.
> > > > > >> > > > > > >> >> > >> We
> > > > > >> > > > > > >> >> > >> have seen some library, using the consumers
> > > > > >> internally,
> > > > > >> > > > needs
> > > > > >> > > > > to
> > > > > >> > > > > > >> >> provide
> > > > > >> > > > > > >> >> > >> an
> > > > > >> > > > > > >> >> > >> external flexible timeout interface. Also,
> > user
> > > > can
> > > > > >> > easily
> > > > > >> > > > > hard
> > > > > >> > > > > > >> code
> > > > > >> > > > > > >> >> a
> > > > > >> > > > > > >> >> > >> value to get the same as a config based
> > > solution.
> > > > > >> > > > > > >> >> > >>
> > > > > >> > > > > > >> >> > >> The KIP looks good overall. A few comments:
> > > > > >> > > > > > >> >> > >>
> > > > > >> > > > > > >> >> > >> 1. There are a few other blocking methods
> > that
> > > > are
> > > > > >> not
> > > > > >> > > > > included,
> > > > > >> > > > > > >> e.g.
> > > > > >> > > > > > >> >> > >> offsetsForTimes(), beginningOffsets(),
> > > > > endOffsets().
> > > > > >> Is
> > > > > >> > > > there
> > > > > >> > > > > > any
> > > > > >> > > > > > >> >> > reason?
> > > > > >> > > > > > >> >> > >>
> > > > > >> > > > > > >> >> > >> 2. I am wondering can we take the KIP as a
> > > chance
> > > > > to
> > > > > >> > clean
> > > > > >> > > > up
> > > > > >> > > > > > our
> > > > > >> > > > > > >> >> > timeout
> > > > > >> > > > > > >> >> > >> exception(s)? More specifically, instead of
> > > > reusing
> > > > > >> > > > > > >> TimeoutException,
> > > > > >> > > > > > >> >> > can
> > > > > >> > > > > > >> >> > >> we introduce a new ClientTimeoutException
> > with
> > > > > >> different
> > > > > >> > > > > causes,
> > > > > >> > > > > > >> e.g.
> > > > > >> > > > > > >> >> > >> UnknownTopicOrPartition, RequestTimeout,
> > > > > >> > > LeaderNotAvailable,
> > > > > >> > > > > > etc.
> > > > > >> > > > > > >> >> > >> As of now, the TimeoutException is used in
> > the
> > > > > >> following
> > > > > >> > > > three
> > > > > >> > > > > > >> cases:
> > > > > >> > > > > > >> >> > >>
> > > > > >> > > > > > >> >> > >> 1. TimeoutException is a subclass of
> > > > > ApiException
> > > > > >> > which
> > > > > >> > > > > > >> indicates
> > > > > >> > > > > > >> >> the
> > > > > >> > > > > > >> >> > >> exception was returned by the broker.
> The
> > > > > >> > > > TimeoutException
> > > > > >> > > > > > was
> > > > > >> > > > > > >> >> > >> initially
> > > > > >> > > > > > >> >> > >> returned by the leaders when replication
> > was
> > > > not
> > > > > >> done
> > > > > >> > > > > within
> > > > > >> > > > > > >> the
> > > > > >> > > > > > >> >> > >> specified
> > > > > >> > > > > > >> >> > >> timeout in the ProduceRequest. It has an
> > > error
> > > > > >> code
> > > > > >> > of
> > > > > >> > > 7,
> > > > > >> > > > > > >> which is
> > > > > >> > > > > > >> >> > >> returned
> > > > > >> > > > > > >> >> > >> by the broker.
> > > > > >> > > > > > >> >> > >> 2. When we migrate to Java clients, in
> > > Errors
> > > > > >> > > definition,
> > > > > >> > > > > we
> > > > > >> > > > > > >> >> extended
> > > > > >> > > > > > >> >> > >> it
> > > > > >> > > > > > >> >> > >> to indicate request timeout, i.e. a
> > request
> > > > was
> > > > > >> sent
> > > > > >> > > but
> > > > > >> > > > > the
> > > > > >> > > > > > >> >> response
> > > > > >> > > > > > >> >> > >> was
> > > > > >> > > > > > >> >> > >> not received before timeout. In this
> case,
> > > the
> > > > > >> > clients
> > > > > >> > > > did
> > > > > >> > > > > > not
> > > > > >> > > > > > >> >> have a
> > > > > >> > > > > > >> >> > >> return code from the broker.
> > > > > >> > > > > > >> >> > >> 3. Later at some point, we started to
> use
> > > the
> > > > > >> > > > > > TimeoutException
> > > > > >> > > > > > >> for
> > > > > >> > > > > > >> >> > >> clients method call timeout. It is
> neither
> > > > > >> related to
> > > > > >> > > any
> > > > > >> > > > > > >> broker
> > > > > >> > > > > > >> >> > >> returned
> > > > > >> > > > > > >> >> > >> error code, nor to request timeout on
> the
> > > > wire.
> > > > > >> > > > > > >> >> > >>
> > > > > >> > > > > > >> >> > >> Due to the various interpretations, users
> can
> > > > > easily
> > > > > >> be
> > > > > >> > > > > > confused.
> > > > > >> > > > > > >> As
> > > > > >> > > > > > >> >> an
> > > > > >> > > > > > >> >> > >> example, when a timeout is thrown with
> > "Failed
> > > to
> > > > > >> > refresh
> > > > > >> > > > > > metadata
> > > > > >> > > > > > >> >> in X
> > > > > >> > > > > > >> >> > >> ms", it is hard to tell what exactly
> > happened.
> > > > > Since
> > > > > >> we
> > > > > >> > > are
> > > > > >> > > > > > >> changing
> > > > > >> > > > > > >> >> the
> > > > > >> > > > > > >> >> > >> API here, it would be good to avoid
> > introducing
> > > > > more
> > > > > >> > > > ambiguity
> > > > > >> > > > > > and
> > > > > >> > > > > > >> >> see
> > > > > >> > > > > > >> >> > >> whether this can be improved. It would be
> at
> > > > least
> > > > > >> one
> > > > > >> > > step
> > > > > >> > > > > > >> forward
> > > > > >> > > > > > >> >> to
> > > > > >> > > > > > >> >> > >> remove the usage of case 3.
> > > > > >> > > > > > >> >> > >>
> > > > > >> > > > > > >> >> > >> Thanks,
> > > > > >> > > > > > >> >> > >>
> > > > > >> > > > > > >> >> > >> Jiangjie (Becket) Qin
> > > > > >> > > > > > >> >> > >>
> > > > > >> > > > > > >> >> > >>
> > > > > >> > > > > > >> >> > >>
> > > > > >> > > > > > >> >> > >>
> > > > > >> > > > > > >> >> > >> On Mon, Mar 26, 2018 at 5:50 PM, Guozhang
> > Wang
> > > <
> > > > > >> > > > > > >> wangguoz@gmail.com>
> > > > > >> > > > > > >> >> > >> wrote:
> > > > > >> > > > > > >> >> > >>
> > > > > >> > > > > > >> >> > >> > @Richard: TimeoutException inherits from
> > > > > >> > > > RetriableException
> > > > > >> > > > > > >> which
> > > > > >> > > > > > >> >> > >> inherits
> > > > > >> > > > > > >> >> > >> > from ApiException. So users should
> > explicitly
> > > > try
> > > > > >> to
> > > > > >> > > > capture
> > > > > >> > > > > > >> >> > >> > RetriableException in their code and
> handle
> > > the
> > > > > >> > > exception.
> > > > > >> > > > > > >> >> > >> >
> > > > > >> > > > > > >> >> > >> > @Isamel, Ewen: I'm trying to push
> progress
> > > > > forward
> > > > > >> on
> > > > > >> > > this
> > > > > >> > > > > > one,
> > > > > >> > > > > > >> >> are we
> > > > > >> > > > > > >> >> > >> now
> > > > > >> > > > > > >> >> > >> > on the same page for using function
> > > parameters
> > > > > than
> > > > > >> > > > configs?
> > > > > >> > > > > > >> >> > >> >
> > > > > >> > > > > > >> >> > >> >
> > > > > >> > > > > > >> >> > >> > Guozhang
> > > > > >> > > > > > >> >> > >> >
> > > > > >> > > > > > >> >> > >> >
> > > > > >> > > > > > >> >> > >> > On Fri, Mar 23, 2018 at 4:42 PM, Ismael
> > Juma
> > > <
> > > > > >> > > > > > ismael@juma.me.uk
> > > > > >> > > > > > >> >
> > > > > >> > > > > > >> >> > wrote:
> > > > > >> > > > > > >> >> > >> >
> > > > > >> > > > > > >> >> > >> > > Hi Ewen,
> > > > > >> > > > > > >> >> > >> > >
> > > > > >> > > > > > >> >> > >> > > Yeah, I mentioned KAFKA-2391 where some
> > of
> > > > this
> > > > > >> was
> > > > > >> > > > > > discussed.
> > > > > >> > > > > > >> >> Jay
> > > > > >> > > > > > >> >> > was
> > > > > >> > > > > > >> >> > >> > > against having timeouts in the methods
> at
> > > the
> > > > > >> time.
> > > > > >> > > > > However,
> > > > > >> > > > > > >> as
> > > > > >> > > > > > >> >> > Jason
> > > > > >> > > > > > >> >> > >> > said
> > > > > >> > > > > > >> >> > >> > > offline, we did end up with a timeout
> > > > parameter
> > > > > >> in
> > > > > >> > > > `poll`.
> > > > > >> > > > > > >> >> > >> > >
> > > > > >> > > > > > >> >> > >> > > Ismael
> > > > > >> > > > > > >> >> > >> > >
> > > > > >> > > > > > >> >> > >> > > On Fri, Mar 23, 2018 at 4:26 PM, Ewen
> > > > > >> > > Cheslack-Postava <
> > > > > >> > > > > > >> >> > >> > ewen@confluent.io>
> > > > > >> > > > > > >> >> > >> > > wrote:
> > > > > >> > > > > > >> >> > >> > >
> > > > > >> > > > > > >> >> > >> > > > Regarding the flexibility question,
> has
> > > > > someone
> > > > > >> > > tried
> > > > > >> > > > to
> > > > > >> > > > > > >> dig up
> > > > > >> > > > > > >> >> > the
> > > > > >> > > > > > >> >> > >> > > > discussion of the new consumer APIs
> > when
> > > > they
> > > > > >> were
> > > > > >> > > > being
> > > > > >> > > > > > >> >> written?
> > > > > >> > > > > > >> >> > I
> > > > > >> > > > > > >> >> > >> > > vaguely
> > > > > >> > > > > > >> >> > >> > > > recall these exact questions about
> > using
> > > > APIs
> > > > > >> vs
> > > > > >> > > > configs
> > > > > >> > > > > > and
> > > > > >> > > > > > >> >> > >> > flexibility
> > > > > >> > > > > > >> >> > >> > > vs
> > > > > >> > > > > > >> >> > >> > > > bloating the API surface area having
> > > > already
> > > > > >> been
> > > > > >> > > > > > discussed.
> > > > > >> > > > > > >> >> (Not
> > > > > >> > > > > > >> >> > >> that
> > > > > >> > > > > > >> >> > >> > we
> > > > > >> > > > > > >> >> > >> > > > shouldn't revisit, just that it might
> > > also
> > > > > be a
> > > > > >> > > faster
> > > > > >> > > > > way
> > > > > >> > > > > > >> to
> > > > > >> > > > > > >> >> get
> > > > > >> > > > > > >> >> > >> to a
> > > > > >> > > > > > >> >> > >> > > full
> > > > > >> > > > > > >> >> > >> > > > understanding of the options,
> concerns,
> > > and
> > > > > >> > > > tradeoffs).
> > > > > >> > > > > > >> >> > >> > > >
> > > > > >> > > > > > >> >> > >> > > > -Ewen
> > > > > >> > > > > > >> >> > >> > > >
> > > > > >> > > > > > >> >> > >> > > > On Thu, Mar 22, 2018 at 7:19 AM,
> > Richard
> > > > Yu <
> > > > > >> > > > > > >> >> > >> > yohan.richard.yu@gmail.com>
> > > > > >> > > > > > >> >> > >> > > > wrote:
> > > > > >> > > > > > >> >> > >> > > >
> > > > > >> > > > > > >> >> > >> > > > > I do have one question though: in
> the
> > > > > current
> > > > > >> > KIP,
> > > > > >> > > > > > >> throwing
> > > > > >> > > > > > >> >> > >> > > > > TimeoutException to mark
> > > > > >> > > > > > >> >> > >> > > > > that time limit is exceeded is
> > applied
> > > to
> > > > > all
> > > > > >> > new
> > > > > >> > > > > > methods
> > > > > >> > > > > > >> >> > >> introduced
> > > > > >> > > > > > >> >> > >> > in
> > > > > >> > > > > > >> >> > >> > > > > this proposal.
> > > > > >> > > > > > >> >> > >> > > > > However, how would users respond
> > when a
> > > > > >> > > > > TimeoutException
> > > > > >> > > > > > >> >> (since
> > > > > >> > > > > > >> >> > >> it is
> > > > > >> > > > > > >> >> > >> > > > > considered
> > > > > >> > > > > > >> >> > >> > > > > a RuntimeException)?
> > > > > >> > > > > > >> >> > >> > > > >
> > > > > >> > > > > > >> >> > >> > > > > Thanks,
> > > > > >> > > > > > >> >> > >> > > > > Richard
> > > > > >> > > > > > >> >> > >> > > > >
> > > > > >> > > > > > >> >> > >> > > > >
> > > > > >> > > > > > >> >> > >> > > > >
> > > > > >> > > > > > >> >> > >> > > > > On Mon, Mar 19, 2018 at 6:10 PM,
> > > Richard
> > > > > Yu <
> > > > > >> > > > > > >> >> > >> > > yohan.richard.yu@gmail.com>
> > > > > >> > > > > > >> >> > >> > > > > wrote:
> > > > > >> > > > > > >> >> > >> > > > >
> > > > > >> > > > > > >> >> > >> > > > > > Hi Ismael,
> > > > > >> > > > > > >> >> > >> > > > > >
> > > > > >> > > > > > >> >> > >> > > > > > You have a great point. Since
> most
> > of
> > > > the
> > > > > >> > > methods
> > > > > >> > > > in
> > > > > >> > > > > > >> this
> > > > > >> > > > > > >> >> KIP
> > > > > >> > > > > > >> >> > >> have
> > > > > >> > > > > > >> >> > >> > > > > similar
> > > > > >> > > > > > >> >> > >> > > > > > callbacks (position() and
> > committed()
> > > > > both
> > > > > >> use
> > > > > >> > > > > > >> >> > >> > > fetchCommittedOffsets(),
> > > > > >> > > > > > >> >> > >> > > > > > and
> > > > > >> > > > > > >> >> > >> > > > > > commitSync() is similar to
> > > position(),
> > > > > >> except
> > > > > >> > > just
> > > > > >> > > > > > >> updating
> > > > > >> > > > > > >> >> > >> > offsets),
> > > > > >> > > > > > >> >> > >> > > > the
> > > > > >> > > > > > >> >> > >> > > > > > amount of time
> > > > > >> > > > > > >> >> > >> > > > > > they block should be also about
> > > equal.
> > > > > >> > > > > > >> >> > >> > > > > >
> > > > > >> > > > > > >> >> > >> > > > > > However, I think that we need to
> > take
> > > > > into
> > > > > >> > > > account a
> > > > > >> > > > > > >> >> couple of
> > > > > >> > > > > > >> >> > >> > > things.
> > > > > >> > > > > > >> >> > >> > > > > For
> > > > > >> > > > > > >> >> > >> > > > > > starters,
> > > > > >> > > > > > >> >> > >> > > > > > if the new methods were all
> reliant
> > > on
> > > > > one
> > > > > >> > > config,
> > > > > >> > > > > > >> there is
> > > > > >> > > > > > >> >> > >> > > likelihood
> > > > > >> > > > > > >> >> > >> > > > > > that the
> > > > > >> > > > > > >> >> > >> > > > > > shortcomings for this approach
> > would
> > > be
> > > > > >> > similar
> > > > > >> > > to
> > > > > >> > > > > > what
> > > > > >> > > > > > >> we
> > > > > >> > > > > > >> >> > >> faced if
> > > > > >> > > > > > >> >> > >> > > we
> > > > > >> > > > > > >> >> > >> > > > > let
> > > > > >> > > > > > >> >> > >> > > > > > request.timeout.ms control all
> > > method
> > > > > >> > timeouts.
> > > > > >> > > > In
> > > > > >> > > > > > >> >> > comparison,
> > > > > >> > > > > > >> >> > >> > > adding
> > > > > >> > > > > > >> >> > >> > > > > > overloads
> > > > > >> > > > > > >> >> > >> > > > > > does not have this problem.
> > > > > >> > > > > > >> >> > >> > > > > >
> > > > > >> > > > > > >> >> > >> > > > > > If you have further thoughts,
> > please
> > > > let
> > > > > me
> > > > > >> > > know.
> > > > > >> > > > > > >> >> > >> > > > > >
> > > > > >> > > > > > >> >> > >> > > > > > Richard
> > > > > >> > > > > > >> >> > >> > > > > >
> > > > > >> > > > > > >> >> > >> > > > > >
> > > > > >> > > > > > >> >> > >> > > > > > On Mon, Mar 19, 2018 at 5:12 PM,
> > > Ismael
> > > > > >> Juma <
> > > > > >> > > > > > >> >> > ismael@juma.me.uk
> > > > > >> > > > > > >> >> > >> >
> > > > > >> > > > > > >> >> > >> > > > wrote:
> > > > > >> > > > > > >> >> > >> > > > > >
> > > > > >> > > > > > >> >> > >> > > > > >> Hi,
> > > > > >> > > > > > >> >> > >> > > > > >>
> > > > > >> > > > > > >> >> > >> > > > > >> An option that is not currently
> > > > covered
> > > > > in
> > > > > >> > the
> > > > > >> > > > KIP
> > > > > >> > > > > is
> > > > > >> > > > > > >> to
> > > > > >> > > > > > >> >> > have a
> > > > > >> > > > > > >> >> > >> > > > separate
> > > > > >> > > > > > >> >> > >> > > > > >> config max.block.ms, which is
> > > similar
> > > > > to
> > > > > >> the
> > > > > >> > > > > > producer
> > > > > >> > > > > > >> >> config
> > > > > >> > > > > > >> >> > >> with
> > > > > >> > > > > > >> >> > >> > > the
> > > > > >> > > > > > >> >> > >> > > > > >> same
> > > > > >> > > > > > >> >> > >> > > > > >> name. This came up during the
> > > > KAFKA-2391
> > > > > >> > > > > discussion.
> > > > > >> > > > > > I
> > > > > >> > > > > > >> >> think
> > > > > >> > > > > > >> >> > >> it's
> > > > > >> > > > > > >> >> > >> > > > clear
> > > > > >> > > > > > >> >> > >> > > > > >> that we can't rely on
> > > > > request.timeout.ms,
> > > > > >> so
> > > > > >> > > the
> > > > > >> > > > > > >> >> decision is
> > > > > >> > > > > > >> >> > >> > > between
> > > > > >> > > > > > >> >> > >> > > > > >> adding
> > > > > >> > > > > > >> >> > >> > > > > >> overloads or adding a new
> config.
> > > > People
> > > > > >> > seemed
> > > > > >> > > > to
> > > > > >> > > > > be
> > > > > >> > > > > > >> >> leaning
> > > > > >> > > > > > >> >> > >> > > towards
> > > > > >> > > > > > >> >> > >> > > > > the
> > > > > >> > > > > > >> >> > >> > > > > >> latter in KAFKA-2391, but Jason
> > > makes
> > > > a
> > > > > >> good
> > > > > >> > > > point
> > > > > >> > > > > > that
> > > > > >> > > > > > >> >> the
> > > > > >> > > > > > >> >> > >> > > overloads
> > > > > >> > > > > > >> >> > >> > > > > are
> > > > > >> > > > > > >> >> > >> > > > > >> more flexible. A couple of
> > questions
> > > > > from
> > > > > >> me:
> > > > > >> > > > > > >> >> > >> > > > > >>
> > > > > >> > > > > > >> >> > >> > > > > >> 1. Do we need the additional
> > > > > flexibility?
> > > > > >> > > > > > >> >> > >> > > > > >> 2. If we do, do we need it for
> > every
> > > > > >> blocking
> > > > > >> > > > > method?
> > > > > >> > > > > > >> >> > >> > > > > >>
> > > > > >> > > > > > >> >> > >> > > > > >> Ismael
> > > > > >> > > > > > >> >> > >> > > > > >>
> > > > > >> > > > > > >> >> > >> > > > > >> On Mon, Mar 19, 2018 at 5:03 PM,
> > > > Richard
> > > > > >> Yu <
> > > > > >> > > > > > >> >> > >> > > > yohan.richard.yu@gmail.com
> > > > > >> > > > > > >> >> > >> > > > > >
> > > > > >> > > > > > >> >> > >> > > > > >> wrote:
> > > > > >> > > > > > >> >> > >> > > > > >>
> > > > > >> > > > > > >> >> > >> > > > > >> > Hi Guozhang,
> > > > > >> > > > > > >> >> > >> > > > > >> >
> > > > > >> > > > > > >> >> > >> > > > > >> > I made some clarifications to
> > > > KIP-266,
> > > > > >> > > namely:
> > > > > >> > > > > > >> >> > >> > > > > >> > 1. Stated more specifically
> that
> > > > > >> commitSync
> > > > > >> > > > will
> > > > > >> > > > > > >> accept
> > > > > >> > > > > > >> >> > user
> > > > > >> > > > > > >> >> > >> > > input.
> > > > > >> > > > > > >> >> > >> > > > > >> > 2. fetchCommittedOffsets():
> Made
> > > its
> > > > > >> role
> > > > > >> > in
> > > > > >> > > > > > blocking
> > > > > >> > > > > > >> >> more
> > > > > >> > > > > > >> >> > >> clear
> > > > > >> > > > > > >> >> > >> > > to
> > > > > >> > > > > > >> >> > >> > > > > the
> > > > > >> > > > > > >> >> > >> > > > > >> > reader.
> > > > > >> > > > > > >> >> > >> > > > > >> > 3. Sketched what would happen
> > when
> > > > > time
> > > > > >> > limit
> > > > > >> > > > is
> > > > > >> > > > > > >> >> exceeded.
> > > > > >> > > > > > >> >> > >> > > > > >> >
> > > > > >> > > > > > >> >> > >> > > > > >> > These changes should make the
> > KIP
> > > > > >> easier to
> > > > > >> > > > > > >> understand.
> > > > > >> > > > > > >> >> > >> > > > > >> >
> > > > > >> > > > > > >> >> > >> > > > > >> > Cheers,
> > > > > >> > > > > > >> >> > >> > > > > >> > Richard
> > > > > >> > > > > > >> >> > >> > > > > >> >
> > > > > >> > > > > > >> >> > >> > > > > >> > On Mon, Mar 19, 2018 at 9:33
> AM,
> > > > > >> Guozhang
> > > > > >> > > Wang
> > > > > >> > > > <
> > > > > >> > > > > > >> >> > >> > > wangguoz@gmail.com>
> > > > > >> > > > > > >> >> > >> > > > > >> wrote:
> > > > > >> > > > > > >> >> > >> > > > > >> >
> > > > > >> > > > > > >> >> > >> > > > > >> > > Hi Richard,
> > > > > >> > > > > > >> >> > >> > > > > >> > >
> > > > > >> > > > > > >> >> > >> > > > > >> > > I made a pass over the KIP
> > > again,
> > > > > some
> > > > > >> > more
> > > > > >> > > > > > >> >> > clarifications
> > > > > >> > > > > > >> >> > >> /
> > > > > >> > > > > > >> >> > >> > > > > comments:
> > > > > >> > > > > > >> >> > >> > > > > >> > >
> > > > > >> > > > > > >> >> > >> > > > > >> > > 1. seek() call itself is not
> > > > > blocking,
> > > > > >> > only
> > > > > >> > > > the
> > > > > >> > > > > > >> >> following
> > > > > >> > > > > > >> >> > >> > poll()
> > > > > >> > > > > > >> >> > >> > > > > call
> > > > > >> > > > > > >> >> > >> > > > > >> may
> > > > > >> > > > > > >> >> > >> > > > > >> > > be blocking as the actually
> > > > metadata
> > > > > >> rq
> > > > > >> > > will
> > > > > >> > > > > > >> happen.
> > > > > >> > > > > > >> >> > >> > > > > >> > >
> > > > > >> > > > > > >> >> > >> > > > > >> > > 2. I saw you did not include
> > > > > >> > > > > > >> Consumer.partitionFor(),
> > > > > >> > > > > > >> >> > >> > > > > >> > >
> Consumer.OffsetAndTimestamp()
> > > and
> > > > > >> > > > > > >> >> Consumer.listTopics()
> > > > > >> > > > > > >> >> > in
> > > > > >> > > > > > >> >> > >> > your
> > > > > >> > > > > > >> >> > >> > > > KIP.
> > > > > >> > > > > > >> >> > >> > > > > >> > After
> > > > > >> > > > > > >> >> > >> > > > > >> > > a second thought, I think
> this
> > > may
> > > > > be
> > > > > >> a
> > > > > >> > > > better
> > > > > >> > > > > > >> idea to
> > > > > >> > > > > > >> >> > not
> > > > > >> > > > > > >> >> > >> > > tackle
> > > > > >> > > > > > >> >> > >> > > > > >> them in
> > > > > >> > > > > > >> >> > >> > > > > >> > > the same KIP, and probably
> we
> > > > should
> > > > > >> > > consider
> > > > > >> > > > > > >> whether
> > > > > >> > > > > > >> >> we
> > > > > >> > > > > > >> >> > >> would
> > > > > >> > > > > > >> >> > >> > > > > change
> > > > > >> > > > > > >> >> > >> > > > > >> the
> > > > > >> > > > > > >> >> > >> > > > > >> > > behavior or not in another
> > > > > discussion.
> > > > > >> > So I
> > > > > >> > > > > agree
> > > > > >> > > > > > >> to
> > > > > >> > > > > > >> >> not
> > > > > >> > > > > > >> >> > >> > include
> > > > > >> > > > > > >> >> > >> > > > > them.
> > > > > >> > > > > > >> >> > >> > > > > >> > >
> > > > > >> > > > > > >> >> > >> > > > > >> > > 3. In your wiki you
> mentioned
> > > > > "Another
> > > > > >> > > change
> > > > > >> > > > > > >> shall be
> > > > > >> > > > > > >> >> > >> made to
> > > > > >> > > > > > >> >> > >> > > > > >> > > KafkaConsumer#poll(), due to
> > its
> > > > > call
> > > > > >> to
> > > > > >> > > > > > >> >> > >> > updateFetchPositions()
> > > > > >> > > > > > >> >> > >> > > > > which
> > > > > >> > > > > > >> >> > >> > > > > >> > > blocks indefinitely." This
> > part
> > > > may
> > > > > a
> > > > > >> bit
> > > > > >> > > > > obscure
> > > > > >> > > > > > >> to
> > > > > >> > > > > > >> >> most
> > > > > >> > > > > > >> >> > >> > > readers
> > > > > >> > > > > > >> >> > >> > > > > >> who's
> > > > > >> > > > > > >> >> > >> > > > > >> > not
> > > > > >> > > > > > >> >> > >> > > > > >> > > familiar with the
> > KafkaConsumer
> > > > > >> > internals,
> > > > > >> > > > > could
> > > > > >> > > > > > >> you
> > > > > >> > > > > > >> >> > please
> > > > > >> > > > > > >> >> > >> > add
> > > > > >> > > > > > >> >> > >> > > > more
> > > > > >> > > > > > >> >> > >> > > > > >> > > elaborations. More
> > > specifically, I
> > > > > >> think
> > > > > >> > > the
> > > > > >> > > > > root
> > > > > >> > > > > > >> >> causes
> > > > > >> > > > > > >> >> > of
> > > > > >> > > > > > >> >> > >> > the
> > > > > >> > > > > > >> >> > >> > > > > public
> > > > > >> > > > > > >> >> > >> > > > > >> > APIs
> > > > > >> > > > > > >> >> > >> > > > > >> > > mentioned are a bit
> different
> > > > while
> > > > > >> the
> > > > > >> > > KIP's
> > > > > >> > > > > > >> >> explanation
> > > > > >> > > > > > >> >> > >> > sounds
> > > > > >> > > > > > >> >> > >> > > > > like
> > > > > >> > > > > > >> >> > >> > > > > >> > they
> > > > > >> > > > > > >> >> > >> > > > > >> > > are due to the same reason:
> > > > > >> > > > > > >> >> > >> > > > > >> > >
> > > > > >> > > > > > >> >> > >> > > > > >> > > 3.1 fetchCommittedOffsets():
> > > this
> > > > > >> > internal
> > > > > >> > > > call
> > > > > >> > > > > > >> will
> > > > > >> > > > > > >> >> > block
> > > > > >> > > > > > >> >> > >> > > forever
> > > > > >> > > > > > >> >> > >> > > > > if
> > > > > >> > > > > > >> >> > >> > > > > >> the
> > > > > >> > > > > > >> >> > >> > > > > >> > > committed offsets cannot be
> > > > fetched
> > > > > >> > > > > successfully
> > > > > >> > > > > > >> and
> > > > > >> > > > > > >> >> > affect
> > > > > >> > > > > > >> >> > >> > > > > position()
> > > > > >> > > > > > >> >> > >> > > > > >> > and
> > > > > >> > > > > > >> >> > >> > > > > >> > > committed(). We need to
> break
> > > out
> > > > of
> > > > > >> its
> > > > > >> > > > > internal
> > > > > >> > > > > > >> >> while
> > > > > >> > > > > > >> >> > >> loop.
> > > > > >> > > > > > >> >> > >> > > > > >> > > 3.2 position() itself will
> > while
> > > > > loop
> > > > > >> > when
> > > > > >> > > > > > offsets
> > > > > >> > > > > > >> >> cannot
> > > > > >> > > > > > >> >> > >> be
> > > > > >> > > > > > >> >> > >> > > > > >> retrieved in
> > > > > >> > > > > > >> >> > >> > > > > >> > > the underlying async call.
> We
> > > need
> > > > > to
> > > > > >> > break
> > > > > >> > > > out
> > > > > >> > > > > > >> this
> > > > > >> > > > > > >> >> > while
> > > > > >> > > > > > >> >> > >> > loop.
> > > > > >> > > > > > >> >> > >> > > > > >> > > 3.3 commitSync() passed
> > > > > >> Long.MAX_VALUE as
> > > > > >> > > the
> > > > > >> > > > > > >> timeout
> > > > > >> > > > > > >> >> > >> value,
> > > > > >> > > > > > >> >> > >> > we
> > > > > >> > > > > > >> >> > >> > > > > should
> > > > > >> > > > > > >> >> > >> > > > > >> > take
> > > > > >> > > > > > >> >> > >> > > > > >> > > the user specified timeouts
> > when
> > > > > >> > > applicable.
> > > > > >> > > > > > >> >> > >> > > > > >> > >
> > > > > >> > > > > > >> >> > >> > > > > >> > >
> > > > > >> > > > > > >> >> > >> > > > > >> > >
> > > > > >> > > > > > >> >> > >> > > > > >> > > Guozhang
> > > > > >> > > > > > >> >> > >> > > > > >> > >
> > > > > >> > > > > > >> >> > >> > > > > >> > > On Sat, Mar 17, 2018 at 4:44
> > PM,
> > > > > >> Richard
> > > > > >> > > Yu <
> > > > > >> > > > > > >> >> > >> > > > > >> yohan.richard.yu@gmail.com>
> > > > > >> > > > > > >> >> > >> > > > > >> > > wrote:
> > > > > >> > > > > > >> >> > >> > > > > >> > >
> > > > > >> > > > > > >> >> > >> > > > > >> > > > Actually, what I said
> above
> > is
> > > > > >> > > inaccurate.
