Hi Jeyhun, All KIP-182 API PRs have now been merged. So you can consider it as stable. Thanks, Damian
On Thu, 21 Sep 2017 at 15:23 Jeyhun Karimov <je.kari...@gmail.com> wrote: > Hi all, > > Thanks a lot for your comments. For the single interface (RichXXX and > XXXWithKey) solution, I have already submitted a PR but probably it is > outdated (when the KIP first proposed), I need to revisit that one. > > @Guozhang, from our (offline) discussion, I understood that we may not make > it merge this KIP into the upcoming release, as KIP-159 is not voted yet > (because we want both KIP-149 and KIP-159 to be as an "atomic" merge). So > I decided to wait until KIP-182 gets stable (there are some minor updates > AFAIK) and update the KIP accordingly. Please correct me if I am wrong or I > misunderstood. > > Cheers, > Jeyhun > > > On Thu, Sep 21, 2017 at 4:11 PM Damian Guy <damian....@gmail.com> wrote: > > > +1 > > > > On Thu, 21 Sep 2017 at 13:46 Guozhang Wang <wangg...@gmail.com> wrote: > > > > > +1 for me as well for collapsing. > > > > > > Jeyhun, could you update the wiki accordingly to show what's the final > > > updates post KIP-182 that needs to be done in KIP-159 including > KIP-149? > > > The child page I made is just a suggestion, but you would still need to > > > update your proposal for people to comment and vote on. > > > > > > > > > Guozhang > > > > > > > > > On Thu, Sep 14, 2017 at 10:37 PM, Ted Yu <yuzhih...@gmail.com> wrote: > > > > > > > +1 > > > > > > > > One interface is cleaner. > > > > > > > > On Thu, Sep 14, 2017 at 7:26 AM, Bill Bejeck <bbej...@gmail.com> > > wrote: > > > > > > > > > +1 for me on collapsing the RichXXXX and ValueXXXXWithKey > interfaces > > > > into 1 > > > > > interface. > > > > > > > > > > Thanks, > > > > > Bill > > > > > > > > > > On Wed, Sep 13, 2017 at 11:31 AM, Jeyhun Karimov < > > je.kari...@gmail.com > > > > > > > > > wrote: > > > > > > > > > > > Hi Damian, > > > > > > > > > > > > Thanks for your feedback. Actually, this (what you propose) was > the > > > > first > > > > > > idea of KIP-149. Then we decided to divide it into two KIPs. I > also > > > > > > expressed my opinion that keeping the two interfaces (Rich and > > > withKey) > > > > > > separate would add more overloads. So, email discussion resulted > > that > > > > > this > > > > > > would not be a problem. > > > > > > > > > > > > Our initial idea was similar to : > > > > > > > > > > > > public abstract class RichValueMapper<K, V, VR> implements > > > > > > ValueMapperWithKey<K, V, VR>, RichFunction { > > > > > > ...... > > > > > > } > > > > > > > > > > > > > > > > > > So, we check the type of object, whether it is RichXXX or > > XXXWithKey > > > > > inside > > > > > > the called method and continue accordingly. > > > > > > > > > > > > If this is ok with the community, I would like to revert the > > current > > > > > design > > > > > > to this again. > > > > > > > > > > > > Cheers, > > > > > > Jeyhun > > > > > > > > > > > > On Wed, Sep 13, 2017 at 3:02 PM Damian Guy <damian....@gmail.com > > > > > > wrote: > > > > > > > > > > > > > Hi Jeyhun, > > > > > > > > > > > > > > Thanks for sending out the update. I guess i was thinking more > > > along > > > > > the > > > > > > > lines of option 2 where we collapse the RichXXXX and > > > ValueXXXXWithKey > > > > > etc > > > > > > > interfaces into 1 interface that has all of the arguments. I > > think > > > we > > > > > > then > > > > > > > only need to add one additional overload for each operator? > > > > > > > > > > > > > > Thanks, > > > > > > > Damian > > > > > > > > > > > > > > On Wed, 13 Sep 2017 at 10:59 Jeyhun Karimov < > > je.kari...@gmail.com> > > > > > > wrote: > > > > > > > > > > > > > > > Dear all, > > > > > > > > > > > > > > > > I would like to resume the discussion on KIP-159. I (and > > > Guozhang) > > > > > > think > > > > > > > > that releasing KIP-149 and KIP-159 in the same release would > > make > > > > > sense > > > > > > > to > > > > > > > > avoid a release with "partial" public APIs. There is a KIP > [1] > > > > > proposed > > > > > > > by > > > > > > > > Guozhang (and approved by me) to unify both KIPs. > > > > > > > > Please feel free to comment on this. > > > > > > > > > > > > > > > > [1] > > > > > > > > > > > > > > > https://cwiki.apache.org/confluence/pages/viewpage. > > > > > > action?pageId=73637757 > > > > > > > > > > > > > > > > Cheers, > > > > > > > > Jeyhun > > > > > > > > > > > > > > > > On Fri, Jul 21, 2017 at 2:00 AM Jeyhun Karimov < > > > > je.kari...