For 1), the current design allow you to do it. The customizable message
handler takes in a ConsumerRecord and spit a List<ProducerRecord>, you can
just put a topic for the ProducerRecord different from ConsumerRecord.
WRT performance, we did some test in LinkedIn, the performance looks good
to us.
Jiangjie (Becket) Qin
On 2/25/15, 3:41 PM, "Bhavesh Mistry" <mistry.p.bhav...@gmail.com> wrote:
>Hi Jiangjie,
>
>It might be too late. But, I wanted to bring-up following use case for
>adopting new MM:
>
>1) Ability to publish message from src topic to different destination
>topic
>via --overidenTopics=srcTopic:newDestinationTopic
>
>In order to adopt, new MM enhancement customer will compare performance of
>new MM and data quality while running old MM against same destination
>cluster in Prod.
>
>Let me know if you agree to that or not. Also, If yes, will be able to
>able to provide this feature in release version.
>
>Thanks,
>
>Bhavesh
>
>
>On Tue, Feb 24, 2015 at 5:31 PM, Jiangjie Qin <j...@linkedin.com.invalid>
>wrote:
>
>> Sure! Just created the voting thread :)
>>
>> On 2/24/5, 4:44 PM, "Jay Kreps" <j...@confluent.io> wrote:
>>
>> >Hey Jiangjie,
>> >
>> >Let's do an official vote so that we know what we are voting on and we
>>are
>> >crisp on what the outcome was. This thread is very long :-
>> >
>> >-Jay
>> >
>> >On Tue, Feb 24, 2015 at 2:53 PM, Jiangjie Qin
>><j...@linkedin.com.invalid>
>> >wrote:
>> >
>> >> I updated the KIP page based on the discussion we had.
>> >>
>> >> Should I launch another vote or we can think of this mail thread has
>> >> already included a vote?
>> >>
>> >> Jiangjie (Becket) Qin
>> >>
>> >> On 2/11/15, 5:15 PM, "Neha Nakhede" <n...@confluent.io> wrote:
>> >>
>> >> >Thanks for the explanation, Joel! Would love to see the results of
>>the
>> >> >throughput experiment and I'm a +1 on everything els, ncluding the
>> >> >rebalance callback and record handler.
>> >> >
>> >> >-Neha
>> >> >
>> >> >On Wed, Feb 11, 2015 at 1:13 PM Jay Kreps <jay.kr...@gmail.com>
>>wrote:
>> >> >
>> >> >> Cool, I agree with all that.
>> >> >>
>> >> >> I agree about the need for a rebalancing callback.
>> >> >>
>> >> >> Totally agree about record handler.
> >> >>
>> >> >> It would be great to see if a prototype of this is workable.
>> >> >>
>> >> >> Thanks guys!
>> >> >>
>> >> >> -Jay
>> >> >>
>> >> >> On Wed, Feb 11, 2015 at 12:36 PM, Joel Koshy <jjkosh...@gmail.com>
>> >> >>wrote:
>> >> >>
>> >> >> > Hey Jay,
>> >> >> >
>> >> >> > Guozhang, Becket and I got together to discus this and we
>>think:
>> >> >> >
>> >> >> > - It seems that your proposal based on the new consumr and flush
>> >>call
>> >> >> > should work.
>> >> >> > - We would likely need to call the poll with a timeout that
>>matches
>> >> >> > the offset commit interval in ordr to deal with low volume
>> >> >> > mirroring pipelines.
>> >> >> > - We will still need a rebalnce callback to reduce duplicates -
>> >>the
>> >> >> > rebalance callback would need to flush and commit offsets.
>> >> >> > - The only remaining question is if the overall throughput is
>> >> >> > sufficient. I think someone at LinkedIn (I don't remember who)
>> >>did
>> >> >> > some experiments with data channel size == 1 and ran into
>>issues.
>> >> >> > That was not thoroughly investigated though.
>> >> >> > - The addition of flush may actually make this solution viable
>>for
>> >>the
>> >> >> > current mirror-maker (wih the old consumer). We can prototype
>> >>that
>> >> >> > offline and if it works out well we can redo KAFKA-1650 (i.e.,
>> >> >> > refactor the current mirror maker). The flush call and the new
>> >> >> > consumer didn't exist at the time we did KAFKA-1650 so this
>>did
>> >>not
>> >> >> > occur to us.
>> >> >> > - We think the RecordHandler is still a useful small addition
>>for
>> >>the
>> >> >> > use-cases mentioned earlier in this thread.
>> >> >> >
>> >> >> > Thanks,
>> >> >> >
>> >> >> > Joel
>> >> >> >
>> >> >> > On Wed, Feb 11, 2015 at 09:05:39AM -0800, Jay Kreps wrote:
>> >> >> > > Guozhang, I agree with 1-3, I do think what I was proposing
>>was
>> >> >>simpler
>> >> >> > but
>> >> >> > > perhaps there re gaps in that?
>> >> >> > >
>> >> >> > > Hey Joel--Here was a sketch of what I was proposing. I do
>>think
>> >>this
>> >> >> > get's
>> >> >> > > rid of manual offset tracking, espcially doing so across
>>threads
>> >> >>with
>> >> >> > > dedicated commit threads, which I think is prety complex.
>> >> >> > >
>> >> >> > > while(true) {
>> >> >> > > val recs = consumer.poll(Long.MaxValue);
>> >> >> > > for (rec <- recs)
>> >> >> > > producer.snd(rec, logErrorCallback)
>> >> >> > > if(System.currentTimeMillis - lastCommit >
>>commitInterval) {
>> >> >> > > producer.flush()
>> >> >> > > consumer.commit()
>> >> >> > > lastCommit = System.currentTimeMillis
>> >> >> > > }
>> >> >> > > }
>> >> >> > >
>> >> >> > > (See the previous email for details). I think the question
>>is: is
>> >> >>there
>> >> >> > any
>> >> >> > > reason--performance, correctness, etc--that this won't work?
>> >> >>Basically
>> >> >> I
>> >> >> > > think you guys have thought about this more so I may be
>>missing
>> > >> > something.
>> >> >> > > If so let's flag it while we still have leeway on the
>>consumer.
>> >> >> > >
>> >> >> > > If we think that will work, well I do think it is
>>conceptually a
>> >>lot
>> >> >> > > simpler than the current code, though I suppose one could
>> >>disagree
>> >> >>on
>> >> >> > that.
>> >> >> > >
>> >> >> > > -Jay
>> >> >> > >
>> >> >> > > On Wed, Feb 11, 2015 at 5:53 AM, Joel Koshy
>><jjkosh...@gmail.com
>> >
>> >> >> wrote:
>> >> >> > >
>> >> >> > > > Hi Jay,
>> >> >> > > >
>> >> >> > > > > The data channels are actually a big part of the
>>complexity
>> >>of
>> >> >>the
>> >> >> > zero
>> >> >> > > > > data loss design, though, right? Because then you need
>>ome
>> >> >>reverse
>> >> >> > > > channel
>> >> >> > > > > to flo the acks back to the consumer based on where you
>>are
>> >> >>versus
>> >> >> > just
>> >> >> > > > > acking what you have read and written (as in the code
>> >>snippet I
>> >> >>put
>> >> >> > up).
>> >> >> > > >
>> >> >> > > > I'm not sure if we are on the same page. Even if the data
>> >>channel
>> >> >>was
>> >> >> > > > not there the current handling fr zero data loss would
>>remain
>> >> >>very
>> >> >> > > > similar - you would need to maintain lists of unacked source
>> >> >>offsets.
>> >> >> > > > I'm wondering if the KIP needs more detail on how it is
>> >>currently
>> >> >> > > > implemented; or are suggesting a different approach (in
>>which
>> >> >>case I
>> >> >> > > > have not fully understood). I'm not sure whatyou mean by
>> >>flowing
>> >> >> acks
>> >> >> > > > back to the consumer - the MM commits offsets after the
>> >>producer
>> >> >>ack
>> >> >> > > > has been received. There is some additional complexity
>> >>introduced
>> >> >>in
>> >> >> > > > reducing duplicates on a rebalance - this is actually
>>optional
>> >> >>(since
>> >> >> > > > duplicates are currently a given). The reason that was done
>> >> >>anyway is
>> >> >> > > > that with the auto-commit turned off duplicates are almost
>> >> >>guaranteed
>> >> >> > > > on a rebalance.
>> >> >> > > >
>> >> >> > > > > I think the point that Neha and I were trying to make was
>> >>that
>> >> >>the
>> >> >> > > > > motivation to embed stuff into MM kind of is related to
>>how
>> >> >> complex a
>> >> >> > > > > simple "consume and prouce" with good throughput will
>>be. If
>> >> >>it is
>> >> >> > > > simple
>> >> >> > > > > to write such a thing in a few lines, the pain of
>>embedding a
>> >> >>bunch
>> >> >> > of
>> >> >> > > > > stuff won't be worth it, if it has to be as complex as the
>> >> >>current
>> >> >> mm
>> >> >> > > > then
>> >> >> > > > > of course we will need all kinds of plug ins because no
>>one
>> >> >>will be
>> >> >> > able
>> >> >> > > > to
>> >> >> > > > > write such a thing. I don't have a huge concern with a
>>simple
>> >> >> plug-in
>> >> >> > > > but I
>> >> >> > > > > think if it turns into something more complex with
>>filtering
>> >>and
>> >> >> > > > > aggregation or whatever we really need to stop and think a
>> >>bit
>> >> >> about
>> >> >> > the
>> > >> > > > > design.
>> >> >> > > >
>> >> >> > > > I agree - I don't think there is a use-case for any comple
>> >> >>plug-in.
>> >> >> > > > It is pretty much what Becket has described curently for
>>the
>> >> >>message
>> >> >> > > > handler - i.e., take an incoming record and return a list of
>> >> >>outgoing
>> >> >> > > > records (which could be empty if you filter).
>> >> >> > > >
>> >> >> > > > So here is my ake on the MM:
>> >> >> > > > - Bare bones: simple consumer - producer pairs (07 style).
>> >>This
>> >> >>is
>> >> >> > > > ideal, but does not handle no data los
>> >> >> > > > - Above plus support no data loss. This actually adds quite
>>a
>> >>bit
>> >> >>of
>> >> >> > > > complexity.
>> >> >> > > > - Above plus the message handler. This is a trivial
>>addition I
>> >> >>think
>> >> >> > > > that makes the MM usable in a few other mirroring-like
>> >> >> applications.
>> >> >> > > >
>> >> >> > > > Joel
>> >> >> > > >
>> >> >> > > > > On Tue, Feb 10, 2015 at 12:31 PM, Joel Koshy
>> >> >><jjkosh...@gmail.com>
>> >> >> > > > wrote:
>> >> >> > > > >
>> >> >> > > > > >
>> >> >> > > > > >
>> >> >> > > > > > On Tue, Feb 10, 2015 at 12:13:46PM -0800, Neha Narkhede
>> >>wrote:
>> >> >> > > > > > > I think all of us agree that we want to design
>> >>MirrorMaker
>> >> >>for
>> >> >> 0
>> >> >> > data
>> >> >> > > > > > loss.
>> >> >> > > > > > > With the absence of the data channel, 0 data loss
>>will be
>> >> >>much
>> >> >> > > > simpler to
>> >> >> > > > > > > implement.
>> >> >> > > > > >
>> >> >> > > > > > The data channel is irrelevant to theimplementation of
>> >>zero
>> >> >>data
>> >> >> > > > > > loss. The complexity in the implementation of no data
>>loss
>> >> >>that
>> >> >> you
>> >> >> > > > > > are seeing in mirror-maker affects all
>>consume-then-produce
>> >> >> > patterns
>> >> >> > > > > > whether or not there is a data hannel. You still need
>>to
>> >> >> > maintain a
>> >> >> > > > > > list of unacked offsets. What I meant earlier is that we
>> >>can
>> >> >> > > > > > brainstorm completely different approaches to
>>supporting no
>> >> >>data
>> >> >> > loss,
>> >> >> > > > > > but the current implementation is the only solution we
>>are
>> >> >>aware
>> >> >> > of.
>> >> >> > > > > >
>> >> >> > > > > > >
>> >> >> > > > > > > My arguments for adding a message handler are that:
>> >> >> > > > > > > > 1. It is more efficient to do something in common
>>for
>> >>all
>> >> >>the
>> >> >> > > > clients
>> >> >> > > > > > in
>> >> >> > > > > > > > pipeline than letting each client do the same thing
>>for
>> >> >>many
>> >> >> > > > times. And
>> >> >> > > > > > > > there are concrete use cases for the message handler
>> >> >>already.
>> >> >> > > > > > > >
>> >> >> > > > > > >
>> >> >> > > > > > > What are the concrete use cases?
>> >> >> > > > > >
>> >> >> > > > > > I think Becket already described a couple of use cases
>> >> >>earlier in
>> >> >> > the
>> >> >> > > > > > thread.
>> >> >> > > > > >
>> >> >> > > > > > <quote>
>> >> >> > > > > >
>> >> >> > > > > > 1. Format conversion. We have a use case where clients
>>of
>> >> >>source
>> >> >> > > > > > cluster
>> >> >> > > > > > use an internal schema and clients of target cluster
>>use a
>> >> >> > different
>> >> >> > > > > > public schema.
>> >> >> > > > > > 2. Message filtering: For the messages published to
>>source
>> >> >> cluster,
>> >> >> > > > > > there
>> >> >> > > > > > ar some messages private to source cluster clients and
>> >>should
>> >> >> not
>> >> >> > > > > > exposed
>> >> >> > > > > > to target cluster clients. It would be difficult to
>>publish
>> >> >>those
>> >> >> > > > > > messages
>> >> >> > > > > > into different partitions because they need to be
>>ordered.