> > > > > >> > > > In
> > > > > >> > > > > > >> >> > >> > > > > >> > > >
> > testSeekAndCommitWithBrokerFai
> > > > > >> lures,
> > > > > >> > > > > > >> >> > >> > TestUtils.waitUntilTrue
> > > > > >> > > > > > >> >> > >> > > > > >> blocks,
> > > > > >> > > > > > >> >> > >> > > > > >> > not
> > > > > >> > > > > > >> >> > >> > > > > >> > > > seek.
> > > > > >> > > > > > >> >> > >> > > > > >> > > > My assumption is that seek
> > did
> > > > not
> > > > > >> > update
> > > > > >> > > > > > >> >> correctly. I
> > > > > >> > > > > > >> >> > >> will
> > > > > >> > > > > > >> >> > >> > be
> > > > > >> > > > > > >> >> > >> > > > > >> digging
> > > > > >> > > > > > >> >> > >> > > > > >> > > > further into this.
> > > > > >> > > > > > >> >> > >> > > > > >> > > >
> > > > > >> > > > > > >> >> > >> > > > > >> > > >
> > > > > >> > > > > > >> >> > >> > > > > >> > > >
> > > > > >> > > > > > >> >> > >> > > > > >> > > > On Sat, Mar 17, 2018 at
> 4:16
> > > PM,
> > > > > >> > Richard
> > > > > >> > > > Yu <
> > > > > >> > > > > > >> >> > >> > > > > >> > yohan.richard.yu@gmail.com>
> > > > > >> > > > > > >> >> > >> > > > > >> > > > wrote:
> > > > > >> > > > > > >> >> > >> > > > > >> > > >
> > > > > >> > > > > > >> >> > >> > > > > >> > > > > One more thing: when
> > looking
> > > > > >> through
> > > > > >> > > > > tests, I
> > > > > >> > > > > > >> have
> > > > > >> > > > > > >> >> > >> > realized
> > > > > >> > > > > > >> >> > >> > > > that
> > > > > >> > > > > > >> >> > >> > > > > >> > seek()
> > > > > >> > > > > > >> >> > >> > > > > >> > > > > methods can potentially
> > > block
> > > > > >> > > > indefinitely.
> > > > > >> > > > > > As
> > > > > >> > > > > > >> you
> > > > > >> > > > > > >> >> > well
> > > > > >> > > > > > >> >> > >> > > know,
> > > > > >> > > > > > >> >> > >> > > > > >> seek()
> > > > > >> > > > > > >> >> > >> > > > > >> > is
> > > > > >> > > > > > >> >> > >> > > > > >> > > > > called when pollOnce()
> or
> > > > > >> position()
> > > > > >> > is
> > > > > >> > > > > > active.
> > > > > >> > > > > > >> >> Thus,
> > > > > >> > > > > > >> >> > >> if
> > > > > >> > > > > > >> >> > >> > > > > >> position()
> > > > > >> > > > > > >> >> > >> > > > > >> > > > blocks
> > > > > >> > > > > > >> >> > >> > > > > >> > > > > indefinitely, then so
> > would
> > > > > >> seek().
> > > > > >> > > > Should
> > > > > >> > > > > > >> >> bounding
> > > > > >> > > > > > >> >> > >> seek()
> > > > > >> > > > > > >> >> > >> > > > also
> > > > > >> > > > > > >> >> > >> > > > > be
> > > > > >> > > > > > >> >> > >> > > > > >> > > > included
> > > > > >> > > > > > >> >> > >> > > > > >> > > > > in this KIP?
> > > > > >> > > > > > >> >> > >> > > > > >> > > > >
> > > > > >> > > > > > >> >> > >> > > > > >> > > > > Thanks, Richard
> > > > > >> > > > > > >> >> > >> > > > > >> > > > >
> > > > > >> > > > > > >> >> > >> > > > > >> > > > > On Sat, Mar 17, 2018 at
> > 1:16
> > > > PM,
> > > > > >> > > Richard
> > > > > >> > > > > Yu <
> > > > > >> > > > > > >> >> > >> > > > > >> > > yohan.richard.yu@gmail.com>
> > > > > >> > > > > > >> >> > >> > > > > >> > > > > wrote:
> > > > > >> > > > > > >> >> > >> > > > > >> > > > >
> > > > > >> > > > > > >> >> > >> > > > > >> > > > >> Thanks for the advice,
> > > Jason
> > > > > >> > > > > > >> >> > >> > > > > >> > > > >>
> > > > > >> > > > > > >> >> > >> > > > > >> > > > >> I have modified KIP-266
> > to
> > > > > >> include
> > > > > >> > the
> > > > > >> > > > > java
> > > > > >> > > > > > >> doc
> > > > > >> > > > > > >> >> for
> > > > > >> > > > > > >> >> > >> > > > committed()
> > > > > >> > > > > > >> >> > >> > > > > >> and
> > > > > >> > > > > > >> >> > >> > > > > >> > > > other
> > > > > >> > > > > > >> >> > >> > > > > >> > > > >> blocking methods, and I
> > > also
> > > > > >> > > > > > >> >> > >> > > > > >> > > > >> mentioned poll() which
> > will
> > > > > also
> > > > > >> be
> > > > > >> > > > > bounded.
> > > > > >> > > > > > >> Let
> > > > > >> > > > > > >> >> me
> > > > > >> > > > > > >> >> > >> know
> > > > > >> > > > > > >> >> > >> > if
> > > > > >> > > > > > >> >> > >> > > > > >> there is
> > > > > >> > > > > > >> >> > >> > > > > >> > > > >> anything else. :)
> > > > > >> > > > > > >> >> > >> > > > > >> > > > >>
> > > > > >> > > > > > >> >> > >> > > > > >> > > > >> Sincerely, Richard
> > > > > >> > > > > > >> >> > >> > > > > >> > > > >>
> > > > > >> > > > > > >> >> > >> > > > > >> > > > >>
> > > > > >> > > > > > >> >> > >> > > > > >> > > > >>
> > > > > >> > > > > > >> >> > >> > > > > >> > > > >>
> > > > > >> > > > > > >> >> > >> > > > > >> > > > >>
> > > > > >> > > > > > >> >> > >> > > > > >> > > > >> On Sat, Mar 17, 2018 at
> > > 12:00
> > > > > PM,
> > > > > >> > > Jason
> > > > > >> > > > > > >> >> Gustafson <
> > > > > >> > > > > > >> >> > >> > > > > >> > jason@confluent.io
> > > > > >> > > > > > >> >> > >> > > > > >> > > >
> > > > > >> > > > > > >> >> > >> > > > > >> > > > >> wrote:
> > > > > >> > > > > > >> >> > >> > > > > >> > > > >>
> > > > > >> > > > > > >> >> > >> > > > > >> > > > >>> Hi Richard,
> > > > > >> > > > > > >> >> > >> > > > > >> > > > >>>
> > > > > >> > > > > > >> >> > >> > > > > >> > > > >>> Thanks for the
> updates.
> > > I'm
> > > > > >> really
> > > > > >> > > glad
> > > > > >> > > > > you
> > > > > >> > > > > > >> >> picked
> > > > > >> > > > > > >> >> > >> this
> > > > > >> > > > > > >> >> > >> > > up.
> > > > > >> > > > > > >> >> > >> > > > A
> > > > > >> > > > > > >> >> > >> > > > > >> > couple
> > > > > >> > > > > > >> >> > >> > > > > >> > > > >>> minor
> > > > > >> > > > > > >> >> > >> > > > > >> > > > >>> comments:
> > > > > >> > > > > > >> >> > >> > > > > >> > > > >>>
> > > > > >> > > > > > >> >> > >> > > > > >> > > > >>> 1. Can you list the
> full
> > > set
> > > > > of
> > > > > >> new
> > > > > >> > > > APIs
> > > > > >> > > > > > >> >> explicitly
> > > > > >> > > > > > >> >> > >> in
> > > > > >> > > > > > >> >> > >> > the
> > > > > >> > > > > > >> >> > >> > > > > KIP?
> > > > > >> > > > > > >> >> > >> > > > > >> > > > >>> Currently I
> > > > > >> > > > > > >> >> > >> > > > > >> > > > >>> only see the javadoc
> for
> > > > > >> > > `position()`.
> > > > > >> > > > > > >> >> > >> > > > > >> > > > >>>
> > > > > >> > > > > > >> >> > >> > > > > >> > > > >>> 2. We should consider
> > > adding
> > > > > >> > > `TimeUnit`
> > > > > >> > > > > to
> > > > > >> > > > > > >> the
> > > > > >> > > > > > >> >> new
> > > > > >> > > > > > >> >> > >> > methods
> > > > > >> > > > > > >> >> > >> > > > to
> > > > > >> > > > > > >> >> > >> > > > > >> avoid
> > > > > >> > > > > > >> >> > >> > > > > >> > > > unit
> > > > > >> > > > > > >> >> > >> > > > > >> > > > >>> confusion. I know it's
> > > > > >> inconsistent
> > > > > >> > > > with
> > > > > >> > > > > > the
> > > > > >> > > > > > >> >> poll()
> > > > > >> > > > > > >> >> > >> API,
> > > > > >> > > > > > >> >> > >> > > > but I
> > > > > >> > > > > > >> >> > >> > > > > >> > think
> > > > > >> > > > > > >> >> > >> > > > > >> > > it
> > > > > >> > > > > > >> >> > >> > > > > >> > > > >>> was
> > > > > >> > > > > > >> >> > >> > > > > >> > > > >>> probably a mistake not
> > to
> > > > > >> include
> > > > > >> > it
> > > > > >> > > > > there,
> > > > > >> > > > > > >> so
> > > > > >> > > > > > >> >> > better
> > > > > >> > > > > > >> >> > >> > not
> > > > > >> > > > > > >> >> > >> > > to
> > > > > >> > > > > > >> >> > >> > > > > >> double
> > > > > >> > > > > > >> >> > >> > > > > >> > > > down
> > > > > >> > > > > > >> >> > >> > > > > >> > > > >>> on
> > > > > >> > > > > > >> >> > >> > > > > >> > > > >>> that mistake. And note
> > > that
> > > > we
> > > > > >> do
> > > > > >> > > > already
> > > > > >> > > > > > >> have
> > > > > >> > > > > > >> >> > >> > > `close(long,
> > > > > >> > > > > > >> >> > >> > > > > >> > > TimeUnit)`.
> > > > > >> > > > > > >> >> > >> > > > > >> > > > >>>
> > > > > >> > > > > > >> >> > >> > > > > >> > > > >>> Other than that, I
> think
> > > the
> > > > > >> > current
> > > > > >> > > > KIP
> > > > > >> > > > > > >> seems
> > > > > >> > > > > > >> >> > >> > reasonable.
> > > > > >> > > > > > >> >> > >> > > > > >> > > > >>>
> > > > > >> > > > > > >> >> > >> > > > > >> > > > >>> Thanks,
> > > > > >> > > > > > >> >> > >> > > > > >> > > > >>> Jason
> > > > > >> > > > > > >> >> > >> > > > > >> > > > >>>
> > > > > >> > > > > > >> >> > >> > > > > >> > > > >>> On Wed, Mar 14, 2018
> at
> > > 5:00
> > > > > PM,
> > > > > >> > > > Richard
> > > > > >> > > > > > Yu <
> > > > > >> > > > > > >> >> > >> > > > > >> > > >
> yohan.richard.yu@gmail.com>
> > > > > >> > > > > > >> >> > >> > > > > >> > > > >>> wrote:
> > > > > >> > > > > > >> >> > >> > > > > >> > > > >>>
> > > > > >> > > > > > >> >> > >> > > > > >> > > > >>> > Note to all: I have
> > > > included
> > > > > >> > > bounding
> > > > > >> > > > > > >> >> > commitSync()
> > > > > >> > > > > > >> >> > >> and
> > > > > >> > > > > > >> >> > >> > > > > >> > committed()
> > > > > >> > > > > > >> >> > >> > > > > >> > > in
> > > > > >> > > > > > >> >> > >> > > > > >> > > > >>> this
> > > > > >> > > > > > >> >> > >> > > > > >> > > > >>> > KIP.
> > > > > >> > > > > > >> >> > >> > > > > >> > > > >>> >
> > > > > >> > > > > > >> >> > >> > > > > >> > > > >>> > On Sun, Mar 11, 2018
> > at
> > > > 5:05
> > > > > >> PM,
> > > > > >> > > > > Richard
> > > > > >> > > > > > >> Yu <
> > > > > >> > > > > > >> >> > >> > > > > >> > > > >>>
> > > yohan.richard.yu@gmail.com>
> > > > > >> > > > > > >> >> > >> > > > > >> > > > >>> > wrote:
> > > > > >> > > > > > >> >> > >> > > > > >> > > > >>> >
> > > > > >> > > > > > >> >> > >> > > > > >> > > > >>> > > Hi all,
> > > > > >> > > > > > >> >> > >> > > > > >> > > > >>> > >
> > > > > >> > > > > > >> >> > >> > > > > >> > > > >>> > > I updated the KIP
> > > where
> > > > > >> > > overloading
> > > > > >> > > > > > >> >> position()
> > > > > >> > > > > > >> >> > is
> > > > > >> > > > > > >> >> > >> > now
> > > > > >> > > > > > >> >> > >> > > > the
> > > > > >> > > > > > >> >> > >> > > > > >> > favored
> > > > > >> > > > > > >> >> > >> > > > > >> > > > >>> > approach.
> > > > > >> > > > > > >> >> > >> > > > > >> > > > >>> > > Bounding
> position()
> > > > using
> > > > > >> > > > > > >> requestTimeoutMs
> > > > > >> > > > > > >> >> has
> > > > > >> > > > > > >> >> > >> been
> > > > > >> > > > > > >> >> > >> > > > listed
> > > > > >> > > > > > >> >> > >> > > > > >> as
> > > > > >> > > > > > >> >> > >> > > > > >> > > > >>> rejected.
> > > > > >> > > > > > >> >> > >> > > > > >> > > > >>> > >
> > > > > >> > > > > > >> >> > >> > > > > >> > > > >>> > > Any thoughts?
> > > > > >> > > > > > >> >> > >> > > > > >> > > > >>> > >
> > > > > >> > > > > > >> >> > >> > > > > >> > > > >>> > > On Tue, Mar 6,
> 2018
> > at
> > > > > 6:00
> > > > > >> PM,
> > > > > >> > > > > > Guozhang
> > > > > >> > > > > > >> >> Wang <
> > > > > >> > > > > > >> >> > >> > > > > >> > > wangguoz@gmail.com>
> > > > > >> > > > > > >> >> > >> > > > > >> > > > >>> > wrote:
> > > > > >> > > > > > >> >> > >> > > > > >> > > > >>> > >
> > > > > >> > > > > > >> >> > >> > > > > >> > > > >>> > >> I agree that
> adding
> > > the
> > > > > >> > > overloads
> > > > > >> > > > is
> > > > > >> > > > > > >> most
> > > > > >> > > > > > >> >> > >> flexible.
> > > > > >> > > > > > >> >> > >> > > But
> > > > > >> > > > > > >> >> > >> > > > > >> going
> > > > > >> > > > > > >> >> > >> > > > > >> > > for
> > > > > >> > > > > > >> >> > >> > > > > >> > > > >>> that
> > > > > >> > > > > > >> >> > >> > > > > >> > > > >>> > >> direction we'd do
> > > that
> > > > > for
> > > > > >> all
> > > > > >> > > the
> > > > > >> > > > > > >> blocking
> > > > > >> > > > > > >> >> > call
> > > > > >> > > > > > >> >> > >> > that
> > > > > >> > > > > > >> >> > >> > > > > I've
> > > > > >> > > > > > >> >> > >> > > > > >> > > listed
> > > > > >> > > > > > >> >> > >> > > > > >> > > > >>> above,
> > > > > >> > > > > > >> >> > >> > > > > >> > > > >>> > >> with this timeout
> > > value
> > > > > >> > covering
> > > > > >> > > > the
> > > > > >> > > > > > >> >> > end-to-end
> > > > > >> > > > > > >> >> > >> > > waiting
> > > > > >> > > > > > >> >> > >> > > > > >> time.
> > > > > >> > > > > > >> >> > >> > > > > >> > > > >>> > >>
> > > > > >> > > > > > >> >> > >> > > > > >> > > > >>> > >>
> > > > > >> > > > > > >> >> > >> > > > > >> > > > >>> > >> Guozhang
> > > > > >> > > > > > >> >> > >> > > > > >> > > > >>> > >>
> > > > > >> > > > > > >> >> > >> > > > > >> > > > >>> > >> On Tue, Mar 6,
> 2018
> > > at
> > > > > >> 10:02
> > > > > >> > AM,
> > > > > >> > > > Ted
> > > > > >> > > > > > Yu
> > > > > >> > > > > > >> <
> > > > > >> > > > > > >> >> > >> > > > > >> yuzhihong@gmail.com>
> > > > > >> > > > > > >> >> > >> > > > > >> > > > >>> wrote:
> > > > > >> > > > > > >> >> > >> > > > > >> > > > >>> > >>
> > > > > >> > > > > > >> >> > >> > > > > >> > > > >>> > >> > bq. The most
> > > flexible
> > > > > >> option
> > > > > >> > > is
> > > > > >> > > > to
> > > > > >> > > > > > add
> > > > > >> > > > > > >> >> > >> overloads
> > > > > >> > > > > > >> >> > >> > to
> > > > > >> > > > > > >> >> > >> > > > the
> > > > > >> > > > > > >> >> > >> > > > > >> > > consumer
> > > > > >> > > > > > >> >> > >> > > > > >> > > > >>> > >> >
> > > > > >> > > > > > >> >> > >> > > > > >> > > > >>> > >> > This option is
> > > > > flexible.
> > > > > >> > > > > > >> >> > >> > > > > >> > > > >>> > >> >
> > > > > >> > > > > > >> >> > >> > > > > >> > > > >>> > >> > Looking at the
> > tail
> > > > of
> > > > > >> > > > > SPARK-18057,
> > > > > >> > > > > > >> Spark
> > > > > >> > > > > > >> >> > dev
> > > > > >> > > > > > >> >> > >> > > voiced
> > > > > >> > > > > > >> >> > >> > > > > the
> > > > > >> > > > > > >> >> > >> > > > > >> > same
> > > > > >> > > > > > >> >> > >> > > > > >> > > > >>> choice.
> > > > > >> > > > > > >> >> > >> > > > > >> > > > >>> > >> >
> > > > > >> > > > > > >> >> > >> > > > > >> > > > >>> > >> > +1 for adding
> > > > overload
> > > > > >> with
> > > > > >> > > > > timeout
> > > > > >> > > > > > >> >> > parameter.
> > > > > >> > > > > > >> >> > >> > > > > >> > > > >>> > >> >
> > > > > >> > > > > > >> >> > >> > > > > >> > > > >>> > >> > Cheers
> > > > > >> > > > > > >> >> > >> > > > > >> > > > >>> > >> >
> > > > > >> > > > > > >> >> > >> > > > > >> > > > >>> > >> > On Mon, Mar 5,
> > 2018
> > > > at
> > > > > >> 2:42
> > > > > >> > > PM,
> > > > > >> > > > > > Jason
> > > > > >> > > > > > >> >> > >> Gustafson <
> > > > > >> > > > > > >> >> > >> > > > > >> > > > >>> jason@confluent.io>
> > > > > >> > > > > > >> >> > >> > > > > >> > > > >>> > >> > wrote:
> > > > > >> > > > > > >> >> > >> > > > > >> > > > >>> > >> >
> > > > > >> > > > > > >> >> > >> > > > > >> > > > >>> > >> > > @Guozhang I
> > > > probably
> > > > > >> have
> > > > > >> > > > > > suggested
> > > > > >> > > > > > >> all
> > > > > >> > > > > > >> >> > >> options
> > > > > >> > > > > > >> >> > >> > > at
> > > > > >> > > > > > >> >> > >> > > > > some
> > > > > >> > > > > > >> >> > >> > > > > >> > > point
> > > > > >> > > > > > >> >> > >> > > > > >> > > > or
> > > > > >> > > > > > >> >> > >> > > > > >> > > > >>> > >> another,
> > > > > >> > > > > > >> >> > >> > > > > >> > > > >>> > >> > > including
> most
> > > > > >> recently,
> > > > > >> > the
> > > > > >> > > > > > current
> > > > > >> > > > > > >> >> KIP!
> > > > > >> > > > > > >> >> > I
> > > > > >> > > > > > >> >> > >> was
> > > > > >> > > > > > >> >> > >> > > > > >> thinking
> > > > > >> > > > > > >> >> > >> > > > > >> > > that
> > > > > >> > > > > > >> >> > >> > > > > >> > > > >>> > >> practically
> > > > > >> > > > > > >> >> > >> > > > > >> > > > >>> > >> > > speaking, the
> > > > request
> > > > > >> > > timeout
> > > > > >> > > > > > >> defines
> > > > > >> > > > > > >> >> how
> > > > > >> > > > > > >> >> > >> long
> > > > > >> > > > > > >> >> > >> > > the
> > > > > >> > > > > > >> >> > >> > > > > >> user is
> > > > > >> > > > > > >> >> > >> > > > > >> > > > >>> willing
> > > > > >> > > > > > >> >> > >> > > > > >> > > > >>> > to
> > > > > >> > > > > > >> >> > >> > > > > >> > > > >>> > >> > wait
> > > > > >> > > > > > >> >> > >> > > > > >> > > > >>> > >> > > for a
> response.
> > > The
> > > > > >> > consumer
> > > > > >> > > > > > doesn't
> > > > > >> > > > > > >> >> > really
> > > > > >> > > > > > >> >> > >> > have
> > > > > >> > > > > > >> >> > >> > > a
> > > > > >> > > > > > >> >> > >> > > > > >> complex
> > > > > >> > > > > > >> >> > >> > > > > >> > > > send
> > > > > >> > > > > > >> >> > >> > > > > >> > > > >>> > >> process
> > > > > >> > > > > > >> >> > >> > > > > >> > > > >>> > >> > > like the
> > producer
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> > > > 2018
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> > > > > >> yohan.richard.yu@gmail.com>
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> > > > > >> > > > > > >> >> > >> > > > > >> > > > >>> > >> > > > >
> > > > > >> > > https://cwiki.apache.org/
> > > > > >> > > > > > >> >> > >> > > > > confluence/pages/viewpage
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> > > > > >> > > > > > >> >> > >> > > > > >> > > > >>> > >> > > > >
> > > > > >> > > > > > >> >> > >> > > > > >> > > > >>> > >> > > > > Thanks,
> > > > > >> > > > > > >> >> > >> > > > > >> > > > >>> > >> > > > > Richard
> Yu
> > > > > >> > > > > > >> >> > >> > > > > >> > > > >>> > >> > > > >
> > > > > >> > > > > > >> >> > >> > > > > >> > > > >>> > >> > > >
> > > > > >> > > > > > >> >> > >> > > > > >> > > > >>> > >> > > >
> > > > > >> > > > > > >> >> > >> > > > > >> > > > >>> > >> > > >
> > > > > >> > > > > > >> >> > >> > > > > >> > > > >>> > >> > > > --
> > > > > >> > > > > > >> >> > >> > > > > >> > > > >>> > >> > > > -- Guozhang
> > > > > >> > > > > > >> >> > >> > > > > >> > > > >>> > >> > > >
> > > > > >> > > > > > >> >> > >> > > > > >> > > > >>> > >> > >
> > > > > >> > > > > > >> >> > >> > > > > >> > > > >>> > >> >
> > > > > >> > > > > > >> >> > >> > > > > >> > > > >>> > >>
> > > > > >> > > > > > >> >> > >> > > > > >> > > > >>> > >>
> > > > > >> > > > > > >> >> > >> > > > > >> > > > >>> > >>
> > > > > >> > > > > > >> >> > >> > > > > >> > > > >>> > >> --
> > > > > >> > > > > > >> >> > >> > > > > >> > > > >>> > >> -- Guozhang
> > > > > >> > > > > > >> >> > >> > > > > >> > > > >>> > >>
> > > > > >> > > > > > >> >> > >> > > > > >> > > > >>> > >
> > > > > >> > > > > > >> >> > >> > > > > >> > > > >>> > >
> > > > > >> > > > > > >> >> > >> > > > > >> > > > >>> >
> > > > > >> > > > > > >> >> > >> > > > > >> > > > >>>
> > > > > >> > > > > > >> >> > >> > > > > >> > > > >>
> > > > > >> > > > > > >> >> > >> > > > > >> > > > >>
> > > > > >> > > > > > >> >> > >> > > > > >> > > > >
> > > > > >> > > > > > >> >> > >> > > > > >> > > >
> > > > > >> > > > > > >> >> > >> > > > > >> > >
> > > > > >> > > > > > >> >> > >> > > > > >> > >
> > > > > >> > > > > > >> >> > >> > > > > >> > >
> > > > > >> > > > > > >> >> > >> > > > > >> > > --
> > > > > >> > > > > > >> >> > >> > > > > >> > > -- Guozhang
> > > > > >> > > > > > >> >> > >> > > > > >> > >
> > > > > >> > > > > > >> >> > >> > > > > >> >
> > > > > >> > > > > > >> >> > >> > > > > >>
> > > > > >> > > > > > >> >> > >> > > > > >
> > > > > >> > > > > > >> >> > >> > > > > >
> > > > > >> > > > > > >> >> > >> > > > >
> > > > > >> > > > > > >> >> > >> > > >
> > > > > >> > > > > > >> >> > >> > >
> > > > > >> > > > > > >> >> > >> >
> > > > > >> > > > > > >> >> > >> >
> > > > > >> > > > > > >> >> > >> >
> > > > > >> > > > > > >> >> > >> > --
> > > > > >> > > > > > >> >> > >> > -- Guozhang
> > > > > >> > > > > > >> >> > >> >
> > > > > >> > > > > > >> >> > >>
> > > > > >> > > > > > >> >> > >
> > > > > >> > > > > > >> >> > >
> > > > > >> > > > > > >> >> >
> > > > > >> > > > > > >> >>
> > > > > >> > > > > > >> >>
> > > > > >> > > > > > >> >>
> > > > > >> > > > > > >> >> --
> > > > > >> > > > > > >> >> -- Guozhang
> > > > > >> > > > > > >> >>
> > > > > >> > > > > > >> >
> > > > > >> > > > > > >> >
> > > > > >> > > > > > >>
> > > > > >> > > > > > >
> > > > > >> > > > > > >
> > > > > >> > > > > >
> > > > > >> > > > >
> > > > > >> > > >
> > > > > >> > >
> > > > > >> >
> > > > > >>
> > > > > >
> > > > > >
> > > > >
> > > >
> > > >
> > > >
> > > > --
> > > > -- Guozhang
> > > >
> > >
> >
>
Re: [DISCUSSION] KIP-266: Add TimeoutException to KafkaConsumer#position()
Posted by Richard Yu <yo...@gmail.com>.
Hi John,
I don't have any objections to this KIP change. Please go ahead.
Thanks,
Richard
On Wed, May 2, 2018 at 2:54 PM, John Roesler <jo...@confluent.io> wrote:
> Thanks Jason,
>
> I did find some production use cases "on the internet" that use poll(0)
> *just* to join the group initially and ignore the response. I suppose the
> assumption is that it'll be empty on the very first call to poll with
> timeout=0. In my opinion, this usage is unsafe, since there's a declared
> return value. I proposed the method to give these use cases a safe
> alternative.
>
> Of course, there's another safe alternative: just don't ignore the
> response.
>
> I'd agree with the decision to just deprecate the old poll(long) and add
> only a new poll(Duration). It should be obvious that there's no
> non-deprecated way to do what the code I found is doing, so those
> developers will either alter their code to handle the response or they will
> come back and ask us for the awaitAssignmentMetadata method.
>
> Better to present a simpler api and wait for a reason to make it more
> complicated.
>
> I'm fine with suggestions 1,2, and 3. Unless Richard objects super fast,
> I'll update the KIP momentarily.
>
> Regarding the ClientTimeoutException, this was introduced earlier in this
> discussion when Becket pointed out that the TimeoutException is a subclass
> of ApiException, and therefore implies that a call to the broker timed out.
>
> Reconsidering this point, I found the javadoc on ApiException to be a
> little ambiguous. All it says is that "any API exception that is part of
> the public protocol should be a subclass of this class...". It's not clear
> to me whether this is the broker's API/protocol or more generally *any*
> API/protocol. So we'd have to bring the lawyers in, but I think we can just
> say it's the latter and keep the old exception.
>
> I'm not sure if it's an important distiction to users whether their request
> timed out as a broker side timeout, an HTTP timeout, or a client-side
> timeout. In any case, they'd want to retry for a while and then fail if
> they can't get their request through.
>
> Plus RetryableException also inherits from ApiException, and that one is
> ubiquitous. Adding a new exception would require users to catch both
> RetriableException and ClientTimeoutException, which seems odd since the
> latter is retriable.
>
> All in all, I'm now in favor of sticking with the current TimeoutException.
> If there's some higher-level problem with the ApiException being used this
> way, I think it should be addressed holistically in a separate KIP.
>
> So, I'll go ahead and switch the KIP back to TimeoutException, unless
> Becket wants to argue (harder) in favor of the ClientTimeoutException.
>
> Thanks,
> -John
>
>
> On Wed, May 2, 2018 at 3:55 PM, Jason Gustafson <ja...@confluent.io>
> wrote:
>
> > I think John's proposal look reasonable to me. My only doubt is about use
> > cases for the new `awaitAssignmentMetadata` API. I think the basic idea
> is
> > that we want a way to block until we have joined the consumer group, but
> we
> > do not want to await fetched data. Maybe another way to accomplish this
> > would be to add a `PollOptions` argument which specified the condition we
> > are awaiting? It's a little weird that we'd have two separate APIs where
> > the group membership can change. I know this functionality can be helpful
> > in testing, but we should probably spend some more time understanding and
> > motivating the general use cases.
> >
> > Since we're leaving around the old poll() with its current behavior for
> > now, I wonder if we could leave this as potential future work?
> >
> > Other than that, I have a few minor suggestions and I'm happy with the
> KIP:
> >
> > 1. Can we use Duration across the board for all of these APIs?
> > 2. Can we cover the following blocking APIs with in this KIP:
> > `partitionsFor`, `listTopics`, `offsetsForTimes`, `beginningOffsets`,
> > `endOffsets`?
> > 3. Perhaps we can add a `close(Duration)` and deprecate the one accepting
> > `TimeUnit`?
> > 4. Seems we don't really need `ClientTimeoutException` since we already
> > have `TimeoutException`?
> >
> > Thanks,
> > Jason
> >
> >
> >
> > On Wed, Apr 25, 2018 at 2:14 PM, Guozhang Wang <wa...@gmail.com>
> wrote:
> >
> > > Previously there are some debates on whether we should add this
> > nonblocking
> > > behavior via a config v.s. via overloaded functions. To make progress
> on
> > > this discussion we need to first figure that part out. I'm in favor of
> > the
> > > current approach of overloaded functions over the config since if we
> are
> > > going to have multiple configs other than a single one to control
> timeout
> > > semantics it may be even confusing: take our producer side configs for
> an
> > > example, right now we have "request.timeout.ms" and "max.block.ms" and
> > we
> > > are proposing to add another one in KIP-91. But I'd also like to hear
> > from
> > > people who's in favor of the configs.
> > >
> > >
> > > Guozhang
> > >
> > >
> > > On Wed, Apr 25, 2018 at 1:39 PM, John Roesler <jo...@confluent.io>
> wrote:
> > >
> > > > Re Ted's last comment, that style of async API requires some thread
> to
> > > > actually drive the request/response cycle and invoke the callback
> when
> > > it's
> > > > complete. Right now, this happens in the caller's thread as a
> > side-effect
> > > > of calling poll(). But that clearly won't work for poll() itself!
> > > >
> > > > In the future, I think we'd like to add a background thread to drive
> > the
> > > > request/response loops, and then make all these methods return
> > > > Future<Whatever>.
> > > >
> > > > But we don't need to bite that off right now.