@gmail.com > > > > > > > > > > > > > > wrote: > > > > > > > > > > > > > > > > > Hi Matthias, Damian, all, > > > > > > > > > > > > > > > > > > Thanks for your comments and sorry for super-late update. > > > > > > > > > > > > > > > > > > Sure, the DSL refactoring is not blocking for this KIP. > > > > > > > > > I made some changes to KIP document based on my prototype. > > > > > > > > > > > > > > > > > > Please feel free to comment. > > > > > > > > > > > > > > > > > > Cheers, > > > > > > > > > Jeyhun > > > > > > > > > > > > > > > > > > On Fri, Jul 7, 2017 at 9:35 PM Matthias J. Sax < > > > > > > matth...@confluent.io> > > > > > > > > > wrote: > > > > > > > > > > > > > > > > > >> I would not block this KIP with regard to DSL refactoring. > > > IMHO, > > > > > we > > > > > > > can > > > > > > > > >> just finish this one and the DSL refactoring will help > later > > > on > > > > to > > > > > > > > >> reduce the number of overloads. > > > > > > > > >> > > > > > > > > >> -Matthias > > > > > > > > >> > > > > > > > > >> On 7/7/17 5:28 AM, Jeyhun Karimov wrote: > > > > > > > > >> > I am following the related thread in the mailing list > and > > > > > looking > > > > > > > > >> forward > > > > > > > > >> > for one-shot solution for overloads issue. > > > > > > > > >> > > > > > > > > > >> > Cheers, > > > > > > > > >> > Jeyhun > > > > > > > > >> > > > > > > > > > >> > On Fri, Jul 7, 2017 at 10:32 AM Damian Guy < > > > > > damian....@gmail.com> > > > > > > > > >> wrote: > > > > > > > > >> > > > > > > > > > >> >> Hi Jeyhun, > > > > > > > > >> >> > > > > > > > > >> >> About overrides, what other alternatives do we have? > For > > > > > > > > >> >>> backwards-compatibility we have to add extra methods > to > > > the > > > > > > > existing > > > > > > > > >> >> ones. > > > > > > > > >> >>> > > > > > > > > >> >>> > > > > > > > > >> >> It wasn't clear to me in the KIP if these are new > methods > > > or > > > > > > > > replacing > > > > > > > > >> >> existing ones. > > > > > > > > >> >> Also, we are currently discussing options for replacing > > the > > > > > > > > overrides. > > > > > > > > >> >> > > > > > > > > >> >> Thanks, > > > > > > > > >> >> Damian > > > > > > > > >> >> > > > > > > > > >> >> > > > > > > > > >> >>> About ProcessorContext vs RecordContext, you are > right. > > I > > > > > think > > > > > > I > > > > > > > > >> need to > > > > > > > > >> >>> implement a prototype to understand the full picture > as > > > some > > > > > > parts > > > > > > > > of > > > > > > > > >> the > > > > > > > > >> >>> KIP might not be as straightforward as I thought. > > > > > > > > >> >>> > > > > > > > > >> >>> > > > > > > > > >> >>> Cheers, > > > > > > > > >> >>> Jeyhun > > > > > > > > >> >>> > > > > > > > > >> >>> On Wed, Jul 5, 2017 at 10:40 AM Damian Guy < > > > > > > damian....@gmail.com> > > > > > > > > >> wrote: > > > > > > > > >> >>> > > > > > > > > >> >>>> HI Jeyhun, > > > > > > > > >> >>>> > > > > > > > > >> >>>> Is the intention that these methods are new overloads > > on > > > > the > > > > > > > > KStream, > > > > > > > > >> >>>> KTable, etc? > > > > > > > > >> >>>> > > > > > > > > >> >>>> It is worth noting that a ProcessorContext is not a > > > > > > > RecordContext. > > > > > > > > A > > > > > > > > >> >>>> RecordContext, as it stands, only exists during the > > > > > processing > > > > > > > of a > > > > > > > > >> >>> single > > > > > > > > >> >>>> record. Whereas the ProcessorContext exists for the > > > > lifetime > > > > > of > > > > > > > the > > > > > > > > >> >>>> Processor. Sot it doesn't make sense to cast a > > > > > ProcessorContext > > > > > > > to > > > > > > > > a > > > > > > > > >> >>>> RecordContext. > > > > > > > > >> >>>> You mentioned above passing the > > InternalProcessorContext > > > to > > > > > the > > > > > > > > >> init() > > > > > > > > >> >>>> calls. It is internal for a reason and i