>> >> >> > > > > > I agree that we can always filter/convert messages after
>> >>they
>> >> >>are
>> >> >> > > > > > copied
>> >> >> > > > > > to the target cluster, but that costs network bandwidth
>> >> >> > unnecessarily,
>> >> >> > > > > > especially if that is a cross colo mirror. With the
>> >>handler,
>> >> >>we
>> >> >> can
>> >> >> > > > > > co-locate the mirror maker with source cluster and save
>> >>that
>> >> >> cost.
>> >> >> > > > > > Also,
>> >> >> > > > > > imagine there are many downstream consumers consuming
>>from
>> >>the
>> >> >> > target
>> >> >> > > > > > cluster, filtering/reformatting the messages before the
>> >> >>messages
>> >> >> > reach
>> >> >> > > > > > te
>> >> >> > > > > > target cluster is much more efficient than having each
>>of
>> >>the
>> >> >> > > > > > consumers do
>> >> >> > > > > > this individually on their own.
>> >> >> > > > > >
>> >> >> > > > > > </quote>
>> >> >> > > > > >
>> >> >> > > > > > >
>> >> >> > > > > > > Also the KIP still refers to the datachannel in a few
>> >> >>places
>> >> >> > > > (Motivation
>> >> >> > > > > > > and "On consumer rebalance" sections). Can you update
>>the
>> >> >>wiki
>> >> >> > so it
>> >> >> > > > is
>> >> >> > > > > > > easier to review the new design, especially the data
>>loss
>> >> >>part.
>> >> >> > > > > > >
>> >> >> > > > > > >
>> >> >> > > > > > > On Tue, Feb 10, 2015 at 10:36 AM, Joel Koshy <
>> >> >> > jjkosh...@gmail.com>
>> >> >> > > > > > wrote:
>> >> >> > > > > > >
>> >> >> > > > > > > > I think the message handler adds little to no>>
>> >> >> > > > > > > > >>complexity
>> >> >>to
>> >> >> the
>> >> >> > > > mirror
>> >> >> > > > > > > > maker. Jay/Neha, the MM became scary due to the
>> >> >> rearchitecture
>> >> >> > we
>> >> >> > > > did
>> >> >> > > > > > > > for 0.8 due to performance issues compared with 0.7
>>-
>> >>we
>> >> >> should
>> >> >> > > > remove
>> >> >> > > > > > > > the data channel if it can match the current
>> >>throughput. I
>> >> >> > agree
>> >> >> > > > it is
>> >> >> > > > > > > > worth prototyping and testing that so the MM
>> >>architecture
>> >> >>is
>> >> >> > > > > > > > simplified.
>> >> >> > > > > > > >
>> >> >> > > > > > > > The MM became a little scarier in KAFKA-1650 in
>>order
>> >>to
>> >> >> > support no
>> >> >> > > > > > > > data loss. I think the implementation for no data
>>loss
>> >> >>will
>> >> >> > remain
>> >> >> > > > > > > > about the same even in the new model (even without
>>the
>> >> >>data
>> >> >> > > > channel) -
>> >> >> > > > > > > > we can probably brainstorm more if there is a
>> >> >>better/simpler
>> >> >> > way
>> >> >> > > > to do
>> >> >> > > > > > > > it (maybe there is in the absence of the data
>>channel)
>> >> >>but at
>> >> >> > the
>> >> >> > > > time
>> >> >> > > > > > > > it was the best we (i.e., Becket, myself, Jun and
>> >>Guozhang
>> >> >> who
>> >> >> > > > > > > > participated on the review) could come up with.
>> >> >> > > > > > > >
>> >> >> > > > > > > > So I'm definitely +1 on whatever it takes to
>>support no
>> >> >>data
>> >> >> > loss.
>> >> >> > > > I
>> >> >> > > > > > > > think most people would want that out of the box.
>> >> >> > > > > > > >
>> >> >> > > > > > > > As for the message handler, as Becket wrote and I
>>agree
>> >> >>with,
>> >> >> > it is
>> >> >> > > > > > > > really a trivial addition that would benefit
>>(perhaps
>> >>not
>> >> >> most,
>> >> >> > > > but at
>> >> >> > > > > > > > least some). So I'm personally +1 on that as well.
>>That
>> >> >>said,
>> >> >> > I'm
>> >> >> > > > also
>> >> >> > > > > > > > okay with it not being there. I think the MM is
>>fairly
>> >> >> > stand-alone
>> >> >> > > > and
>> >> >> > > > > > > > simple enough that it is entirely reasonable and
>> >> >>absolutely
>> >> >> > > > feasible
>> >> >> > > > > > > > for companies to fork/re-implement the mirror maker
>>for
>> >> >>their
>> >> >> > own
>> >> >> > > > > > > > needs.
>> >> >> > > > > > > >
>> >> >> > > > > > > > So in summary, I'm +1 on the KIP.
>> >> >> > > > > > > >
>> >> >> > > > > > > > Thanks,
>> >> >> > > > > > > >
>> >> >> > > > > > > > Joel
>> >> >> > > > > > > >
>> >> >> > > > > > > > On Mon, Feb 09, 2015 at 09:19:57PM +0000, Jiangjie
>>Qin
>> >> >>wrote:
>> >> >> > > > > > > > > I just updated the KIP page and incorporated Jay
>>and
>> >> >>Neha’s
>> >> >> > > > > > suggestion.
>> >> >> > > > > > > > As
>> >> >> > > > > > > > > a brief summary of where we are:
>> >> >> > > > > > > > >
>> >> >> > > > > > > > > Consensus reached:
>> >> >> > > > > > > > > Have N independent mirror maker threads each has
>> >>their
>> >> >>own
>> >> >> > > > consumers
>> >> >> > > > > > but
>> >> >> > > > > > > > > share a producer. The mirror maker threads will be
>> >> >> > responsible
>> >> >> > > > for
>> >> >> > > > > > > > > decompression, compression and offset commit. No
>>data
>> >> >> > channel and
>> >> >> > > > > > > > separate
>> >> >> > > > > > > > > offset commit thread is needed. Consumer rebalance
>> >> >>callback
>> >> >> > will
>> >> >> > > > be
>> >> >> > > > > > used
>> >> >> > > > > > > > > to avoid duplicates on rebalance.
>> >> >> > > > > > > > >
>> >> >> > > > > > > > > Still under discussion:
>> >> >> > > > > > > > > Whether message handler is needed.
>> >> >> > > > > > > > >
>> >> >> > > > > > > > > My arguments for adding a message handler are
>>that:
>> >> >> > > > > > > > > 1. It is more efficient to do something in common
>>for
>> >> >>all
>> >> >> the
>> >> >> > > > > > clients in
>> >> >> > > > > > > > > pipeline than letting each client do the same
>>thing
>> >>for
>> >> >> many
>> >> >> > > > times.
>> >> >> > > > > > And
>> >> >> > > > > > > > > there are concrete use cases for the message
>>handler
>> >> >> already.
>> >> >> > > > > > > > > 2. It is not a big complicated add-on to mirror
>> >>maker.
>> >> >> > > > > > > > > 3. Without a message handler, for customers needs
>>it,
>> >> >>they
>> >> >> > have
>> >> >> > > > to
>> >> >> > > > > > > > > re-implement all the logics of mirror maker by
>> >> >>themselves
>> >> >> > just in
>> >> >> > > > > > order
>> >> >> > > > > > > > to
>> >> >> > > > > > > > > add this handling in pipeline.
>> >> >> > > > > > > > >
>> >> >> > > > > > > > > Any thoughts?
>> >> >> > > > > > > > >
>> >> >> > > > > > > > > Thanks.
>> >> >> > > > > > > > >
>> >> >> > > > > > > > > ―Jiangjie (Becket) Qin
>> >> >> > > > > > > > >
>> >> >> > > > > > > > > On 2/8/15, 6:35 PM, "Jiangjie Qin"
>> >><j...@linkedin.com>
>> >> >> > wrote:
>> >> >> > > > > > > > >
>> >> >> > > > > > > > > >Hi Jay, thanks a lot for the comments.
>> >> >> > > > > > > > > >I think this solution is better. We probably
>>don’t
>> >>need
>> >> >> data
>> >> >> > > > channel
>> >> >> > > > > > > > > >anymore. It can be replaced with a list of
>>producer
>> >>if
>> >> >>we
>> >> >> > need
>> >> >> > > > more
>> >> >> > > > > > > > sender
>> >> >> > > > > > > > > >thread.
>> >> >> > > > > > > > > >I’ll update the KIP page.
>> >> >> > > > > > > > > >
>> >> >> > > > > > > > > >The reasoning about message handler is mainly for
>> >> >> efficiency
>> >> >> > > > > > purpose.
>> >> >> > > > > > > > I’m
>> >> >> > > > > > > > > >thinking that if something can be done in
>>pipeline
>> >>for
>> >> >>all
>> >> >> > the
>> >> >> > > > > > clients
>> >> >> > > > > > > > > >such as filtering/reformatting, it is probably
>> >>better
>> >> >>to
>> >> >> do
>> >> >> > it
>> >> >> > > > in
>> >> >> > > > > > the
>> >> >> > > > > > > > > >pipeline than asking 100 clients do the same
>>thing
>> >>for
>> >> >>100
>> >> >> > > > times.
>> >> >> > > > > > > > > >
>> >> >> > > > > > > > > >―Jiangjie (Becket) Qin
>> >> >> > > > > > > > > >
>> >> >> > > > > > > > > >
>> >> >> > > > > > > > > >On 2/8/15, 4:59 PM, "Jay Kreps"
>> >><jay.kr...@gmail.com>
>> >> >> > wrote:
>> >> >> > > > > > > > > >
>> >> >> > > > > > > > > >>Yeah, I second Neha's comments. The current mm
>>code
>> >> >>has
>> >> >> > taken
>> >> >> > > > > > something
>> >> >> > > > > > > > > >>pretty simple and made it pretty scary with
>> >>callbacks
>> >> >>and
>> >> >> > > > > > wait/notify
>> >> >> > > > > > > > > >>stuff. Do we believe this works? I can't tell by
>> >> >>looking
>> >> >> > at it
>> >> >> > > > > > which is
>> >> >> > > > > > > > > >>kind of bad for something important like this. I
>> >>don't
>> >> >> mean
>> >> >> > > > this as
>> >> >> > > > > > > > > >>criticism, I know the history: we added in
>>memory
>> >> >>queues
>> >> >> to
>> >> >> > > > help
>> >> >> > > > > > with
>> >> >> > > > > > > > > >>other
>> >> >> > > > > > > > > >>performance problems without thinking about
>> >> >>correctness,
>> >> >> > then
>> >> >> > > > we
>> >> >> > > > > > added
>> >> >> > > > > > > > > >>stuff to work around the in-memory queues not
>>lose
>> >> >>data,
>> >> >> > and
>> >> >> > > > so on.
>> >> >> > > > > > > > > >>
>> >> >> > > > > > > > > >>Can we instead do the opposite exercise and
>>start
>> >>with
>> >> >> the
>> >> >> > > > basics
>> >> >> > > > > > of
>> >> >> > > > > > > > what
>> >> >> > > > > > > > > >>mm should do and think about what deficiencies
>> >> >>prevents
>> >> >> > this
>> >> >> > > > > > approach
>> >> >> > > > > > > > > >>from
>> >> >> > > > > > > > > >>working? Then let's make sure the currently
>> >>in-flight
>> >> >> work
>> >> >> > will
>> >> >> > > > > > remove
>> >> >> > > > > > > > > >>these deficiencies. After all mm is kind of the
>> >> >> > prototypical
>> >> >> > > > kafka
>> >> >> > > > > > use
>> >> >> > > > > > > > > >>case
>> >> >> > > > > > > > > >>so if we can't make our clients to this
>>probably no
>> >> >>one
>> >> >> > else
>> >> >> > > > can.
>> >> >> > > > > > > > > >>
>> >> >> > > > > > > > > >>I think mm should just be N independent threads
>> >>each
>> >> >>of
>> >> >> > which
>> >> >> > > > has
>> >> >> > > > > > their
>> >> >> > > > > > > > > >>own
>> >> >> > > > > > > > > >>consumer but share a producer and each of which
>> >>looks
>> >> >> like
>> >> >> > > > this:
>> >> >> > > > > > > > > >>
>> >> >> > > > > > > > > >>while(true) {
>> >> >> > > > > > > > > >> val recs = consumer.poll(Long.MaxValue);
>> >> >> > > > > > > > > >> for (rec <- recs)
>> >> >> > > > > > > > > >> producer.send(rec, logErrorCallback)
>> >> >> > > > > > > > > >> if(System.currentTimeMillis - lastCommit >
>> >> >> > commitInterval)
>> >> >> > > > {
>> >> >> > > > > > > > > >> producer.flush()
>> >> >> > > > > > > > > >> consumer.commit()
>> >> >> > > > > > > > > >> lastCommit = System.currentTimeMillis
>> >> >> > > > > > > > > >> }
>> >> >> > > > > > > > > >>}
>> >> >> > > > > > > > > >>
>> >> >> > > > > > > > > >>This will depend on setting the retry count in
>>the
>> >> >> > producer to
>> >> >> > > > > > > > something
>> >> >> > > > > > > > > >>high with a largish backoff so that a failed
>>send
>> >> >>attempt
>> >> >> > > > doesn't
>> >> >> > > > > > drop
>> >> >> > > > > > > > > >>data.
>> >> >> > > > > > > > > >>
>> >> >> > > > > > > > > >>We will need to use the callback to force a
>>flush
>> >>and
>> >> >> > offset
>> >> >> > > > > > commit on
>> >> >> > > > > > > > > >>rebalance.