> > > >
> > > > The "async" model I'm proposing is really just a generalization of
> the
> > > one
> > > > that poll already partially implements: when you call poll, it fires
> > off
> > > > any requests it needs to make and checks if any responses are ready.
> If
> > > so,
> > > > it returns them. If not, it returns empty. When you call poll()
> again,
> > it
> > > > again checks on the responses from last time, and so forth.
> > > >
> > > > But that model currently only applies to the "fetch" part of poll.
> I'm
> > > > proposing that we extend it to the "metadata update" part of poll as
> > > well.
> > > >
> > > > However, as previously discussed, doing this in place would break the
> > > > semantics of poll that folks currently rely on, so I propose to add
> new
> > > > methods and deprecate the existing poll method. Here's what I'm
> > thinking:
> > > > https://github.com/apache/kafka/pull/4855 . In the discussion on
> that
> > > PR,
> > > > I've described in greater detail how the async+blocking semantics
> work.
> > > >
> > > > I'll update KIP-266 with this interface for poll().
> > > >
> > > > It would be great to get this discussion moving again so we can get
> > these
> > > > changes into 2.0. What does everyone think about this?
> > > >
> > > > Thanks,
> > > > -John
> > > >
> > > > On Thu, Apr 19, 2018 at 5:12 PM, John Roesler <jo...@confluent.io>
> > wrote:
> > > >
> > > > > Thanks for the tip, Ted!
> > > > >
> > > > > On Thu, Apr 19, 2018 at 12:12 PM, Ted Yu <yu...@gmail.com>
> > wrote:
> > > > >
> > > > >> John:
> > > > >> In case you want to pursue async poll, it seems (by looking at
> > current
> > > > >> API)
> > > > >> that introducing PollCallback follows existing pattern(s).
> > > > >>
> > > > >> e.g. KafkaConsumer#commitAsync(OffsetCommitCallback)
> > > > >>
> > > > >> FYI
> > > > >>
> > > > >> On Thu, Apr 19, 2018 at 10:08 AM, John Roesler <john@confluent.io
> >
> > > > wrote:
> > > > >>
> > > > >> > Hi Richard,
> > > > >> >
> > > > >> > Thanks for the invitation! I do think it would be safer to
> > > introduce a
> > > > >> new
> > > > >> > poll
> > > > >> > method than to change the semantics of the old one. I've been
> > > mulling
> > > > >> about
> > > > >> > whether the new one could still have (slightly different) async
> > > > >> semantics
> > > > >> > with
> > > > >> > a timeout of 0. If possible, I'd like to avoid introducing
> another
> > > new
> > > > >> > "asyncPoll".
> > > > >> >
> > > > >> > I'm planning to run some experiments and dig into the
> > > implementation a
> > > > >> bit
> > > > >> > more before solidifying the proposal. I'll update the KIP as you
> > > > >> suggest at
> > > > >> > that point,
> > > > >> > and then can call for another round of reviews and voting.
> > > > >> >
> > > > >> > Thanks,
> > > > >> > -John
> > > > >> >
> > > > >> > On Tue, Apr 17, 2018 at 4:53 PM, Richard Yu <
> > > > yohan.richard.yu@gmail.com
> > > > >> >
> > > > >> > wrote:
> > > > >> >
> > > > >> > > Hi John,
> > > > >> > >
> > > > >> > > Do you have a preference for fixing the poll() method (e.g.
> > using
> > > > >> > asyncPoll
> > > > >> > > or just sticking with the current method but with an extra
> > timeout
> > > > >> > > parameter) ? I think your current proposition for KIP-288 is
> > > better
> > > > >> than
> > > > >> > > what I have on my side. If you think there is something that
> you
> > > > want
> > > > >> to
> > > > >> > > add, you could go ahead and change KIP-266 to your liking.
> Just
> > to
> > > > >> note
> > > > >> > > that it would be preferable that if one of us modifies this
> KIP,
> > > it
> > > > >> would
> > > > >> > > be best to mention your change on this thread to let each
> other
> > > know
> > > > >> > (makes
> > > > >> > > it easier to coordinate progress).
> > > > >> > >
> > > > >> > > Thanks,
> > > > >> > > Richard
> > > > >> > >
> > > > >> > > On Tue, Apr 17, 2018 at 2:07 PM, John Roesler <
> > john@confluent.io>
> > > > >> wrote:
> > > > >> > >
> > > > >> > > > Ok, I'll close the discussion on KIP-288 and mark it
> > discarded.
> > > > >> > > >
> > > > >> > > > We can solidify the design for poll in KIP-266, and once
> it's
> > > > >> approved,
> > > > >> > > > I'll coordinate with Qiang Zhao on the PR for the poll part
> of
> > > the
> > > > >> > work.
> > > > >> > > > Once that is merged, you'll have a clean slate for the rest
> of
> > > the
> > > > >> > work.
> > > > >> > > >
> > > > >> > > > On Tue, Apr 17, 2018 at 3:39 PM, Richard Yu <
> > > > >> > yohan.richard.yu@gmail.com>
> > > > >> > > > wrote:
> > > > >> > > >
> > > > >> > > > > Hi John,
> > > > >> > > > >
> > > > >> > > > > I think that you could finish your PR that corresponds
> with
> > > > >> KIP-288
> > > > >> > and
> > > > >> > > > > merge it. I can finish my side of the work afterwards.
> > > > >> > > > >
> > > > >> > > > > On another note, adding an asynchronized version of poll()
> > > would
> > > > >> make
> > > > >> > > > > sense, particularily since the current version of Kafka
> does
> > > not
> > > > >> > > support
> > > > >> > > > > it.
> > > > >> > > > >
> > > > >> > > > > Thanks
> > > > >> > > > > Richar
> > > > >> > > > >
> > > > >> > > > > On Tue, Apr 17, 2018 at 12:30 PM, John Roesler <
> > > > john@confluent.io
> > > > >> >
> > > > >> > > > wrote:
> > > > >> > > > >
> > > > >> > > > > > Cross-pollinating from some discussion we've had on
> > KIP-288,
> > > > >> > > > > >
> > > > >> > > > > > I think there's a good reason that poll() takes a
> timeout
> > > when
> > > > >> none
> > > > >> > > of
> > > > >> > > > > the
> > > > >> > > > > > other methods do, and it's relevant to this discussion.
> > The
> > > > >> timeout
> > > > >> > > in
> > > > >> > > > > > poll() is effectively implementing a long-poll API (on
> the
> > > > >> client
> > > > >> > > side,
> > > > >> > > > > so
> > > > >> > > > > > it's not really long-poll, but the programmer-facing
> > > behavior
> > > > is
> > > > >> > the
> > > > >> > > > > same).
> > > > >> > > > > > The timeout isn't really bounding the execution time of
> > the
> > > > >> method,
> > > > >> > > but
> > > > >> > > > > > instead giving a max time that callers are willing to
> wait
> > > > >> around
> > > > >> > and
> > > > >> > > > see
> > > > >> > > > > > if any results show up.
> > > > >> > > > > >
> > > > >> > > > > > If I understand the code sufficiently, it would be
> > perfectly
> > > > >> > > reasonable
> > > > >> > > > > for
> > > > >> > > > > > a caller to use a timeout of 0 to implement async poll,
> it
> > > > would
> > > > >> > just
> > > > >> > > > > mean
> > > > >> > > > > > that KafkaConsumer would just check on each call if
> > there's
> > > a
> > > > >> > > response
> > > > >> > > > > > ready and if not, fire off a new request without waiting
> > > for a
> > > > >> > > > response.
> > > > >> > > > > >
> > > > >> > > > > > As such, it seems inappropriate to throw a
> > > > >> ClientTimeoutException
> > > > >> > > from
> > > > >> > > > > > poll(), except possibly if the initial phase of ensuring
> > an
> > > > >> > > assignment
> > > > >> > > > > > times out. We wouldn't want the method contract to be
> > > > "returns a
> > > > >> > > > > non-empty
> > > > >> > > > > > collection or throws a ClientTimeoutException"
> > > > >> > > > > >
> > > > >> > > > > > Now, I'm wondering if we should actually consider one of
> > my
> > > > >> > rejected
> > > > >> > > > > > alternatives, to treat the "operation timeout" as a
> > separate
> > > > >> > > parameter
> > > > >> > > > > from
> > > > >> > > > > > the "long-poll time". Or maybe adding an
> > "asyncPoll(timeout,
> > > > >> time
> > > > >> > > > unit)"
> > > > >> > > > > > that only uses the timeout to bound metadata updates and
> > > > >> otherwise
> > > > >> > > > > behaves
> > > > >> > > > > > like the current "poll(0)".
> > > > >> > > > > >
> > > > >> > > > > > Thanks,
> > > > >> > > > > > -John
> > > > >> > > > > >
> > > > >> > > > > > On Tue, Apr 17, 2018 at 2:05 PM, John Roesler <
> > > > >> john@confluent.io>
> > > > >> > > > wrote:
> > > > >> > > > > >
> > > > >> > > > > > > Hey Richard,
> > > > >> > > > > > >
> > > > >> > > > > > > As you noticed, the newly introduced KIP-288 overlaps
> > with
> > > > >> this
> > > > >> > > one.
> > > > >> > > > > > Sorry
> > > > >> > > > > > > for stepping on your toes... How would you like to
> > > proceed?
> > > > >> I'm
> > > > >> > > happy
> > > > >> > > > > to
> > > > >> > > > > > > "close" KIP-288 in deference to this KIP.
> > > > >> > > > > > >
> > > > >> > > > > > > With respect to poll(), reading this discussion gave
> me
> > a
> > > > new
> > > > >> > idea
> > > > >> > > > for
> > > > >> > > > > > > providing a non-breaking update path... What if we
> > > > introduce a
> > > > >> > new
> > > > >> > > > > > variant
> > > > >> > > > > > > 'poll(long timeout, TimeUnit unit)' that displays the
> > new,
> > > > >> > desired
> > > > >> > > > > > > behavior, and just leave the old method alone?
> > > > >> > > > > > >
> > > > >> > > > > > > Thanks,
> > > > >> > > > > > > -John
> > > > >> > > > > > >
> > > > >> > > > > > > On Tue, Apr 17, 2018 at 12:09 PM, Richard Yu <
> > > > >> > > > > yohan.richard.yu@gmail.com
> > > > >> > > > > > >
> > > > >> > > > > > > wrote:
> > > > >> > > > > > >
> > > > >> > > > > > >> Hi all,
> > > > >> > > > > > >>
> > > > >> > > > > > >> If possible, would a committer please review?
> > > > >> > > > > > >>
> > > > >> > > > > > >> Thanks
> > > > >> > > > > > >>
> > > > >> > > > > > >> On Sun, Apr 1, 2018 at 7:24 PM, Richard Yu <
> > > > >> > > > > yohan.richard.yu@gmail.com>
> > > > >> > > > > > >> wrote:
> > > > >> > > > > > >>
> > > > >> > > > > > >> > Hi Guozhang,
> > > > >> > > > > > >> >
> > > > >> > > > > > >> > I have clarified the KIP a bit to account for
> > Becket's
> > > > >> > > suggestion
> > > > >> > > > on
> > > > >> > > > > > >> > ClientTimeoutException.
> > > > >> > > > > > >> > About adding an extra config, you were right about
> my
> > > > >> > > intentions.
> > > > >> > > > I
> > > > >> > > > > am
> > > > >> > > > > > >> > just wondering if the config
> > > > >> > > > > > >> > should be included, since Ismael seems to favor an
> > > extra
> > > > >> > > > > > configuration,
> > > > >> > > > > > >> >
> > > > >> > > > > > >> > Thanks,
> > > > >> > > > > > >> > Richard
> > > > >> > > > > > >> >
> > > > >> > > > > > >> > On Sun, Apr 1, 2018 at 5:35 PM, Guozhang Wang <
> > > > >> > > wangguoz@gmail.com
> > > > >> > > > >
> > > > >> > > > > > >> wrote:
> > > > >> > > > > > >> >
> > > > >> > > > > > >> >> Hi Richard,
> > > > >> > > > > > >> >>
> > > > >> > > > > > >> >> Regarding the streams side changes, we plan to
> > > > incorporate
> > > > >> > with
> > > > >> > > > the
> > > > >> > > > > > new
> > > > >> > > > > > >> >> APIs once the KIP is done, which is only internal
> > code
> > > > >> > changes
> > > > >> > > > and
> > > > >> > > > > > >> hence
> > > > >> > > > > > >> >> do
> > > > >> > > > > > >> >> not need to include in the KIP.
> > > > >> > > > > > >> >>
> > > > >> > > > > > >> >> Could you update the KIP because it has been quite
> > > > >> obsoleted
> > > > >> > > from
> > > > >> > > > > the
> > > > >> > > > > > >> >> discussed topics, and I'm a bit loosing track on
> > what
> > > is
> > > > >> your
> > > > >> > > > final
> > > > >> > > > > > >> >> proposal right now. For example, I'm not
> completely
> > > > >> following
> > > > >> > > > your
> > > > >> > > > > > >> >> "compromise
> > > > >> > > > > > >> >> of sorts": are you suggesting that we still add
> > > > >> overloading
> > > > >> > > > > functions
> > > > >> > > > > > >> and
> > > > >> > > > > > >> >> add a config that will be applied to all overload
> > > > >> functions
> > > > >> > > > without
> > > > >> > > > > > the
> > > > >> > > > > > >> >> timeout, while for other overloaded functions with
> > the
> > > > >> > timeout
> > > > >> > > > > value
> > > > >> > > > > > >> the
> > > > >> > > > > > >> >> config will be ignored?
> > > > >> > > > > > >> >>
> > > > >> > > > > > >> >>
> > > > >> > > > > > >> >> Guozhang
> > > > >> > > > > > >> >>
> > > > >> > > > > > >> >> On Fri, Mar 30, 2018 at 8:36 PM, Richard Yu <
> > > > >> > > > > > >> yohan.richard.yu@gmail.com>
> > > > >> > > > > > >> >> wrote:
> > > > >> > > > > > >> >>
> > > > >> > > > > > >> >> > On a side note, I have noticed that the several
> > > other
> > > > >> > methods
> > > > >> > > > in
> > > > >> > > > > > >> classes
> > > > >> > > > > > >> >> > such as StoreChangeLogReader in Streams calls
> > > > position()
> > > > >> > > which
> > > > >> > > > > > causes
> > > > >> > > > > > >> >> tests
> > > > >> > > > > > >> >> > to hang. It might be out of the scope of the
> KIP,
> > > but
> > > > >> > should
> > > > >> > > I
> > > > >> > > > > also
> > > > >> > > > > > >> >> change
> > > > >> > > > > > >> >> > the methods which use position() as a callback
> to
> > at
> > > > the
> > > > >> > very
> > > > >> > > > > least
> > > > >> > > > > > >> >> prevent
> > > > >> > > > > > >> >> > the tests from hanging? This issue might be out
> of
> > > the
> > > > >> KIP,
> > > > >> > > > but I
> > > > >> > > > > > >> >> prefer it
> > > > >> > > > > > >> >> > if we could at least make my PR pass the Jenkins
> > > Q&A.
> > > > >> > > > > > >> >> >
> > > > >> > > > > > >> >> > Thanks
> > > > >> > > > > > >> >> >
> > > > >> > > > > > >> >> > On Fri, Mar 30, 2018 at 8:24 PM, Richard Yu <
> > > > >> > > > > > >> yohan.richard.yu@gmail.com
> > > > >> > > > > > >> >> >
> > > > >> > > > > > >> >> > wrote:
> > > > >> > > > > > >> >> >
> > > > >> > > > > > >> >> > > Thanks for the review Becket.
> > > > >> > > > > > >> >> > >
> > > > >> > > > > > >> >> > > About the methods beginningOffsets(),
> > > endOffsets(),
> > > > >> ...:
> > > > >> > > > > > >> >> > > I took a look through the code of
> KafkaConsumer,
> > > but
> > > > >> > after
> > > > >> > > > > > looking
> > > > >> > > > > > >> >> > through
> > > > >> > > > > > >> >> > > the offsetsByTimes() method
> > > > >> > > > > > >> >> > > and its callbacks in Fetcher, I think these
> > > methods
> > > > >> > already
> > > > >> > > > > block
> > > > >> > > > > > >> for
> > > > >> > > > > > >> >> a
> > > > >> > > > > > >> >> > > set period of time. I know that there
> > > > >> > > > > > >> >> > > is a chance that the offsets methods in
> > > > KafkaConsumer
> > > > >> > might
> > > > >> > > > be
> > > > >> > > > > > like
> > > > >> > > > > > >> >> poll
> > > > >> > > > > > >> >> > > (that is one section of the method
> > > > >> > > > > > >> >> > > honors the timeout while another --
> > > > >> updateFetchPositions
> > > > >> > --
> > > > >> > > > > does
> > > > >> > > > > > >> not).
> > > > >> > > > > > >> >> > > However, I don't think that this is the
> > > > >> > > > > > >> >> > > case with offsetsByTimes since the callbacks
> > that
> > > I
> > > > >> > checked
> > > > >> > > > > does
> > > > >> > > > > > >> not
> > > > >> > > > > > >> >> seem
> > > > >> > > > > > >> >> > > to hang.
> > > > >> > > > > > >> >> > >
> > > > >> > > > > > >> >> > > The clarity of the exception message is a
> > > problem. I
> > > > >> > > thought
> > > > >> > > > > your
> > > > >> > > > > > >> >> > > suggestion there was reasonable. I included
> > > > >> > > > > > >> >> > > it in the KIP.
> > > > >> > > > > > >> >> > >
> > > > >> > > > > > >> >> > > And on another note, I have noticed that
> several
> > > > >> people
> > > > >> > has
> > > > >> > > > > > voiced
> > > > >> > > > > > >> the
> > > > >> > > > > > >> >> > > opinion that adding a config might
> > > > >> > > > > > >> >> > > be advisable in relation to adding an extra
> > > > >> parameter. I
> > > > >> > > > think
> > > > >> > > > > > >> that we
> > > > >> > > > > > >> >> > can
> > > > >> > > > > > >> >> > > have a compromise of sorts: some
> > > > >> > > > > > >> >> > > methods in KafkaConsumer are relatively
> similar
> > --
> > > > for
> > > > >> > > > example,
> > > > >> > > > > > >> >> > position()
> > > > >> > > > > > >> >> > > and committed() both call
> > > > >> > > > > > >> >> > > updateFetchPositions(). I think that we could
> > use
> > > > the
> > > > >> > same
> > > > >> > > > > config
> > > > >> > > > > > >> for
> > > > >> > > > > > >> >> > > these method as a default timeout if
> > > > >> > > > > > >> >> > > the user does not provide one. On the other
> > hand,
> > > if
> > > > >> they
> > > > >> > > > wish
> > > > >> > > > > to
> > > > >> > > > > > >> >> specify
> > > > >> > > > > > >> >> > > a longer or shorter blocking time,
> > > > >> > > > > > >> >> > > they have the option of changing the timeout.
> (I
> > > > >> included
> > > > >> > > the
> > > > >> > > > > > >> config
> > > > >> > > > > > >> >> as
> > > > >> > > > > > >> >> > an
> > > > >> > > > > > >> >> > > alternative in the KIP) WDYT?
> > > > >> > > > > > >> >> > >
> > > > >> > > > > > >> >> > > Thanks,
> > > > >> > > > > > >> >> > > Richard
> > > > >> > > > > > >> >> > >
> > > > >> > > > > > >> >> > >
> > > > >> > > > > > >> >> > > On Fri, Mar 30, 2018 at 1:26 AM, Becket Qin <
> > > > >> > > > > > becket.qin@gmail.com>
> > > > >> > > > > > >> >> > wrote:
> > > > >> > > > > > >> >> > >
> > > > >> > > > > > >> >> > >> Glad to see the KIP, Richard. This has been a
> > > > really
> > > > >> > long
> > > > >> > > > > > pending
> > > > >> > > > > > >> >> issue.
> > > > >> > > > > > >> >> > >>
> > > > >> > > > > > >> >> > >> The original arguments from Jay for using
> > config,
> > > > >> such
> > > > >> > as
> > > > >> > > > > > >> >> max.block.ms,
> > > > >> > > > > > >> >> > >> instead of using timeout parameters was that
> > > people
> > > > >> will
> > > > >> > > > > always
> > > > >> > > > > > >> hard
> > > > >> > > > > > >> >> > code
> > > > >> > > > > > >> >> > >> the timeout, and the hard coded timeout is
> > rarely
> > > > >> > correct
> > > > >> > > > > > because
> > > > >> > > > > > >> it
> > > > >> > > > > > >> >> has
> > > > >> > > > > > >> >> > >> to
> > > > >> > > > > > >> >> > >> consider different scenarios. For example,
> > users
> > > > may
> > > > >> > > receive
> > > > >> > > > > > >> timeout
> > > > >> > > > > > >> >> > >> exception when the group coordinator moves.
> > > Having
> > > > a
> > > > >> > > > > > configuration
> > > > >> > > > > > >> >> with
> > > > >> > > > > > >> >> > >> some reasonable default value will make
> users'
> > > life
> > > > >> > > easier.
> > > > >> > > > > > >> >> > >>
> > > > >> > > > > > >> >> > >> That said, in practice, it seems more useful
> to
> > > > have
> > > > >> > > timeout
> > > > >> > > > > > >> >> parameters.
> > > > >> > > > > > >> >> > >> We
> > > > >> > > > > > >> >> > >> have seen some library, using the consumers
> > > > >> internally,
> > > > >> > > > needs
> > > > >> > > > > to
> > > > >> > > > > > >> >> provide
> > > > >> > > > > > >> >> > >> an
> > > > >> > > > > > >> >> > >> external flexible timeout interface. Also,
> user
> > > can
> > > > >> > easily
> > > > >> > > > > hard
> > > > >> > > > > > >> code
> > > > >> > > > > > >> >> a
> > > > >> > > > > > >> >> > >> value to get the same as a config based
> > solution.
> > > > >> > > > > > >> >> > >>
> > > > >> > > > > > >> >> > >> The KIP looks good overall. A few comments:
> > > > >> > > > > > >> >> > >>
> > > > >> > > > > > >> >> > >> 1. There are a few other blocking methods
> that
> > > are
> > > > >> not
> > > > >> > > > > included,
> > > > >> > > > > > >> e.g.
> > > > >> > > > > > >> >> > >> offsetsForTimes(), beginningOffsets(),
> > > > endOffsets().
> > > > >> Is
> > > > >> > > > there
> > > > >> > > > > > any
> > > > >> > > > > > >> >> > reason?
> > > > >> > > > > > >> >> > >>
> > > > >> > > > > > >> >> > >> 2. I am wondering can we take the KIP as a
> > chance
> > > > to
> > > > >> > clean
> > > > >> > > > up
> > > > >> > > > > > our
> > > > >> > > > > > >> >> > timeout
> > > > >> > > > > > >> >> > >> exception(s)? More specifically, instead of
> > > reusing
> > > > >> > > > > > >> TimeoutException,
> > > > >> > > > > > >> >> > can
> > > > >> > > > > > >> >> > >> we introduce a new ClientTimeoutException
> with
> > > > >> different
> > > > >> > > > > causes,
> > > > >> > > > > > >> e.g.
> > > > >> > > > > > >> >> > >> UnknownTopicOrPartition, RequestTimeout,
> > > > >> > > LeaderNotAvailable,
> > > > >> > > > > > etc.
> > > > >> > > > > > >> >> > >> As of now, the TimeoutException is used in
> the
> > > > >> following
> > > > >> > > > three
> > > > >> > > > > > >> cases:
> > > > >> > > > > > >> >> > >>
> > > > >> > > > > > >> >> > >> 1. TimeoutException is a subclass of
> > > > ApiException
> > > > >> > which
> > > > >> > > > > > >> indicates
> > > > >> > > > > > >> >> the
> > > > >> > > > > > >> >> > >> exception was returned by the broker. The
> > > > >> > > > TimeoutException
> > > > >> > > > > > was
> > > > >> > > > > > >> >> > >> initially
> > > > >> > > > > > >> >> > >> returned by the leaders when replication
> was
> > > not
> > > > >> done
> > > > >> > > > > within
> > > > >> > > > > > >> the
> > > > >> > > > > > >> >> > >> specified
> > > > >> > > > > > >> >> > >> timeout in the ProduceRequest. It has an
> > error
> > > > >> code
> > > > >> > of
> > > > >> > > 7,
> > > > >> > > > > > >> which is
> > > > >> > > > > > >> >> > >> returned
> > > > >> > > > > > >> >> > >> by the broker.
> > > > >> > > > > > >> >> > >> 2. When we migrate to Java clients, in
> > Errors
> > > > >> > > definition,
> > > > >> > > > > we
> > > > >> > > > > > >> >> extended
> > > > >> > > > > > >> >> > >> it
> > > > >> > > > > > >> >> > >> to indicate request timeout, i.e. a
> request
> > > was
> > > > >> sent
> > > > >> > > but
> > > > >> > > > > the
> > > > >> > > > > > >> >> response
> > > > >> > > > > > >> >> > >> was
> > > > >> > > > > > >> >> > >> not received before timeout. In this case,
> > the
> > > > >> > clients
> > > > >> > > > did
> > > > >> > > > > > not
> > > > >> > > > > > >> >> have a
> > > > >> > > > > > >> >> > >> return code from the broker.
> > > > >> > > > > > >> >> > >> 3. Later at some point, we started to use
> > the
> > > > >> > > > > > TimeoutException
> > > > >> > > > > > >> for
> > > > >> > > > > > >> >> > >> clients method call timeout. It is neither
> > > > >> related to
> > > > >> > > any
> > > > >> > > > > > >> broker
> > > > >> > > > > > >> >> > >> returned
> > > > >> > > > > > >> >> > >> error code, nor to request timeout on the
> > > wire.
> > > > >> > > > > > >> >> > >>
> > > > >> > > > > > >> >> > >> Due to the various interpretations, users can
> > > > easily
> > > > >> be
> > > > >> > > > > > confused.
> > > > >> > > > > > >> As
> > > > >> > > > > > >> >> an
> > > > >> > > > > > >> >> > >> example, when a timeout is thrown with
> "Failed
> > to
> > > > >> > refresh
> > > > >> > > > > > metadata
> > > > >> > > > > > >> >> in X
> > > > >> > > > > > >> >> > >> ms", it is hard to tell what exactly
> happened.
> > > > Since
> > > > >> we
> > > > >> > > are
> > > > >> > > > > > >> changing
> > > > >> > > > > > >> >> the
> > > > >> > > > > > >> >> > >> API here, it would be good to avoid
> introducing
> > > > more
> > > > >> > > > ambiguity
> > > > >> > > > > > and
> > > > >> > > > > > >> >> see
> > > > >> > > > > > >> >> > >> whether this can be improved. It would be at
> > > least
> > > > >> one
> > > > >> > > step
> > > > >> > > > > > >> forward
> > > > >> > > > > > >> >> to
> > > > >> > > > > > >> >> > >> remove the usage of case 3.
> > > > >> > > > > > >> >> > >>
> > > > >> > > > > > >> >> > >> Thanks,
> > > > >> > > > > > >> >> > >>
> > > > >> > > > > > >> >> > >> Jiangjie (Becket) Qin
> > > > >> > > > > > >> >> > >>
> > > > >> > > > > > >> >> > >>
> > > > >> > > > > > >> >> > >>
> > > > >> > > > > > >> >> > >>
> > > > >> > > > > > >> >> > >> On Mon, Mar 26, 2018 at 5:50 PM, Guozhang
> Wang
> > <
> > > > >> > > > > > >> wangguoz@gmail.com>
> > > > >> > > > > > >> >> > >> wrote:
> > > > >> > > > > > >> >> > >>
> > > > >> > > > > > >> >> > >> > @Richard: TimeoutException inherits from
> > > > >> > > > RetriableException
> > > > >> > > > > > >> which
> > > > >> > > > > > >> >> > >> inherits
> > > > >> > > > > > >> >> > >> > from ApiException. So users should
> explicitly
> > > try
> > > > >> to
> > > > >> > > > capture
> > > > >> > > > > > >> >> > >> > RetriableException in their code and handle
> > the
> > > > >> > > exception.
> > > > >> > > > > > >> >> > >> >
> > > > >> > > > > > >> >> > >> > @Isamel, Ewen: I'm trying to push progress
> > > > forward
> > > > >> on
> > > > >> > > this
> > > > >> > > > > > one,
> > > > >> > > > > > >> >> are we
> > > > >> > > > > > >> >> > >> now
> > > > >> > > > > > >> >> > >> > on the same page for using function
> > parameters
> > > > than
> > > > >> > > > configs?
> > > > >> > > > > > >> >> > >> >
> > > > >> > > > > > >> >> > >> >
> > > > >> > > > > > >> >> > >> > Guozhang
> > > > >> > > > > > >> >> > >> >
> > > > >> > > > > > >> >> > >> >
> > > > >> > > > > > >> >> > >> > On Fri, Mar 23, 2018 at 4:42 PM, Ismael
> Juma
> > <
> > > > >> > > > > > ismael@juma.me.uk
> > > > >> > > > > > >> >
> > > > >> > > > > > >> >> > wrote:
> > > > >> > > > > > >> >> > >> >
> > > > >> > > > > > >> >> > >> > > Hi Ewen,
> > > > >> > > > > > >> >> > >> > >
> > > > >> > > > > > >> >> > >> > > Yeah, I mentioned KAFKA-2391 where some
> of
> > > this
> > > > >> was
> > > > >> > > > > > discussed.
> > > > >> > > > > > >> >> Jay
> > > > >> > > > > > >> >> > was
> > > > >> > > > > > >> >> > >> > > against having timeouts in the methods at
> > the
> > > > >> time.
> > > > >> > > > > However,
> > > > >> > > > > > >> as
> > > > >> > > > > > >> >> > Jason
> > > > >> > > > > > >> >> > >> > said
> > > > >> > > > > > >> >> > >> > > offline, we did end up with a timeout
> > > parameter
> > > > >> in
> > > > >> > > > `poll`.
> > > > >> > > > > > >> >> > >> > >
> > > > >> > > > > > >> >> > >> > > Ismael
> > > > >> > > > > > >> >> > >> > >
> > > > >> > > > > > >> >> > >> > > On Fri, Mar 23, 2018 at 4:26 PM, Ewen
> > > > >> > > Cheslack-Postava <
> > > > >> > > > > > >> >> > >> > ewen@confluent.io>
> > > > >> > > > > > >> >> > >> > > wrote:
> > > > >> > > > > > >> >> > >> > >
> > > > >> > > > > > >> >> > >> > > > Regarding the flexibility question, has
> > > > someone
> > > > >> > > tried
> > > > >> > > > to
> > > > >> > > > > > >> dig up
> > > > >> > > > > > >> >> > the
> > > > >> > > > > > >> >> > >> > > > discussion of the new consumer APIs
> when
> > > they
> > > > >> were
> > > > >> > > > being
> > > > >> > > > > > >> >> written?
> > > > >> > > > > > >> >> > I
> > > > >> > > > > > >> >> > >> > > vaguely
> > > > >> > > > > > >> >> > >> > > > recall these exact questions about
> using
> > > APIs
> > > > >> vs
> > > > >> > > > configs
> > > > >> > > > > > and
> > > > >> > > > > > >> >> > >> > flexibility
> > > > >> > > > > > >> >> > >> > > vs
> > > > >> > > > > > >> >> > >> > > > bloating the API surface area having
> > > already
> > > > >> been
> > > > >> > > > > > discussed.
> > > > >> > > > > > >> >> (Not
> > > > >> > > > > > >> >> > >> that
> > > > >> > > > > > >> >> > >> > we
> > > > >> > > > > > >> >> > >> > > > shouldn't revisit, just that it might
> > also
> > > > be a
> > > > >> > > faster
> > > > >> > > > > way
> > > > >> > > > > > >> to
> > > > >> > > > > > >> >> get
> > > > >> > > > > > >> >> > >> to a
> > > > >> > > > > > >> >> > >> > > full
> > > > >> > > > > > >> >> > >> > > > understanding of the options, concerns,
> > and
> > > > >> > > > tradeoffs).
> > > > >> > > > > > >> >> > >> > > >
> > > > >> > > > > > >> >> > >> > > > -Ewen
> > > > >> > > > > > >> >> > >> > > >
> > > > >> > > > > > >> >> > >> > > > On Thu, Mar 22, 2018 at 7:19 AM,
> Richard
> > > Yu <
> > > > >> > > > > > >> >> > >> > yohan.richard.yu@gmail.com>
> > > > >> > > > > > >> >> > >> > > > wrote:
> > > > >> > > > > > >> >> > >> > > >
> > > > >> > > > > > >> >> > >> > > > > I do have one question though: in the
> > > > current
> > > > >> > KIP,
> > > > >> > > > > > >> throwing
> > > > >> > > > > > >> >> > >> > > > > TimeoutException to mark
> > > > >> > > > > > >> >> > >> > > > > that time limit is exceeded is
> applied
> > to
> > > > all
> > > > >> > new
> > > > >> > > > > > methods
> > > > >> > > > > > >> >> > >> introduced
> > > > >> > > > > > >> >> > >> > in
> > > > >> > > > > > >> >> > >> > > > > this proposal.
> > > > >> > > > > > >> >> > >> > > > > However, how would users respond
> when a
> > > > >> > > > > TimeoutException
> > > > >> > > > > > >> >> (since
> > > > >> > > > > > >> >> > >> it is
> > > > >> > > > > > >> >> > >> > > > > considered
> > > > >> > > > > > >> >> > >> > > > > a RuntimeException)?
> > > > >> > > > > > >> >> > >> > > > >
> > > > >> > > > > > >> >> > >> > > > > Thanks,
> > > > >> > > > > > >> >> > >> > > > > Richard
> > > > >> > > > > > >> >> > >> > > > >
> > > > >> > > > > > >> >> > >> > > > >
> > > > >> > > > > > >> >> > >> > > > >
> > > > >> > > > > > >> >> > >> > > > > On Mon, Mar 19, 2018 at 6:10 PM,
> > Richard
> > > > Yu <
> > > > >> > > > > > >> >> > >> > > yohan.richard.yu@gmail.com>
> > > > >> > > > > > >> >> > >> > > > > wrote:
> > > > >> > > > > > >> >> > >> > > > >
> > > > >> > > > > > >> >> > >> > > > > > Hi Ismael,
> > > > >> > > > > > >> >> > >> > > > > >
> > > > >> > > > > > >> >> > >> > > > > > You have a great point. Since most
> of
> > > the
> > > > >> > > methods
> > > > >> > > > in
> > > > >> > > > > > >> this
> > > > >> > > > > > >> >> KIP
> > > > >> > > > > > >> >> > >> have
> > > > >> > > > > > >> >> > >> > > > > similar
> > > > >> > > > > > >> >> > >> > > > > > callbacks (position() and
> committed()
> > > > both
> > > > >> use
> > > > >> > > > > > >> >> > >> > > fetchCommittedOffsets(),
> > > > >> > > > > > >> >> > >> > > > > > and
> > > > >> > > > > > >> >> > >> > > > > > commitSync() is similar to
> > position(),
> > > > >> except
> > > > >> > > just
> > > > >> > > > > > >> updating
> > > > >> > > > > > >> >> > >> > offsets),
> > > > >> > > > > > >> >> > >> > > > the
> > > > >> > > > > > >> >> > >> > > > > > amount of time
> > > > >> > > > > > >> >> > >> > > > > > they block should be also about
> > equal.
> > > > >> > > > > > >> >> > >> > > > > >
> > > > >> > > > > > >> >> > >> > > > > > However, I think that we need to
> take
> > > > into
> > > > >> > > > account a
> > > > >> > > > > > >> >> couple of
> > > > >> > > > > > >> >> > >> > > things.
> > > > >> > > > > > >> >> > >> > > > > For
> > > > >> > > > > > >> >> > >> > > > > > starters,
> > > > >> > > > > > >> >> > >> > > > > > if the new methods were all reliant
> > on
> > > > one
> > > > >> > > config,
> > > > >> > > > > > >> there is
> > > > >> > > > > > >> >> > >> > > likelihood
> > > > >> > > > > > >> >> > >> > > > > > that the
> > > > >> > > > > > >> >> > >> > > > > > shortcomings for this approach
> would
> > be
> > > > >> > similar
> > > > >> > > to
> > > > >> > > > > > what
> > > > >> > > > > > >> we
> > > > >> > > > > > >> >> > >> faced if
> > > > >> > > > > > >> >> > >> > > we
> > > > >> > > > > > >> >> > >> > > > > let
> > > > >> > > > > > >> >> > >> > > > > > request.timeout.ms control all
> > method
> > > > >> > timeouts.
> > > > >> > > > In
> > > > >> > > > > > >> >> > comparison,
> > > > >> > > > > > >> >> > >> > > adding
> > > > >> > > > > > >> >> > >> > > > > > overloads
> > > > >> > > > > > >> >> > >> > > > > > does not have this problem.
> > > > >> > > > > > >> >> > >> > > > > >
> > > > >> > > > > > >> >> > >> > > > > > If you have further thoughts,
> please
> > > let
> > > > me
> > > > >> > > know.
> > > > >> > > > > > >> >> > >> > > > > >
> > > > >> > > > > > >> >> > >> > > > > > Richard
> > > > >> > > > > > >> >> > >> > > > > >
> > > > >> > > > > > >> >> > >> > > > > >
> > > > >> > > > > > >> >> > >> > > > > > On Mon, Mar 19, 2018 at 5:12 PM,
> > Ismael
> > > > >> Juma <
> > > > >> > > > > > >> >> > ismael@juma.me.uk
> > > > >> > > > > > >> >> > >> >
> > > > >> > > > > > >> >> > >> > > > wrote:
> > > > >> > > > > > >> >> > >> > > > > >
> > > > >> > > > > > >> >> > >> > > > > >> Hi,
> > > > >> > > > > > >> >> > >> > > > > >>
> > > > >> > > > > > >> >> > >> > > > > >> An option that is not currently
> > > covered
> > > > in
> > > > >> > the
> > > > >> > > > KIP
> > > > >> > > > > is
> > > > >> > > > > > >> to
> > > > >> > > > > > >> >> > have a
> > > > >> > > > > > >> >> > >> > > > separate
> > > > >> > > > > > >> >> > >> > > > > >> config max.block.ms, which is
> > similar
> > > > to
> > > > >> the
> > > > >> > > > > > producer
> > > > >> > > > > > >> >> config
> > > > >> > > > > > >> >> > >> with
> > > > >> > > > > > >> >> > >> > > the
> > > > >> > > > > > >> >> > >> > > > > >> same
> > > > >> > > > > > >> >> > >> > > > > >> name. This came up during the
> > > KAFKA-2391
> > > > >> > > > > discussion.
> > > > >> > > > > > I
> > > > >> > > > > > >> >> think
> > > > >> > > > > > >> >> > >> it's
> > > > >> > > > > > >> >> > >> > > > clear
> > > > >> > > > > > >> >> > >> > > > > >> that we can't rely on
> > > > request.timeout.ms,
> > > > >> so
> > > > >> > > the
> > > > >> > > > > > >> >> decision is
> > > > >> > > > > > >> >> > >> > > between
> > > > >> > > > > > >> >> > >> > > > > >> adding
> > > > >> > > > > > >> >> > >> > > > > >> overloads or adding a new config.
> > > People
> > > > >> > seemed
> > > > >> > > > to
> > > > >> > > > > be
> > > > >> > > > > > >> >> leaning
> > > > >> > > > > > >> >> > >> > > towards
> > > > >> > > > > > >> >> > >> > > > > the
> > > > >> > > > > > >> >> > >> > > > > >> latter in KAFKA-2391, but Jason
> > makes
> > > a
> > > > >> good
> > > > >> > > > point
> > > > >> > > > > > that
> > > > >> > > > > > >> >> the
> > > > >> > > > > > >> >> > >> > > overloads
> > > > >> > > > > > >> >> > >> > > > > are
> > > > >> > > > > > >> >> > >> > > > > >> more flexible. A couple of
> questions
> > > > from
> > > > >> me:
> > > > >> > > > > > >> >> > >> > > > > >>
> > > > >> > > > > > >> >> > >> > > > > >> 1. Do we need the additional
> > > > flexibility?
> > > > >> > > > > > >> >> > >> > > > > >> 2. If we do, do we need it for
> every
> > > > >> blocking
> > > > >> > > > > method?
> > > > >> > > > > > >> >> > >> > > > > >>
> > > > >> > > > > > >> >> > >> > > > > >> Ismael
> > > > >> > > > > > >> >> > >> > > > > >>
> > > > >> > > > > > >> >> > >> > > > > >> On Mon, Mar 19, 2018 at 5:03 PM,
> > > Richard
> > > > >> Yu <
> > > > >> > > > > > >> >> > >> > > > yohan.richard.yu@gmail.com
> > > > >> > > > > > >> >> > >> > > > > >
> > > > >> > > > > > >> >> > >> > > > > >> wrote:
> > > > >> > > > > > >> >> > >> > > > > >>
> > > > >> > > > > > >> >> > >> > > > > >> > Hi Guozhang,
> > > > >> > > > > > >> >> > >> > > > > >> >
> > > > >> > > > > > >> >> > >> > > > > >> > I made some clarifications to
> > > KIP-266,
> > > > >> > > namely:
> > > > >> > > > > > >> >> > >> > > > > >> > 1. Stated more specifically that
> > > > >> commitSync
> > > > >> > > > will
> > > > >> > > > > > >> accept
> > > > >> > > > > > >> >> > user
> > > > >> > > > > > >> >> > >> > > input.
> > > > >> > > > > > >> >> > >> > > > > >> > 2. fetchCommittedOffsets(): Made
> > its
> > > > >> role
> > > > >> > in
> > > > >> > > > > > blocking
> > > > >> > > > > > >> >> more
> > > > >> > > > > > >> >> > >> clear
> > > > >> > > > > > >> >> > >> > > to
> > > > >> > > > > > >> >> > >> > > > > the
> > > > >> > > > > > >> >> > >> > > > > >> > reader.
> > > > >> > > > > > >> >> > >> > > > > >> > 3. Sketched what would happen
> when
> > > > time
> > > > >> > limit
> > > > >> > > > is
> > > > >> > > > > > >> >> exceeded.
> > > > >> > > > > > >> >> > >> > > > > >> >
> > > > >> > > > > > >> >> > >> > > > > >> > These changes should make the
> KIP
> > > > >> easier to
> > > > >> > > > > > >> understand.
> > > > >> > > > > > >> >> > >> > > > > >> >
> > > > >> > > > > > >> >> > >> > > > > >> > Cheers,
> > > > >> > > > > > >> >> > >> > > > > >> > Richard
> > > > >> > > > > > >> >> > >> > > > > >> >
> > > > >> > > > > > >> >> > >> > > > > >> > On Mon, Mar 19, 2018 at 9:33 AM,
> > > > >> Guozhang
> > > > >> > > Wang
> > > > >> > > > <
> > > > >> > > > > > >> >> > >> > > wangguoz@gmail.com>
> > > > >> > > > > > >> >> > >> > > > > >> wrote:
> > > > >> > > > > > >> >> > >> > > > > >> >
> > > > >> > > > > > >> >> > >> > > > > >> > > Hi Richard,
> > > > >> > > > > > >> >> > >> > > > > >> > >
> > > > >> > > > > > >> >> > >> > > > > >> > > I made a pass over the KIP
> > again,
> > > > some
> > > > >> > more
> > > > >> > > > > > >> >> > clarifications
> > > > >> > > > > > >> >> > >> /
> > > > >> > > > > > >> >> > >> > > > > comments:
> > > > >> > > > > > >> >> > >> > > > > >> > >
> > > > >> > > > > > >> >> > >> > > > > >> > > 1. seek() call itself is not
> > > > blocking,
> > > > >> > only
> > > > >> > > > the
> > > > >> > > > > > >> >> following
> > > > >> > > > > > >> >> > >> > poll()
> > > > >> > > > > > >> >> > >> > > > > call
> > > > >> > > > > > >> >> > >> > > > > >> may
> > > > >> > > > > > >> >> > >> > > > > >> > > be blocking as the actually
> > > metadata
> > > > >> rq
> > > > >> > > will
> > > > >> > > > > > >> happen.
> > > > >> > > > > > >> >> > >> > > > > >> > >
> > > > >> > > > > > >> >> > >> > > > > >> > > 2. I saw you did not include
> > > > >> > > > > > >> Consumer.partitionFor(),
> > > > >> > > > > > >> >> > >> > > > > >> > > Consumer.OffsetAndTimestamp()
> > and
> > > > >> > > > > > >> >> Consumer.listTopics()
> > > > >> > > > > > >> >> > in
> > > > >> > > > > > >> >> > >> > your
> > > > >> > > > > > >> >> > >> > > > KIP.
> > > > >> > > > > > >> >> > >> > > > > >> > After
> > > > >> > > > > > >> >> > >> > > > > >> > > a second thought, I think this
> > may
> > > > be
> > > > >> a
> > > > >> > > > better
> > > > >> > > > > > >> idea to
> > > > >> > > > > > >> >> > not
> > > > >> > > > > > >> >> > >> > > tackle
> > > > >> > > > > > >> >> > >> > > > > >> them in
> > > > >> > > > > > >> >> > >> > > > > >> > > the same KIP, and probably we
> > > should
> > > > >> > > consider
> > > > >> > > > > > >> whether
> > > > >> > > > > > >> >> we
> > > > >> > > > > > >> >> > >> would
> > > > >> > > > > > >> >> > >> > > > > change
> > > > >> > > > > > >> >> > >> > > > > >> the
> > > > >> > > > > > >> >> > >> > > > > >> > > behavior or not in another
> > > > discussion.
> > > > >> > So I
> > > > >> > > > > agree
> > > > >> > > > > > >> to
> > > > >> > > > > > >> >> not
> > > > >> > > > > > >> >> > >> > include
> > > > >> > > > > > >> >> > >> > > > > them.
> > > > >> > > > > > >> >> > >> > > > > >> > >
> > > > >> > > > > > >> >> > >> > > > > >> > > 3. In your wiki you mentioned
> > > > "Another
> > > > >> > > change
> > > > >> > > > > > >> shall be
> > > > >> > > > > > >> >> > >> made to
> > > > >> > > > > > >> >> > >> > > > > >> > > KafkaConsumer#poll(), due to
> its
> > > > call
> > > > >> to
> > > > >> > > > > > >> >> > >> > updateFetchPositions()
> > > > >> > > > > > >> >> > >> > > > > which
> > > > >> > > > > > >> >> > >> > > > > >> > > blocks indefinitely." This
> part
> > > may
> > > > a
> > > > >> bit
> > > > >> > > > > obscure
> > > > >> > > > > > >> to
> > > > >> > > > > > >> >> most
> > > > >> > > > > > >> >> > >> > > readers
> > > > >> > > > > > >> >> > >> > > > > >> who's
> > > > >> > > > > > >> >> > >> > > > > >> > not
> > > > >> > > > > > >> >> > >> > > > > >> > > familiar with the
> KafkaConsumer
> > > > >> > internals,
> > > > >> > > > > could
> > > > >> > > > > > >> you
> > > > >> > > > > > >> >> > please
> > > > >> > > > > > >> >> > >> > add
> > > > >> > > > > > >> >> > >> > > > more
> > > > >> > > > > > >> >> > >> > > > > >> > > elaborations. More
> > specifically, I
> > > > >> think
> > > > >> > > the
> > > > >> > > > > root
> > > > >> > > > > > >> >> causes
> > > > >> > > > > > >> >> > of
> > > > >> > > > > > >> >> > >> > the
> > > > >> > > > > > >> >> > >> > > > > public
> > > > >> > > > > > >> >> > >> > > > > >> > APIs
> > > > >> > > > > > >> >> > >> > > > > >> > > mentioned are a bit different
> > > while
> > > > >> the
> > > > >> > > KIP's
> > > > >> > > > > > >> >> explanation
> > > > >> > > > > > >> >> > >> > sounds
> > > > >> > > > > > >> >> > >> > > > > like
> > > > >> > > > > > >> >> > >> > > > > >> > they
> > > > >> > > > > > >> >> > >> > > > > >> > > are due to the same reason:
> > > > >> > > > > > >> >> > >> > > > > >> > >
> > > > >> > > > > > >> >> > >> > > > > >> > > 3.1 fetchCommittedOffsets():
> > this
> > > > >> > internal
> > > > >> > > > call
> > > > >> > > > > > >> will
> > > > >> > > > > > >> >> > block
> > > > >> > > > > > >> >> > >> > > forever
> > > > >> > > > > > >> >> > >> > > > > if
> > > > >> > > > > > >> >> > >> > > > > >> the
> > > > >> > > > > > >> >> > >> > > > > >> > > committed offsets cannot be
> > > fetched
> > > > >> > > > > successfully
> > > > >> > > > > > >> and
> > > > >> > > > > > >> >> > affect
> > > > >> > > > > > >> >> > >> > > > > position()
> > > > >> > > > > > >> >> > >> > > > > >> > and
> > > > >> > > > > > >> >> > >> > > > > >> > > committed(). We need to break
> > out
> > > of
> > > > >> its
> > > > >> > > > > internal
> > > > >> > > > > > >> >> while
> > > > >> > > > > > >> >> > >> loop.
> > > > >> > > > > > >> >> > >> > > > > >> > > 3.2 position() itself will
> while
> > > > loop
> > > > >> > when
> > > > >> > > > > > offsets
> > > > >> > > > > > >> >> cannot
> > > > >> > > > > > >> >> > >> be
> > > > >> > > > > > >> >> > >> > > > > >> retrieved in
> > > > >> > > > > > >> >> > >> > > > > >> > > the underlying async call. We
> > need
> > > > to
> > > > >> > break
> > > > >> > > > out
> > > > >> > > > > > >> this
> > > > >> > > > > > >> >> > while
> > > > >> > > > > > >> >> > >> > loop.
> > > > >> > > > > > >> >> > >> > > > > >> > > 3.3 commitSync() passed
> > > > >> Long.MAX_VALUE as
> > > > >> > > the
> > > > >> > > > > > >> timeout
> > > > >> > > > > > >> >> > >> value,
> > > > >> > > > > > >> >> > >> > we
> > > > >> > > > > > >> >> > >> > > > > should
> > > > >> > > > > > >> >> > >> > > > > >> > take
> > > > >> > > > > > >> >> > >> > > > > >> > > the user specified timeouts
> when
> > > > >> > > applicable.
> > > > >> > > > > > >> >> > >> > > > > >> > >
> > > > >> > > > > > >> >> > >> > > > > >> > >
> > > > >> > > > > > >> >> > >> > > > > >> > >
> > > > >> > > > > > >> >> > >> > > > > >> > > Guozhang
> > > > >> > > > > > >> >> > >> > > > > >> > >
> > > > >> > > > > > >> >> > >> > > > > >> > > On Sat, Mar 17, 2018 at 4:44
> PM,
> > > > >> Richard
> > > > >> > > Yu <
> > > > >> > > > > > >> >> > >> > > > > >> yohan.richard.yu@gmail.com>
> > > > >> > > > > > >> >> > >> > > > > >> > > wrote:
> > > > >> > > > > > >> >> > >> > > > > >> > >
> > > > >> > > > > > >> >> > >> > > > > >> > > > Actually, what I said above
> is
> > > > >> > > inaccurate.
> > > > >> > > > In
> > > > >> > > > > > >> >> > >> > > > > >> > > >
> testSeekAndCommitWithBrokerFai
> > > > >> lures,
> > > > >> > > > > > >> >> > >> > TestUtils.waitUntilTrue
> > > > >> > > > > > >> >> > >> > > > > >> blocks,
> > > > >> > > > > > >> >> > >> > > > > >> > not
> > > > >> > > > > > >> >> > >> > > > > >> > > > seek.
> > > > >> > > > > > >> >> > >> > > > > >> > > > My assumption is that seek
> did
> > > not
> > > > >> > update
> > > > >> > > > > > >> >> correctly. I
> > > > >> > > > > > >> >> > >> will
> > > > >> > > > > > >> >> > >> > be
> > > > >> > > > > > >> >> > >> > > > > >> digging
> > > > >> > > > > > >> >> > >> > > > > >> > > > further into this.
> > > > >> > > > > > >> >> > >> > > > > >> > > >
> > > > >> > > > > > >> >> > >> > > > > >> > > >
> > > > >> > > > > > >> >> > >> > > > > >> > > >
> > > > >> > > > > > >> >> > >> > > > > >> > > > On Sat, Mar 17, 2018 at 4:16
> > PM,
> > > > >> > Richard
> > > > >> > > > Yu <
> > > > >> > > > > > >> >> > >> > > > > >> > yohan.richard.yu@gmail.com>
> > > > >> > > > > > >> >> > >> > > > > >> > > > wrote:
> > > > >> > > > > > >> >> > >> > > > > >> > > >
> > > > >> > > > > > >> >> > >> > > > > >> > > > > One more thing: when
> looking
> > > > >> through
> > > > >> > > > > tests, I
> > > > >> > > > > > >> have
> > > > >> > > > > > >> >> > >> > realized
> > > > >> > > > > > >> >> > >> > > > that
> > > > >> > > > > > >> >> > >> > > > > >> > seek()
> > > > >> > > > > > >> >> > >> > > > > >> > > > > methods can potentially
> > block
> > > > >> > > > indefinitely.
> > > > >> > > > > > As
> > > > >> > > > > > >> you
> > > > >> > > > > > >> >> > well
> > > > >> > > > > > >> >> > >> > > know,
> > > > >> > > > > > >> >> > >> > > > > >> seek()
> > > > >> > > > > > >> >> > >> > > > > >> > is
> > > > >> > > > > > >> >> > >> > > > > >> > > > > called when pollOnce() or
> > > > >> position()
> > > > >> > is
> > > > >> > > > > > active.
> > > > >> > > > > > >> >> Thus,
> > > > >> > > > > > >> >> > >> if
> > > > >> > > > > > >> >> > >> > > > > >> position()
> > > > >> > > > > > >> >> > >> > > > > >> > > > blocks
> > > > >> > > > > > >> >> > >> > > > > >> > > > > indefinitely, then so
> would
> > > > >> seek().
> > > > >> > > > Should
> > > > >> > > > > > >> >> bounding
> > > > >> > > > > > >> >> > >> seek()
> > > > >> > > > > > >> >> > >> > > > also
> > > > >> > > > > > >> >> > >> > > > > be
> > > > >> > > > > > >> >> > >> > > > > >> > > > included
> > > > >> > > > > > >> >> > >> > > > > >> > > > > in this KIP?
> > > > >> > > > > > >> >> > >> > > > > >> > > > >
> > > > >> > > > > > >> >> > >> > > > > >> > > > > Thanks, Richard
> > > > >> > > > > > >> >> > >> > > > > >> > > > >
> > > > >> > > > > > >> >> > >> > > > > >> > > > > On Sat, Mar 17, 2018 at
> 1:16
> > > PM,
> > > > >> > > Richard
> > > > >> > > > > Yu <
> > > > >> > > > > > >> >> > >> > > > > >> > > yohan.richard.yu@gmail.com>
> > > > >> > > > > > >> >> > >> > > > > >> > > > > wrote:
> > > > >> > > > > > >> >> > >> > > > > >> > > > >
> > > > >> > > > > > >> >> > >> > > > > >> > > > >> Thanks for the advice,
> > Jason
> > > > >> > > > > > >> >> > >> > > > > >> > > > >>
> > > > >> > > > > > >> >> > >> > > > > >> > > > >> I have modified KIP-266
> to
> > > > >> include
> > > > >> > the
> > > > >> > > > > java
> > > > >> > > > > > >> doc
> > > > >> > > > > > >> >> for
> > > > >> > > > > > >> >> > >> > > > committed()
> > > > >> > > > > > >> >> > >> > > > > >> and
> > > > >> > > > > > >> >> > >> > > > > >> > > > other
> > > > >> > > > > > >> >> > >> > > > > >> > > > >> blocking methods, and I
> > also
> > > > >> > > > > > >> >> > >> > > > > >> > > > >> mentioned poll() which
> will
> > > > also
> > > > >> be
> > > > >> > > > > bounded.
> > > > >> > > > > > >> Let
> > > > >> > > > > > >> >> me
> > > > >> > > > > > >> >> > >> know
> > > > >> > > > > > >> >> > >> > if
> > > > >> > > > > > >> >> > >> > > > > >> there is
> > > > >> > > > > > >> >> > >> > > > > >> > > > >> anything else. :)
> > > > >> > > > > > >> >> > >> > > > > >> > > > >>
> > > > >> > > > > > >> >> > >> > > > > >> > > > >> Sincerely, Richard
> > > > >> > > > > > >> >> > >> > > > > >> > > > >>
> > > > >> > > > > > >> >> > >> > > > > >> > > > >>
> > > > >> > > > > > >> >> > >> > > > > >> > > > >>
> > > > >> > > > > > >> >> > >> > > > > >> > > > >>
> > > > >> > > > > > >> >> > >> > > > > >> > > > >>
> > > > >> > > > > > >> >> > >> > > > > >> > > > >> On Sat, Mar 17, 2018 at
> > 12:00
> > > > PM,
> > > > >> > > Jason
> > > > >> > > > > > >> >> Gustafson <
> > > > >> > > > > > >> >> > >> > > > > >> > jason@confluent.io
> > > > >> > > > > > >> >> > >> > > > > >> > > >
> > > > >> > > > > > >> >> > >> > > > > >> > > > >> wrote:
> > > > >> > > > > > >> >> > >> > > > > >> > > > >>
> > > > >> > > > > > >> >> > >> > > > > >> > > > >>> Hi Richard,
> > > > >> > > > > > >> >> > >> > > > > >> > > > >>>
> > > > >> > > > > > >> >> > >> > > > > >> > > > >>> Thanks for the updates.
> > I'm
> > > > >> really
> > > > >> > > glad
> > > > >> > > > > you
> > > > >> > > > > > >> >> picked
> > > > >> > > > > > >> >> > >> this
> > > > >> > > > > > >> >> > >> > > up.
> > > > >> > > > > > >> >> > >> > > > A
> > > > >> > > > > > >> >> > >> > > > > >> > couple
> > > > >> > > > > > >> >> > >> > > > > >> > > > >>> minor
> > > > >> > > > > > >> >> > >> > > > > >> > > > >>> comments:
> > > > >> > > > > > >> >> > >> > > > > >> > > > >>>
> > > > >> > > > > > >> >> > >> > > > > >> > > > >>> 1. Can you list the full
> > set
> > > > of
> > > > >> new
> > > > >> > > > APIs
> > > > >> > > > > > >> >> explicitly
> > > > >> > > > > > >> >> > >> in
> > > > >> > > > > > >> >> > >> > the
> > > > >> > > > > > >> >> > >> > > > > KIP?
> > > > >> > > > > > >> >> > >> > > > > >> > > > >>> Currently I
> > > > >> > > > > > >> >> > >> > > > > >> > > > >>> only see the javadoc for
> > > > >> > > `position()`.
> > > > >> > > > > > >> >> > >> > > > > >> > > > >>>
> > > > >> > > > > > >> >> > >> > > > > >> > > > >>> 2. We should consider
> > adding
> > > > >> > > `TimeUnit`
> > > > >> > > > > to
> > > > >> > > > > > >> the
> > > > >> > > > > > >> >> new
> > > > >> > > > > > >> >> > >> > methods
> > > > >> > > > > > >> >> > >> > > > to
> > > > >> > > > > > >> >> > >> > > > > >> avoid
> > > > >> > > > > > >> >> > >> > > > > >> > > > unit
> > > > >> > > > > > >> >> > >> > > > > >> > > > >>> confusion. I know it's
> > > > >> inconsistent
> > > > >> > > > with
> > > > >> > > > > > the
> > > > >> > > > > > >> >> poll()
> > > > >> > > > > > >> >> > >> API,
> > > > >> > > > > > >> >> > >> > > > but I
> > > > >> > > > > > >> >> > >> > > > > >> > think
> > > > >> > > > > > >> >> > >> > > > > >> > > it
> > > > >> > > > > > >> >> > >> > > > > >> > > > >>> was
> > > > >> > > > > > >> >> > >> > > > > >> > > > >>> probably a mistake not
> to
> > > > >> include
> > > > >> > it
> > > > >> > > > > there,
> > > > >> > > > > > >> so
> > > > >> > > > > > >> >> > better
> > > > >> > > > > > >> >> > >> > not
> > > > >> > > > > > >> >> > >> > > to
> > > > >> > > > > > >> >> > >> > > > > >> double
> > > > >> > > > > > >> >> > >> > > > > >> > > > down
> > > > >> > > > > > >> >> > >> > > > > >> > > > >>> on
> > > > >> > > > > > >> >> > >> > > > > >> > > > >>> that mistake. And note
> > that
> > > we
> > > > >> do
> > > > >> > > > already
> > > > >> > > > > > >> have
> > > > >> > > > > > >> >> > >> > > `close(long,
> > > > >> > > > > > >> >> > >> > > > > >> > > TimeUnit)`.
> > > > >> > > > > > >> >> > >> > > > > >> > > > >>>
> > > > >> > > > > > >> >> > >> > > > > >> > > > >>> Other than that, I think
> > the
> > > > >> > current
> > > > >> > > > KIP
> > > > >> > > > > > >> seems
> > > > >> > > > > > >> >> > >> > reasonable.
> > > > >> > > > > > >> >> > >> > > > > >> > > > >>>
> > > > >> > > > > > >> >> > >> > > > > >> > > > >>> Thanks,
> > > > >> > > > > > >> >> > >> > > > > >> > > > >>> Jason
> > > > >> > > > > > >> >> > >> > > > > >> > > > >>>
> > > > >> > > > > > >> >> > >> > > > > >> > > > >>> On Wed, Mar 14, 2018 at
> > 5:00
> > > > PM,
> > > > >> > > > Richard
> > > > >> > > > > > Yu <
> > > > >> > > > > > >> >> > >> > > > > >> > > > yohan.richard.yu@gmail.com>
> > > > >> > > > > > >> >> > >> > > > > >> > > > >>> wrote:
> > > > >> > > > > > >> >> > >> > > > > >> > > > >>>
> > > > >> > > > > > >> >> > >> > > > > >> > > > >>> > Note to all: I have
> > > included
> > > > >> > > bounding
> > > > >> > > > > > >> >> > commitSync()
> > > > >> > > > > > >> >> > >> and
> > > > >> > > > > > >> >> > >> > > > > >> > committed()
> > > > >> > > > > > >> >> > >> > > > > >> > > in
> > > > >> > > > > > >> >> > >> > > > > >> > > > >>> this
> > > > >> > > > > > >> >> > >> > > > > >> > > > >>> > KIP.
> > > > >> > > > > > >> >> > >> > > > > >> > > > >>> >
> > > > >> > > > > > >> >> > >> > > > > >> > > > >>> > On Sun, Mar 11, 2018
> at
> > > 5:05
> > > > >> PM,
> > > > >> > > > > Richard
> > > > >> > > > > > >> Yu <
> > > > >> > > > > > >> >> > >> > > > > >> > > > >>>
> > yohan.richard.yu@gmail.com>
> > > > >> > > > > > >> >> > >> > > > > >> > > > >>> > wrote:
> > > > >> > > > > > >> >> > >> > > > > >> > > > >>> >
> > > > >> > > > > > >> >> > >> > > > > >> > > > >>> > > Hi all,
> > > > >> > > > > > >> >> > >> > > > > >> > > > >>> > >
> > > > >> > > > > > >> >> > >> > > > > >> > > > >>> > > I updated the KIP
> > where
> > > > >> > > overloading
> > > > >> > > > > > >> >> position()
> > > > >> > > > > > >> >> > is
> > > > >> > > > > > >> >> > >> > now
> > > > >> > > > > > >> >> > >> > > > the
> > > > >> > > > > > >> >> > >> > > > > >> > favored
> > > > >> > > > > > >> >> > >> > > > > >> > > > >>> > approach.