>> >> >> > > > > > > > > >>
>> >> >> > > > > > > > > >>This approach may have a few more TCP
>>connections
>> >>due
>> >> >>to
>> >> >> > using
>> >> >> > > > > > multiple
>> >> >> > > > > > > > > >>consumers but I think it is a lot easier to
>>reason
>> >> >>about
>> >> >> > and
>> >> >> > > > the
>> >> >> > > > > > total
>> >> >> > > > > > > > > >>number of mm instances is always going to be
>>small.
>> >> >> > > > > > > > > >>
>> >> >> > > > > > > > > >>Let's talk about where this simple approach
>>falls
>> >> >>short,
>> >> >> I
>> >> >> > > > think
>> >> >> > > > > > that
>> >> >> > > > > > > > > >>will
>> >> >> > > > > > > > > >>help us understand your motivations for
>>additional
>> >> >> > elements.
>> >> >> > > > > > > > > >>
>> >> >> > > > > > > > > >>Another advantage of this is that it is so
>>simple I
>> >> >>don't
>> >> >> > > > think we
>> >> >> > > > > > > > really
>> >> >> > > > > > > > > >>even need to both making mm extensible because
>> >>writing
>> >> >> > your own
>> >> >> > > > > > code
>> >> >> > > > > > > > that
>> >> >> > > > > > > > > >>does custom processing or transformation is just
>> >>ten
>> >> >> lines
>> >> >> > and
>> >> >> > > > no
>> >> >> > > > > > plug
>> >> >> > > > > > > > in
>> >> >> > > > > > > > > >>system is going to make it simpler.
>> >> >> > > > > > > > > >>
>> >> >> > > > > > > > > >>-Jay
>> >> >> > > > > > > > > >>
>> >> >> > > > > > > > > >>
>> >> >> > > > > > > > > >>On Sun, Feb 8, 2015 at 2:40 PM, Neha Narkhede <
>> >> >> > > > n...@confluent.io>
>> >> >> > > > > > > > wrote:
>> >> >> > > > > > > > > >>
>> >> >> > > > > > > > > >>> Few comments -
>> >> >> > > > > > > > > >>>
>> >> >> > > > > > > > > >>> 1. Why do we need the message handler? Do you
>> >>have
>> >> >> > concrete
>> >> >> > > > use
>> >> >> > > > > > cases
>> >> >> > > > > > > > > >>>in
>> >> >> > > > > > > > > >>> mind? If not, we should consider adding it in
>>the
>> >> >> future
>> >> >> > > > when/if
>> >> >> > > > > > we
>> >> >> > > > > > > > do
>> >> >> > > > > > > > > >>>have
>> >> >> > > > > > > > > >>> use cases for it. The purpose of the mirror
>>maker
>> >> >>is a
>> >> >> > simple
>> >> >> > > > > > tool
>> >> >> > > > > > > > for
>> >> >> > > > > > > > > >>> setting up Kafka cluster replicas. I don't see
>> >>why
>> >> >>we
>> >> >> > need to
>> >> >> > > > > > > > include a
>> >> >> > > > > > > > > >>> message handler for doing stream
>>transformations
>> >>or
>> >> >> > > > filtering.
>> >> >> > > > > > You
>> >> >> > > > > > > > can
>> >> >> > > > > > > > > >>> always write a simple process for doing that
>>once
>> >> >>the
>> >> >> > data is
>> >> >> > > > > > copied
>> >> >> > > > > > > > as
>> >> >> > > > > > > > > >>>is
>> >> >> > > > > > > > > >>> in the target cluster
>> >> >> > > > > > > > > >>> 2. Why keep both designs? We should prefer the
>> >> >>simpler
>> >> >> > design
>> >> >> > > > > > unless
>> >> >> > > > > > > > it
>> >> >> > > > > > > > > >>>is
>> >> >> > > > > > > > > >>> not feasible due to the performance issue
>>that we
>> >> >> > previously
>> >> >> > > > > > had. Did
>> >> >> > > > > > > > > >>>you
>> >> >> > > > > > > > > >>> get a chance to run some tests to see if that
>>is
>> >> >>really
>> >> >> > > > still a
>> >> >> > > > > > > > problem
>> >> >> > > > > > > > > >>>or
>> >> >> > > > > > > > > >>> not? It will be easier to think about the
>>design
>> >>and
>> >> >> also
>> >> >> > > > make
>> >> >> > > > > > the
>> >> >> > > > > > > > KIP
>> >> >> > > > > > > > > >>> complete if we make a call on the design
>>first.
>> >> >> > > > > > > > > >>> 3. Can you explain the need for keeping a
>>list of
>> >> >> unacked
>> >> >> > > > > > offsets per
>> >> >> > > > > > > > > >>> partition? Consider adding a section on
>>retries
>> >>and
>> >> >>how
>> >> >> > you
>> >> >> > > > plan
>> >> >> > > > > > to
>> >> >> > > > > > > > > >>>handle
>> >> >> > > > > > > > > >>> the case when the producer runs out of all
>> >>retries.
>> >> >> > > > > > > > > >>>
>> >> >> > > > > > > > > >>> Thanks,
>> >> >> > > > > > > > > >>> Neha
>> >> >> > > > > > > > > >>>
>> >> >> > > > > > > > > >>> On Sun, Feb 8, 2015 at 2:06 PM, Jiangjie Qin
>> >> >> > > > > > > > > >>><j...@linkedin.com.invalid>
>> >> >> > > > > > > > > >>> wrote:
>> >> >> > > > > > > > > >>>
>> >> >> > > > > > > > > >>> > Hi Neha,
>> >> >> > > > > > > > > >>> >
>> >> >> > > > > > > > > >>> > Yes, I’ve updated the KIP so the entire KIP
>>is
>> >> >>based
>> >> >> > on new
>> >> >> > > > > > > > consumer
>> >> >> > > > > > > > > >>>now.
>> >> >> > > > > > > > > >>> > I’ve put both designs with and without data
>> >> >>channel
>> >> >> in
>> >> >> > the
>> >> >> > > > KIP
>> >> >> > > > > > as I
>> >> >> > > > > > > > > >>>still
>> >> >> > > > > > > > > >>> > feel we might need the data channel to
>>provide
>> >> >>more
>> >> >> > > > > > flexibility,
>> >> >> > > > > > > > > >>> > especially after message handler is
>>introduced.
>> >> >>I’ve
>> >> >> > put my
>> >> >> > > > > > > > thinking
>> >> >> > > > > > > > > >>>of
>> >> >> > > > > > > > > >>> > the pros and cons of the two designs in the
>> >>KIP as
>> >> >> > well.
>> >> >> > > > It’ll
>> >> >> > > > > > be
>> >> >> > > > > > > > > >>>great
>> >> >> > > > > > > > > >>> if
>> >> >> > > > > > > > > >>> > you can give a review and comment.
>> >> >> > > > > > > > > >>> >
>> >> >> > > > > > > > > >>> > Thanks.
>> >> >> > > > > > > > > >>> >
>> >> >> > > > > > > > > >>> > Jiangjie (Becket) Qin
>> >> >> > > > > > > > > >>> >
>> >> >> > > > > > > > > >>> > On 2/6/15, 7:30 PM, "Neha Narkhede" <
>> >> >> n...@confluent.io
>> >> >> > >
>> >> >> > > > wrote:
>> >> >> > > > > > > > > >>> >
>> >> >> > > > > > > > > >>> > >Hey Becket,
>> >> >> > > > > > > > > >>> > >
>> >> >> > > > > > > > > >>> > >What are the next steps on this KIP. As per
>> >>your
>> >> >> > comment
>> >> >> > > > > > earlier
>> >> >> > > > > > > > on
>> >> >> > > > > > > > > >>>the
>> >> >> > > > > > > > > >>> > >thread -
>> >> >> > > > > > > > > >>> > >
>> >> >> > > > > > > > > >>> > >I do agree it makes more sense
>> >> >> > > > > > > > > >>> > >> to avoid duplicate effort and plan based
>>on
>> >>new
>> >> >> > > > consumer.
>> >> >> > > > > > I’ll
>> >> >> > > > > > > > > >>>modify
>> >> >> > > > > > > > > >>> > >>the
>> >> >> > > > > > > > > >>> > >> KIP.
>> >> >> > > > > > > > > >>> > >
>> >> >> > > > > > > > > >>> > >
>> >> >> > > > > > > > > >>> > >Did you get a chance to think about the
>> >> >>simplified
>> >> >> > design
>> >> >> > > > > > that we
>> >> >> > > > > > > > > >>> proposed
>> >> >> > > > > > > > > >>> > >earlier? Do you plan to update the KIP with
>> >>that
>> >> >> > proposal?
>> >> >> > > > > > > > > >>> > >
>> >> >> > > > > > > > > >>> > >Thanks,
>> >> >> > > > > > > > > >>> > >Neha
>> >> >> > > > > > > > > >>> > >
>> >> >> > > > > > > > > >>> > >On Wed, Feb 4, 2015 at 12:12 PM, Jiangjie
>>Qin
>> >> >> > > > > > > > > >>><j...@linkedin.com.invalid
>> >> >> > > > > > > > > >>> >
>> >> >> > > > > > > > > >>> > >wrote:
>> >> >> > > > > > > > > >>> > >
>> >> >> > > > > > > > > >>> > >> In mirror maker we do not do
>> >>de-serialization
>> >> >>on
>> >> >> the
>> >> >> > > > > > messages.
>> >> >> > > > > > > > > >>>Mirror
>> >> >> > > > > > > > > >>> > >> maker use source TopicPartition hash to
>> >>chose a
>> >> >> > > > producer to
>> >> >> > > > > > send
>> >> >> > > > > > > > > >>> > >>messages
>> >> >> > > > > > > > > >>> > >> from the same source partition. The
>> >>partition
>> >> >> those
>> >> >> > > > > > messages end
>> >> >> > > > > > > > > >>>up
>> >> >> > > > > > > > > >>> with
>> >> >> > > > > > > > > >>> > >> are decided by Partitioner class in
>> >> >>KafkaProducer
>> >> >> > > > (assuming
>> >> >> > > > > > you
>> >> >> > > > > > > > > >>>are
>> >> >> > > > > > > > > >>> > >>using
>> >> >> > > > > > > > > >>> > >> the new producer), which uses hash code
>>of
>> >> >> bytes[].
>> >> >> > > > > > > > > >>> > >>
>> >> >> > > > > > > > > >>> > >> If deserialization is needed, it has to
>>be
>> >> >>done in
>> >> >> > > > message
>> >> >> > > > > > > > > >>>handler.
>> >> >> > > > > > > > > >>> > >>
>> >> >> > > > > > > > > >>> > >> Thanks.
>> >> >> > > > > > > > > >>> > >>
>> >> >> > > > > > > > > >>> > >> Jiangjie (Becket) Qin
>> >> >> > > > > > > > > >>> > >>
>> >> >> > > > > > > > > >>> > >> On 2/4/15, 11:33 AM, "Bhavesh Mistry" <
>> >> >> > > > > > > > mistry.p.bhav...@gmail.com>
>> >> >> > > > > > > > > >>> > >>wrote:
>> >> >> > > > > > > > > >>> > >>
>> >> >> > > > > > > > > >>> > >> >Hi Jiangjie,
>> >> >> > > > > > > > > >>> > >> >
>> >> >> > > > > > > > > >>> > >> >Thanks for entertaining my question so
>>far.
>> >> >>Last
>> >> >> > > > > > question, I
>> >> >> > > > > > > > > >>>have is
>> >> >> > > > > > > > > >>> > >> >about
>> >> >> > > > > > > > > >>> > >> >serialization of message key. If the
>>key
>> >> >> > > > de-serialization
>> >> >> > > > > > > > > >>>(Class) is
>> >> >> > > > > > > > > >>> > >>not
>> >> >> > > > > > > > > >>> > >> >present at the MM instance, then does it
>> >>use
>> >> >>raw
>> >> >> > byte
>> >> >> > > > > > hashcode
>> >> >> > > > > > > > to
>> >> >> > > > > > > > > >>> > >> >determine
>> >> >> > > > > > > > > >>> > >> >the partition ? How are you going to
>> >>address
>> >> >>the
>> >> >> > > > situation
>> >> >> > > > > > > > where
>> >> >> > > > > > > > > >>>key
>> >> >> > > > > > > > > >>> > >> >needs
>> >> >> > > > > > > > > >>> > >> >to be de-serialization and get actual
>> >>hashcode
>> >> >> > needs
>> >> >> > > > to be
>> >> >> > > > > > > > > >>>computed
>> >> >> > > > > > > > > >>> ?.
>> >> >> > > > > > > > > >>> > >> >
>> >> >> > > > > > > > > >>> > >> >
>> >> >> > > > > > > > > >>> > >> >Thanks,
>> >> >> > > > > > > > > >>> > >> >
>> >> >> > > > > > > > > >>> > >> >Bhavesh
>> >> >> > > > > > > > > >>> > >> >
>> >> >> > > > > > > > > >>> > >> >On Fri, Jan 30, 2015 at 1:41 PM,
>>Jiangjie
>> >>Qin
>> >> >> > > > > > > > > >>> > >><j...@linkedin.com.invalid>
>> >> >> > > > > > > > > >>> > >> >wrote:
>> >> >> > > > > > > > > >>> > >> >
>> >> >> > > > > > > > > >>> > >> >> Hi Bhavesh,
>> >> >> > > > > > > > > >>> > >> >>
>> >> >> > > > > > > > > >>> > >> >> Please see inline comments.