> > > > >> > > > > > >> >> > >> > > > > >> > > > >>> > > Bounding position()
> > > using
> > > > >> > > > > > >> requestTimeoutMs
> > > > >> > > > > > >> >> has
> > > > >> > > > > > >> >> > >> been
> > > > >> > > > > > >> >> > >> > > > listed
> > > > >> > > > > > >> >> > >> > > > > >> as
> > > > >> > > > > > >> >> > >> > > > > >> > > > >>> rejected.
> > > > >> > > > > > >> >> > >> > > > > >> > > > >>> > >
> > > > >> > > > > > >> >> > >> > > > > >> > > > >>> > > Any thoughts?
> > > > >> > > > > > >> >> > >> > > > > >> > > > >>> > >
> > > > >> > > > > > >> >> > >> > > > > >> > > > >>> > > On Tue, Mar 6, 2018
> at
> > > > 6:00
> > > > >> PM,
> > > > >> > > > > > Guozhang
> > > > >> > > > > > >> >> Wang <
> > > > >> > > > > > >> >> > >> > > > > >> > > wangguoz@gmail.com>
> > > > >> > > > > > >> >> > >> > > > > >> > > > >>> > wrote:
> > > > >> > > > > > >> >> > >> > > > > >> > > > >>> > >
> > > > >> > > > > > >> >> > >> > > > > >> > > > >>> > >> I agree that adding
> > the
> > > > >> > > overloads
> > > > >> > > > is
> > > > >> > > > > > >> most
> > > > >> > > > > > >> >> > >> flexible.
> > > > >> > > > > > >> >> > >> > > But
> > > > >> > > > > > >> >> > >> > > > > >> going
> > > > >> > > > > > >> >> > >> > > > > >> > > for
> > > > >> > > > > > >> >> > >> > > > > >> > > > >>> that
> > > > >> > > > > > >> >> > >> > > > > >> > > > >>> > >> direction we'd do
> > that
> > > > for
> > > > >> all
> > > > >> > > the
> > > > >> > > > > > >> blocking
> > > > >> > > > > > >> >> > call
> > > > >> > > > > > >> >> > >> > that
> > > > >> > > > > > >> >> > >> > > > > I've
> > > > >> > > > > > >> >> > >> > > > > >> > > listed
> > > > >> > > > > > >> >> > >> > > > > >> > > > >>> above,
> > > > >> > > > > > >> >> > >> > > > > >> > > > >>> > >> with this timeout
> > value
> > > > >> > covering
> > > > >> > > > the
> > > > >> > > > > > >> >> > end-to-end
> > > > >> > > > > > >> >> > >> > > waiting
> > > > >> > > > > > >> >> > >> > > > > >> time.
> > > > >> > > > > > >> >> > >> > > > > >> > > > >>> > >>
> > > > >> > > > > > >> >> > >> > > > > >> > > > >>> > >>
> > > > >> > > > > > >> >> > >> > > > > >> > > > >>> > >> Guozhang
> > > > >> > > > > > >> >> > >> > > > > >> > > > >>> > >>
> > > > >> > > > > > >> >> > >> > > > > >> > > > >>> > >> On Tue, Mar 6, 2018
> > at
> > > > >> 10:02
> > > > >> > AM,
> > > > >> > > > Ted
> > > > >> > > > > > Yu
> > > > >> > > > > > >> <
> > > > >> > > > > > >> >> > >> > > > > >> yuzhihong@gmail.com>
> > > > >> > > > > > >> >> > >> > > > > >> > > > >>> wrote:
> > > > >> > > > > > >> >> > >> > > > > >> > > > >>> > >>
> > > > >> > > > > > >> >> > >> > > > > >> > > > >>> > >> > bq. The most
> > flexible
> > > > >> option
> > > > >> > > is
> > > > >> > > > to
> > > > >> > > > > > add
> > > > >> > > > > > >> >> > >> overloads
> > > > >> > > > > > >> >> > >> > to
> > > > >> > > > > > >> >> > >> > > > the
> > > > >> > > > > > >> >> > >> > > > > >> > > consumer
> > > > >> > > > > > >> >> > >> > > > > >> > > > >>> > >> >
> > > > >> > > > > > >> >> > >> > > > > >> > > > >>> > >> > This option is
> > > > flexible.
> > > > >> > > > > > >> >> > >> > > > > >> > > > >>> > >> >
> > > > >> > > > > > >> >> > >> > > > > >> > > > >>> > >> > Looking at the
> tail
> > > of
> > > > >> > > > > SPARK-18057,
> > > > >> > > > > > >> Spark
> > > > >> > > > > > >> >> > dev
> > > > >> > > > > > >> >> > >> > > voiced
> > > > >> > > > > > >> >> > >> > > > > the
> > > > >> > > > > > >> >> > >> > > > > >> > same
> > > > >> > > > > > >> >> > >> > > > > >> > > > >>> choice.
> > > > >> > > > > > >> >> > >> > > > > >> > > > >>> > >> >
> > > > >> > > > > > >> >> > >> > > > > >> > > > >>> > >> > +1 for adding
> > > overload
> > > > >> with
> > > > >> > > > > timeout
> > > > >> > > > > > >> >> > parameter.
> > > > >> > > > > > >> >> > >> > > > > >> > > > >>> > >> >
> > > > >> > > > > > >> >> > >> > > > > >> > > > >>> > >> > Cheers
> > > > >> > > > > > >> >> > >> > > > > >> > > > >>> > >> >
> > > > >> > > > > > >> >> > >> > > > > >> > > > >>> > >> > On Mon, Mar 5,
> 2018
> > > at
> > > > >> 2:42
> > > > >> > > PM,
> > > > >> > > > > > Jason
> > > > >> > > > > > >> >> > >> Gustafson <
> > > > >> > > > > > >> >> > >> > > > > >> > > > >>> jason@confluent.io>
> > > > >> > > > > > >> >> > >> > > > > >> > > > >>> > >> > wrote:
> > > > >> > > > > > >> >> > >> > > > > >> > > > >>> > >> >
> > > > >> > > > > > >> >> > >> > > > > >> > > > >>> > >> > > @Guozhang I
> > > probably
> > > > >> have
> > > > >> > > > > > suggested
> > > > >> > > > > > >> all
> > > > >> > > > > > >> >> > >> options
> > > > >> > > > > > >> >> > >> > > at
> > > > >> > > > > > >> >> > >> > > > > some
> > > > >> > > > > > >> >> > >> > > > > >> > > point
> > > > >> > > > > > >> >> > >> > > > > >> > > > or
> > > > >> > > > > > >> >> > >> > > > > >> > > > >>> > >> another,
> > > > >> > > > > > >> >> > >> > > > > >> > > > >>> > >> > > including most
> > > > >> recently,
> > > > >> > the
> > > > >> > > > > > current
> > > > >> > > > > > >> >> KIP!
> > > > >> > > > > > >> >> > I
> > > > >> > > > > > >> >> > >> was
> > > > >> > > > > > >> >> > >> > > > > >> thinking
> > > > >> > > > > > >> >> > >> > > > > >> > > that
> > > > >> > > > > > >> >> > >> > > > > >> > > > >>> > >> practically
> > > > >> > > > > > >> >> > >> > > > > >> > > > >>> > >> > > speaking, the
> > > request
> > > > >> > > timeout
> > > > >> > > > > > >> defines
> > > > >> > > > > > >> >> how
> > > > >> > > > > > >> >> > >> long
> > > > >> > > > > > >> >> > >> > > the
> > > > >> > > > > > >> >> > >> > > > > >> user is
> > > > >> > > > > > >> >> > >> > > > > >> > > > >>> willing
> > > > >> > > > > > >> >> > >> > > > > >> > > > >>> > to
> > > > >> > > > > > >> >> > >> > > > > >> > > > >>> > >> > wait
> > > > >> > > > > > >> >> > >> > > > > >> > > > >>> > >> > > for a response.
> > The
> > > > >> > consumer
> > > > >> > > > > > doesn't
> > > > >> > > > > > >> >> > really
> > > > >> > > > > > >> >> > >> > have
> > > > >> > > > > > >> >> > >> > > a
> > > > >> > > > > > >> >> > >> > > > > >> complex
> > > > >> > > > > > >> >> > >> > > > > >> > > > send
> > > > >> > > > > > >> >> > >> > > > > >> > > > >>> > >> process
> > > > >> > > > > > >> >> > >> > > > > >> > > > >>> > >> > > like the
> producer
> > > for
> > > > >> any
> > > > >> > of
> > > > >> > > > > these
> > > > >> > > > > > >> >> APIs,
> > > > >> > > > > > >> >> > so
> > > > >> > > > > > >> >> > >> I
> > > > >> > > > > > >> >> > >> > > > wasn't
> > > > >> > > > > > >> >> > >> > > > > >> sure
> > > > >> > > > > > >> >> > >> > > > > >> > > how
> > > > >> > > > > > >> >> > >> > > > > >> > > > >>> much
> > > > >> > > > > > >> >> > >> > > > > >> > > > >>> > >> > benefit
> > > > >> > > > > > >> >> > >> > > > > >> > > > >>> > >> > > there would be
> > from
> > > > >> having
> > > > >> > > > more
> > > > >> > > > > > >> >> granular
> > > > >> > > > > > >> >> > >> > control
> > > > >> > > > > > >> >> > >> > > > over
> > > > >> > > > > > >> >> > >> > > > > >> > > timeouts
> > > > >> > > > > > >> >> > >> > > > > >> > > > >>> (in
> > > > >> > > > > > >> >> > >> > > > > >> > > > >>> > the
> > > > >> > > > > > >> >> > >> > > > > >> > > > >>> > >> > end,
> > > > >> > > > > > >> >> > >> > > > > >> > > > >>> > >> > > KIP-91 just
> adds
> > a
> > > > >> single
> > > > >> > > > > timeout
> > > > >> > > > > > to
> > > > >> > > > > > >> >> > control
> > > > >> > > > > > >> >> > >> > the
> > > > >> > > > > > >> >> > >> > > > > whole
> > > > >> > > > > > >> >> > >> > > > > >> > > send).
> > > > >> > > > > > >> >> > >> > > > > >> > > > >>> That
> > > > >> > > > > > >> >> > >> > > > > >> > > > >>> > >> said,
> > > > >> > > > > > >> >> > >> > > > > >> > > > >>> > >> > it
> > > > >> > > > > > >> >> > >> > > > > >> > > > >>> > >> > > might indeed be
> > > > better
> > > > >> to
> > > > >> > > > avoid
> > > > >> > > > > > >> >> > overloading
> > > > >> > > > > > >> >> > >> the
> > > > >> > > > > > >> >> > >> > > > > config
> > > > >> > > > > > >> >> > >> > > > > >> as
> > > > >> > > > > > >> >> > >> > > > > >> > > you
> > > > >> > > > > > >> >> > >> > > > > >> > > > >>> > suggest
> > > > >> > > > > > >> >> > >> > > > > >> > > > >>> > >> > since
> > > > >> > > > > > >> >> > >> > > > > >> > > > >>> > >> > > at least it
> > avoids
> > > > >> > > > inconsistency
> > > > >> > > > > > >> with
> > > > >> > > > > > >> >> the
> > > > >> > > > > > >> >> > >> > > > producer's
> > > > >> > > > > > >> >> > >> > > > > >> > usage.
> > > > >> > > > > > >> >> > >> > > > > >> > > > >>> > >> > >
> > > > >> > > > > > >> >> > >> > > > > >> > > > >>> > >> > > The most
> flexible
> > > > >> option
> > > > >> > is
> > > > >> > > to
> > > > >> > > > > add
> > > > >> > > > > > >> >> > >> overloads to
> > > > >> > > > > > >> >> > >> > > the
> > > > >> > > > > > >> >> > >> > > > > >> > consumer
> > > > >> > > > > > >> >> > >> > > > > >> > > > so
> > > > >> > > > > > >> >> > >> > > > > >> > > > >>> that
> > > > >> > > > > > >> >> > >> > > > > >> > > > >>> > >> > users
> > > > >> > > > > > >> >> > >> > > > > >> > > > >>> > >> > > can pass the
> > > timeout
> > > > >> > > directly.
> > > > >> > > > > I'm
> > > > >> > > > > > >> not
> > > > >> > > > > > >> >> > sure
> > > > >> > > > > > >> >> > >> if
> > > > >> > > > > > >> >> > >> > > that
> > > > >> > > > > > >> >> > >> > > > > is
> > > > >> > > > > > >> >> > >> > > > > >> > more
> > > > >> > > > > > >> >> > >> > > > > >> > > or
> > > > >> > > > > > >> >> > >> > > > > >> > > > >>> less
> > > > >> > > > > > >> >> > >> > > > > >> > > > >>> > >> > > annoying than a
> > new
> > > > >> > config,
> > > > >> > > > but
> > > > >> > > > > > I've
> > > > >> > > > > > >> >> found
> > > > >> > > > > > >> >> > >> > config
> > > > >> > > > > > >> >> > >> > > > > >> > timeouts a
> > > > >> > > > > > >> >> > >> > > > > >> > > > >>> little
> > > > >> > > > > > >> >> > >> > > > > >> > > > >>> > >> > > constraining in
> > > > >> practice.
> > > > >> > > For
> > > > >> > > > > > >> example,
> > > > >> > > > > > >> >> I
> > > > >> > > > > > >> >> > >> could
> > > > >> > > > > > >> >> > >> > > > > imagine
> > > > >> > > > > > >> >> > >> > > > > >> > users
> > > > >> > > > > > >> >> > >> > > > > >> > > > >>> wanting
> > > > >> > > > > > >> >> > >> > > > > >> > > > >>> > >> to
> > > > >> > > > > > >> >> > >> > > > > >> > > > >>> > >> > > wait longer for
> > an
> > > > >> offset
> > > > >> > > > commit
> > > > >> > > > > > >> >> operation
> > > > >> > > > > > >> >> > >> > than a
> > > > >> > > > > > >> >> > >> > > > > >> position
> > > > >> > > > > > >> >> > >> > > > > >> > > > >>> lookup;
> > > > >> > > > > > >> >> > >> > > > > >> > > > >>> > if
> > > > >> > > > > > >> >> > >> > > > > >> > > > >>> > >> the
> > > > >> > > > > > >> >> > >> > > > > >> > > > >>> > >> > > latter isn't
> > > timely,
> > > > >> users
> > > > >> > > can
> > > > >> > > > > > just
> > > > >> > > > > > >> >> pause
> > > > >> > > > > > >> >> > >> the
> > > > >> > > > > > >> >> > >> > > > > partition
> > > > >> > > > > > >> >> > >> > > > > >> > and
> > > > >> > > > > > >> >> > >> > > > > >> > > > >>> continue
> > > > >> > > > > > >> >> > >> > > > > >> > > > >>> > >> > > fetching on
> > others.
> > > > If
> > > > >> you
> > > > >> > > > > cannot
> > > > >> > > > > > >> >> commit
> > > > >> > > > > > >> >> > >> > offsets,
> > > > >> > > > > > >> >> > >> > > > > >> however,
> > > > >> > > > > > >> >> > >> > > > > >> > > it
> > > > >> > > > > > >> >> > >> > > > > >> > > > >>> might
> > > > >> > > > > > >> >> > >> > > > > >> > > > >>> > be
> > > > >> > > > > > >> >> > >> > > > > >> > > > >>> > >> > > safer for an
> > > > >> application
> > > > >> > to
> > > > >> > > > wait
> > > > >> > > > > > >> >> > >> availability
> > > > >> > > > > > >> >> > >> > of
> > > > >> > > > > > >> >> > >> > > > the
> > > > >> > > > > > >> >> > >> > > > > >> > > > coordinator
> > > > >> > > > > > >> >> > >> > > > > >> > > > >>> > than
> > > > >> > > > > > >> >> > >> > > > > >> > > > >>> > >> > > continuing.
> > > > >> > > > > > >> >> > >> > > > > >> > > > >>> > >> > >
> > > > >> > > > > > >> >> > >> > > > > >> > > > >>> > >> > > -Jason
> > > > >> > > > > > >> >> > >> > > > > >> > > > >>> > >> > >
> > > > >> > > > > > >> >> > >> > > > > >> > > > >>> > >> > > On Sun, Mar 4,
> > 2018
> > > > at
> > > > >> > 10:14
> > > > >> > > > PM,
> > > > >> > > > > > >> >> Guozhang
> > > > >> > > > > > >> >> > >> Wang
> > > > >> > > > > > >> >> > >> > <
> > > > >> > > > > > >> >> > >> > > > > >> > > > >>> wangguoz@gmail.com>
> > > > >> > > > > > >> >> > >> > > > > >> > > > >>> > >> > wrote:
> > > > >> > > > > > >> >> > >> > > > > >> > > > >>> > >> > >
> > > > >> > > > > > >> >> > >> > > > > >> > > > >>> > >> > > > Hello
> Richard,
> > > > >> > > > > > >> >> > >> > > > > >> > > > >>> > >> > > >
> > > > >> > > > > > >> >> > >> > > > > >> > > > >>> > >> > > > Thanks for
> the
> > > > >> proposed
> > > > >> > > > KIP. I
> > > > >> > > > > > >> have a
> > > > >> > > > > > >> >> > >> couple
> > > > >> > > > > > >> >> > >> > of
> > > > >> > > > > > >> >> > >> > > > > >> general
> > > > >> > > > > > >> >> > >> > > > > >> > > > >>> comments:
> > > > >> > > > > > >> >> > >> > > > > >> > > > >>> > >> > > >
> > > > >> > > > > > >> >> > >> > > > > >> > > > >>> > >> > > > 1. I'm not
> sure
> > > if
> > > > >> > > > > piggy-backing
> > > > >> > > > > > >> the
> > > > >> > > > > > >> >> > >> timeout
> > > > >> > > > > > >> >> > >> > > > > >> exception
> > > > >> > > > > > >> >> > >> > > > > >> > on
> > > > >> > > > > > >> >> > >> > > > > >> > > > the
> > > > >> > > > > > >> >> > >> > > > > >> > > > >>> > >> > > > existing
> > > > >> > requestTimeoutMs
> > > > >> > > > > > >> configured
> > > > >> > > > > > >> >> in
> > > > >> > > > > > >> >> > "
> > > > >> > > > > > >> >> > >> > > > > >> > > request.timeout.ms
> > > > >> > > > > > >> >> > >> > > > > >> > > > "
> > > > >> > > > > > >> >> > >> > > > > >> > > > >>> is a
> > > > >> > > > > > >> >> > >> > > > > >> > > > >>> > >> good
> > > > >> > > > > > >> >> > >> > > > > >> > > > >>> > >> > > > idea
> > > > >> > > > > > >> >> > >> > > > > >> > > > >>> > >> > > > since a) it
> is
> > a
> > > > >> general
> > > > >> > > > > config
> > > > >> > > > > > >> that
> > > > >> > > > > > >> >> > >> applies
> > > > >> > > > > > >> >> > >> > > for
> > > > >> > > > > > >> >> > >> > > > > all
> > > > >> > > > > > >> >> > >> > > > > >> > types
> > > > >> > > > > > >> >> > >> > > > > >> > > > of
> > > > >> > > > > > >> >> > >> > > > > >> > > > >>> > >> requests,
> > > > >> > > > > > >> >> > >> > > > > >> > > > >>> > >> > > and
> > > > >> > > > > > >> >> > >> > > > > >> > > > >>> > >> > > > 2) using it
> to
> > > > cover
> > > > >> all
> > > > >> > > the
> > > > >> > > > > > >> phases
> > > > >> > > > > > >> >> of
> > > > >> > > > > > >> >> > an
> > > > >> > > > > > >> >> > >> API
> > > > >> > > > > > >> >> > >> > > > call,
> > > > >> > > > > > >> >> > >> > > > > >> > > > including
> > > > >> > > > > > >> >> > >> > > > > >> > > > >>> > >> network
> > > > >> > > > > > >> >> > >> > > > > >> > > > >>> > >> > > round
> > > > >> > > > > > >> >> > >> > > > > >> > > > >>> > >> > > > trip and
> > > potential
> > > > >> > > metadata
> > > > >> > > > > > >> refresh
> > > > >> > > > > > >> >> is
> > > > >> > > > > > >> >> > >> shown
> > > > >> > > > > > >> >> > >> > to
> > > > >> > > > > > >> >> > >> > > > not
> > > > >> > > > > > >> >> > >> > > > > >> be a
> > > > >> > > > > > >> >> > >> > > > > >> > > > good
> > > > >> > > > > > >> >> > >> > > > > >> > > > >>> > idea,
> > > > >> > > > > > >> >> > >> > > > > >> > > > >>> > >> as
> > > > >> > > > > > >> >> > >> > > > > >> > > > >>> > >> > > > illustrated
> in
> > > > >> KIP-91:
> > > > >> > > > > > >> >> > >> > > > > >> > > > >>> > >> > > >
> > > > >> > > > > > >> >> > >> > > > > >> > > > >>> > >> > > >
> > > > >> > > > > https://cwiki.apache.org/confl
> > > > >> > > > > > >> >> > >> > > > > >> uence/display/KAFKA/KIP-
> > > > >> > > > > > >> >> > >> > > > > >> > > > >>> > >> > > >
> > > > >> > 91+Provide+Intuitive+User+
> > > > >> > > > > > >> >> > >> > > > Timeouts+in+The+Producer
> > > > >> > > > > > >> >> > >> > > > > >> > > > >>> > >> > > >
> > > > >> > > > > > >> >> > >> > > > > >> > > > >>> > >> > > > In fact, I
> > think
> > > in
> > > > >> > > > KAFKA-4879
> > > > >> > > > > > >> which
> > > > >> > > > > > >> >> is
> > > > >> > > > > > >> >> > >> aimed
> > > > >> > > > > > >> >> > >> > > for
> > > > >> > > > > > >> >> > >> > > > > the
> > > > >> > > > > > >> >> > >> > > > > >> > same
> > > > >> > > > > > >> >> > >> > > > > >> > > > >>> issue
> > > > >> > > > > > >> >> > >> > > > > >> > > > >>> > as
> > > > >> > > > > > >> >> > >> > > > > >> > > > >>> > >> > > > KAFKA-6608,
> > > > >> > > > > > >> >> > >> > > > > >> > > > >>> > >> > > > Jason has
> > > suggested
> > > > >> we
> > > > >> > > use a
> > > > >> > > > > new
> > > > >> > > > > > >> >> config
> > > > >> > > > > > >> >> > >> for
> > > > >> > > > > > >> >> > >> > the
> > > > >> > > > > > >> >> > >> > > > > API.
> > > > >> > > > > > >> >> > >> > > > > >> > Maybe
> > > > >> > > > > > >> >> > >> > > > > >> > > > >>> this
> > > > >> > > > > > >> >> > >> > > > > >> > > > >>> > >> would
> > > > >> > > > > > >> >> > >> > > > > >> > > > >>> > >> > be
> > > > >> > > > > > >> >> > >> > > > > >> > > > >>> > >> > > a
> > > > >> > > > > > >> >> > >> > > > > >> > > > >>> > >> > > > more
> intuitive
> > > > manner
> > > > >> > than
> > > > >> > > > > > reusing
> > > > >> > > > > > >> >> the
> > > > >> > > > > > >> >> > >> > > > > >> > request.timeout.ms
> > > > >> > > > > > >> >> > >> > > > > >> > > > >>> config.
> > > > >> > > > > > >> >> > >> > > > > >> > > > >>> > >> > > >
> > > > >> > > > > > >> >> > >> > > > > >> > > > >>> > >> > > >
> > > > >> > > > > > >> >> > >> > > > > >> > > > >>> > >> > > > 2. Besides
> the
> > > > >> > > > > > Consumer.position()
> > > > >> > > > > > >> >> call,
> > > > >> > > > > > >> >> > >> > there
> > > > >> > > > > > >> >> > >> > > > are
> > > > >> > > > > > >> >> > >> > > > > a
> > > > >> > > > > > >> >> > >> > > > > >> > > couple
> > > > >> > > > > > >> >> > >> > > > > >> > > > of
> > > > >> > > > > > >> >> > >> > > > > >> > > > >>> > more
> > > > >> > > > > > >> >> > >> > > > > >> > > > >>> > >> > > > blocking
> calls
> > > > today
> > > > >> > that
> > > > >> > > > > could
> > > > >> > > > > > >> >> result
> > > > >> > > > > > >> >> > in
> > > > >> > > > > > >> >> > >> > > > infinite
> > > > >> > > > > > >> >> > >> > > > > >> > > blocking:
> > > > >> > > > > > >> >> > >> > > > > >> > > > >>> > >> > > >
> > > > Consumer.commitSync()
> > > > >> > and
> > > > >> > > > > > >> >> > >> > Consumer.committed(),
> > > > >> > > > > > >> >> > >> > > > > >> should
> > > > >> > > > > > >> >> > >> > > > > >> > > they
> > > > >> > > > > > >> >> > >> > > > > >> > > > be
> > > > >> > > > > > >> >> > >> > > > > >> > > > >>> > >> > considered
> > > > >> > > > > > >> >> > >> > > > > >> > > > >>> > >> > > > in this KIP
> as
> > > > well?
> > > > >> > > > > > >> >> > >> > > > > >> > > > >>> > >> > > >
> > > > >> > > > > > >> >> > >> > > > > >> > > > >>> > >> > > > 3. There are
> a
> > > few
> > > > >> other
> > > > >> > > > APIs
> > > > >> > > > > > that
> > > > >> > > > > > >> >> are
> > > > >> > > > > > >> >> > >> today
> > > > >> > > > > > >> >> > >> > > > > relying
> > > > >> > > > > > >> >> > >> > > > > >> on
> > > > >> > > > > > >> >> > >> > > > > >> > > > >>> > >> > >
> > request.timeout.ms
> > > > >> > > > > > >> >> > >> > > > > >> > > > >>> > >> > > > already for
> > > > breaking
> > > > >> the
> > > > >> > > > > > infinite
> > > > >> > > > > > >> >> > >> blocking,
> > > > >> > > > > > >> >> > >> > > > namely
> > > > >> > > > > > >> >> > >> > > > > >> > > > >>> > >> > >
> > > > >> Consumer.partitionFor(),
> > > > >> > > > > > >> >> > >> > > > > >> > > > >>> > >> > > >
> > > > >> > > > Consumer.OffsetAndTimestamp()
> > > > >> > > > > > and
> > > > >> > > > > > >> >> > >> > > > > >> Consumer.listTopics(),
> > > > >> > > > > > >> >> > >> > > > > >> > > if
> > > > >> > > > > > >> >> > >> > > > > >> > > > >>> we are
> > > > >> > > > > > >> >> > >> > > > > >> > > > >>> > >> > making
> > > > >> > > > > > >> >> > >> > > > > >> > > > >>> > >> > > > the other
> > > blocking
> > > > >> calls
> > > > >> > > to
> > > > >> > > > be
> > > > >> > > > > > >> >> relying a
> > > > >> > > > > > >> >> > >> new
> > > > >> > > > > > >> >> > >> > > > config
> > > > >> > > > > > >> >> > >> > > > > >> as
> > > > >> > > > > > >> >> > >> > > > > >> > > > >>> suggested
> > > > >> > > > > > >> >> > >> > > > > >> > > > >>> > in
> > > > >> > > > > > >> >> > >> > > > > >> > > > >>> > >> 1)
> > > > >> > > > > > >> >> > >> > > > > >> > > > >>> > >> > > > above, should
> > we
> > > > also
> > > > >> > > change
> > > > >> > > > > the
> > > > >> > > > > > >> >> > >> semantics of
> > > > >> > > > > > >> >> > >> > > > these
> > > > >> > > > > > >> >> > >> > > > > >> API
> > > > >> > > > > > >> >> > >> > > > > >> > > > >>> functions
> > > > >> > > > > > >> >> > >> > > > > >> > > > >>> > >> for
> > > > >> > > > > > >> >> > >> > > > > >> > > > >>> > >> > > > consistency?
> > > > >> > > > > > >> >> > >> > > > > >> > > > >>> > >> > > >
> > > > >> > > > > > >> >> > >> > > > > >> > > > >>> > >> > > >
> > > > >> > > > > > >> >> > >> > > > > >> > > > >>> > >> > > > Guozhang
> > > > >> > > > > > >> >> > >> > > > > >> > > > >>> > >> > > >
> > > > >> > > > > > >> >> > >> > > > > >> > > > >>> > >> > > >
> > > > >> > > > > > >> >> > >> > > > > >> > > > >>> > >> > > >
> > > > >> > > > > > >> >> > >> > > > > >> > > > >>> > >> > > >
> > > > >> > > > > > >> >> > >> > > > > >> > > > >>> > >> > > > On Sun, Mar
> 4,
> > > 2018
> > > > >> at
> > > > >> > > 11:13
> > > > >> > > > > AM,
> > > > >> > > > > > >> >> Richard
> > > > >> > > > > > >> >> > >> Yu <
> > > > >> > > > > > >> >> > >> > > > > >> > > > >>> > >> >
> > > > >> yohan.richard.yu@gmail.com>
> > > > >> > > > > > >> >> > >> > > > > >> > > > >>> > >> > > > wrote:
> > > > >> > > > > > >> >> > >> > > > > >> > > > >>> > >> > > >
> > > > >> > > > > > >> >> > >> > > > > >> > > > >>> > >> > > > > Hi all,
> > > > >> > > > > > >> >> > >> > > > > >> > > > >>> > >> > > > >
> > > > >> > > > > > >> >> > >> > > > > >> > > > >>> > >> > > > > I would
> like
> > to
> > > > >> > discuss
> > > > >> > > a
> > > > >> > > > > > >> potential
> > > > >> > > > > > >> >> > >> change
> > > > >> > > > > > >> >> > >> > > > which
> > > > >> > > > > > >> >> > >> > > > > >> would
> > > > >> > > > > > >> >> > >> > > > > >> > > be
> > > > >> > > > > > >> >> > >> > > > > >> > > > >>> made
> > > > >> > > > > > >> >> > >> > > > > >> > > > >>> > to
> > > > >> > > > > > >> >> > >> > > > > >> > > > >>> > >> > > > >
> > KafkaConsumer:
> > > > >> > > > > > >> >> > >> > > > > >> > > > >>> > >> > > > >
> > > > >> > > https://cwiki.apache.org/
> > > > >> > > > > > >> >> > >> > > > > confluence/pages/viewpage
> > > > >> > > > > > >> >> > >> > > > > >> .
> > > > >> > > > > > >> >> > >> > > > > >> > > > >>> > >> > > >
> > > > >> action?pageId=75974886
> > > > >> > > > > > >> >> > >> > > > > >> > > > >>> > >> > > > >
> > > > >> > > > > > >> >> > >> > > > > >> > > > >>> > >> > > > > Thanks,
> > > > >> > > > > > >> >> > >> > > > > >> > > > >>> > >> > > > > Richard Yu
> > > > >> > > > > > >> >> > >> > > > > >> > > > >>> > >> > > > >
> > > > >> > > > > > >> >> > >> > > > > >> > > > >>> > >> > > >
> > > > >> > > > > > >> >> > >> > > > > >> > > > >>> > >> > > >
> > > > >> > > > > > >> >> > >> > > > > >> > > > >>> > >> > > >
> > > > >> > > > > > >> >> > >> > > > > >> > > > >>> > >> > > > --
> > > > >> > > > > > >> >> > >> > > > > >> > > > >>> > >> > > > -- Guozhang
> > > > >> > > > > > >> >> > >> > > > > >> > > > >>> > >> > > >
> > > > >> > > > > > >> >> > >> > > > > >> > > > >>> > >> > >
> > > > >> > > > > > >> >> > >> > > > > >> > > > >>> > >> >
> > > > >> > > > > > >> >> > >> > > > > >> > > > >>> > >>
> > > > >> > > > > > >> >> > >> > > > > >> > > > >>> > >>
> > > > >> > > > > > >> >> > >> > > > > >> > > > >>> > >>
> > > > >> > > > > > >> >> > >> > > > > >> > > > >>> > >> --
> > > > >> > > > > > >> >> > >> > > > > >> > > > >>> > >> -- Guozhang
> > > > >> > > > > > >> >> > >> > > > > >> > > > >>> > >>
> > > > >> > > > > > >> >> > >> > > > > >> > > > >>> > >
> > > > >> > > > > > >> >> > >> > > > > >> > > > >>> > >
> > > > >> > > > > > >> >> > >> > > > > >> > > > >>> >
> > > > >> > > > > > >> >> > >> > > > > >> > > > >>>
> > > > >> > > > > > >> >> > >> > > > > >> > > > >>
> > > > >> > > > > > >> >> > >> > > > > >> > > > >>
> > > > >> > > > > > >> >> > >> > > > > >> > > > >
> > > > >> > > > > > >> >> > >> > > > > >> > > >
> > > > >> > > > > > >> >> > >> > > > > >> > >
> > > > >> > > > > > >> >> > >> > > > > >> > >
> > > > >> > > > > > >> >> > >> > > > > >> > >
> > > > >> > > > > > >> >> > >> > > > > >> > > --
> > > > >> > > > > > >> >> > >> > > > > >> > > -- Guozhang
> > > > >> > > > > > >> >> > >> > > > > >> > >
> > > > >> > > > > > >> >> > >> > > > > >> >
> > > > >> > > > > > >> >> > >> > > > > >>
> > > > >> > > > > > >> >> > >> > > > > >
> > > > >> > > > > > >> >> > >> > > > > >
> > > > >> > > > > > >> >> > >> > > > >
> > > > >> > > > > > >> >> > >> > > >
> > > > >> > > > > > >> >> > >> > >
> > > > >> > > > > > >> >> > >> >
> > > > >> > > > > > >> >> > >> >
> > > > >> > > > > > >> >> > >> >
> > > > >> > > > > > >> >> > >> > --
> > > > >> > > > > > >> >> > >> > -- Guozhang
> > > > >> > > > > > >> >> > >> >
> > > > >> > > > > > >> >> > >>
> > > > >> > > > > > >> >> > >
> > > > >> > > > > > >> >> > >
> > > > >> > > > > > >> >> >
> > > > >> > > > > > >> >>
> > > > >> > > > > > >> >>
> > > > >> > > > > > >> >>
> > > > >> > > > > > >> >> --
> > > > >> > > > > > >> >> -- Guozhang
> > > > >> > > > > > >> >>
> > > > >> > > > > > >> >
> > > > >> > > > > > >> >
> > > > >> > > > > > >>
> > > > >> > > > > > >
> > > > >> > > > > > >
> > > > >> > > > > >
> > > > >> > > > >
> > > > >> > > >
> > > > >> > >
> > > > >> >
> > > > >>
> > > > >
> > > > >
> > > >
> > >
> > >
> > >
> > > --
> > > -- Guozhang
> > >
> >
>
Re: [DISCUSSION] KIP-266: Add TimeoutException to KafkaConsumer#position()
Posted by John Roesler <jo...@confluent.io>.
Thanks Jason,
I did find some production use cases "on the internet" that use poll(0)
*just* to join the group initially and ignore the response. I suppose the
assumption is that it'll be empty on the very first call to poll with
timeout=0. In my opinion, this usage is unsafe, since there's a declared
return value. I proposed the method to give these use cases a safe
alternative.
Of course, there's another safe alternative: just don't ignore the response.
I'd agree with the decision to just deprecate the old poll(long) and add
only a new poll(Duration). It should be obvious that there's no
non-deprecated way to do what the code I found is doing, so those
developers will either alter their code to handle the response or they will
come back and ask us for the awaitAssignmentMetadata method.
Better to present a simpler api and wait for a reason to make it more
complicated.
I'm fine with suggestions 1,2, and 3. Unless Richard objects super fast,
I'll update the KIP momentarily.
Regarding the ClientTimeoutException, this was introduced earlier in this
discussion when Becket pointed out that the TimeoutException is a subclass
of ApiException, and therefore implies that a call to the broker timed out.
Reconsidering this point, I found the javadoc on ApiException to be a
little ambiguous. All it says is that "any API exception that is part of
the public protocol should be a subclass of this class...". It's not clear
to me whether this is the broker's API/protocol or more generally *any*
API/protocol. So we'd have to bring the lawyers in, but I think we can just
say it's the latter and keep the old exception.
I'm not sure if it's an important distiction to users whether their request
timed out as a broker side timeout, an HTTP timeout, or a client-side
timeout. In any case, they'd want to retry for a while and then fail if
they can't get their request through.
Plus RetryableException also inherits from ApiException, and that one is
ubiquitous. Adding a new exception would require users to catch both
RetriableException and ClientTimeoutException, which seems odd since the
latter is retriable.
All in all, I'm now in favor of sticking with the current TimeoutException.
If there's some higher-level problem with the ApiException being used this
way, I think it should be addressed holistically in a separate KIP.
So, I'll go ahead and switch the KIP back to TimeoutException, unless
Becket wants to argue (harder) in favor of the ClientTimeoutException.
Thanks,
-John
On Wed, May 2, 2018 at 3:55 PM, Jason Gustafson <ja...@confluent.io> wrote:
> I think John's proposal look reasonable to me. My only doubt is about use
> cases for the new `awaitAssignmentMetadata` API. I think the basic idea is
> that we want a way to block until we have joined the consumer group, but we
> do not want to await fetched data. Maybe another way to accomplish this
> would be to add a `PollOptions` argument which specified the condition we
> are awaiting? It's a little weird that we'd have two separate APIs where
> the group membership can change. I know this functionality can be helpful
> in testing, but we should probably spend some more time understanding and
> motivating the general use cases.
>
> Since we're leaving around the old poll() with its current behavior for
> now, I wonder if we could leave this as potential future work?
>
> Other than that, I have a few minor suggestions and I'm happy with the KIP:
>
> 1. Can we use Duration across the board for all of these APIs?
> 2. Can we cover the following blocking APIs with in this KIP:
> `partitionsFor`, `listTopics`, `offsetsForTimes`, `beginningOffsets`,
> `endOffsets`?
> 3. Perhaps we can add a `close(Duration)` and deprecate the one accepting
> `TimeUnit`?
> 4. Seems we don't really need `ClientTimeoutException` since we already
> have `TimeoutException`?
>
> Thanks,
> Jason
>
>
>
> On Wed, Apr 25, 2018 at 2:14 PM, Guozhang Wang <wa...@gmail.com> wrote:
>
> > Previously there are some debates on whether we should add this
> nonblocking
> > behavior via a config v.s. via overloaded functions. To make progress on
> > this discussion we need to first figure that part out. I'm in favor of
> the
> > current approach of overloaded functions over the config since if we are
> > going to have multiple configs other than a single one to control timeout
> > semantics it may be even confusing: take our producer side configs for an
> > example, right now we have "request.timeout.ms" and "max.block.ms" and
> we
> > are proposing to add another one in KIP-91. But I'd also like to hear
> from
> > people who's in favor of the configs.
> >
> >
> > Guozhang
> >
> >
> > On Wed, Apr 25, 2018 at 1:39 PM, John Roesler <jo...@confluent.io> wrote:
> >
> > > Re Ted's last comment, that style of async API requires some thread to
> > > actually drive the request/response cycle and invoke the callback when
> > it's
> > > complete. Right now, this happens in the caller's thread as a
> side-effect
> > > of calling poll(). But that clearly won't work for poll() itself!
> > >
> > > In the future, I think we'd like to add a background thread to drive
> the
> > > request/response loops, and then make all these methods return
> > > Future<Whatever>.
> > >
> > > But we don't need to bite that off right now.
> > >
> > > The "async" model I'm proposing is really just a generalization of the
> > one
> > > that poll already partially implements: when you call poll, it fires
> off
> > > any requests it needs to make and checks if any responses are ready. If
> > so,
> > > it returns them. If not, it returns empty. When you call poll() again,
> it
> > > again checks on the responses from last time, and so forth.
> > >
> > > But that model currently only applies to the "fetch" part of poll. I'm
> > > proposing that we extend it to the "metadata update" part of poll as
> > well.
> > >
> > > However, as previously discussed, doing this in place would break the
> > > semantics of poll that folks currently rely on, so I propose to add new
> > > methods and deprecate the existing poll method. Here's what I'm
> thinking:
> > > https://github.com/apache/kafka/pull/4855 . In the discussion on that
> > PR,
> > > I've described in greater detail how the async+blocking semantics work.
> > >
> > > I'll update KIP-266 with this interface for poll().
> > >
> > > It would be great to get this discussion moving again so we can get
> these
> > > changes into 2.0. What does everyone think about this?
> > >
> > > Thanks,
> > > -John
> > >
> > > On Thu, Apr 19, 2018 at 5:12 PM, John Roesler <jo...@confluent.io>
> wrote:
> > >
> > > > Thanks for the tip, Ted!
> > > >
> > > > On Thu, Apr 19, 2018 at 12:12 PM, Ted Yu <yu...@gmail.com>
> wrote:
> > > >
> > > >> John:
> > > >> In case you want to pursue async poll, it seems (by looking at
> current
> > > >> API)
> > > >> that introducing PollCallback follows existing pattern(s).
> > > >>
> > > >> e.g. KafkaConsumer#commitAsync(OffsetCommitCallback)
> > > >>
> > > >> FYI
> > > >>
> > > >> On Thu, Apr 19, 2018 at 10:08 AM, John Roesler <jo...@confluent.io>
> > > wrote:
> > > >>
> > > >> > Hi Richard,
> > > >> >
> > > >> > Thanks for the invitation! I do think it would be safer to
> > introduce a
> > > >> new
> > > >> > poll
> > > >> > method than to change the semantics of the old one. I've been
> > mulling
> > > >> about
> > > >> > whether the new one could still have (slightly different) async
> > > >> semantics
> > > >> > with
> > > >> > a timeout of 0. If possible, I'd like to avoid introducing another
> > new
> > > >> > "asyncPoll".
> > > >> >
> > > >> > I'm planning to run some experiments and dig into the
> > implementation a
> > > >> bit
> > > >> > more before solidifying the proposal. I'll update the KIP as you
> > > >> suggest at
> > > >> > that point,
> > > >> > and then can call for another round of reviews and voting.
> > > >> >
> > > >> > Thanks,
> > > >> > -John
> > > >> >
> > > >> > On Tue, Apr 17, 2018 at 4:53 PM, Richard Yu <
> > > yohan.richard.yu@gmail.com
> > > >> >
> > > >> > wrote:
> > > >> >
> > > >> > > Hi John,
> > > >> > >
> > > >> > > Do you have a preference for fixing the poll() method (e.g.
> using
> > > >> > asyncPoll
> > > >> > > or just sticking with the current method but with an extra
> timeout
> > > >> > > parameter) ? I think your current proposition for KIP-288 is
> > better
> > > >> than
> > > >> > > what I have on my side. If you think there is something that you
> > > want
> > > >> to
> > > >> > > add, you could go ahead and change KIP-266 to your liking. Just
> to
> > > >> note
> > > >> > > that it would be preferable that if one of us modifies this KIP,
> > it
> > > >> would
> > > >> > > be best to mention your change on this thread to let each other
> > know
> > > >> > (makes
> > > >> > > it easier to coordinate progress).
> > > >> > >
> > > >> > > Thanks,
> > > >> > > Richard
> > > >> > >
> > > >> > > On Tue, Apr 17, 2018 at 2:07 PM, John Roesler <
> john@confluent.io>
> > > >> wrote:
> > > >> > >
> > > >> > > > Ok, I'll close the discussion on KIP-288 and mark it
> discarded.
> > > >> > > >
> > > >> > > > We can solidify the design for poll in KIP-266, and once it's
> > > >> approved,
> > > >> > > > I'll coordinate with Qiang Zhao on the PR for the poll part of
> > the
> > > >> > work.
> > > >> > > > Once that is merged, you'll have a clean slate for the rest of
> > the
> > > >> > work.
> > > >> > > >
> > > >> > > > On Tue, Apr 17, 2018 at 3:39 PM, Richard Yu <
> > > >> > yohan.richard.yu@gmail.com>
> > > >> > > > wrote:
> > > >> > > >
> > > >> > > > > Hi John,
> > > >> > > > >
> > > >> > > > > I think that you could finish your PR that corresponds with
> > > >> KIP-288
> > > >> > and
> > > >> > > > > merge it. I can finish my side of the work afterwards.
> > > >> > > > >
> > > >> > > > > On another note, adding an asynchronized version of poll()
> > would
> > > >> make
> > > >> > > > > sense, particularily since the current version of Kafka does
> > not
> > > >> > > support
> > > >> > > > > it.
> > > >> > > > >
> > > >> > > > > Thanks
> > > >> > > > > Richar
> > > >> > > > >
> > > >> > > > > On Tue, Apr 17, 2018 at 12:30 PM, John Roesler <
> > > john@confluent.io
> > > >> >
> > > >> > > > wrote:
> > > >> > > > >
> > > >> > > > > > Cross-pollinating from some discussion we've had on
> KIP-288,
> > > >> > > > > >
> > > >> > > > > > I think there's a good reason that poll() takes a timeout
> > when
> > > >> none
> > > >> > > of
> > > >> > > > > the
> > > >> > > > > > other methods do, and it's relevant to this discussion.
> The
> > > >> timeout
> > > >> > > in
> > > >> > > > > > poll() is effectively implementing a long-poll API (on the
> > > >> client
> > > >> > > side,
> > > >> > > > > so
> > > >> > > > > > it's not really long-poll, but the programmer-facing
> > behavior
> > > is
> > > >> > the
> > > >> > > > > same).
> > > >> > > > > > The timeout isn't really bounding the execution time of
> the
> > > >> method,
> > > >> > > but
> > > >> > > > > > instead giving a max time that callers are willing to wait
> > > >> around
> > > >> > and
> > > >> > > > see
> > > >> > > > > > if any results show up.
> > > >> > > > > >
> > > >> > > > > > If I understand the code sufficiently, it would be
> perfectly
> > > >> > > reasonable
> > > >> > > > > for
> > > >> > > > > > a caller to use a timeout of 0 to implement async poll, it
> > > would
> > > >> > just
> > > >> > > > > mean
> > > >> > > > > > that KafkaConsumer would just check on each call if
> there's
> > a
> > > >> > > response
> > > >> > > > > > ready and if not, fire off a new request without waiting
> > for a
> > > >> > > > response.
> > > >> > > > > >
> > > >> > > > > > As such, it seems inappropriate to throw a
> > > >> ClientTimeoutException
> > > >> > > from
> > > >> > > > > > poll(), except possibly if the initial phase of ensuring
> an
> > > >> > > assignment
> > > >> > > > > > times out. We wouldn't want the method contract to be
> > > "returns a
> > > >> > > > > non-empty
> > > >> > > > > > collection or throws a ClientTimeoutException"
> > > >> > > > > >
> > > >> > > > > > Now, I'm wondering if we should actually consider one of
> my
> > > >> > rejected
> > > >> > > > > > alternatives, to treat the "operation timeout" as a
> separate
> > > >> > > parameter
> > > >> > > > > from
> > > >> > > > > > the "long-poll time". Or maybe adding an
> "asyncPoll(timeout,
> > > >> time
> > > >> > > > unit)"
> > > >> > > > > > that only uses the timeout to bound metadata updates and
> > > >> otherwise
> > > >> > > > > behaves
> > > >> > > > > > like the current "poll(0)".
> > > >> > > > > >
> > > >> > > > > > Thanks,
> > > >> > > > > > -John
> > > >> > > > > >
> > > >> > > > > > On Tue, Apr 17, 2018 at 2:05 PM, John Roesler <
> > > >> john@confluent.io>
> > > >> > > > wrote:
> > > >> > > > > >
> > > >> > > > > > > Hey Richard,
> > > >> > > > > > >
> > > >> > > > > > > As you noticed, the newly introduced KIP-288 overlaps
> with
> > > >> this
> > > >> > > one.
> > > >> > > > > > Sorry
> > > >> > > > > > > for stepping on your toes... How would you like to
> > proceed?
> > > >> I'm
> > > >> > > happy
> > > >> > > > > to
> > > >> > > > > > > "close" KIP-288 in deference to this KIP.
> > > >> > > > > > >
> > > >> > > > > > > With respect to poll(), reading this discussion gave me
> a
> > > new
> > > >> > idea
> > > >> > > > for
> > > >> > > > > > > providing a non-breaking update path... What if we
> > > introduce a
> > > >> > new
> > > >> > > > > > variant
> > > >> > > > > > > 'poll(long timeout, TimeUnit unit)' that displays the
> new,
> > > >> > desired
> > > >> > > > > > > behavior, and just leave the old method alone?
> > > >> > > > > > >
> > > >> > > > > > > Thanks,
> > > >> > > > > > > -John
> > > >> > > > > > >
> > > >> > > > > > > On Tue, Apr 17, 2018 at 12:09 PM, Richard Yu <
> > > >> > > > > yohan.richard.yu@gmail.com
> > > >> > > > > > >
> > > >> > > > > > > wrote:
> > > >> > > > > > >
> > > >> > > > > > >> Hi all,
> > > >> > > > > > >>
> > > >> > > > > > >> If possible, would a committer please review?
> > > >> > > > > > >>
> > > >> > > > > > >> Thanks
> > > >> > > > > > >>
> > > >> > > > > > >> On Sun, Apr 1, 2018 at 7:24 PM, Richard Yu <
> > > >> > > > > yohan.richard.yu@gmail.com>
> > > >> > > > > > >> wrote:
> > > >> > > > > > >>
> > > >> > > > > > >> > Hi Guozhang,
> > > >> > > > > > >> >
> > > >> > > > > > >> > I have clarified the KIP a bit to account for
> Becket's
> > > >> > > suggestion
> > > >> > > > on
> > > >> > > > > > >> > ClientTimeoutException.
> > > >> > > > > > >> > About adding an extra config, you were right about my
> > > >> > > intentions.
> > > >> > > > I
> > > >> > > > > am
> > > >> > > > > > >> > just wondering if the config
> > > >> > > > > > >> > should be included, since Ismael seems to favor an
> > extra
> > > >> > > > > > configuration,
> > > >> > > > > > >> >
> > > >> > > > > > >> > Thanks,
> > > >> > > > > > >> > Richard
> > > >> > > > > > >> >
> > > >> > > > > > >> > On Sun, Apr 1, 2018 at 5:35 PM, Guozhang Wang <
> > > >> > > wangguoz@gmail.com
> > > >> > > > >
> > > >> > > > > > >> wrote:
> > > >> > > > > > >> >
> > > >> > > > > > >> >> Hi Richard,
> > > >> > > > > > >> >>
> > > >> > > > > > >> >> Regarding the streams side changes, we plan to
> > > incorporate
> > > >> > with
> > > >> > > > the
> > > >> > > > > > new
> > > >> > > > > > >> >> APIs once the KIP is done, which is only internal
> code
> > > >> > changes
> > > >> > > > and
> > > >> > > > > > >> hence
> > > >> > > > > > >> >> do
> > > >> > > > > > >> >> not need to include in the KIP.
> > > >> > > > > > >> >>
> > > >> > > > > > >> >> Could you update the KIP because it has been quite
> > > >> obsoleted
> > > >> > > from
> > > >> > > > > the
> > > >> > > > > > >> >> discussed topics, and I'm a bit loosing track on
> what
> > is
> > > >> your
> > > >> > > > final
> > > >> > > > > > >> >> proposal right now. For example, I'm not completely
> > > >> following
> > > >> > > > your
> > > >> > > > > > >> >> "compromise
> > > >> > > > > > >> >> of sorts": are you suggesting that we still add
> > > >> overloading
> > > >> > > > > functions
> > > >> > > > > > >> and
> > > >> > > > > > >> >> add a config that will be applied to all overload
> > > >> functions
> > > >> > > > without
> > > >> > > > > > the
> > > >> > > > > > >> >> timeout, while for other overloaded functions with
> the
> > > >> > timeout
> > > >> > > > > value
> > > >> > > > > > >> the
> > > >> > > > > > >> >> config will be ignored?
> > > >> > > > > > >> >>
> > > >> > > > > > >> >>
> > > >> > > > > > >> >> Guozhang
> > > >> > > > > > >> >>
> > > >> > > > > > >> >> On Fri, Mar 30, 2018 at 8:36 PM, Richard Yu <
> > > >> > > > > > >> yohan.richard.yu@gmail.com>
> > > >> > > > > > >> >> wrote:
> > > >> > > > > > >> >>
> > > >> > > > > > >> >> > On a side note, I have noticed that the several
> > other
> > > >> > methods
> > > >> > > > in
> > > >> > > > > > >> classes
> > > >> > > > > > >> >> > such as StoreChangeLogReader in Streams calls
> > > position()
> > > >> > > which
> > > >> > > > > > causes
> > > >> > > > > > >> >> tests
> > > >> > > > > > >> >> > to hang. It might be out of the scope of the KIP,
> > but
> > > >> > should
> > > >> > > I
> > > >> > > > > also
> > > >> > > > > > >> >> change
> > > >> > > > > > >> >> > the methods which use position() as a callback to
> at
> > > the
> > > >> > very
> > > >> > > > > least
> > > >> > > > > > >> >> prevent
> > > >> > > > > > >> >> > the tests from hanging? This issue might be out of
> > the
> > > >> KIP,
> > > >> > > > but I
> > > >> > > > > > >> >> prefer it
> > > >> > > > > > >> >> > if we could at least make my PR pass the Jenkins
> > Q&A.
> > > >> > > > > > >> >> >
> > > >> > > > > > >> >> > Thanks
> > > >> > > > > > >> >> >
> > > >> > > > > > >> >> > On Fri, Mar 30, 2018 at 8:24 PM, Richard Yu <
> > > >> > > > > > >> yohan.richard.yu@gmail.com
> > > >> > > > > > >> >> >
> > > >> > > > > > >> >> > wrote:
> > > >> > > > > > >> >> >
> > > >> > > > > > >> >> > > Thanks for the review Becket.
> > > >> > > > > > >> >> > >
> > > >> > > > > > >> >> > > About the methods beginningOffsets(),
> > endOffsets(),
> > > >> ...:
> > > >> > > > > > >> >> > > I took a look through the code of KafkaConsumer,
> > but
> > > >> > after
> > > >> > > > > > looking
> > > >> > > > > > >> >> > through
> > > >> > > > > > >> >> > > the offsetsByTimes() method
> > > >> > > > > > >> >> > > and its callbacks in Fetcher, I think these
> > methods
> > > >> > already
> > > >> > > > > block
> > > >> > > > > > >> for
> > > >> > > > > > >> >> a
> > > >> > > > > > >> >> > > set period of time. I know that there
> > > >> > > > > > >> >> > > is a chance that the offsets methods in
> > > KafkaConsumer
> > > >> > might
> > > >> > > > be
> > > >> > > > > > like
> > > >> > > > > > >> >> poll
> > > >> > > > > > >> >> > > (that is one section of the method
> > > >> > > > > > >> >> > > honors the timeout while another --
> > > >> updateFetchPositions
> > > >> > --
> > > >> > > > > does
> > > >> > > > > > >> not).
> > > >> > > > > > >> >> > > However, I don't think that this is the
> > > >> > > > > > >> >> > > case with offsetsByTimes since the callbacks
> that
> > I
> > > >> > checked
> > > >> > > > > does
> > > >> > > > > > >> not
> > > >> > > > > > >> >> seem
> > > >> > > > > > >> >> > > to hang.
> > > >> > > > > > >> >> > >
> > > >> > > > > > >> >> > > The clarity of the exception message is a
> > problem. I
> > > >> > > thought
> > > >> > > > > your
> > > >> > > > > > >> >> > > suggestion there was reasonable. I included
> > > >> > > > > > >> >> > > it in the KIP.
> > > >> > > > > > >> >> > >
> > > >> > > > > > >> >> > > And on another note, I have noticed that several
> > > >> people
> > > >> > has
> > > >> > > > > > voiced
> > > >> > > > > > >> the
> > > >> > > > > > >> >> > > opinion that adding a config might
> > > >> > > > > > >> >> > > be advisable in relation to adding an extra
> > > >> parameter. I
> > > >> > > > think
> > > >> > > > > > >> that we
> > > >> > > > > > >> >> > can
> > > >> > > > > > >> >> > > have a compromise of sorts: some
> > > >> > > > > > >> >> > > methods in KafkaConsumer are relatively similar
> --
> > > for
> > > >> > > > example,
> > > >> > > > > > >> >> > position()
> > > >> > > > > > >> >> > > and committed() both call
> > > >> > > > > > >> >> > > updateFetchPositions(). I think that we could
> use
> > > the
> > > >> > same
> > > >> > > > > config
> > > >> > > > > > >> for
> > > >> > > > > > >> >> > > these method as a default timeout if
> > > >> > > > > > >> >> > > the user does not provide one. On the other
> hand,
> > if
> > > >> they
> > > >> > > > wish
> > > >> > > > > to
> > > >> > > > > > >> >> specify
> > > >> > > > > > >> >> > > a longer or shorter blocking time,
> > > >> > > > > > >> >> > > they have the option of changing the timeout. (I
> > > >> included
> > > >> > > the
> > > >> > > > > > >> config
> > > >> > > > > > >> >> as
> > > >> > > > > > >> >> > an
> > > >> > > > > > >> >> > > alternative in the KIP) WDYT?
> > > >> > > > > > >> >> > >
> > > >> > > > > > >> >> > > Thanks,
> > > >> > > > > > >> >> > > Richard
> > > >> > > > > > >> >> > >
> > > >> > > > > > >> >> > >
> > > >> > > > > > >> >> > > On Fri, Mar 30, 2018 at 1:26 AM, Becket Qin <
> > > >> > > > > > becket.qin@gmail.com>
> > > >> > > > > > >> >> > wrote:
> > > >> > > > > > >> >> > >
> > > >> > > > > > >> >> > >> Glad to see the KIP, Richard. This has been a
> > > really
> > > >> > long
> > > >> > > > > > pending
> > > >> > > > > > >> >> issue.
> > > >> > > > > > >> >> > >>
> > > >> > > > > > >> >> > >> The original arguments from Jay for using
> config,
> > > >> such
> > > >> > as
> > > >> > > > > > >> >> max.block.ms,
> > > >> > > > > > >> >> > >> instead of using timeout parameters was that
> > people
> > > >> will
> > > >> > > > > always
> > > >> > > > > > >> hard
> > > >> > > > > > >> >> > code
> > > >> > > > > > >> >> > >> the timeout, and the hard coded timeout is
> rarely
> > > >> > correct
> > > >> > > > > > because
> > > >> > > > > > >> it
> > > >> > > > > > >> >> has
> > > >> > > > > > >> >> > >> to
> > > >> > > > > > >> >> > >> consider different scenarios. For example,
> users
> > > may
> > > >> > > receive
> > > >> > > > > > >> timeout
> > > >> > > > > > >> >> > >> exception when the group coordinator moves.
> > Having
> > > a
> > > >> > > > > > configuration
> > > >> > > > > > >> >> with
> > > >> > > > > > >> >> > >> some reasonable default value will make users'
> > life
> > > >> > > easier.
> > > >> > > > > > >> >> > >>
> > > >> > > > > > >> >> > >> That said, in practice, it seems more useful to
> > > have
> > > >> > > timeout
> > > >> > > > > > >> >> parameters.
> > > >> > > > > > >> >> > >> We
> > > >> > > > > > >> >> > >> have seen some library, using the consumers
> > > >> internally,
> > > >> > > > needs
> > > >> > > > > to
> > > >> > > > > > >> >> provide
> > > >> > > > > > >> >> > >> an
> > > >> > > > > > >> >> > >> external flexible timeout interface. Also, user
> > can
> > > >> > easily
> > > >> > > > > hard
> > > >> > > > > > >> code
> > > >> > > > > > >> >> a
> > > >> > > > > > >> >> > >> value to get the same as a config based
> solution.
> > > >> > > > > > >> >> > >>
> > > >> > > > > > >> >> > >> The KIP looks good overall. A few comments:
> > > >> > > > > > >> >> > >>
> > > >> > > > > > >> >> > >> 1. There are a few other blocking methods that
> > are
> > > >> not
> > > >> > > > > included,
> > > >> > > > > > >> e.g.
> > > >> > > > > > >> >> > >> offsetsForTimes(), beginningOffsets(),
> > > endOffsets().
> > > >> Is
> > > >> > > > there
> > > >> > > > > > any
> > > >> > > > > > >> >> > reason?
> > > >> > > > > > >> >> > >>
> > > >> > > > > > >> >> > >> 2. I am wondering can we take the KIP as a
> chance
> > > to
> > > >> > clean
> > > >> > > > up
> > > >> > > > > > our
> > > >> > > > > > >> >> > timeout
> > > >> > > > > > >> >> > >> exception(s)? More specifically, instead of
> > reusing
> > > >> > > > > > >> TimeoutException,
> > > >> > > > > > >> >> > can
> > > >> > > > > > >> >> > >> we introduce a new ClientTimeoutException with
> > > >> different
> > > >> > > > > causes,
> > > >> > > > > > >> e.g.
> > > >> > > > > > >> >> > >> UnknownTopicOrPartition, RequestTimeout,
> > > >> > > LeaderNotAvailable,
> > > >> > > > > > etc.
> > > >> > > > > > >> >> > >> As of now, the TimeoutException is used in the
> > > >> following
> > > >> > > > three
> > > >> > > > > > >> cases:
> > > >> > > > > > >> >> > >>
> > > >> > > > > > >> >> > >> 1. TimeoutException is a subclass of
> > > ApiException
> > > >> > which
> > > >> > > > > > >> indicates
> > > >> > > > > > >> >> the
> > > >> > > > > > >> >> > >> exception was returned by the broker. The
> > > >> > > > TimeoutException
> > > >> > > > > > was
> > > >> > > > > > >> >> > >> initially
> > > >> > > > > > >> >> > >> returned by the leaders when replication was
> > not
> > > >> done
> > > >> > > > > within
> > > >> > > > > > >> the
> > > >> > > > > > >> >> > >> specified
> > > >> > > > > > >> >> > >> timeout in the ProduceRequest. It has an
> error
> > > >> code
> > > >> > of
> > > >> > > 7,
> > > >> > > > > > >> which is
> > > >> > > > > > >> >> > >> returned
> > > >> > > > > > >> >> > >> by the broker.
> > > >> > > > > > >> >> > >> 2. When we migrate to Java clients, in
> Errors
> > > >> > > definition,
> > > >> > > > > we
> > > >> > > > > > >> >> extended
> > > >> > > > > > >> >> > >> it
> > > >> > > > > > >> >> > >> to indicate request timeout, i.e. a request
> > was
> > > >> sent
> > > >> > > but
> > > >> > > > > the
> > > >> > > > > > >> >> response
> > > >> > > > > > >> >> > >> was
> > > >> > > > > > >> >> > >> not received before timeout. In this case,
> the
> > > >> > clients
> > > >> > > > did
> > > >> > > > > > not
> > > >> > > > > > >> >> have a
> > > >> > > > > > >> >> > >> return code from the broker.
> > > >> > > > > > >> >> > >> 3. Later at some point, we started to use
> the
> > > >> > > > > > TimeoutException
> > > >> > > > > > >> for
> > > >> > > > > > >> >> > >> clients method call timeout. It is neither
> > > >> related to
> > > >> > > any
> > > >> > > > > > >> broker
> > > >> > > > > > >> >> > >> returned
> > > >> > > > > > >> >> > >> error code, nor to request timeout on the
> > wire.
> > > >> > > > > > >> >> > >>
> > > >> > > > > > >> >> > >> Due to the various interpretations, users can
> > > easily
> > > >> be
> > > >> > > > > > confused.
> > > >> > > > > > >> As
> > > >> > > > > > >> >> an
> > > >> > > > > > >> >> > >> example, when a timeout is thrown with "Failed
> to
> > > >> > refresh
> > > >> > > > > > metadata
> > > >> > > > > > >> >> in X
> > > >> > > > > > >> >> > >> ms", it is hard to tell what exactly happened.