>> >> >> > > > > > > > > >>> > >> >>
>> >> >> > > > > > > > > >>> > >> >> Jiangjie (Becket) Qin
>> >> >> > > > > > > > > >>> > >> >>
>> >> >> > > > > > > > > >>> > >> >> On 1/29/15, 7:00 PM, "Bhavesh Mistry"
>> >> >> > > > > > > > > >>><mistry.p.bhav...@gmail.com>
>> >> >> > > > > > > > > >>> > >> >>wrote:
>> >> >> > > > > > > > > >>> > >> >>
>> >> >> > > > > > > > > >>> > >> >> >Hi Jiangjie,
>> >> >> > > > > > > > > >>> > >> >> >
>> >> >> > > > > > > > > >>> > >> >> >Thanks for the input.
>> >> >> > > > > > > > > >>> > >> >> >
>> >> >> > > > > > > > > >>> > >> >> >a) Is MM will producer ack will be
>> >>attach
>> >> >>to
>> >> >> > > > Producer
>> >> >> > > > > > > > > >>>Instance or
>> >> >> > > > > > > > > >>> > >>per
>> >> >> > > > > > > > > >>> > >> >> >topic. Use case is that one instance
>> >>of MM
>> >> >> > > > > > > > > >>> > >> >> >needs to handle both strong ack and
>>also
>> >> >>ack=0
>> >> >> > for
>> >> >> > > > some
>> >> >> > > > > > > > topic.
>> >> >> > > > > > > > > >>> Or
>> >> >> > > > > > > > > >>> > >>it
>> >> >> > > > > > > > > >>> > >> >> >would
>> >> >> > > > > > > > > >>> > >> >> >be better to set-up another instance
>>of
>> >>MM.
>> >> >> > > > > > > > > >>> > >> >> The acks setting is producer level
>> >>setting
>> >> >> > instead of
>> >> >> > > > > > topic
>> >> >> > > > > > > > > >>>level
>> >> >> > > > > > > > > >>> > >> >>setting.
>> >> >> > > > > > > > > >>> > >> >> In this case you probably need to set
>>up
>> >> >> another
>> >> >> > > > > > instance.
>> >> >> > > > > > > > > >>> > >> >> >
>> >> >> > > > > > > > > >>> > >> >> >b) Regarding TCP connections, Why
>>does
>> >> >> #producer
>> >> >> > > > > > instance
>> >> >> > > > > > > > > >>>attach
>> >> >> > > > > > > > > >>> to
>> >> >> > > > > > > > > >>> > >>TCP
>> >> >> > > > > > > > > >>> > >> >> >connection. Is it possible to use
>> >>Broker
>> >> >> > > > Connection TCP
>> >> >> > > > > > > > Pool,
>> >> >> > > > > > > > > >>> > >>producer
>> >> >> > > > > > > > > >>> > >> >> >will just checkout TCP connection to
>> >> >>Broker.
>> >> >> > So,
>> >> >> > > > # of
>> >> >> > > > > > > > > >>>Producer
>> >> >> > > > > > > > > >>> > >> >>Instance
>> >> >> > > > > > > > > >>> > >> >> >does not correlation to Brokers
>> >>Connection.
>> >> >> Is
>> >> >> > this
>> >> >> > > > > > > > possible
>> >> >> > > > > > > > > >>>?
>> >> >> > > > > > > > > >>> > >> >> In new producer, each producer
>>maintains
>> >>a
>> >> >> > > > connection to
>> >> >> > > > > > each
>> >> >> > > > > > > > > >>> broker
>> >> >> > > > > > > > > >>> > >> >> within the producer instance. Making
>> >> >>producer
>> >> >> > > > instances
>> >> >> > > > > > to
>> >> >> > > > > > > > > >>>share
>> >> >> > > > > > > > > >>> the
>> >> >> > > > > > > > > >>> > >>TCP
>> >> >> > > > > > > > > >>> > >> >> connections is a very big change to
>>the
>> >> >>current
>> >> >> > > > design,
>> >> >> > > > > > so I
>> >> >> > > > > > > > > >>> suppose
>> >> >> > > > > > > > > >>> > >>we
>> >> >> > > > > > > > > >>> > >> >> won’t be able to do that.
>> >> >> > > > > > > > > >>> > >> >> >
>> >> >> > > > > > > > > >>> > >> >> >
>> >> >> > > > > > > > > >>> > >> >> >Thanks,
>> >> >> > > > > > > > > >>> > >> >> >
>> >> >> > > > > > > > > >>> > >> >> >Bhavesh
>> >> >> > > > > > > > > >>> > >> >> >
>> >> >> > > > > > > > > >>> > >> >> >On Thu, Jan 29, 2015 at 11:50 AM,
>> >>Jiangjie
>> >> >>Qin
>> >> >> > > > > > > > > >>> > >> >><j...@linkedin.com.invalid
>> >> >> > > > > > > > > >>> > >> >> >
>> >> >> > > > > > > > > >>> > >> >> >wrote:
>> >> >> > > > > > > > > >>> > >> >> >
>> >> >> > > > > > > > > >>> > >> >> >> Hi Bhavesh,
>> >> >> > > > > > > > > >>> > >> >> >>
>> >> >> > > > > > > > > >>> > >> >> >> I think it is the right discussion
>>to
>> >> >>have
>> >> >> > when
>> >> >> > > > we are
>> >> >> > > > > > > > > >>>talking
>> >> >> > > > > > > > > >>> > >>about
>> >> >> > > > > > > > > >>> > >> >>the
>> >> >> > > > > > > > > >>> > >> >> >> new new design for MM.
>> >> >> > > > > > > > > >>> > >> >> >> Please see the inline comments.
>> >> >> > > > > > > > > >>> > >> >> >>
>> >> >> > > > > > > > > >>> > >> >> >> Jiangjie (Becket) Qin
>> >> >> > > > > > > > > >>> > >> >> >>
>> >> >> > > > > > > > > >>> > >> >> >> On 1/28/15, 10:48 PM, "Bhavesh
>>Mistry"
>> >> >> > > > > > > > > >>> > >><mistry.p.bhav...@gmail.com>
>> >> >> > > > > > > > > >>> > >> >> >>wrote:
>> >> >> > > > > > > > > >>> > >> >> >>
>> >> >> > > > > > > > > >>> > >> >> >> >Hi Jiangjie,
>> >> >> > > > > > > > > >>> > >> >> >> >
>> >> >> > > > > > > > > >>> > >> >> >> >I just wanted to let you know
>>about
>> >>our
>> >> >>use
>> >> >> > case
>> >> >> > > > and
>> >> >> > > > > > > > stress
>> >> >> > > > > > > > > >>>the
>> >> >> > > > > > > > > >>> > >> >>point
>> >> >> > > > > > > > > >>> > >> >> >>that
>> >> >> > > > > > > > > >>> > >> >> >> >local data center broker cluster
>>have
>> >> >>fewer
>> >> >> > > > > > partitions
>> >> >> > > > > > > > than
>> >> >> > > > > > > > > >>>the
>> >> >> > > > > > > > > >>> > >> >> >> >destination
>> >> >> > > > > > > > > >>> > >> >> >> >offline broker cluster. Just
>>because
>> >>we
>> >> >>do
>> >> >> > the
>> >> >> > > > batch
>> >> >> > > > > > pull
>> >> >> > > > > > > > > >>>from
>> >> >> > > > > > > > > >>> > >>CAMUS
>> >> >> > > > > > > > > >>> > >> >> >>and
>> >> >> > > > > > > > > >>> > >> >> >> >in
>> >> >> > > > > > > > > >>> > >> >> >> >order to drain data faster than
>>the
>> >> >> injection
>> >> >> > > > rate
>> >> >> > > > > > (from
>> >> >> > > > > > > > > >>>four
>> >> >> > > > > > > > > >>> DCs
>> >> >> > > > > > > > > >>> > >> >>for
>> >> >> > > > > > > > > >>> > >> >> >>same
>> >> >> > > > > > > > > >>> > >> >> >> >topic).
>> >> >> > > > > > > > > >>> > >> >> >> Keeping the same partition number
>>in
>> >> >>source
>> >> >> > and
>> >> >> > > > target
>> >> >> > > > > > > > > >>>cluster
>> >> >> > > > > > > > > >>> > >>will
>> >> >> > > > > > > > > >>> > >> >>be
>> >> >> > > > > > > > > >>> > >> >> >>an
>> >> >> > > > > > > > > >>> > >> >> >> option but will not be enforced by
>> >> >>default.
>> >> >> > > > > > > > > >>> > >> >> >> >
>> >> >> > > > > > > > > >>> > >> >> >> >We are facing following issues
>> >>(probably
>> >> >> due
>> >> >> > to
>> >> >> > > > > > > > > >>>configuration):
>> >> >> > > > > > > > > >>> > >> >> >> >
>> >> >> > > > > > > > > >>> > >> >> >> >1) We occasionally loose data
>> >>due
>> >> >>to
>> >> >> > message
>> >> >> > > > > > batch
>> >> >> > > > > > > > > >>>size is
>> >> >> > > > > > > > > >>> > >>too
>> >> >> > > > > > > > > >>> > >> >> >>large
>> >> >> > > > > > > > > >>> > >> >> >> >(2MB) on target data (we are using
>> >>old
>> >> >> > producer
>> >> >> > > > but I
>> >> >> > > > > > > > think
>> >> >> > > > > > > > > >>>new
>> >> >> > > > > > > > > >>> > >> >> >>producer
>> >> >> > > > > > > > > >>> > >> >> >> >will solve this problem to some
>> >>extend).
>> >> >> > > > > > > > > >>> > >> >> >> We do see this issue in LinkedIn as
>> >>well.
>> >> >> New
>> >> >> > > > producer
>> >> >> > > > > > > > also
>> >> >> > > > > > > > > >>> might
>> >> >> > > > > > > > > >>> > >> >>have
>> >> >> > > > > > > > > >>> > >> >> >> this issue. There are some
>>proposal of
>> >> >> > solutions,
>> >> >> > > > but
>> >> >> > > > > > no
>> >> >> > > > > > > > > >>>real
>> >> >> > > > > > > > > >>> work
>> >> >> > > > > > > > > >>> > >> >> >>started
>> >> >> > > > > > > > > >>> > >> >> >> yet. For now, as a workaround,
>> >>setting a
>> >> >> more
>> >> >> > > > > > aggressive
>> >> >> > > > > > > > > >>>batch
>> >> >> > > > > > > > > >>> > >>size
>> >> >> > > > > > > > > >>> > >> >>on
>> >> >> > > > > > > > > >>> > >> >> >> producer side should work.
>> >> >> > > > > > > > > >>> > >> >> >> >2) Since only one instance is
>> >>set
>> >> >>to
>> >> >> MM
>> >> >> > > > data,
>> >> >> > > > > > we
>> >> >> > > > > > > > are
>> >> >> > > > > > > > > >>>not
>> >> >> > > > > > > > > >>> > >>able
>> >> >> > > > > > > > > >>> > >> >>to
>> >> >> > > > > > > > > >>> > >> >> >> >set-up ack per topic instead ack
>>is
>> >> >> attached
>> >> >> > to
>> >> >> > > > > > producer
>> >> >> > > > > > > > > >>> > >>instance.
>> >> >> > > > > > > > > >>> > >> >> >> I don’t quite get the question
>>here.
>> >> >> > > > > > > > > >>> > >> >> >> >3) How are you going to
>>address
>> >>two
>> >> >> > phase
>> >> >> > > > commit
>> >> >> > > > > > > > > >>>problem
>> >> >> > > > > > > > > >>> if
>> >> >> > > > > > > > > >>> > >> >>ack is
>> >> >> > > > > > > > > >>> > >> >> >> >set
>> >> >> > > > > > > > > >>> > >> >> >> >to strongest, but auto commit is
>>on
>> >>for
>> >> >> > consumer
>> >> >> > > > > > (meaning
>> >> >> > > > > > > > > >>> > >>producer
>> >> >> > > > > > > > > >>> > >> >>does
>> >> >> > > > > > > > > >>> > >> >> >> >not
>> >> >> > > > > > > > > >>> > >> >> >> >get ack, but consumer auto
>>committed
>> >> >> offset
>> >> >> > that
>> >> >> > > > > > > > message).
>> >> >> > > > > > > > > >>> Is
>> >> >> > > > > > > > > >>> > >> >>there
>> >> >> > > > > > > > > >>> > >> >> >> >transactional (Kafka transaction
>>is
>> >>in
>> >> >> > process)
>> >> >> > > > > > based ack
>> >> >> > > > > > > > > >>>and
>> >> >> > > > > > > > > >>> > >>commit
>> >> >> > > > > > > > > >>> > >> >> >> >offset
>> >> >> > > > > > > > > >>> > >> >> >> >?
>> >> >> > > > > > > > > >>> > >> >> >> Auto offset commit should be turned
>> >>off
>> >> >>in
>> >> >> > this
>> >> >> > > > case.
>> >> >> > > > > > The
>> >> >> > > > > > > > > >>>offset
>> >> >> > > > > > > > > >>> > >>will
>> >> >> > > > > > > > > >>> > >> >> >>only
>> >> >> > > > > > > > > >>> > >> >> >> be committed once by the offset
>>commit
>> >> >> > thread. So
>> >> >> > > > > > there is
>> >> >> > > > > > > > > >>>no
>> >> >> > > > > > > > > >>> two
>> >> >> > > > > > > > > >>> > >> >>phase
>> >> >> > > > > > > > > >>> > >> >> >> commit.
>> >> >> > > > > > > > > >>> > >> >> >> >4) How are you planning to
>>avoid
>> >> >> > duplicated
>> >> >> > > > > > message?
>> >> >> > > > > > > > > >>>( Is
>> >> >> > > > > > > > > >>> > >> >> >> >brokergoing
>> >> >> > > > > > > > > >>> > >> >> >> >have moving window of message
>> >>collected
>> >> >>and
>> >> >> > > > de-dupe
>> >> >> > > > > > ?)
>> >> >> > > > > > > > > >>> > >>Possibly, we
>> >> >> > > > > > > > > >>> > >> >> >>get
>> >> >> > > > > > > > > >>> > >> >> >> >this from retry set to 5…?