> > > Since
> > > >> we
> > > >> > > are
> > > >> > > > > > >> changing
> > > >> > > > > > >> >> the
> > > >> > > > > > >> >> > >> API here, it would be good to avoid introducing
> > > more
> > > >> > > > ambiguity
> > > >> > > > > > and
> > > >> > > > > > >> >> see
> > > >> > > > > > >> >> > >> whether this can be improved. It would be at
> > least
> > > >> one
> > > >> > > step
> > > >> > > > > > >> forward
> > > >> > > > > > >> >> to
> > > >> > > > > > >> >> > >> remove the usage of case 3.
> > > >> > > > > > >> >> > >>
> > > >> > > > > > >> >> > >> Thanks,
> > > >> > > > > > >> >> > >>
> > > >> > > > > > >> >> > >> Jiangjie (Becket) Qin
> > > >> > > > > > >> >> > >>
> > > >> > > > > > >> >> > >>
> > > >> > > > > > >> >> > >>
> > > >> > > > > > >> >> > >>
> > > >> > > > > > >> >> > >> On Mon, Mar 26, 2018 at 5:50 PM, Guozhang Wang
> <
> > > >> > > > > > >> wangguoz@gmail.com>
> > > >> > > > > > >> >> > >> wrote:
> > > >> > > > > > >> >> > >>
> > > >> > > > > > >> >> > >> > @Richard: TimeoutException inherits from
> > > >> > > > RetriableException
> > > >> > > > > > >> which
> > > >> > > > > > >> >> > >> inherits
> > > >> > > > > > >> >> > >> > from ApiException. So users should explicitly
> > try
> > > >> to
> > > >> > > > capture
> > > >> > > > > > >> >> > >> > RetriableException in their code and handle
> the
> > > >> > > exception.
> > > >> > > > > > >> >> > >> >
> > > >> > > > > > >> >> > >> > @Isamel, Ewen: I'm trying to push progress
> > > forward
> > > >> on
> > > >> > > this
> > > >> > > > > > one,
> > > >> > > > > > >> >> are we
> > > >> > > > > > >> >> > >> now
> > > >> > > > > > >> >> > >> > on the same page for using function
> parameters
> > > than
> > > >> > > > configs?
> > > >> > > > > > >> >> > >> >
> > > >> > > > > > >> >> > >> >
> > > >> > > > > > >> >> > >> > Guozhang
> > > >> > > > > > >> >> > >> >
> > > >> > > > > > >> >> > >> >
> > > >> > > > > > >> >> > >> > On Fri, Mar 23, 2018 at 4:42 PM, Ismael Juma
> <
> > > >> > > > > > ismael@juma.me.uk
> > > >> > > > > > >> >
> > > >> > > > > > >> >> > wrote:
> > > >> > > > > > >> >> > >> >
> > > >> > > > > > >> >> > >> > > Hi Ewen,
> > > >> > > > > > >> >> > >> > >
> > > >> > > > > > >> >> > >> > > Yeah, I mentioned KAFKA-2391 where some of
> > this
> > > >> was
> > > >> > > > > > discussed.
> > > >> > > > > > >> >> Jay
> > > >> > > > > > >> >> > was
> > > >> > > > > > >> >> > >> > > against having timeouts in the methods at
> the
> > > >> time.
> > > >> > > > > However,
> > > >> > > > > > >> as
> > > >> > > > > > >> >> > Jason
> > > >> > > > > > >> >> > >> > said
> > > >> > > > > > >> >> > >> > > offline, we did end up with a timeout
> > parameter
> > > >> in
> > > >> > > > `poll`.
> > > >> > > > > > >> >> > >> > >
> > > >> > > > > > >> >> > >> > > Ismael
> > > >> > > > > > >> >> > >> > >
> > > >> > > > > > >> >> > >> > > On Fri, Mar 23, 2018 at 4:26 PM, Ewen
> > > >> > > Cheslack-Postava <
> > > >> > > > > > >> >> > >> > ewen@confluent.io>
> > > >> > > > > > >> >> > >> > > wrote:
> > > >> > > > > > >> >> > >> > >
> > > >> > > > > > >> >> > >> > > > Regarding the flexibility question, has
> > > someone
> > > >> > > tried
> > > >> > > > to
> > > >> > > > > > >> dig up
> > > >> > > > > > >> >> > the
> > > >> > > > > > >> >> > >> > > > discussion of the new consumer APIs when
> > they
> > > >> were
> > > >> > > > being
> > > >> > > > > > >> >> written?
> > > >> > > > > > >> >> > I
> > > >> > > > > > >> >> > >> > > vaguely
> > > >> > > > > > >> >> > >> > > > recall these exact questions about using
> > APIs
> > > >> vs
> > > >> > > > configs
> > > >> > > > > > and
> > > >> > > > > > >> >> > >> > flexibility
> > > >> > > > > > >> >> > >> > > vs
> > > >> > > > > > >> >> > >> > > > bloating the API surface area having
> > already
> > > >> been
> > > >> > > > > > discussed.
> > > >> > > > > > >> >> (Not
> > > >> > > > > > >> >> > >> that
> > > >> > > > > > >> >> > >> > we
> > > >> > > > > > >> >> > >> > > > shouldn't revisit, just that it might
> also
> > > be a
> > > >> > > faster
> > > >> > > > > way
> > > >> > > > > > >> to
> > > >> > > > > > >> >> get
> > > >> > > > > > >> >> > >> to a
> > > >> > > > > > >> >> > >> > > full
> > > >> > > > > > >> >> > >> > > > understanding of the options, concerns,
> and
> > > >> > > > tradeoffs).
> > > >> > > > > > >> >> > >> > > >
> > > >> > > > > > >> >> > >> > > > -Ewen
> > > >> > > > > > >> >> > >> > > >
> > > >> > > > > > >> >> > >> > > > On Thu, Mar 22, 2018 at 7:19 AM, Richard
> > Yu <
> > > >> > > > > > >> >> > >> > yohan.richard.yu@gmail.com>
> > > >> > > > > > >> >> > >> > > > wrote:
> > > >> > > > > > >> >> > >> > > >
> > > >> > > > > > >> >> > >> > > > > I do have one question though: in the
> > > current
> > > >> > KIP,
> > > >> > > > > > >> throwing
> > > >> > > > > > >> >> > >> > > > > TimeoutException to mark
> > > >> > > > > > >> >> > >> > > > > that time limit is exceeded is applied
> to
> > > all
> > > >> > new
> > > >> > > > > > methods
> > > >> > > > > > >> >> > >> introduced
> > > >> > > > > > >> >> > >> > in
> > > >> > > > > > >> >> > >> > > > > this proposal.
> > > >> > > > > > >> >> > >> > > > > However, how would users respond when a
> > > >> > > > > TimeoutException
> > > >> > > > > > >> >> (since
> > > >> > > > > > >> >> > >> it is
> > > >> > > > > > >> >> > >> > > > > considered
> > > >> > > > > > >> >> > >> > > > > a RuntimeException)?
> > > >> > > > > > >> >> > >> > > > >
> > > >> > > > > > >> >> > >> > > > > Thanks,
> > > >> > > > > > >> >> > >> > > > > Richard
> > > >> > > > > > >> >> > >> > > > >
> > > >> > > > > > >> >> > >> > > > >
> > > >> > > > > > >> >> > >> > > > >
> > > >> > > > > > >> >> > >> > > > > On Mon, Mar 19, 2018 at 6:10 PM,
> Richard
> > > Yu <
> > > >> > > > > > >> >> > >> > > yohan.richard.yu@gmail.com>
> > > >> > > > > > >> >> > >> > > > > wrote:
> > > >> > > > > > >> >> > >> > > > >
> > > >> > > > > > >> >> > >> > > > > > Hi Ismael,
> > > >> > > > > > >> >> > >> > > > > >
> > > >> > > > > > >> >> > >> > > > > > You have a great point. Since most of
> > the
> > > >> > > methods
> > > >> > > > in
> > > >> > > > > > >> this
> > > >> > > > > > >> >> KIP
> > > >> > > > > > >> >> > >> have
> > > >> > > > > > >> >> > >> > > > > similar
> > > >> > > > > > >> >> > >> > > > > > callbacks (position() and committed()
> > > both
> > > >> use
> > > >> > > > > > >> >> > >> > > fetchCommittedOffsets(),
> > > >> > > > > > >> >> > >> > > > > > and
> > > >> > > > > > >> >> > >> > > > > > commitSync() is similar to
> position(),
> > > >> except
> > > >> > > just
> > > >> > > > > > >> updating
> > > >> > > > > > >> >> > >> > offsets),
> > > >> > > > > > >> >> > >> > > > the
> > > >> > > > > > >> >> > >> > > > > > amount of time
> > > >> > > > > > >> >> > >> > > > > > they block should be also about
> equal.
> > > >> > > > > > >> >> > >> > > > > >
> > > >> > > > > > >> >> > >> > > > > > However, I think that we need to take
> > > into
> > > >> > > > account a
> > > >> > > > > > >> >> couple of
> > > >> > > > > > >> >> > >> > > things.
> > > >> > > > > > >> >> > >> > > > > For
> > > >> > > > > > >> >> > >> > > > > > starters,
> > > >> > > > > > >> >> > >> > > > > > if the new methods were all reliant
> on
> > > one
> > > >> > > config,
> > > >> > > > > > >> there is
> > > >> > > > > > >> >> > >> > > likelihood
> > > >> > > > > > >> >> > >> > > > > > that the
> > > >> > > > > > >> >> > >> > > > > > shortcomings for this approach would
> be
> > > >> > similar
> > > >> > > to
> > > >> > > > > > what
> > > >> > > > > > >> we
> > > >> > > > > > >> >> > >> faced if
> > > >> > > > > > >> >> > >> > > we
> > > >> > > > > > >> >> > >> > > > > let
> > > >> > > > > > >> >> > >> > > > > > request.timeout.ms control all
> method
> > > >> > timeouts.
> > > >> > > > In
> > > >> > > > > > >> >> > comparison,
> > > >> > > > > > >> >> > >> > > adding
> > > >> > > > > > >> >> > >> > > > > > overloads
> > > >> > > > > > >> >> > >> > > > > > does not have this problem.
> > > >> > > > > > >> >> > >> > > > > >
> > > >> > > > > > >> >> > >> > > > > > If you have further thoughts, please
> > let
> > > me
> > > >> > > know.
> > > >> > > > > > >> >> > >> > > > > >
> > > >> > > > > > >> >> > >> > > > > > Richard
> > > >> > > > > > >> >> > >> > > > > >
> > > >> > > > > > >> >> > >> > > > > >
> > > >> > > > > > >> >> > >> > > > > > On Mon, Mar 19, 2018 at 5:12 PM,
> Ismael
> > > >> Juma <
> > > >> > > > > > >> >> > ismael@juma.me.uk
> > > >> > > > > > >> >> > >> >
> > > >> > > > > > >> >> > >> > > > wrote:
> > > >> > > > > > >> >> > >> > > > > >
> > > >> > > > > > >> >> > >> > > > > >> Hi,
> > > >> > > > > > >> >> > >> > > > > >>
> > > >> > > > > > >> >> > >> > > > > >> An option that is not currently
> > covered
> > > in
> > > >> > the
> > > >> > > > KIP
> > > >> > > > > is
> > > >> > > > > > >> to
> > > >> > > > > > >> >> > have a
> > > >> > > > > > >> >> > >> > > > separate
> > > >> > > > > > >> >> > >> > > > > >> config max.block.ms, which is
> similar
> > > to
> > > >> the
> > > >> > > > > > producer
> > > >> > > > > > >> >> config
> > > >> > > > > > >> >> > >> with
> > > >> > > > > > >> >> > >> > > the
> > > >> > > > > > >> >> > >> > > > > >> same
> > > >> > > > > > >> >> > >> > > > > >> name. This came up during the
> > KAFKA-2391
> > > >> > > > > discussion.
> > > >> > > > > > I
> > > >> > > > > > >> >> think
> > > >> > > > > > >> >> > >> it's
> > > >> > > > > > >> >> > >> > > > clear
> > > >> > > > > > >> >> > >> > > > > >> that we can't rely on
> > > request.timeout.ms,
> > > >> so
> > > >> > > the
> > > >> > > > > > >> >> decision is
> > > >> > > > > > >> >> > >> > > between
> > > >> > > > > > >> >> > >> > > > > >> adding
> > > >> > > > > > >> >> > >> > > > > >> overloads or adding a new config.
> > People
> > > >> > seemed
> > > >> > > > to
> > > >> > > > > be
> > > >> > > > > > >> >> leaning
> > > >> > > > > > >> >> > >> > > towards
> > > >> > > > > > >> >> > >> > > > > the
> > > >> > > > > > >> >> > >> > > > > >> latter in KAFKA-2391, but Jason
> makes
> > a
> > > >> good
> > > >> > > > point
> > > >> > > > > > that
> > > >> > > > > > >> >> the
> > > >> > > > > > >> >> > >> > > overloads
> > > >> > > > > > >> >> > >> > > > > are
> > > >> > > > > > >> >> > >> > > > > >> more flexible. A couple of questions
> > > from
> > > >> me:
> > > >> > > > > > >> >> > >> > > > > >>
> > > >> > > > > > >> >> > >> > > > > >> 1. Do we need the additional
> > > flexibility?
> > > >> > > > > > >> >> > >> > > > > >> 2. If we do, do we need it for every
> > > >> blocking
> > > >> > > > > method?
> > > >> > > > > > >> >> > >> > > > > >>
> > > >> > > > > > >> >> > >> > > > > >> Ismael
> > > >> > > > > > >> >> > >> > > > > >>
> > > >> > > > > > >> >> > >> > > > > >> On Mon, Mar 19, 2018 at 5:03 PM,
> > Richard
> > > >> Yu <
> > > >> > > > > > >> >> > >> > > > yohan.richard.yu@gmail.com
> > > >> > > > > > >> >> > >> > > > > >
> > > >> > > > > > >> >> > >> > > > > >> wrote:
> > > >> > > > > > >> >> > >> > > > > >>
> > > >> > > > > > >> >> > >> > > > > >> > Hi Guozhang,
> > > >> > > > > > >> >> > >> > > > > >> >
> > > >> > > > > > >> >> > >> > > > > >> > I made some clarifications to
> > KIP-266,
> > > >> > > namely:
> > > >> > > > > > >> >> > >> > > > > >> > 1. Stated more specifically that
> > > >> commitSync
> > > >> > > > will
> > > >> > > > > > >> accept
> > > >> > > > > > >> >> > user
> > > >> > > > > > >> >> > >> > > input.
> > > >> > > > > > >> >> > >> > > > > >> > 2. fetchCommittedOffsets(): Made
> its
> > > >> role
> > > >> > in
> > > >> > > > > > blocking
> > > >> > > > > > >> >> more
> > > >> > > > > > >> >> > >> clear
> > > >> > > > > > >> >> > >> > > to
> > > >> > > > > > >> >> > >> > > > > the
> > > >> > > > > > >> >> > >> > > > > >> > reader.
> > > >> > > > > > >> >> > >> > > > > >> > 3. Sketched what would happen when
> > > time
> > > >> > limit
> > > >> > > > is
> > > >> > > > > > >> >> exceeded.
> > > >> > > > > > >> >> > >> > > > > >> >
> > > >> > > > > > >> >> > >> > > > > >> > These changes should make the KIP
> > > >> easier to
> > > >> > > > > > >> understand.
> > > >> > > > > > >> >> > >> > > > > >> >
> > > >> > > > > > >> >> > >> > > > > >> > Cheers,
> > > >> > > > > > >> >> > >> > > > > >> > Richard
> > > >> > > > > > >> >> > >> > > > > >> >
> > > >> > > > > > >> >> > >> > > > > >> > On Mon, Mar 19, 2018 at 9:33 AM,
> > > >> Guozhang
> > > >> > > Wang
> > > >> > > > <
> > > >> > > > > > >> >> > >> > > wangguoz@gmail.com>
> > > >> > > > > > >> >> > >> > > > > >> wrote:
> > > >> > > > > > >> >> > >> > > > > >> >
> > > >> > > > > > >> >> > >> > > > > >> > > Hi Richard,
> > > >> > > > > > >> >> > >> > > > > >> > >
> > > >> > > > > > >> >> > >> > > > > >> > > I made a pass over the KIP
> again,
> > > some
> > > >> > more
> > > >> > > > > > >> >> > clarifications
> > > >> > > > > > >> >> > >> /
> > > >> > > > > > >> >> > >> > > > > comments:
> > > >> > > > > > >> >> > >> > > > > >> > >
> > > >> > > > > > >> >> > >> > > > > >> > > 1. seek() call itself is not
> > > blocking,
> > > >> > only
> > > >> > > > the
> > > >> > > > > > >> >> following
> > > >> > > > > > >> >> > >> > poll()
> > > >> > > > > > >> >> > >> > > > > call
> > > >> > > > > > >> >> > >> > > > > >> may
> > > >> > > > > > >> >> > >> > > > > >> > > be blocking as the actually
> > metadata
> > > >> rq
> > > >> > > will
> > > >> > > > > > >> happen.
> > > >> > > > > > >> >> > >> > > > > >> > >
> > > >> > > > > > >> >> > >> > > > > >> > > 2. I saw you did not include
> > > >> > > > > > >> Consumer.partitionFor(),
> > > >> > > > > > >> >> > >> > > > > >> > > Consumer.OffsetAndTimestamp()
> and
> > > >> > > > > > >> >> Consumer.listTopics()
> > > >> > > > > > >> >> > in
> > > >> > > > > > >> >> > >> > your
> > > >> > > > > > >> >> > >> > > > KIP.
> > > >> > > > > > >> >> > >> > > > > >> > After
> > > >> > > > > > >> >> > >> > > > > >> > > a second thought, I think this
> may
> > > be
> > > >> a
> > > >> > > > better
> > > >> > > > > > >> idea to
> > > >> > > > > > >> >> > not
> > > >> > > > > > >> >> > >> > > tackle
> > > >> > > > > > >> >> > >> > > > > >> them in
> > > >> > > > > > >> >> > >> > > > > >> > > the same KIP, and probably we
> > should
> > > >> > > consider
> > > >> > > > > > >> whether
> > > >> > > > > > >> >> we
> > > >> > > > > > >> >> > >> would
> > > >> > > > > > >> >> > >> > > > > change
> > > >> > > > > > >> >> > >> > > > > >> the
> > > >> > > > > > >> >> > >> > > > > >> > > behavior or not in another
> > > discussion.
> > > >> > So I
> > > >> > > > > agree
> > > >> > > > > > >> to
> > > >> > > > > > >> >> not
> > > >> > > > > > >> >> > >> > include
> > > >> > > > > > >> >> > >> > > > > them.
> > > >> > > > > > >> >> > >> > > > > >> > >
> > > >> > > > > > >> >> > >> > > > > >> > > 3. In your wiki you mentioned
> > > "Another
> > > >> > > change
> > > >> > > > > > >> shall be
> > > >> > > > > > >> >> > >> made to
> > > >> > > > > > >> >> > >> > > > > >> > > KafkaConsumer#poll(), due to its
> > > call
> > > >> to
> > > >> > > > > > >> >> > >> > updateFetchPositions()
> > > >> > > > > > >> >> > >> > > > > which
> > > >> > > > > > >> >> > >> > > > > >> > > blocks indefinitely." This part
> > may
> > > a
> > > >> bit
> > > >> > > > > obscure
> > > >> > > > > > >> to
> > > >> > > > > > >> >> most
> > > >> > > > > > >> >> > >> > > readers
> > > >> > > > > > >> >> > >> > > > > >> who's
> > > >> > > > > > >> >> > >> > > > > >> > not
> > > >> > > > > > >> >> > >> > > > > >> > > familiar with the KafkaConsumer
> > > >> > internals,
> > > >> > > > > could
> > > >> > > > > > >> you
> > > >> > > > > > >> >> > please
> > > >> > > > > > >> >> > >> > add
> > > >> > > > > > >> >> > >> > > > more
> > > >> > > > > > >> >> > >> > > > > >> > > elaborations. More
> specifically, I
> > > >> think
> > > >> > > the
> > > >> > > > > root
> > > >> > > > > > >> >> causes
> > > >> > > > > > >> >> > of
> > > >> > > > > > >> >> > >> > the
> > > >> > > > > > >> >> > >> > > > > public
> > > >> > > > > > >> >> > >> > > > > >> > APIs
> > > >> > > > > > >> >> > >> > > > > >> > > mentioned are a bit different
> > while
> > > >> the
> > > >> > > KIP's
> > > >> > > > > > >> >> explanation
> > > >> > > > > > >> >> > >> > sounds
> > > >> > > > > > >> >> > >> > > > > like
> > > >> > > > > > >> >> > >> > > > > >> > they
> > > >> > > > > > >> >> > >> > > > > >> > > are due to the same reason:
> > > >> > > > > > >> >> > >> > > > > >> > >
> > > >> > > > > > >> >> > >> > > > > >> > > 3.1 fetchCommittedOffsets():
> this
> > > >> > internal
> > > >> > > > call
> > > >> > > > > > >> will
> > > >> > > > > > >> >> > block
> > > >> > > > > > >> >> > >> > > forever
> > > >> > > > > > >> >> > >> > > > > if
> > > >> > > > > > >> >> > >> > > > > >> the
> > > >> > > > > > >> >> > >> > > > > >> > > committed offsets cannot be
> > fetched
> > > >> > > > > successfully
> > > >> > > > > > >> and
> > > >> > > > > > >> >> > affect
> > > >> > > > > > >> >> > >> > > > > position()
> > > >> > > > > > >> >> > >> > > > > >> > and
> > > >> > > > > > >> >> > >> > > > > >> > > committed(). We need to break
> out
> > of
> > > >> its
> > > >> > > > > internal
> > > >> > > > > > >> >> while
> > > >> > > > > > >> >> > >> loop.
> > > >> > > > > > >> >> > >> > > > > >> > > 3.2 position() itself will while
> > > loop
> > > >> > when
> > > >> > > > > > offsets
> > > >> > > > > > >> >> cannot
> > > >> > > > > > >> >> > >> be
> > > >> > > > > > >> >> > >> > > > > >> retrieved in
> > > >> > > > > > >> >> > >> > > > > >> > > the underlying async call. We
> need
> > > to
> > > >> > break
> > > >> > > > out
> > > >> > > > > > >> this
> > > >> > > > > > >> >> > while
> > > >> > > > > > >> >> > >> > loop.
> > > >> > > > > > >> >> > >> > > > > >> > > 3.3 commitSync() passed
> > > >> Long.MAX_VALUE as
> > > >> > > the
> > > >> > > > > > >> timeout
> > > >> > > > > > >> >> > >> value,
> > > >> > > > > > >> >> > >> > we
> > > >> > > > > > >> >> > >> > > > > should
> > > >> > > > > > >> >> > >> > > > > >> > take
> > > >> > > > > > >> >> > >> > > > > >> > > the user specified timeouts when
> > > >> > > applicable.
> > > >> > > > > > >> >> > >> > > > > >> > >
> > > >> > > > > > >> >> > >> > > > > >> > >
> > > >> > > > > > >> >> > >> > > > > >> > >
> > > >> > > > > > >> >> > >> > > > > >> > > Guozhang
> > > >> > > > > > >> >> > >> > > > > >> > >
> > > >> > > > > > >> >> > >> > > > > >> > > On Sat, Mar 17, 2018 at 4:44 PM,
> > > >> Richard
> > > >> > > Yu <
> > > >> > > > > > >> >> > >> > > > > >> yohan.richard.yu@gmail.com>
> > > >> > > > > > >> >> > >> > > > > >> > > wrote:
> > > >> > > > > > >> >> > >> > > > > >> > >
> > > >> > > > > > >> >> > >> > > > > >> > > > Actually, what I said above is
> > > >> > > inaccurate.
> > > >> > > > In
> > > >> > > > > > >> >> > >> > > > > >> > > > testSeekAndCommitWithBrokerFai
> > > >> lures,
> > > >> > > > > > >> >> > >> > TestUtils.waitUntilTrue
> > > >> > > > > > >> >> > >> > > > > >> blocks,
> > > >> > > > > > >> >> > >> > > > > >> > not
> > > >> > > > > > >> >> > >> > > > > >> > > > seek.
> > > >> > > > > > >> >> > >> > > > > >> > > > My assumption is that seek did
> > not
> > > >> > update
> > > >> > > > > > >> >> correctly. I
> > > >> > > > > > >> >> > >> will
> > > >> > > > > > >> >> > >> > be
> > > >> > > > > > >> >> > >> > > > > >> digging
> > > >> > > > > > >> >> > >> > > > > >> > > > further into this.
> > > >> > > > > > >> >> > >> > > > > >> > > >
> > > >> > > > > > >> >> > >> > > > > >> > > >
> > > >> > > > > > >> >> > >> > > > > >> > > >
> > > >> > > > > > >> >> > >> > > > > >> > > > On Sat, Mar 17, 2018 at 4:16
> PM,
> > > >> > Richard
> > > >> > > > Yu <
> > > >> > > > > > >> >> > >> > > > > >> > yohan.richard.yu@gmail.com>
> > > >> > > > > > >> >> > >> > > > > >> > > > wrote:
> > > >> > > > > > >> >> > >> > > > > >> > > >
> > > >> > > > > > >> >> > >> > > > > >> > > > > One more thing: when looking
> > > >> through
> > > >> > > > > tests, I
> > > >> > > > > > >> have
> > > >> > > > > > >> >> > >> > realized
> > > >> > > > > > >> >> > >> > > > that
> > > >> > > > > > >> >> > >> > > > > >> > seek()
> > > >> > > > > > >> >> > >> > > > > >> > > > > methods can potentially
> block
> > > >> > > > indefinitely.
> > > >> > > > > > As
> > > >> > > > > > >> you
> > > >> > > > > > >> >> > well
> > > >> > > > > > >> >> > >> > > know,
> > > >> > > > > > >> >> > >> > > > > >> seek()
> > > >> > > > > > >> >> > >> > > > > >> > is
> > > >> > > > > > >> >> > >> > > > > >> > > > > called when pollOnce() or
> > > >> position()
> > > >> > is
> > > >> > > > > > active.
> > > >> > > > > > >> >> Thus,
> > > >> > > > > > >> >> > >> if
> > > >> > > > > > >> >> > >> > > > > >> position()
> > > >> > > > > > >> >> > >> > > > > >> > > > blocks
> > > >> > > > > > >> >> > >> > > > > >> > > > > indefinitely, then so would
> > > >> seek().
> > > >> > > > Should
> > > >> > > > > > >> >> bounding
> > > >> > > > > > >> >> > >> seek()
> > > >> > > > > > >> >> > >> > > > also
> > > >> > > > > > >> >> > >> > > > > be
> > > >> > > > > > >> >> > >> > > > > >> > > > included
> > > >> > > > > > >> >> > >> > > > > >> > > > > in this KIP?
> > > >> > > > > > >> >> > >> > > > > >> > > > >
> > > >> > > > > > >> >> > >> > > > > >> > > > > Thanks, Richard
> > > >> > > > > > >> >> > >> > > > > >> > > > >
> > > >> > > > > > >> >> > >> > > > > >> > > > > On Sat, Mar 17, 2018 at 1:16
> > PM,
> > > >> > > Richard
> > > >> > > > > Yu <
> > > >> > > > > > >> >> > >> > > > > >> > > yohan.richard.yu@gmail.com>
> > > >> > > > > > >> >> > >> > > > > >> > > > > wrote:
> > > >> > > > > > >> >> > >> > > > > >> > > > >
> > > >> > > > > > >> >> > >> > > > > >> > > > >> Thanks for the advice,
> Jason
> > > >> > > > > > >> >> > >> > > > > >> > > > >>
> > > >> > > > > > >> >> > >> > > > > >> > > > >> I have modified KIP-266 to
> > > >> include
> > > >> > the
> > > >> > > > > java
> > > >> > > > > > >> doc
> > > >> > > > > > >> >> for
> > > >> > > > > > >> >> > >> > > > committed()
> > > >> > > > > > >> >> > >> > > > > >> and
> > > >> > > > > > >> >> > >> > > > > >> > > > other
> > > >> > > > > > >> >> > >> > > > > >> > > > >> blocking methods, and I
> also
> > > >> > > > > > >> >> > >> > > > > >> > > > >> mentioned poll() which will
> > > also
> > > >> be
> > > >> > > > > bounded.
> > > >> > > > > > >> Let
> > > >> > > > > > >> >> me
> > > >> > > > > > >> >> > >> know
> > > >> > > > > > >> >> > >> > if
> > > >> > > > > > >> >> > >> > > > > >> there is
> > > >> > > > > > >> >> > >> > > > > >> > > > >> anything else. :)
> > > >> > > > > > >> >> > >> > > > > >> > > > >>
> > > >> > > > > > >> >> > >> > > > > >> > > > >> Sincerely, Richard
> > > >> > > > > > >> >> > >> > > > > >> > > > >>
> > > >> > > > > > >> >> > >> > > > > >> > > > >>
> > > >> > > > > > >> >> > >> > > > > >> > > > >>
> > > >> > > > > > >> >> > >> > > > > >> > > > >>
> > > >> > > > > > >> >> > >> > > > > >> > > > >>
> > > >> > > > > > >> >> > >> > > > > >> > > > >> On Sat, Mar 17, 2018 at
> 12:00
> > > PM,
> > > >> > > Jason
> > > >> > > > > > >> >> Gustafson <
> > > >> > > > > > >> >> > >> > > > > >> > jason@confluent.io
> > > >> > > > > > >> >> > >> > > > > >> > > >
> > > >> > > > > > >> >> > >> > > > > >> > > > >> wrote:
> > > >> > > > > > >> >> > >> > > > > >> > > > >>
> > > >> > > > > > >> >> > >> > > > > >> > > > >>> Hi Richard,
> > > >> > > > > > >> >> > >> > > > > >> > > > >>>
> > > >> > > > > > >> >> > >> > > > > >> > > > >>> Thanks for the updates.
> I'm
> > > >> really
> > > >> > > glad
> > > >> > > > > you
> > > >> > > > > > >> >> picked
> > > >> > > > > > >> >> > >> this
> > > >> > > > > > >> >> > >> > > up.
> > > >> > > > > > >> >> > >> > > > A
> > > >> > > > > > >> >> > >> > > > > >> > couple
> > > >> > > > > > >> >> > >> > > > > >> > > > >>> minor
> > > >> > > > > > >> >> > >> > > > > >> > > > >>> comments:
> > > >> > > > > > >> >> > >> > > > > >> > > > >>>
> > > >> > > > > > >> >> > >> > > > > >> > > > >>> 1. Can you list the full
> set
> > > of
> > > >> new
> > > >> > > > APIs
> > > >> > > > > > >> >> explicitly
> > > >> > > > > > >> >> > >> in
> > > >> > > > > > >> >> > >> > the
> > > >> > > > > > >> >> > >> > > > > KIP?
> > > >> > > > > > >> >> > >> > > > > >> > > > >>> Currently I
> > > >> > > > > > >> >> > >> > > > > >> > > > >>> only see the javadoc for
> > > >> > > `position()`.