>> >> >> > > > > > > > > >>> > >> >> >> We are not trying to completely
>>avoid
>> >> >> > duplicates.
>> >> >> > > > The
>> >> >> > > > > > > > > >>>duplicates
>> >> >> > > > > > > > > >>> > >>will
>> >> >> > > > > > > > > >>> > >> >> >> still be there if:
>> >> >> > > > > > > > > >>> > >> >> >> 1. Producer retries on failure.
>> >> >> > > > > > > > > >>> > >> >> >> 2. Mirror maker is hard killed.
>> >> >> > > > > > > > > >>> > >> >> >> Currently, dedup is expected to be
>> >>done
>> >> >>by
>> >> >> > user if
>> >> >> > > > > > > > > >>>necessary.
>> >> >> > > > > > > > > >>> > >> >> >> >5) Last, is there any
>>warning or
>> >> >>any
>> >> >> > thing
>> >> >> > > > you
>> >> >> > > > > > can
>> >> >> > > > > > > > > >>>provide
>> >> >> > > > > > > > > >>> > >> >>insight
>> >> >> > > > > > > > > >>> > >> >> >> >from MM component about data
>> >>injection
>> >> >>rate
>> >> >> > into
>> >> >> > > > > > > > > >>>destination
>> >> >> > > > > > > > > >>> > >> >> >>partitions is
>> >> >> > > > > > > > > >>> > >> >> >> >NOT evenly distributed regardless
>> of
>> >> >> keyed
>> >> >> > or
>> >> >> > > > > > non-keyed
>> >> >> > > > > > > > > >>> message
>> >> >> > > > > > > > > >>> > >> >> >>(Hence
>> >> >> > > > > > > > > >>> > >> >> >> >there is ripple effect such as
>>data
>> >>not
>> >> >> > arriving
>> >> >> > > > > > late, or
>> >> >> > > > > > > > > >>>data
>> >> >> > > > > > > > > >>> is
>> >> >> > > > > > > > > >>> > >> >> >>arriving
>> >> >> > > > > > > > > >>> > >> >> >> >out of order in intern of time
>>stamp
>> >> >>and
>> >> >> > early
>> >> >> > > > some
>> >> >> > > > > > > > time,
>> >> >> > > > > > > > > >>>and
>> >> >> > > > > > > > > >>> > >> >>CAMUS
>> >> >> > > > > > > > > >>> > >> >> >> >creates huge number of file count
>>on
>> >> >>HDFS
>> >> >> > due to
>> >> >> > > > > > uneven
>> >> >> > > > > > > > > >>> injection
>> >> >> > > > > > > > > >>> > >> >>rate
>> >> >> > > > > > > > > >>> > >> >> >>.
>> >> >> > > > > > > > > >>> > >> >> >> >Camus Job is configured to run
>> >>every 3
>> >> >> > minutes.)
>> >> >> > > > > > > > > >>> > >> >> >> I think uneven data distribution is
>> >> >> typically
>> >> >> > > > caused
>> >> >> > > > > > by
>> >> >> > > > > > > > > >>>server
>> >> >> > > > > > > > > >>> > >>side
>> >> >> > > > > > > > > >>> > >> >> >> unbalance, instead of something
>>mirror
>> >> >>maker
>> >> >> > could
>> >> >> > > > > > > > control.
>> >> >> > > > > > > > > >>>In
>> >> >> > > > > > > > > >>> new
>> >> >> > > > > > > > > >>> > >> >> >>mirror
>> >> >> > > > > > > > > >>> > >> >> >> maker, however, there is a
>> >>customizable
>> >> >> > message
>> >> >> > > > > > handler,
>> >> >> > > > > > > > > >>>that
>> >> >> > > > > > > > > >>> > >>might
>> >> >> > > > > > > > > >>> > >> >>be
>> >> >> > > > > > > > > >>> > >> >> >> able to help a little bit. In
>>message
>> >> >> handler,
>> >> >> > > > you can
>> >> >> > > > > > > > > >>> explicitly
>> >> >> > > > > > > > > >>> > >> >>set a
>> >> >> > > > > > > > > >>> > >> >> >> partition that you want to produce
>>the
>> >> >> message
>> >> >> > > > to. So
>> >> >> > > > > > if
>> >> >> > > > > > > > you
>> >> >> > > > > > > > > >>> know
>> >> >> > > > > > > > > >>> > >>the
>> >> >> > > > > > > > > >>> > >> >> >> uneven data distribution in target
>> >> >>cluster,
>> >> >> > you
>> >> >> > > > may
>> >> >> > > > > > offset
>> >> >> > > > > > > > > >>>it
>> >> >> > > > > > > > > >>> > >>here.
>> >> >> > > > > > > > > >>> > >> >>But
>> >> >> > > > > > > > > >>> > >> >> >> that probably only works for
>>non-keyed
>> >> >> > messages.
>> >> >> > > > > > > > > >>> > >> >> >> >
>> >> >> > > > > > > > > >>> > >> >> >> >I am not sure if this is right
>> >> >>discussion
>> >> >> > form to
>> >> >> > > > > > bring
>> >> >> > > > > > > > > >>>these
>> >> >> > > > > > > > > >>> to
>> >> >> > > > > > > > > >>> > >> >> >> >your/kafka
>> >> >> > > > > > > > > >>> > >> >> >> >Dev team attention. This might be
>> >>off
>> >> >> track,
>> >> >> > > > > > > > > >>> > >> >> >> >
>> >> >> > > > > > > > > >>> > >> >> >> >
>> >> >> > > > > > > > > >>> > >> >> >> >Thanks,
>> >> >> > > > > > > > > >>> > >> >> >> >
>> >> >> > > > > > > > > >>> > >> >> >> >Bhavesh
>> >> >> > > > > > > > > >>> > >> >> >> >
>> >> >> > > > > > > > > >>> > >> >> >> >On Wed, Jan 28, 2015 at 11:07 AM,
>> >> >>Jiangjie
>> >> >> > Qin
>> >> >> > > > > > > > > >>> > >> >> >><j...@linkedin.com.invalid
>> >> >> > > > > > > > > >>> > >> >> >> >
>> >> >> > > > > > > > > >>> > >> >> >> >wrote:
>> >> >> > > > > > > > > >>> > >> >> >> >
>> >> >> > > > > > > > > >>> > >> >> >> >> I’ve updated the KIP page.
>> >>Feedbacks
>> >> >>are
>> >> >> > > > welcome.
>> >> >> > > > > > > > > >>> > >> >> >> >>
>> >> >> > > > > > > > > >>> > >> >> >> >> Regarding the simple mirror
>>maker
>> >> >> design. I
>> >> >> > > > thought
>> >> >> > > > > > > > over
>> >> >> > > > > > > > > >>>it
>> >> >> > > > > > > > > >>> and
>> >> >> > > > > > > > > >>> > >> >>have
>> >> >> > > > > > > > > >>> > >> >> >> >>some
>> >> >> > > > > > > > > >>> > >> >> >> >> worries:
>> >> >> > > > > > > > > >>> > >> >> >> >> There are two things that might
>> >>worth
>> >> >> > thinking:
>> >> >> > > > > > > > > >>> > >> >> >> >> 1. One of the enhancement to
>>mirror
>> >> >>maker
>> >> >> > is
>> >> >> > > > > > adding a
>> >> >> > > > > > > > > >>>message
>> >> >> > > > > > > > > >>> > >> >> >>handler to
>> >> >> > > > > > > > > >>> > >> >> >> >> do things like reformatting. I
>> >>think
>> >> >>we
>> >> >> > might
>> >> >> > > > > > > > potentially
>> >> >> > > > > > > > > >>> want
>> >> >> > > > > > > > > >>> > >>to
>> >> >> > > > > > > > > >>> > >> >> >>have
>> >> >> > > > > > > > > >>> > >> >> >> >> more threads processing the
>> >>messages
>> >> >>than
>> >> >> > the
>> >> >> > > > > > number of
>> >> >> > > > > > > > > >>> > >>consumers.
>> >> >> > > > > > > > > >>> > >> >> >>If we
>> >> >> > > > > > > > > >>> > >> >> >> >> follow the simple mirror maker
>> >> >>solution,
>> >> >> we
>> >> >> > > > lose
>> >> >> > > > > > this
>> >> >> > > > > > > > > >>> > >>flexibility.
>> >> >> > > > > > > > > >>> > >> >> >> >> 2. This might not matter too
>>much,
>> >>but
>> >> >> > creating
>> >> >> > > > > > more
>> >> >> > > > > > > > > >>> consumers
>> >> >> > > > > > > > > >>> > >> >>means
>> >> >> > > > > > > > > >>> > >> >> >> >>more
>> >> >> > > > > > > > > >>> > >> >> >> >> footprint of TCP connection /
>> >>memory.
>> >> >> > > > > > > > > >>> > >> >> >> >>
>> >> >> > > > > > > > > >>> > >> >> >> >> Any thoughts on this?
>> >> >> > > > > > > > > >>> > >> >> >> >>
>> >> >> > > > > > > > > >>> > >> >> >> >> Thanks.
>> >> >> > > > > > > > > >>> > >> >> >> >>
>> >> >> > > > > > > > > >>> > >> >> >> >> Jiangjie (Becket) Qin
>> >> >> > > > > > > > > >>> > >> >> >> >>
>> >> >> > > > > > > > > >>> > >> >> >> >> On 1/26/15, 10:35 AM, "Jiangjie
>> >>Qin" <
>> >> >> > > > > > > > j...@linkedin.com>
>> >> >> > > > > > > > > >>> > wrote:
>> >> >> > > > > > > > > >>> > >> >> >> >>
>> >> >> > > > > > > > > >>> > >> >> >> >> >Hi Jay and Neha,
>> >> >> > > > > > > > > >>> > >> >> >> >> >
>> >> >> > > > > > > > > >>> > >> >> >> >> >Thanks a lot for the reply and
>> >> >> > explanation. I
>> >> >> > > > do
>> >> >> > > > > > agree
>> >> >> > > > > > > > > >>>it
>> >> >> > > > > > > > > >>> > >>makes
>> >> >> > > > > > > > > >>> > >> >>more
>> >> >> > > > > > > > > >>> > >> >> >> >>sense
>> >> >> > > > > > > > > >>> > >> >> >> >> >to avoid duplicate effort and
>>plan
>> >> >>based
>> >> >> > on
>> >> >> > > > new
>> >> >> > > > > > > > > >>>consumer.
>> >> >> > > > > > > > > >>> I’ll
>> >> >> > > > > > > > > >>> > >> >> >>modify
>> >> >> > > > > > > > > >>> > >> >> >> >>the
>> >> >> > > > > > > > > >>> > >> >> >> >> >KIP.
>> >> >> > > > > > > > > >>> > >> >> >> >> >
>> >> >> > > > > > > > > >>> > >> >> >> >> >To Jay’s question on message
>> >> >>ordering -
>> >> >> > The
>> >> >> > > > data
>> >> >> > > > > > > > channel
>> >> >> > > > > > > > > >>> > >> >>selection
>> >> >> > > > > > > > > >>> > >> >> >> >>makes
>> >> >> > > > > > > > > >>> > >> >> >> >> >sure that the messages from the
>> >>same
>> >> >> > source
>> >> >> > > > > > partition
>> >> >> > > > > > > > > >>>will
>> >> >> > > > > > > > > >>> > >>sent
>> >> >> > > > > > > > > >>> > >> >>by
>> >> >> > > > > > > > > >>> > >> >> >>the
>> >> >> > > > > > > > > >>> > >> >> >> >> >same producer. So the order of
>>the
>> >> >> > messages is
>> >> >> > > > > > > > > >>>guaranteed
>> >> >> > > > > > > > > >>> with
>> >> >> > > > > > > > > >>> > >> >> >>proper
>> >> >> > > > > > > > > >>> > >> >> >> >> >producer settings
>> >> >> > > > > > > > > >>> > >>
>> >> >>>>(MaxInFlightRequests=1,retries=Integer.MaxValue,
>> >> >> > > > > > > > > >>> > >> >> >> >>etc.)
>> >> >> > > > > > > > > >>> > >> >> >> >> >For keyed messages, because
>>they
>> >>come
>> >> >> > from the
>> >> >> > > > > > same
>> >> >> > > > > > > > > >>>source
>> >> >> > > > > > > > > >>> > >> >>partition
>> >> >> > > > > > > > > >>> > >> >> >> >>and
>> >> >> > > > > > > > > >>> > >> >> >> >> >will end up in the same target
>> >> >> partition,
>> >> >> > as
>> >> >> > > > long
>> >> >> > > > > > as
>> >> >> > > > > > > > > >>>they
>> >> >> > > > > > > > > >>> are
>> >> >> > > > > > > > > >>> > >> >>sent
>> >> >> > > > > > > > > >>> > >> >> >>by
>> >> >> > > > > > > > > >>> > >> >> >> >>the
>> >> >> > > > > > > > > >>> > >> >> >> >> >same producer, the order is
>> >> >>guaranteed.
>> >> >> > > > > > > > > >>> > >> >> >> >> >For non-keyed messages, the
>> >>messages
>> >> >> > coming
>> >> >> > > > from
>> >> >> > > > > > the
>> >> >> > > > > > > > > >>>same
>> >> >> > > > > > > > > >>> > >>source
>> >> >> > > > > > > > > >>> > >> >> >> >>partition
>> >> >> > > > > > > > > >>> > >> >> >> >> >might go to different target
>> >> >>partitions.
>> >> >> > The
>> >> >> > > > > > order is
>> >> >> > > > > > > > > >>>only
>> >> >> > > > > > > > > >>> > >> >> >>guaranteed
>> >> >> > > > > > > > > >>> > >> >> >> >> >within each partition.
>> >> >> > > > > > > > > >>> > >> >> >> >> >
>> >> >> > > > > > > > > >>> > >> >> >> >> >Anyway, I’ll modify the KIP and
>> >>data
>> >> >> > channel
>> >> >> > > > will
>> >> >> > > > > > be
>> >> >> > > > > > > > > >>>away.
>> >> >> > > > > > > > > >>> > >> >> >> >> >
>> >> >> > > > > > > > > >>> > >> >> >> >> >Thanks.
>> >> >> > > > > > > > > >>> > >> >> >> >> >
>> >> >> > > > > > > > > >>> > >> >> >> >> >Jiangjie (Becket) Qin
>> >> >> > > > > > > > > >>> > >> >> >> >> >
>> >> >> > > > > > > > > >>> > >> >> >> >> >
>> >> >> > > > > > > > > >>> > >> >> >> >> >On 1/25/15, 4:34 PM, "Neha
>> >>Narkhede"
>> >> >><
>> >> >> > > > > > > > n...@confluent.io>
>> >> >> > > > > > > > > >>> > >>wrote:
>> >> >> > > > > > > > > >>> > >> >> >> >> >
>> >> >> > > > > > > > > >>> > >> >> >> >> >>I think there is some value in
>> >> >> > investigating
>> >> >> > > > if
>> >> >> > > > > > we
>> >> >> > > > > > > > can
>> >> >> > > > > > > > > >>>go
>> >> >> > > > > > > > > >>> > >>back
>> >> >> > > > > > > > > >>> > >> >>to
>> >> >> > > > > > > > > >>> > >> >> >>the
>> >> >> > > > > > > > > >>> > >> >> >> >> >>simple mirror maker design, as
>> >>Jay
>> >> >> points
>> >> >> > > > out.
>> >> >> > > > > > Here
>> >> >> > > > > > > > you
>> >> >> > > > > > > > > >>> have
>> >> >> > > > > > > > > >>> > >>N
>> >> >> > > > > > > > > >>> > >> >> >> >>threads,
>> >> >> > > > > > > > > >>> > >> >> >> >> >>each has a consumer and a
>> >>producer.
>> >> >> > > > > > > > > >>> > >> >> >> >> >>
>> >> >> > > > > > > > > >>> > >> >> >> >> >>The reason why we had to move
>> >>away
>> >> >>from
>> >> >> > that
>> >> >> > > > was
>> >> >> > > > > > a
>> >> >> > > > > > > > > >>> > >>combination
>> >> >> > > > > > > > > >>> > >> >>of
>> >> >> > > > > > > > > >>> > >> >> >>the
>> >> >> > > > > > > > > >>> > >> >> >> >> >>difference in throughput
>>between
>> >>the
>> >> >> > consumer
>> >> >> > > > > > and the
>> >> >> > > > > > > > > >>>old
>> >> >> > > > > > > > > >>> > >> >>producer
>> >> >> > > > > > > > > >>> > >> >> >>and
>> >> >> > > > > > > > > >>> > >> >> >> >> >>the
>> >> >> > > > > > > > > >>> > >> >> >> >> >>deficiency of the consumer
>> >> >>rebalancing
>> >> >> > that
>> >> >> > > > > > limits
>> >> >> > > > > > > > the
>> >> >> > > > > > > > > >>> total
>> >> >> > > > > > > > > >>> > >> >> >>number of
>> >> >> > > > > > > > > >>> > >> >> >> >> >>mirror maker threads. So the
>>only
>> >> >> option
>> >> >> > > > > > available
>> >> >> > > > > > > > was
>> >> >> > > > > > > > > >>>to
>> >> >> > > > > > > > > >>> > >> >>increase
>> >> >> > > > > > > > > >>> > >> >> >>the
>> >> >> > > > > > > > > >>> > >> >> >> >> >>throughput of the limited # of
>> >> >>mirror
>> >> >> > maker
>> >> >> > > > > > threads
>> >> >> > > > > > > > > >>>that
>> >> >> > > > > > > > > >>> > >>could
>> >> >> > > > > > > > > >>> > >> >>be
>> >> >> > > > > > > > > >>> > >> >> >> >> >>deployed.
>> >> >> > > > > > > > > >>> > >> >> >> >> >>Now that queuing design may
>>not
>> >>make
>> >> >> > sense,
>> >> >> > > > if
>> >> >> > > > > > the
>> >> >> > > > > > > > new
>> >> >> > > > > > > > > >>> > >> >>producer's
>> >> >> > > > > > > > > >>> > >> >> >> >> >>throughput is almost similar
>>to
>> >>the
>> >> >> > consumer
>> >> >> > > > AND
>> >> >> > > > > > the
>> >> >> > > > > > > > > >>>fact
>> >> >> > > > > > > > > >>> > >>that
>> >> >> > > > > > > > > >>> > >> >>the
>> >> >> > > > > > > > > >>> > >> >> >>new
>> >> >> > > > > > > > > >>> > >> >> >> >> >>round-robin based consumer
>> >> >>rebalancing
>> >> >> > can
>> >> >> > > > allow
>> >> >> > > > > > a
>> >> >> > > > > > > > very
>> >> >> > > > > > > > > >>> high
>> >> >> > > > > > > > > >>> > >> >> >>number of
>> >> >> > > > > > > > > >>> > >> >> >> >> >>mirror maker instances to
>>exist.
>> >> >> > > > > > > > > >>> > >> >> >> >> >>
>> >> >> > > > > > > > > >>> > >> >> >> >> >>This is the end state that the
>> >> >>mirror
>> >> >> > maker
>> >> >> > > > > > should be
>> >> >> > > > > > > > > >>>in
>> >> >> > > > > > > > > >>> once
>> >> >> > > > > > > > > >>> > >> >>the
>> >> >> > > > > > > > > >>> > >> >> >>new
>> >> >> > > > > > > > > >>> > >> >> >> >> >>consumer is complete, so it
>> >>wouldn't
>> >> >> > hurt to
>> >> >> > > > see
>> >> >> > > > > > if
>> >> >> > > > > > > > we
>> >> >> > > > > > > > > >>>can
>> >> >> > > > > > > > > >>> > >>just
>> >> >> > > > > > > > > >>> > >> >> >>move
>> >> >> > > > > > > > > >>> > >> >> >> >>to
>> >> >> > > > > > > > > >>> > >> >> >> >> >>that right now.
>> >> >> > > > > > > > > >>> > >> >> >> >> >>
>> >> >> > > > > > > > > >>> > >> >> >> >> >>On Fri, Jan 23, 2015 at 8:40
>>PM,
>> >>Jay
>> >> >> > Kreps
>> >> >> > > > > > > > > >>> > >><jay.kr...@gmail.com
>> >> >> > > > > > > > > >>> > >> >
>> >> >> > > > > > > > > >>> > >> >> >> >>wrote:
>> >> >> > > > > > > > > >>> > >> >> >> >> >>
>> >> >> > > > > > > > > >>> > >> >> >> >> >>> QQ: If we ever use a
>>different
>> >> >> > technique
>> >> >> > > > for
>> >> >> > > > > > the
>> >> >> > > > > > > > data
>> >> >> > > > > > > > > >>> > >>channel
>> >> >> > > > > > > > > >>> > >> >> >> >>selection
>> >> >> > > > > > > > > >>> > >> >> >> >> >>> than for the producer
>> >>partitioning
>> >> >> > won't
>> >> >> > > > that
>> >> >> > > > > > break
>> >> >> > > > > > > > > >>> > >>ordering?
>> >> >> > > > > > > > > >>> > >> >>How
>> >> >> > > > > > > > > >>> > >> >> >> >>can
>> >> >> > > > > > > > > >>> > >> >> >> >> >>>we
>> >> >> > > > > > > > > >>> > >> >> >> >> >>> ensure these things stay in
>> >>sync?
>> >> >> > > > > > > > > >>> > >> >> >> >> >>>
>> >> >> > > > > > > > > >>> > >> >> >> >> >>> With respect to the new
>> >> >>consumer--I
>> >> >> > really
>> >> >> > > > do
>> >> >> > > > > > want
>> >> >> > > > > > > > to
>> >> >> > > > > > > > > >>> > >> >>encourage
>> >> >> > > > > > > > > >>> > >> >> >> >>people
>> >> >> > > > > > > > > >>> > >> >> >> >> >>>to
>> >> >> > > > > > > > > >>> > >> >> >> >> >>> think through how MM will
>>work
>> >> >>with
>> >> >> > the new
>> >> >> > > > > > > > consumer.
>> >> >> > > > > > > > > >>>I
>> >> >> > > > > > > > > >>> > >>mean
>> >> >> > > > > > > > > >>> > >> >>this
>> >> >> > > > > > > > > >>> > >> >> >> >>isn't
>> >> >> > > > > > > > > >>> > >> >> >> >> >>> very far off, maybe a few
>> >>months
>> >> >>if
>> >> >> we
>> >> >> > > > hustle?
>> >> >> > > > > > I
>> >> >> > > > > > > > > >>>could
>> >> >> > > > > > > > > >>> > >> >>imagine us
>> >> >> > > > > > > > > >>> > >> >> >> >> >>>getting
>> >> >> > > > > > > > > >>> > >> >> >> >> >>> this mm fix done maybe
>>sooner,
>> >> >>maybe
>> >> >> > in a
>> >> >> > > > > > month?
>> >> >> > > > > > > > So I
>> >> >> > > > > > > > > >>> guess
>> >> >> > > > > > > > > >>> > >> >>this
>> >> >> > > > > > > > > >>> > >> >> >> >>buys
>> >> >> > > > > > > > > >>> > >> >> >> >> >>>us an
>> >> >> > > > > > > > > >>> > >> >> >> >> >>> extra month before we rip it
>> >>out
>> >> >>and
>> >> >> > throw
>> >> >> > > > it
>> >> >> > > > > > away?
>> >> >> > > > > > > > > >>>Maybe
>> >> >> > > > > > > > > >>> > >>two?
>> >> >> > > > > > > > > >>> > >> >> >>This
>> >> >> > > > > > > > > >>> > >> >> >> >>bug
>> >> >> > > > > > > > > >>> > >> >> >> >> >>>has
>> >> >> > > > > > > > > >>> > >> >> >> >> >>> been there for a while,
>>though,
>> >> >> right?
>> >> >> > Is
>> >> >> > > > it
>> >> >> > > > > > worth
>> >> >> > > > > > > > > >>>it?
>> >> >> > > > > > > > > >>> > >> >>Probably
>> >> >> > > > > > > > > >>> > >> >> >>it
>> >> >> > > > > > > > > >>> > >> >> >> >>is,
>> >> >> > > > > > > > > >>> > >> >> >> >> >>>but
>> >> >> > > > > > > > > >>> > >> >> >> >> >>> it still kind of sucks to
>>have
>> >>the
>> >> >> > > > duplicate
>> >> >> > > > > > > > effort.
>> >> >> > > > > > > > > >>> > >> >> >> >> >>>
>> >> >> > > > > > > > > >>> > >> >> >> >> >>> So anyhow let's definitely
>> >>think
>> >> >> about
>> >> >> > how
>> >> >> > > > > > things
>> >> >> > > > > > > > > >>>will
>> >> >> > > > > > > > > >>> work
>> >> >> > > > > > > > > >>> > >> >>with
>> >> >> > > > > > > > > >>> > >> >> >>the
>> >> >> > > > > > > > > >>> > >> >> >> >> >>>new
>> >> >> > > > > > > > > >>> > >> >> >> >> >>> consumer. I think we can
>> >>probably
>> >> >> just
>> >> >> > > > have N
>> >> >> > > > > > > > > >>>threads,
>> >> >> > > > > > > > > >>> each
>> >> >> > > > > > > > > >>> > >> >> >>thread
>> >> >> > > > > > > > > >>> > >> >> >> >>has
>> >> >> > > > > > > > > >>> > >> >> >> >> >>>a
>> >> >> > > > > > > > > >>> > >> >> >> >> >>> producer and consumer and is
>> >> >> internally
>> >> >> > > > single
>> >> >> > > > > > > > > >>>threaded.
>> >> >> > > > > > > > > >>> > >>Any
>> >> >> > > > > > > > > >>> > >> >> >>reason
>> >> >> > > > > > > > > >>> > >> >> >> >> >>>this
>> >> >> > > > > > > > > >>> > >> >> >> >> >>> wouldn't work?
>> >> >> > > > > > > > > >>> > >> >> >> >> >>>
>> >> >> > > > > > > > > >>> > >> >> >> >> >>> -Jay
>> >> >> > > > > > > > > >>> > >> >> >> >> >>>
>> >> >> > > > > > > > > >>> > >> >> >> >> >>>
>> >> >> > > > > > > > > >>> > >> >> >> >> >>> On Wed, Jan 21, 2015 at 5:29
>> >>PM,
>> >> >> > Jiangjie
>> >> >> > > > Qin
>> >> >> > > > > > > > > >>> > >> >> >> >> >>><j...@linkedin.com.invalid>
>> >> >> > > > > > > > > >>> > >> >> >> >> >>> wrote:
>> >> >> > > > > > > > > >>> > >> >> >> >> >>>
>> >> >> > > > > > > > > >>> > >> >> >> >> >>> > Hi Jay,
>> >> >> > > > > > > > > >>> > >> >> >> >> >>> >
>> >> >> > > > > > > > > >>> > >> >> >> >> >>> > Thanks for comments.
>>Please
>> >>see
>> >> >> > inline
>> >> >> > > > > > responses.