> > > >> > > > > > >> >> > >> > > > > >> > > > >>>
> > > >> > > > > > >> >> > >> > > > > >> > > > >>> 2. We should consider
> adding
> > > >> > > `TimeUnit`
> > > >> > > > > to
> > > >> > > > > > >> the
> > > >> > > > > > >> >> new
> > > >> > > > > > >> >> > >> > methods
> > > >> > > > > > >> >> > >> > > > to
> > > >> > > > > > >> >> > >> > > > > >> avoid
> > > >> > > > > > >> >> > >> > > > > >> > > > unit
> > > >> > > > > > >> >> > >> > > > > >> > > > >>> confusion. I know it's
> > > >> inconsistent
> > > >> > > > with
> > > >> > > > > > the
> > > >> > > > > > >> >> poll()
> > > >> > > > > > >> >> > >> API,
> > > >> > > > > > >> >> > >> > > > but I
> > > >> > > > > > >> >> > >> > > > > >> > think
> > > >> > > > > > >> >> > >> > > > > >> > > it
> > > >> > > > > > >> >> > >> > > > > >> > > > >>> was
> > > >> > > > > > >> >> > >> > > > > >> > > > >>> probably a mistake not to
> > > >> include
> > > >> > it
> > > >> > > > > there,
> > > >> > > > > > >> so
> > > >> > > > > > >> >> > better
> > > >> > > > > > >> >> > >> > not
> > > >> > > > > > >> >> > >> > > to
> > > >> > > > > > >> >> > >> > > > > >> double
> > > >> > > > > > >> >> > >> > > > > >> > > > down
> > > >> > > > > > >> >> > >> > > > > >> > > > >>> on
> > > >> > > > > > >> >> > >> > > > > >> > > > >>> that mistake. And note
> that
> > we
> > > >> do
> > > >> > > > already
> > > >> > > > > > >> have
> > > >> > > > > > >> >> > >> > > `close(long,
> > > >> > > > > > >> >> > >> > > > > >> > > TimeUnit)`.
> > > >> > > > > > >> >> > >> > > > > >> > > > >>>
> > > >> > > > > > >> >> > >> > > > > >> > > > >>> Other than that, I think
> the
> > > >> > current
> > > >> > > > KIP
> > > >> > > > > > >> seems
> > > >> > > > > > >> >> > >> > reasonable.
> > > >> > > > > > >> >> > >> > > > > >> > > > >>>
> > > >> > > > > > >> >> > >> > > > > >> > > > >>> Thanks,
> > > >> > > > > > >> >> > >> > > > > >> > > > >>> Jason
> > > >> > > > > > >> >> > >> > > > > >> > > > >>>
> > > >> > > > > > >> >> > >> > > > > >> > > > >>> On Wed, Mar 14, 2018 at
> 5:00
> > > PM,
> > > >> > > > Richard
> > > >> > > > > > Yu <
> > > >> > > > > > >> >> > >> > > > > >> > > > yohan.richard.yu@gmail.com>
> > > >> > > > > > >> >> > >> > > > > >> > > > >>> wrote:
> > > >> > > > > > >> >> > >> > > > > >> > > > >>>
> > > >> > > > > > >> >> > >> > > > > >> > > > >>> > Note to all: I have
> > included
> > > >> > > bounding
> > > >> > > > > > >> >> > commitSync()
> > > >> > > > > > >> >> > >> and
> > > >> > > > > > >> >> > >> > > > > >> > committed()
> > > >> > > > > > >> >> > >> > > > > >> > > in
> > > >> > > > > > >> >> > >> > > > > >> > > > >>> this
> > > >> > > > > > >> >> > >> > > > > >> > > > >>> > KIP.
> > > >> > > > > > >> >> > >> > > > > >> > > > >>> >
> > > >> > > > > > >> >> > >> > > > > >> > > > >>> > On Sun, Mar 11, 2018 at
> > 5:05
> > > >> PM,
> > > >> > > > > Richard
> > > >> > > > > > >> Yu <
> > > >> > > > > > >> >> > >> > > > > >> > > > >>>
> yohan.richard.yu@gmail.com>
> > > >> > > > > > >> >> > >> > > > > >> > > > >>> > wrote:
> > > >> > > > > > >> >> > >> > > > > >> > > > >>> >
> > > >> > > > > > >> >> > >> > > > > >> > > > >>> > > Hi all,
> > > >> > > > > > >> >> > >> > > > > >> > > > >>> > >
> > > >> > > > > > >> >> > >> > > > > >> > > > >>> > > I updated the KIP
> where
> > > >> > > overloading
> > > >> > > > > > >> >> position()
> > > >> > > > > > >> >> > is
> > > >> > > > > > >> >> > >> > now
> > > >> > > > > > >> >> > >> > > > the
> > > >> > > > > > >> >> > >> > > > > >> > favored
> > > >> > > > > > >> >> > >> > > > > >> > > > >>> > approach.
> > > >> > > > > > >> >> > >> > > > > >> > > > >>> > > Bounding position()
> > using
> > > >> > > > > > >> requestTimeoutMs
> > > >> > > > > > >> >> has
> > > >> > > > > > >> >> > >> been
> > > >> > > > > > >> >> > >> > > > listed
> > > >> > > > > > >> >> > >> > > > > >> as
> > > >> > > > > > >> >> > >> > > > > >> > > > >>> rejected.
> > > >> > > > > > >> >> > >> > > > > >> > > > >>> > >
> > > >> > > > > > >> >> > >> > > > > >> > > > >>> > > Any thoughts?
> > > >> > > > > > >> >> > >> > > > > >> > > > >>> > >
> > > >> > > > > > >> >> > >> > > > > >> > > > >>> > > On Tue, Mar 6, 2018 at
> > > 6:00
> > > >> PM,
> > > >> > > > > > Guozhang
> > > >> > > > > > >> >> Wang <
> > > >> > > > > > >> >> > >> > > > > >> > > wangguoz@gmail.com>
> > > >> > > > > > >> >> > >> > > > > >> > > > >>> > wrote:
> > > >> > > > > > >> >> > >> > > > > >> > > > >>> > >
> > > >> > > > > > >> >> > >> > > > > >> > > > >>> > >> I agree that adding
> the
> > > >> > > overloads
> > > >> > > > is
> > > >> > > > > > >> most
> > > >> > > > > > >> >> > >> flexible.
> > > >> > > > > > >> >> > >> > > But
> > > >> > > > > > >> >> > >> > > > > >> going
> > > >> > > > > > >> >> > >> > > > > >> > > for
> > > >> > > > > > >> >> > >> > > > > >> > > > >>> that
> > > >> > > > > > >> >> > >> > > > > >> > > > >>> > >> direction we'd do
> that
> > > for
> > > >> all
> > > >> > > the
> > > >> > > > > > >> blocking
> > > >> > > > > > >> >> > call
> > > >> > > > > > >> >> > >> > that
> > > >> > > > > > >> >> > >> > > > > I've
> > > >> > > > > > >> >> > >> > > > > >> > > listed
> > > >> > > > > > >> >> > >> > > > > >> > > > >>> above,
> > > >> > > > > > >> >> > >> > > > > >> > > > >>> > >> with this timeout
> value
> > > >> > covering
> > > >> > > > the
> > > >> > > > > > >> >> > end-to-end
> > > >> > > > > > >> >> > >> > > waiting
> > > >> > > > > > >> >> > >> > > > > >> time.
> > > >> > > > > > >> >> > >> > > > > >> > > > >>> > >>
> > > >> > > > > > >> >> > >> > > > > >> > > > >>> > >>
> > > >> > > > > > >> >> > >> > > > > >> > > > >>> > >> Guozhang
> > > >> > > > > > >> >> > >> > > > > >> > > > >>> > >>
> > > >> > > > > > >> >> > >> > > > > >> > > > >>> > >> On Tue, Mar 6, 2018
> at
> > > >> 10:02
> > > >> > AM,
> > > >> > > > Ted
> > > >> > > > > > Yu
> > > >> > > > > > >> <
> > > >> > > > > > >> >> > >> > > > > >> yuzhihong@gmail.com>
> > > >> > > > > > >> >> > >> > > > > >> > > > >>> wrote:
> > > >> > > > > > >> >> > >> > > > > >> > > > >>> > >>
> > > >> > > > > > >> >> > >> > > > > >> > > > >>> > >> > bq. The most
> flexible
> > > >> option
> > > >> > > is
> > > >> > > > to
> > > >> > > > > > add
> > > >> > > > > > >> >> > >> overloads
> > > >> > > > > > >> >> > >> > to
> > > >> > > > > > >> >> > >> > > > the
> > > >> > > > > > >> >> > >> > > > > >> > > consumer
> > > >> > > > > > >> >> > >> > > > > >> > > > >>> > >> >
> > > >> > > > > > >> >> > >> > > > > >> > > > >>> > >> > This option is
> > > flexible.
> > > >> > > > > > >> >> > >> > > > > >> > > > >>> > >> >
> > > >> > > > > > >> >> > >> > > > > >> > > > >>> > >> > Looking at the tail
> > of
> > > >> > > > > SPARK-18057,
> > > >> > > > > > >> Spark
> > > >> > > > > > >> >> > dev
> > > >> > > > > > >> >> > >> > > voiced
> > > >> > > > > > >> >> > >> > > > > the
> > > >> > > > > > >> >> > >> > > > > >> > same
> > > >> > > > > > >> >> > >> > > > > >> > > > >>> choice.
> > > >> > > > > > >> >> > >> > > > > >> > > > >>> > >> >
> > > >> > > > > > >> >> > >> > > > > >> > > > >>> > >> > +1 for adding
> > overload
> > > >> with
> > > >> > > > > timeout
> > > >> > > > > > >> >> > parameter.
> > > >> > > > > > >> >> > >> > > > > >> > > > >>> > >> >
> > > >> > > > > > >> >> > >> > > > > >> > > > >>> > >> > Cheers
> > > >> > > > > > >> >> > >> > > > > >> > > > >>> > >> >
> > > >> > > > > > >> >> > >> > > > > >> > > > >>> > >> > On Mon, Mar 5, 2018
> > at
> > > >> 2:42
> > > >> > > PM,
> > > >> > > > > > Jason
> > > >> > > > > > >> >> > >> Gustafson <
> > > >> > > > > > >> >> > >> > > > > >> > > > >>> jason@confluent.io>
> > > >> > > > > > >> >> > >> > > > > >> > > > >>> > >> > wrote:
> > > >> > > > > > >> >> > >> > > > > >> > > > >>> > >> >
> > > >> > > > > > >> >> > >> > > > > >> > > > >>> > >> > > @Guozhang I
> > probably
> > > >> have
> > > >> > > > > > suggested
> > > >> > > > > > >> all
> > > >> > > > > > >> >> > >> options
> > > >> > > > > > >> >> > >> > > at
> > > >> > > > > > >> >> > >> > > > > some
> > > >> > > > > > >> >> > >> > > > > >> > > point
> > > >> > > > > > >> >> > >> > > > > >> > > > or
> > > >> > > > > > >> >> > >> > > > > >> > > > >>> > >> another,
> > > >> > > > > > >> >> > >> > > > > >> > > > >>> > >> > > including most
> > > >> recently,
> > > >> > the
> > > >> > > > > > current
> > > >> > > > > > >> >> KIP!
> > > >> > > > > > >> >> > I
> > > >> > > > > > >> >> > >> was
> > > >> > > > > > >> >> > >> > > > > >> thinking
> > > >> > > > > > >> >> > >> > > > > >> > > that
> > > >> > > > > > >> >> > >> > > > > >> > > > >>> > >> practically
> > > >> > > > > > >> >> > >> > > > > >> > > > >>> > >> > > speaking, the
> > request
> > > >> > > timeout
> > > >> > > > > > >> defines
> > > >> > > > > > >> >> how
> > > >> > > > > > >> >> > >> long
> > > >> > > > > > >> >> > >> > > the
> > > >> > > > > > >> >> > >> > > > > >> user is
> > > >> > > > > > >> >> > >> > > > > >> > > > >>> willing
> > > >> > > > > > >> >> > >> > > > > >> > > > >>> > to
> > > >> > > > > > >> >> > >> > > > > >> > > > >>> > >> > wait
> > > >> > > > > > >> >> > >> > > > > >> > > > >>> > >> > > for a response.
> The
> > > >> > consumer
> > > >> > > > > > doesn't
> > > >> > > > > > >> >> > really
> > > >> > > > > > >> >> > >> > have
> > > >> > > > > > >> >> > >> > > a
> > > >> > > > > > >> >> > >> > > > > >> complex
> > > >> > > > > > >> >> > >> > > > > >> > > > send
> > > >> > > > > > >> >> > >> > > > > >> > > > >>> > >> process
> > > >> > > > > > >> >> > >> > > > > >> > > > >>> > >> > > like the producer
> > for
> > > >> any
> > > >> > of
> > > >> > > > > these
> > > >> > > > > > >> >> APIs,
> > > >> > > > > > >> >> > so
> > > >> > > > > > >> >> > >> I
> > > >> > > > > > >> >> > >> > > > wasn't
> > > >> > > > > > >> >> > >> > > > > >> sure
> > > >> > > > > > >> >> > >> > > > > >> > > how
> > > >> > > > > > >> >> > >> > > > > >> > > > >>> much
> > > >> > > > > > >> >> > >> > > > > >> > > > >>> > >> > benefit
> > > >> > > > > > >> >> > >> > > > > >> > > > >>> > >> > > there would be
> from
> > > >> having
> > > >> > > > more
> > > >> > > > > > >> >> granular
> > > >> > > > > > >> >> > >> > control
> > > >> > > > > > >> >> > >> > > > over
> > > >> > > > > > >> >> > >> > > > > >> > > timeouts
> > > >> > > > > > >> >> > >> > > > > >> > > > >>> (in
> > > >> > > > > > >> >> > >> > > > > >> > > > >>> > the
> > > >> > > > > > >> >> > >> > > > > >> > > > >>> > >> > end,
> > > >> > > > > > >> >> > >> > > > > >> > > > >>> > >> > > KIP-91 just adds
> a
> > > >> single
> > > >> > > > > timeout
> > > >> > > > > > to
> > > >> > > > > > >> >> > control
> > > >> > > > > > >> >> > >> > the
> > > >> > > > > > >> >> > >> > > > > whole
> > > >> > > > > > >> >> > >> > > > > >> > > send).
> > > >> > > > > > >> >> > >> > > > > >> > > > >>> That
> > > >> > > > > > >> >> > >> > > > > >> > > > >>> > >> said,
> > > >> > > > > > >> >> > >> > > > > >> > > > >>> > >> > it
> > > >> > > > > > >> >> > >> > > > > >> > > > >>> > >> > > might indeed be
> > > better
> > > >> to
> > > >> > > > avoid
> > > >> > > > > > >> >> > overloading
> > > >> > > > > > >> >> > >> the
> > > >> > > > > > >> >> > >> > > > > config
> > > >> > > > > > >> >> > >> > > > > >> as
> > > >> > > > > > >> >> > >> > > > > >> > > you
> > > >> > > > > > >> >> > >> > > > > >> > > > >>> > suggest
> > > >> > > > > > >> >> > >> > > > > >> > > > >>> > >> > since
> > > >> > > > > > >> >> > >> > > > > >> > > > >>> > >> > > at least it
> avoids
> > > >> > > > inconsistency
> > > >> > > > > > >> with
> > > >> > > > > > >> >> the
> > > >> > > > > > >> >> > >> > > > producer's
> > > >> > > > > > >> >> > >> > > > > >> > usage.
> > > >> > > > > > >> >> > >> > > > > >> > > > >>> > >> > >
> > > >> > > > > > >> >> > >> > > > > >> > > > >>> > >> > > The most flexible
> > > >> option
> > > >> > is
> > > >> > > to
> > > >> > > > > add
> > > >> > > > > > >> >> > >> overloads to
> > > >> > > > > > >> >> > >> > > the
> > > >> > > > > > >> >> > >> > > > > >> > consumer
> > > >> > > > > > >> >> > >> > > > > >> > > > so
> > > >> > > > > > >> >> > >> > > > > >> > > > >>> that
> > > >> > > > > > >> >> > >> > > > > >> > > > >>> > >> > users
> > > >> > > > > > >> >> > >> > > > > >> > > > >>> > >> > > can pass the
> > timeout
> > > >> > > directly.
> > > >> > > > > I'm
> > > >> > > > > > >> not
> > > >> > > > > > >> >> > sure
> > > >> > > > > > >> >> > >> if
> > > >> > > > > > >> >> > >> > > that
> > > >> > > > > > >> >> > >> > > > > is
> > > >> > > > > > >> >> > >> > > > > >> > more
> > > >> > > > > > >> >> > >> > > > > >> > > or
> > > >> > > > > > >> >> > >> > > > > >> > > > >>> less
> > > >> > > > > > >> >> > >> > > > > >> > > > >>> > >> > > annoying than a
> new
> > > >> > config,
> > > >> > > > but
> > > >> > > > > > I've
> > > >> > > > > > >> >> found
> > > >> > > > > > >> >> > >> > config
> > > >> > > > > > >> >> > >> > > > > >> > timeouts a
> > > >> > > > > > >> >> > >> > > > > >> > > > >>> little
> > > >> > > > > > >> >> > >> > > > > >> > > > >>> > >> > > constraining in
> > > >> practice.
> > > >> > > For
> > > >> > > > > > >> example,
> > > >> > > > > > >> >> I
> > > >> > > > > > >> >> > >> could
> > > >> > > > > > >> >> > >> > > > > imagine
> > > >> > > > > > >> >> > >> > > > > >> > users
> > > >> > > > > > >> >> > >> > > > > >> > > > >>> wanting
> > > >> > > > > > >> >> > >> > > > > >> > > > >>> > >> to
> > > >> > > > > > >> >> > >> > > > > >> > > > >>> > >> > > wait longer for
> an
> > > >> offset
> > > >> > > > commit
> > > >> > > > > > >> >> operation
> > > >> > > > > > >> >> > >> > than a
> > > >> > > > > > >> >> > >> > > > > >> position
> > > >> > > > > > >> >> > >> > > > > >> > > > >>> lookup;
> > > >> > > > > > >> >> > >> > > > > >> > > > >>> > if
> > > >> > > > > > >> >> > >> > > > > >> > > > >>> > >> the
> > > >> > > > > > >> >> > >> > > > > >> > > > >>> > >> > > latter isn't
> > timely,
> > > >> users
> > > >> > > can
> > > >> > > > > > just
> > > >> > > > > > >> >> pause
> > > >> > > > > > >> >> > >> the
> > > >> > > > > > >> >> > >> > > > > partition
> > > >> > > > > > >> >> > >> > > > > >> > and
> > > >> > > > > > >> >> > >> > > > > >> > > > >>> continue
> > > >> > > > > > >> >> > >> > > > > >> > > > >>> > >> > > fetching on
> others.
> > > If
> > > >> you
> > > >> > > > > cannot
> > > >> > > > > > >> >> commit
> > > >> > > > > > >> >> > >> > offsets,
> > > >> > > > > > >> >> > >> > > > > >> however,
> > > >> > > > > > >> >> > >> > > > > >> > > it
> > > >> > > > > > >> >> > >> > > > > >> > > > >>> might
> > > >> > > > > > >> >> > >> > > > > >> > > > >>> > be
> > > >> > > > > > >> >> > >> > > > > >> > > > >>> > >> > > safer for an
> > > >> application
> > > >> > to
> > > >> > > > wait
> > > >> > > > > > >> >> > >> availability
> > > >> > > > > > >> >> > >> > of
> > > >> > > > > > >> >> > >> > > > the
> > > >> > > > > > >> >> > >> > > > > >> > > > coordinator
> > > >> > > > > > >> >> > >> > > > > >> > > > >>> > than
> > > >> > > > > > >> >> > >> > > > > >> > > > >>> > >> > > continuing.
> > > >> > > > > > >> >> > >> > > > > >> > > > >>> > >> > >
> > > >> > > > > > >> >> > >> > > > > >> > > > >>> > >> > > -Jason
> > > >> > > > > > >> >> > >> > > > > >> > > > >>> > >> > >
> > > >> > > > > > >> >> > >> > > > > >> > > > >>> > >> > > On Sun, Mar 4,
> 2018
> > > at
> > > >> > 10:14
> > > >> > > > PM,
> > > >> > > > > > >> >> Guozhang
> > > >> > > > > > >> >> > >> Wang
> > > >> > > > > > >> >> > >> > <
> > > >> > > > > > >> >> > >> > > > > >> > > > >>> wangguoz@gmail.com>
> > > >> > > > > > >> >> > >> > > > > >> > > > >>> > >> > wrote:
> > > >> > > > > > >> >> > >> > > > > >> > > > >>> > >> > >
> > > >> > > > > > >> >> > >> > > > > >> > > > >>> > >> > > > Hello Richard,
> > > >> > > > > > >> >> > >> > > > > >> > > > >>> > >> > > >
> > > >> > > > > > >> >> > >> > > > > >> > > > >>> > >> > > > Thanks for the
> > > >> proposed
> > > >> > > > KIP. I
> > > >> > > > > > >> have a
> > > >> > > > > > >> >> > >> couple
> > > >> > > > > > >> >> > >> > of
> > > >> > > > > > >> >> > >> > > > > >> general
> > > >> > > > > > >> >> > >> > > > > >> > > > >>> comments:
> > > >> > > > > > >> >> > >> > > > > >> > > > >>> > >> > > >
> > > >> > > > > > >> >> > >> > > > > >> > > > >>> > >> > > > 1. I'm not sure
> > if
> > > >> > > > > piggy-backing
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> > > >> > > > > > >> >> > >> timeout
> > > >> > > > > > >> >> > >> > > > > >> exception
> > > >> > > > > > >> >> > >> > > > > >> > on
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> > > >> > > > > > >> >> > >> > > > > >> > > > >>> > >> > > > existing
> > > >> > requestTimeoutMs
> > > >> > > > > > >> configured
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> > > >> > > > > > >> >> > "
> > > >> > > > > > >> >> > >> > > > > >> > > request.timeout.ms
> > > >> > > > > > >> >> > >> > > > > >> > > > "
> > > >> > > > > > >> >> > >> > > > > >> > > > >>> is a
> > > >> > > > > > >> >> > >> > > > > >> > > > >>> > >> good
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> > > >> > > > > > >> >> > >> applies
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> > > >> > > > > > >> >> > >> > > > > >> > types
> > > >> > > > > > >> >> > >> > > > > >> > > > of
> > > >> > > > > > >> >> > >> > > > > >> > > > >>> > >> requests,
> > > >> > > > > > >> >> > >> > > > > >> > > > >>> > >> > > and
> > > >> > > > > > >> >> > >> > > > > >> > > > >>> > >> > > > 2) using it to
> > > cover
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> > > >> > > > > > >> phases
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> > > >> > > > > > >> >> > an
> > > >> > > > > > >> >> > >> API
> > > >> > > > > > >> >> > >> > > > call,
> > > >> > > > > > >> >> > >> > > > > >> > > > including
> > > >> > > > > > >> >> > >> > > > > >> > > > >>> > >> network
> > > >> > > > > > >> >> > >> > > > > >> > > > >>> > >> > > round
> > > >> > > > > > >> >> > >> > > > > >> > > > >>> > >> > > > trip and
> > potential
> > > >> > > metadata
> > > >> > > > > > >> refresh
> > > >> > > > > > >> >> is
> > > >> > > > > > >> >> > >> shown
> > > >> > > > > > >> >> > >> > to
> > > >> > > > > > >> >> > >> > > > not
> > > >> > > > > > >> >> > >> > > > > >> be a
> > > >> > > > > > >> >> > >> > > > > >> > > > good
> > > >> > > > > > >> >> > >> > > > > >> > > > >>> > idea,
> > > >> > > > > > >> >> > >> > > > > >> > > > >>> > >> as
> > > >> > > > > > >> >> > >> > > > > >> > > > >>> > >> > > > illustrated in
> > > >> KIP-91:
> > > >> > > > > > >> >> > >> > > > > >> > > > >>> > >> > > >
> > > >> > > > > > >> >> > >> > > > > >> > > > >>> > >> > > >
> > > >> > > > > https://cwiki.apache.org/confl
> > > >> > > > > > >> >> > >> > > > > >> uence/display/KAFKA/KIP-
> > > >> > > > > > >> >> > >> > > > > >> > > > >>> > >> > > >
> > > >> > 91+Provide+Intuitive+User+
> > > >> > > > > > >> >> > >> > > > Timeouts+in+The+Producer
> > > >> > > > > > >> >> > >> > > > > >> > > > >>> > >> > > >
> > > >> > > > > > >> >> > >> > > > > >> > > > >>> > >> > > > In fact, I
> think
> > in
> > > >> > > > KAFKA-4879
> > > >> > > > > > >> which
> > > >> > > > > > >> >> is
> > > >> > > > > > >> >> > >> aimed
> > > >> > > > > > >> >> > >> > > for
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> > > >> > > > > > >> >> > >> > > > > >> > same
> > > >> > > > > > >> >> > >> > > > > >> > > > >>> issue
> > > >> > > > > > >> >> > >> > > > > >> > > > >>> > as
> > > >> > > > > > >> >> > >> > > > > >> > > > >>> > >> > > > KAFKA-6608,
> > > >> > > > > > >> >> > >> > > > > >> > > > >>> > >> > > > Jason has
> > suggested
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> > > >> > > use a
> > > >> > > > > new
> > > >> > > > > > >> >> config
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> > > >> > > > > > >> >> > >> > the
> > > >> > > > > > >> >> > >> > > > > API.
> > > >> > > > > > >> >> > >> > > > > >> > Maybe
> > > >> > > > > > >> >> > >> > > > > >> > > > >>> this
> > > >> > > > > > >> >> > >> > > > > >> > > > >>> > >> would
> > > >> > > > > > >> >> > >> > > > > >> > > > >>> > >> > be
> > > >> > > > > > >> >> > >> > > > > >> > > > >>> > >> > > a
> > > >> > > > > > >> >> > >> > > > > >> > > > >>> > >> > > > more intuitive
> > > manner
> > > >> > than
> > > >> > > > > > reusing
> > > >> > > > > > >> >> the
> > > >> > > > > > >> >> > >> > > > > >> > request.timeout.ms
> > > >> > > > > > >> >> > >> > > > > >> > > > >>> config.
> > > >> > > > > > >> >> > >> > > > > >> > > > >>> > >> > > >
> > > >> > > > > > >> >> > >> > > > > >> > > > >>> > >> > > >
> > > >> > > > > > >> >> > >> > > > > >> > > > >>> > >> > > > 2. Besides the
> > > >> > > > > > Consumer.position()
> > > >> > > > > > >> >> call,
> > > >> > > > > > >> >> > >> > there
> > > >> > > > > > >> >> > >> > > > are
> > > >> > > > > > >> >> > >> > > > > a
> > > >> > > > > > >> >> > >> > > > > >> > > couple
> > > >> > > > > > >> >> > >> > > > > >> > > > of
> > > >> > > > > > >> >> > >> > > > > >> > > > >>> > more
> > > >> > > > > > >> >> > >> > > > > >> > > > >>> > >> > > > blocking calls
> > > today
> > > >> > that
> > > >> > > > > could
> > > >> > > > > > >> >> result
> > > >> > > > > > >> >> > in
> > > >> > > > > > >> >> > >> > > > infinite
> > > >> > > > > > >> >> > >> > > > > >> > > blocking:
> > > >> > > > > > >> >> > >> > > > > >> > > > >>> > >> > > >
> > > Consumer.commitSync()
> > > >> > and
> > > >> > > > > > >> >> > >> > Consumer.committed(),
> > > >> > > > > > >> >> > >> > > > > >> should
> > > >> > > > > > >> >> > >> > > > > >> > > they
> > > >> > > > > > >> >> > >> > > > > >> > > > be
> > > >> > > > > > >> >> > >> > > > > >> > > > >>> > >> > considered
> > > >> > > > > > >> >> > >> > > > > >> > > > >>> > >> > > > in this KIP as
> > > well?
> > > >> > > > > > >> >> > >> > > > > >> > > > >>> > >> > > >
> > > >> > > > > > >> >> > >> > > > > >> > > > >>> > >> > > > 3. There are a
> > few
> > > >> other
> > > >> > > > APIs
> > > >> > > > > > that
> > > >> > > > > > >> >> are
> > > >> > > > > > >> >> > >> today
> > > >> > > > > > >> >> > >> > > > > relying
> > > >> > > > > > >> >> > >> > > > > >> on
> > > >> > > > > > >> >> > >> > > > > >> > > > >>> > >> > >
> request.timeout.ms
> > > >> > > > > > >> >> > >> > > > > >> > > > >>> > >> > > > already for
> > > breaking
> > > >> the
> > > >> > > > > > infinite
> > > >> > > > > > >> >> > >> blocking,
> > > >> > > > > > >> >> > >> > > > namely
> > > >> > > > > > >> >> > >> > > > > >> > > > >>> > >> > >
> > > >> Consumer.partitionFor(),
> > > >> > > > > > >> >> > >> > > > > >> > > > >>> > >> > > >
> > > >> > > > Consumer.OffsetAndTimestamp()
> > > >> > > > > > and
> > > >> > > > > > >> >> > >> > > > > >> Consumer.listTopics(),
> > > >> > > > > > >> >> > >> > > > > >> > > if
> > > >> > > > > > >> >> > >> > > > > >> > > > >>> we are
> > > >> > > > > > >> >> > >> > > > > >> > > > >>> > >> > making
> > > >> > > > > > >> >> > >> > > > > >> > > > >>> > >> > > > the other
> > blocking
> > > >> calls
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> > > >> > > > be
> > > >> > > > > > >> >> relying a
> > > >> > > > > > >> >> > >> new
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> > > >> > > > > > >> >> > >> > > > > >> > > > >>> suggested
> > > >> > > > > > >> >> > >> > > > > >> > > > >>> > in
> > > >> > > > > > >> >> > >> > > > > >> > > > >>> > >> 1)
> > > >> > > > > > >> >> > >> > > > > >> > > > >>> > >> > > > above, should
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> > > also
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> > > >> > > > > the
> > > >> > > > > > >> >> > >> semantics of
> > > >> > > > > > >> >> > >> > > > these
> > > >> > > > > > >> >> > >> > > > > >> API
> > > >> > > > > > >> >> > >> > > > > >> > > > >>> functions
> > > >> > > > > > >> >> > >> > > > > >> > > > >>> > >> for
> > > >> > > > > > >> >> > >> > > > > >> > > > >>> > >> > > > consistency?
> > > >> > > > > > >> >> > >> > > > > >> > > > >>> > >> > > >
> > > >> > > > > > >> >> > >> > > > > >> > > > >>> > >> > > >
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> > > >> > > > > > >> >> > >> > > > > >> > > > >>> > >> > > > On Sun, Mar 4,
> > 2018
> > > >> at
> > > >> > > 11:13
> > > >> > > > > AM,
> > > >> > > > > > >> >> Richard
> > > >> > > > > > >> >> > >> Yu <
> > > >> > > > > > >> >> > >> > > > > >> > > > >>> > >> >
> > > >> yohan.richard.yu@gmail.com>
> > > >> > > > > > >> >> > >> > > > > >> > > > >>> > >> > > > wrote:
> > > >> > > > > > >> >> > >> > > > > >> > > > >>> > >> > > >
> > > >> > > > > > >> >> > >> > > > > >> > > > >>> > >> > > > > Hi all,
> > > >> > > > > > >> >> > >> > > > > >> > > > >>> > >> > > > >
> > > >> > > > > > >> >> > >> > > > > >> > > > >>> > >> > > > > I would like
> to
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> > > >> > > > > > >> potential
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> > > >> > > > > > >> >> > >> > > > which
> > > >> > > > > > >> >> > >> > > > > >> would
> > > >> > > > > > >> >> > >> > > > > >> > > be
> > > >> > > > > > >> >> > >> > > > > >> > > > >>> made
> > > >> > > > > > >> >> > >> > > > > >> > > > >>> > to
> > > >> > > > > > >> >> > >> > > > > >> > > > >>> > >> > > > >
> KafkaConsumer:
> > > >> > > > > > >> >> > >> > > > > >> > > > >>> > >> > > > >
> > > >> > > https://cwiki.apache.org/
> > > >> > > > > > >> >> > >> > > > > confluence/pages/viewpage
> > > >> > > > > > >> >> > >> > > > > >> .
> > > >> > > > > > >> >> > >> > > > > >> > > > >>> > >> > > >
> > > >> action?pageId=75974886
> > > >> > > > > > >> >> > >> > > > > >> > > > >>> > >> > > > >
> > > >> > > > > > >> >> > >> > > > > >> > > > >>> > >> > > > > Thanks,
> > > >> > > > > > >> >> > >> > > > > >> > > > >>> > >> > > > > Richard Yu
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