>> >> >> > > > > > > > > >>> > >> >> >> >> >>> >
>> >> >> > > > > > > > > >>> > >> >> >> >> >>> > Jiangjie (Becket) Qin
>> >> >> > > > > > > > > >>> > >> >> >> >> >>> >
>> >> >> > > > > > > > > >>> > >> >> >> >> >>> > On 1/21/15, 1:33 PM, "Jay
>> >>Kreps"
>> >> >> > > > > > > > > >>><jay.kr...@gmail.com>
>> >> >> > > > > > > > > >>> > >> >>wrote:
>> >> >> > > > > > > > > >>> > >> >> >> >> >>> >
>> >> >> > > > > > > > > >>> > >> >> >> >> >>> > >Hey guys,
>> >> >> > > > > > > > > >>> > >> >> >> >> >>> > >
>> >> >> > > > > > > > > >>> > >> >> >> >> >>> > >A couple
>>questions/comments:
>> >> >> > > > > > > > > >>> > >> >> >> >> >>> > >
>> >> >> > > > > > > > > >>> > >> >> >> >> >>> > >1. The callback and
>> >> >> user-controlled
>> >> >> > > > commit
>> >> >> > > > > > > > offset
>> >> >> > > > > > > > > >>> > >> >> >>functionality
>> >> >> > > > > > > > > >>> > >> >> >> >>is
>> >> >> > > > > > > > > >>> > >> >> >> >> >>> already
>> >> >> > > > > > > > > >>> > >> >> >> >> >>> > >in the new consumer
>>which we
>> >> >>are
>> >> >> > > > working on
>> >> >> > > > > > in
>> >> >> > > > > > > > > >>> parallel.
>> >> >> > > > > > > > > >>> > >> >>If we
>> >> >> > > > > > > > > >>> > >> >> >> >> >>> accelerated
>> >> >> > > > > > > > > >>> > >> >> >> >> >>> > >that work it might help
>> >> >> concentrate
>> >> >> > > > > > efforts. I
>> >> >> > > > > > > > > >>>admit
>> >> >> > > > > > > > > >>> > >>this
>> >> >> > > > > > > > > >>> > >> >> >>might
>> >> >> > > > > > > > > >>> > >> >> >> >>take
>> >> >> > > > > > > > > >>> > >> >> >> >> >>> > >slightly longer in
>>calendar
>> >> >>time
>> >> >> but
>> >> >> > > > could
>> >> >> > > > > > still
>> >> >> > > > > > > > > >>> > >>probably
>> >> >> > > > > > > > > >>> > >> >>get
>> >> >> > > > > > > > > >>> > >> >> >> >>done
>> >> >> > > > > > > > > >>> > >> >> >> >> >>>this
>> >> >> > > > > > > > > >>> > >> >> >> >> >>> > >quarter. Have you guys
>> >> >>considered
>> >> >> > that
>> >> >> > > > > > approach?
>> >> >> > > > > > > > > >>> > >> >> >> >> >>> > Yes, I totally agree that
>> >> >>ideally
>> >> >> we
>> >> >> > > > should
>> >> >> > > > > > put
>> >> >> > > > > > > > > >>>efforts
>> >> >> > > > > > > > > >>> > >>on
>> >> >> > > > > > > > > >>> > >> >>new
>> >> >> > > > > > > > > >>> > >> >> >> >> >>>consumer.
>> >> >> > > > > > > > > >>> > >> >> >> >> >>> > The main reason for still
>> >> >>working
>> >> >> on
>> >> >> > the
>> >> >> > > > old
>> >> >> > > > > > > > > >>>consumer
>> >> >> > > > > > > > > >>> is
>> >> >> > > > > > > > > >>> > >> >>that
>> >> >> > > > > > > > > >>> > >> >> >>we
>> >> >> > > > > > > > > >>> > >> >> >> >> >>>expect
>> >> >> > > > > > > > > >>> > >> >> >> >> >>> it
>> >> >> > > > > > > > > >>> > >> >> >> >> >>> > would still be used in
>> >>LinkedIn
>> >> >>for
>> >> >> > > > quite a
>> >> >> > > > > > while
>> >> >> > > > > > > > > >>> before
>> >> >> > > > > > > > > >>> > >>the
>> >> >> > > > > > > > > >>> > >> >> >>new
>> >> >> > > > > > > > > >>> > >> >> >> >> >>>consumer
>> >> >> > > > > > > > > >>> > >> >> >> >> >>> > could be fully rolled out.
>> >>And
>> >> >>we
>> >> >> > > > recently
>> >> >> > > > > > > > > >>>suffering a
>> >> >> > > > > > > > > >>> > >>lot
>> >> >> > > > > > > > > >>> > >> >>from
>> >> >> > > > > > > > > >>> > >> >> >> >> >>>mirror
>> >> >> > > > > > > > > >>> > >> >> >> >> >>> > maker data loss issue. So
>>our
>> >> >> current
>> >> >> > > > plan is
>> >> >> > > > > > > > > >>>making
>> >> >> > > > > > > > > >>> > >> >>necessary
>> >> >> > > > > > > > > >>> > >> >> >> >> >>>changes to
>> >> >> > > > > > > > > >>> > >> >> >> >> >>> > make current mirror maker
>> >> >>stable in
>> >> >> > > > > > production.
>> >> >> > > > > > > > > >>>Then we
>> >> >> > > > > > > > > >>> > >>can
>> >> >> > > > > > > > > >>> > >> >> >>test
>> >> >> > > > > > > > > >>> > >> >> >> >>and
>> >> >> > > > > > > > > >>> > >> >> >> >> >>> > rollout new consumer
>> >>gradually
>> >> >> > without
>> >> >> > > > > > getting
>> >> >> > > > > > > > > >>>burnt.
>> >> >> > > > > > > > > >>> > >> >> >> >> >>> > >
>> >> >> > > > > > > > > >>> > >> >> >> >> >>> > >2. I think partitioning
>>on
>> >>the
>> >> >> hash
>> >> >> > of
>> >> >> > > > the
>> >> >> > > > > > topic
>> >> >> > > > > > > > > >>> > >>partition
>> >> >> > > > > > > > > >>> > >> >>is
>> >> >> > > > > > > > > >>> > >> >> >> >>not a
>> >> >> > > > > > > > > >>> > >> >> >> >> >>>very
>> >> >> > > > > > > > > >>> > >> >> >> >> >>> > >good idea because that
>>will
>> >> >>make
>> >> >> the
>> >> >> > > > case of
>> >> >> > > > > > > > going
>> >> >> > > > > > > > > >>> from
>> >> >> > > > > > > > > >>> > >>a
>> >> >> > > > > > > > > >>> > >> >> >>cluster
>> >> >> > > > > > > > > >>> > >> >> >> >> >>>with
>> >> >> > > > > > > > > >>> > >> >> >> >> >>> > >fewer partitions to one
>>with
>> >> >>more
>> >> >> > > > > > partitions not
>> >> >> > > > > > > > > >>> work. I
>> >> >> > > > > > > > > >>> > >> >> >>think an
>> >> >> > > > > > > > > >>> > >> >> >> >> >>> > >intuitive
>> >> >> > > > > > > > > >>> > >> >> >> >> >>> > >way to do this would be
>>the
>> >> >> > following:
>> >> >> > > > > > > > > >>> > >> >> >> >> >>> > >a. Default behavior:
>>Just do
>> >> >>what
>> >> >> > the
>> >> >> > > > > > producer
>> >> >> > > > > > > > > >>>does.
>> >> >> > > > > > > > > >>> > >>I.e.
>> >> >> > > > > > > > > >>> > >> >>if
>> >> >> > > > > > > > > >>> > >> >> >>you
>> >> >> > > > > > > > > >>> > >> >> >> >> >>> specify a
>> >> >> > > > > > > > > >>> > >> >> >> >> >>> > >key use it for
>> >>partitioning, if
>> >> >> not
>> >> >> > just
>> >> >> > > > > > > > partition
>> >> >> > > > > > > > > >>>in
>> >> >> > > > > > > > > >>> a
>> >> >> > > > > > > > > >>> > >> >> >> >>round-robin
>> >> >> > > > > > > > > >>> > >> >> >> >> >>> > >fashion.
>> >> >> > > > > > > > > >>> > >> >> >> >> >>> > >b. Add a
>> >>--preserve-partition
>> >> >> option
>> >> >> > > > that
>> >> >> > > > > > will
>> >> >> > > > > > > > > >>> > >>explicitly
>> >> >> > > > > > > > > >>> > >> >> >> >>inherent
>> >> >> > > > > > > > > >>> > >> >> >> >> >>>the
>> >> >> > > > > > > > > >>> > >> >> >> >> >>> > >partition from the source
>> >> >> > irrespective
>> >> >> > > > of
>> >> >> > > > > > > > whether
>> >> >> > > > > > > > > >>> there
>> >> >> > > > > > > > > >>> > >>is
>> >> >> > > > > > > > > >>> > >> >>a
>> >> >> > > > > > > > > >>> > >> >> >>key
>> >> >> > > > > > > > > >>> > >> >> >> >>or
>> >> >> > > > > > > > > >>> > >> >> >> >> >>> which
>> >> >> > > > > > > > > >>> > >> >> >> >> >>> > >partition that key would
>> >>hash
>> >> >>to.
>> >> >> > > > > > > > > >>> > >> >> >> >> >>> > Sorry that I did not
>>explain
>> >> >>this
>> >> >> > clear
>> >> >> > > > > > enough.
>> >> >> > > > > > > > The
>> >> >> > > > > > > > > >>> hash
>> >> >> > > > > > > > > >>> > >>of
>> >> >> > > > > > > > > >>> > >> >> >>topic
>> >> >> > > > > > > > > >>> > >> >> >> >> >>> > partition is only used
>>when
>> >> >>decide
>> >> >> > which
>> >> >> > > > > > mirror
>> >> >> > > > > > > > > >>>maker
>> >> >> > > > > > > > > >>> > >>data
>> >> >> > > > > > > > > >>> > >> >> >>channel
>> >> >> > > > > > > > > >>> > >> >> >> >> >>>queue
>> >> >> > > > > > > > > >>> > >> >> >> >> >>> > the consumer thread should
>> >>put
>> >> >> > message
>> >> >> > > > into.
>> >> >> > > > > > It
>> >> >> > > > > > > > > >>>only
>> >> >> > > > > > > > > >>> > >>tries
>> >> >> > > > > > > > > >>> > >> >>to
>> >> >> > > > > > > > > >>> > >> >> >>make
>> >> >> > > > > > > > > >>> > >> >> >> >> >>>sure
>> >> >> > > > > > > > > >>> > >> >> >> >> >>> > the messages from the same
>> >> >> partition
>> >> >> > is
>> >> >> > > > sent
>> >> >> > > > > > by
>> >> >> > > > > > > > the
>> >> >> > > > > > > > > >>> same
>> >> >> > > > > > > > > >>> > >> >> >>producer
>> >> >> > > > > > > > > >>> > >> >> >> >> >>>thread
>> >> >> > > > > > > > > >>> > >> >> >> >> >>> > to guarantee the sending
>> >>order.
>> >> >> This
>> >> >> > is
>> >> >> > > > not
>> >> >> > > > > > at
>> >> >> > > > > > > > all
>> >> >> > > > > > > > > >>> > >>related
>> >> >> > > > > > > > > >>> > >> >>to
>> >> >> > > > > > > > > >>> > >> >> >> >>which
>> >> >> > > > > > > > > >>> > >> >> >> >> >>> > partition in target
>>cluster
>> >>the
>> >> >> > messages
>> >> >> > > > end
>> >> >> > > > > > up.
>> >> >> > > > > > > > > >>>That
>> >> >> > > > > > > > > >>> is
>> >> >> > > > > > > > > >>> > >> >>still
>> >> >> > > > > > > > > >>> > >> >> >> >> >>>decided by
>> >> >> > > > > > > > > >>> > >> >> >> >> >>> > producer.
>> >> >> > > > > > > > > >>> > >> >> >> >> >>> > >
>> >> >> > > > > > > > > >>> > >> >> >> >> >>> > >3. You don't actually
>>give
>> >>the
>> >> >> > > > > > > > > >>> ConsumerRebalanceListener
>> >> >> > > > > > > > > >>> > >> >> >> >>interface.
>> >> >> > > > > > > > > >>> > >> >> >> >> >>>What
>> >> >> > > > > > > > > >>> > >> >> >> >> >>> > >is
>> >> >> > > > > > > > > >>> > >> >> >> >> >>> > >that going to look like?
>> >> >> > > > > > > > > >>> > >> >> >> >> >>> > Good point! I should have
>>put
>> >> >>it in
>> >> >> > the
>> >> >> > > > > > wiki. I
>> >> >> > > > > > > > > >>>just
>> >> >> > > > > > > > > >>> > >>added
>> >> >> > > > > > > > > >>> > >> >>it.
>> >> >> > > > > > > > > >>> > >> >> >> >> >>> > >
>> >> >> > > > > > > > > >>> > >> >> >> >> >>> > >4. What is
>> >>MirrorMakerRecord? I
>> >> >> > think
>> >> >> > > > > > ideally
>> >> >> > > > > > > > the
>> >> >> > > > > > > > > >>> > >> >> >> >> >>> > >MirrorMakerMessageHandler
>> >> >> > > > > > > > > >>> > >> >> >> >> >>> > >interface would take a
>> >> >> > ConsumerRecord as
>> >> >> > > > > > input
>> >> >> > > > > > > > and
>> >> >> > > > > > > > > >>> > >>return a
>> >> >> > > > > > > > > >>> > >> >> >> >> >>> > >ProducerRecord,
>> >> >> > > > > > > > > >>> > >> >> >> >> >>> > >right? That would allow
>>you
>> >>to
>> >> >> > > > transform the
>> >> >> > > > > > > > key,
>> >> >> > > > > > > > > >>> value,
>> >> >> > > > > > > > > >>> > >> >> >> >>partition,
>> >> >> > > > > > > > > >>> > >> >> >> >> >>>or
>> >> >> > > > > > > > > >>> > >> >> >> >> >>> > >destination topic...
>> >> >> > > > > > > > > >>> > >> >> >> >> >>> > MirrorMakerRecord is
>> >>introduced
>> >> >>in
>> >> >> > > > > > KAFKA-1650,
>> >> >> > > > > > > > > >>>which is
>> >> >> > > > > > > > > >>> > >> >>exactly
>> >> >> > > > > > > > > >>> > >> >> >> >>the
>> >> >> > > > > > > > > >>> > >> >> >> >> >>>same
>> >> >> > > > > > > > > >>> > >> >> >> >> >>> > as ConsumerRecord in
>> >>KAFKA-1760.
>> >> >> > > > > > > > > >>> > >> >> >> >> >>> > private[kafka] class
>> >> >> > MirrorMakerRecord
>> >> >> > > > (val
>> >> >> > > > > > > > > >>> sourceTopic:
>> >> >> > > > > > > > > >>> > >> >> >>String,
>> >> >> > > > > > > > > >>> > >> >> >> >> >>> > val sourcePartition:
>>Int,
>> >> >> > > > > > > > > >>> > >> >> >> >> >>> > val sourceOffset: Long,
>> >> >> > > > > > > > > >>> > >> >> >> >> >>> > val key: Array[Byte],
>> >> >> > > > > > > > > >>> > >> >> >> >> >>> > val value: Array[Byte])
>>{
>> >> >> > > > > > > > > >>> > >> >> >> >> >>> > def size = value.length
>>+
>> >>{if
>> >> >> (key
>> >> >> > ==
>> >> >> > > > > > null) 0
>> >> >> > > > > > > > > >>>else
>> >> >> > > > > > > > > >>> > >> >> >>key.length}
>> >> >> > > > > > > > > >>> > >> >> >> >> >>> > }
>> >> >> > > > > > > > > >>> > >> >> >> >> >>> >
>> >> >> > > > > > > > > >>> > >> >> >> >> >>> > However, because source
>> >> >>partition
>> >> >> and
>> >> >> > > > offset
>> >> >> > > > > > is
>> >> >> > > > > > > > > >>>needed
>> >> >> > > > > > > > > >>> in
>> >> >> > > > > > > > > >>> > >> >> >>producer
>> >> >> > > > > > > > > >>> > >> >> >> >> >>>thread
>> >> >> > > > > > > > > >>> > >> >> >> >> >>> > for consumer offsets
>> >> >>bookkeeping,
>> >> >> the
>> >> >> > > > record
>> >> >> > > > > > > > > >>>returned
>> >> >> > > > > > > > > >>> by
>> >> >> > > > > > > > > >>> > >> >> >> >> >>> > MirrorMakerMessageHandler
>> >>needs
>> >> >>to
>> >> >> > > > contain
>> >> >> > > > > > those
>> >> >> > > > > > > > > >>> > >> >>information.
>> >> >> > > > > > > > > >>> > >> >> >> >> >>>Therefore
>> >> >> > > > > > > > > >>> > >> >> >> >> >>> > ProducerRecord does not
>>work
>> >> >>here.
>> >> >> We
>> >> >> > > > could
>> >> >> > > > > > > > > >>>probably
>> >> >> > > > > > > > > >>> let
>> >> >> > > > > > > > > >>> > >> >> >>message
>> >> >> > > > > > > > > >>> > >> >> >> >> >>>handler
>> >> >> > > > > > > > > >>> > >> >> >> >> >>> > take ConsumerRecord for
>>both
>> >> >>input
>> >> >> > and
>> >> >> > > > > > output.
>> >> >> > > > > > > > > >>> > >> >> >> >> >>> > >
>> >> >> > > > > > > > > >>> > >> >> >> >> >>> > >5. Have you guys thought
>> >>about
>> >> >> what
>> >> >> > the
>> >> >> > > > > > > > > >>>implementation
>> >> >> > > > > > > > > >>> > >>will
>> >> >> > > > > > > > > >>> > >> >> >>look
>> >> >> > > > > > > > > >>> > >> >> >> >> >>>like in
>> >> >> > > > > > > > > >>> > >> >> >> >> >>> > >terms of threading
>> >>architecture
>> >> >> etc
>> >> >> > with
>> >> >> > > > > > the new
>> >> >> > > > > > > > > >>> > >>consumer?
>> >> >> > > > > > > > > >>> > >> >> >>That
>> >> >> > > > > > > > > >>> > >> >> >> >>will
>> >> >> > > > > > > > > >>> > >> >> >> >> >>>be
>> >> >> > > > > > > > > >>> > >> >> >> >> >>> > >soon so even if we aren't
>> >> >>starting
>> >> >> > with
>> >> >> > > > that
>> >> >> > > > > > > > let's
>> >> >> > > > > > > > > >>> make
>> >> >> > > > > > > > > >>> > >> >>sure
>> >> >> > > > > > > > > >>> > >> >> >>we
>> >> >> > > > > > > > > >>> > >> >> >> >>can
>> >> >> > > > > > > > > >>> > >> >> >> >> >>>get
>> >> >> > > > > > > > > >>> > >> >> >> >> >>> > >rid
>> >> >> > > > > > > > > >>> > >> >> >> >> >>> > >of a lot of the current
>> >>mirror
>> >> >> maker
>> >> >> > > > > > accidental
>> >> >> > > > > > > > > >>> > >>complexity
>> >> >> > > > > > > > > >>> > >> >>in
>> >> >> > > > > > > > > >>> > >> >> >> >>terms
>> >> >> > > > > > > > > >>> > >> >> >> >> >>>of
>> >> >> > > > > > > > > >>> > >> >> >> >> >>> > >threads and queues when
>>we
>> >> >>move to
>> >> >> > that.
>> >> >> > > > > > > > > >>> > >> >> >> >> >>> > I haven¹t thought about it
>> >> >> > throughly. The
>> >> >> > > > > > quick
>> >> >> > > > > > > > > >>>idea is
>> >> >> > > > > > > > > >>> > >> >>after
>> >> >> > > > > > > > > >>> > >> >> >> >> >>>migration
>> >> >> > > > > > > > > >>> > >> >> >> >> >>> to
>> >> >> > > > > > > > > >>> > >> >> >> >> >>> > the new consumer, it is
>> >>probably
>> >> >> > better
>> >> >> > > > to
>> >> >> > > > > > use a
>> >> >> > > > > > > > > >>>single
>> >> >> > > > > > > > > >>> > >> >> >>consumer
>> >> >> > > > > > > > > >>> > >> >> >> >> >>>thread.
>> >> >> > > > > > > > > >>> > >> >> >> >> >>> > If multithread is needed,
>> >> >> decoupling
>> >> >> > > > > > consumption
>> >> >> > > > > > > > > >>>and
>> >> >> > > > > > > > > >>> > >> >>processing
>> >> >> > > > > > > > > >>> > >> >> >> >>might
>> >> >> > > > > > > > > >>> > >> >> >> >> >>>be
>> >> >> > > > > > > > > >>> > >> >> >> >> >>> > used. MirrorMaker
>>definitely
>> >> >>needs
>> >> >> > to be
>> >> >> > > > > > changed
>> >> >> > > > > > > > > >>>after
>> >> >> > > > > > > > > >>> > >>new
>> >> >> > > > > > > > > >>> > >> >> >> >>consumer
>> >> >> > > > > > > > > >>> > >> >> >> >> >>>get
>> >> >> > > > > > > > > >>> > >> >> >> >> >>> > checked in. I¹ll document
>>the
>> >> >> changes
>> >> >> > > > and can
>> >> >> > > > > > > > > >>>submit
>> >> >> > > > > > > > > >>> > >>follow
>> >> >> > > > > > > > > >>> > >> >>up
>> >> >> > > > > > > > > >>> > >> >> >> >> >>>patches
>> >> >> > > > > > > > > >>> > >> >> >> >> >>> > after the new consumer is
>> >> >> available.
>> >> >> > > > > > > > > >>> > >> >> >> >> >>> > >
>> >> >> > > > > > > > > >>> > >> >> >> >> >>> > >-Jay
>> >> >> > > > > > > > > >>> > >> >> >> >> >>> > >
>> >> >> > > > > > > > > >>> > >> >> >> >> >>> > >On Tue, Jan 20, 2015 at
>>4:31
>> >> >>PM,
>> >> >> > > > Jiangjie
>> >> >> > > > > > Qin
>> >> >> > > > > > > > > >>> > >> >> >> >> >>><j...@linkedin.com.invalid
>> >> >> > > > > > > > > >>> > >> >> >> >> >>> >
>> >> >> > > > > > > > > >>> > >> >> >> >> >>> > >wrote:
>> >> >> > > > > > > > > >>> > >> >> >> >> >>> > >
>> >> >> > > > > > > > > >>> > >> >> >> >> >>> > >> Hi Kafka Devs,
>> >> >> > > > > > > > > >>> > >> >> >> >> >>> > >>
>> >> >> > > > > > > > > >>> > >> >> >> >> >>> > >> We are working on Kafka
>> >> >>Mirror
>> >> >> > Maker
>> >> >> > > > > > > > > >>>enhancement. A
>> >> >> > > > > > > > > >>> > >>KIP
>> >> >> > > > > > > > > >>> > >> >>is
>> >> >> > > > > > > > > >>> > >> >> >> >>posted
>> >> >> > > > > > > > > >>> > >> >> >> >> >>>to
>> >> >> > > > > > > > > >>> > >> >> >> >> >>> > >> document and discuss on
>> >>the
>> >> >> > > > followings:
>> >> >> > > > > > > > > >>> > >> >> >> >> >>> > >> 1. KAFKA-1650: No Data
>> >>loss
>> >> >> mirror
>> >> >> > > > maker
>> >> >> > > > > > > > change
>> >> >> > > > > > > > > >>> > >> >> >> >> >>> > >> 2. KAFKA-1839: To allow
>> >> >> partition
>> >> >> > > > aware
>> >> >> > > > > > > > mirror.
>> >> >> > > > > > > > > >>> > >> >> >> >> >>> > >> 3. KAFKA-1840: To allow
>> >> >>message
>> >> >> > > > > > > > filtering/format
>> >> >> > > > > > > > > >>> > >> >>conversion
>> >> >> > > > > > > > > >>> > >> >> >> >> >>> > >> Feedbacks are welcome.
>> >>Please
>> >> >> let
>> >> >> > us
>> >> >> > > > know
>> >> >> > > > > > if
>> >> >> > > > > > > > you
>> >> >> > > > > > > > > >>> have
>> >> >> > > > > > > > > >>> > >>any
>> >> >> > > > > > > > > >>> > >> >> >> >> >>>questions or
>> >> >> > > > > > > > > >>> > >> >> >> >> >>> > >> concerns.
>> >> >> > > > > > > > > >>> > >> >> >> >> >>> > >>
>> >> >> > > > > > > > > >>> > >> >> >> >> >>> > >> Thanks.
>> >> >> > > > > > > > > >>> > >> >> >> >> >>> > >>
>> >> >> > > > > > > > > >>> > >> >> >> >> >>> > >> Jiangjie (Becket) Qin
>> >> >> > > > > > > > > >>> > >> >> >> >> >>> > >>
>> >> >> > > > > > > > > >>> > >> >> >> >> >>> >
>> >> >> > > > > > > > > >>> > >> >> >> >> >>> >
>> >> >> > > > > > > > > >>> > >> >> >> >> >>>
>> >> >> > > > > > > > > >>> > >> >> >> >> >>
>> >> >> > > > > > > > > >>> > >> >> >> >> >>
>> >> >> > > > > > > > > >>> > >> >> >> >> >>
>> >> >> > > > > > > > > >>> > >> >> >> >> >>--
>> >> >> > > > > > > > > >>> > >> >> >> >> >>Thanks,
>> >> >> > > > > > > > > >>> > >> >> >> >> >>Neha
>> >> >> > > > > > > > > >>> > >> >> >> >> >
>> >> >> > > > > > > > > >>> > >> >> >> >>
>> >> >> > > > > > > > > >>> > >> >> >> >>
>> >> >> > > > > > > > > >>> > >> >> >>
>> >> >> > > > > > > > > >>> > >> >> >>
>> >> >> > > > > > > > > >>> > >> >>
>> >> >> > > > > > > > > >>> > >> >>
>> >> >> > > > > > > > > >>> > >>
>> >> >> > > > > > > > > >>> > >>
>> >> >> > > > > > > > > >>> > >
>> >> >> > > > > > > > > >>> > >
>> >> >> > > > > > > > > >>> > >--
>> >> >> > > > > > > > > >>> > >Thanks,
>> >> >> > > > > > > > > >>> > >Neha
>> >> >> > > > > > > > > >>> >
>> >> >> > > > > > > > > >>> >
>> >> >> > > > > > > > > >>>
>> >> >> > > > > > > > > >>>
>> >> >> > > > > > > > > >>> --
>> >> >> > > > > > > > > >>> Thanks,
>> >> >> > > > > > > > > >>> Neha
>> >> >> > > > > > > > > >>>
>> >> >> > > > > > > > > >
>> >> >> > > > > > > > >
>> >> >> > > > > > > >
>> >> >> > > > > > > >
>> >> >> > > > > > >
>> >> >> > > > > > >
>> >> >> > > > > > > --
>> >> >> > > > > > > Thanks,
>> >> >> > > > > > > Neha
>> >> >> > > > > >
>> >> >> > > > > >
>> >> >> > > >
>> >> >> > > >
>> >> >> >
>> >> >> >
>> >> >>
>> >> >
>> >> >
>> >> >
>> >> >--
>> >> >Thanks,
>> >> >Neha
>> >>
>> >>
>>
>>