think it > > should > > > > > remain > > > > > > > > that > > > > > > > > >> >> way. > > > > > > > > >> >>>> It might be better to move the recordContext() method > > > from > > > > > > > > >> >>>> InternalProcessorContext to ProcessorContext. > > > > > > > > >> >>>> > > > > > > > > >> >>>> In the KIP you have an example showing: > > > > > > > > >> >>>> richMapper.init((RecordContext) processorContext); > > > > > > > > >> >>>> But the interface is: > > > > > > > > >> >>>> public interface RichValueMapper<V, VR> { > > > > > > > > >> >>>> VR apply(final V value, final RecordContext > > > > > recordContext); > > > > > > > > >> >>>> } > > > > > > > > >> >>>> i.e., there is no init(...), besides as above this > > > wouldn't > > > > > > make > > > > > > > > >> sense. > > > > > > > > >> >>>> > > > > > > > > >> >>>> Thanks, > > > > > > > > >> >>>> Damian > > > > > > > > >> >>>> > > > > > > > > >> >>>> On Tue, 4 Jul 2017 at 23:30 Jeyhun Karimov < > > > > > > je.kari...@gmail.com > > > > > > > > > > > > > > > > >> >> wrote: > > > > > > > > >> >>>> > > > > > > > > >> >>>>> Hi Matthias, > > > > > > > > >> >>>>> > > > > > > > > >> >>>>> Actually my intend was to provide to RichInitializer > > and > > > > > later > > > > > > > on > > > > > > > > we > > > > > > > > >> >>>> could > > > > > > > > >> >>>>> provide the context of the record as you also > > mentioned. > > > > > > > > >> >>>>> I remove that not to confuse the users. > > > > > > > > >> >>>>> Regarding the RecordContext and ProcessorContext > > > > > interfaces, I > > > > > > > > just > > > > > > > > >> >>>>> realized the InternalProcessorContext class. Can't > we > > > pass > > > > > > this > > > > > > > > as a > > > > > > > > >> >>>>> parameter to init() method of processors? Then we > > would > > > be > > > > > > able > > > > > > > to > > > > > > > > >> >> get > > > > > > > > >> >>>>> RecordContext easily with just a method call. > > > > > > > > >> >>>>> > > > > > > > > >> >>>>> > > > > > > > > >> >>>>> Cheers, > > > > > > > > >> >>>>> Jeyhun > > > > > > > > >> >>>>> > > > > > > > > >> >>>>> On Thu, Jun 29, 2017 at 10:14 PM Matthias J. Sax < > > > > > > > > >> >>> matth...@confluent.io> > > > > > > > > >> >>>>> wrote: > > > > > > > > >> >>>>> > > > > > > > > >> >>>>>> One more thing: > > > > > > > > >> >>>>>> > > > > > > > > >> >>>>>> I don't think `RichInitializer` does make sense. As > > we > > > > > don't > > > > > > > have > > > > > > > > >> >> any > > > > > > > > >> >>>>>> input record, there is also no context. We could of > > > > course > > > > > > > > provide > > > > > > > > >> >>> the > > > > > > > > >> >>>>>> context of the record that triggers the init call, > > but > > > > this > > > > > > > seems > > > > > > > > >> >> to > > > > > > > > >> >>> be > > > > > > > > >> >>>>>> semantically questionable. Also, the context for > this > > > > first > > > > > > > > record > > > > > > > > >> >>> will > > > > > > > > >> >>>>>> be provided by the consecutive call to aggregate > > > anyways. > > > > > > > > >> >>>>>> > > > > > > > > >> >>>>>> > > > > > > > > >> >>>>>> -Matthias > > > > > > > > >> >>>>>> > > > > > > > > >> >>>>>> On 6/29/17 1:11 PM, Matthias J. Sax wrote: > > > > > > > > >> >>>>>>> Thanks for updating the KIP. > > > > > > > > >> >>>>>>> > > > > > > > > >> >>>>>>> I have one concern with regard to backward > > > > compatibility. > > > > > > You > > > > > > > > >> >>> suggest > > > > > > > > >> >>>>> to > > > > > > > > >> >>>>>>> use RecrodContext as base interface for > > > > ProcessorContext. > > > > > > This > > > > > > > > >> >> will > > > > > > > > >> >>>>>>> break compatibility. > > > > > > > > >> >>>>>>> > > > > > > > > >> >>>>>>> I think, we should just have two independent > > > interfaces. > > > > > Our > > > > > > > own > > > > > > > > >> >>>>>>> ProcessorContextImpl class would implement both. > > This > > > > > allows > > > > > > > us > > > > > > > > >> >> to > > > > > > > > >> >>>> cast > > > > > > > > >> >>>>>>> it to `RecordContext` and thus limit the visible > > > scope. > > > > > > > > >> >>>>>>> > > > > > > > > >> >>>>>>> > > > > > > > > >> >>>>>>> -Matthias > > > > > > > > >> >>>>>>> > > > > > > > > >> >>>>>>> > > > > > > > > >> >>>>>>> > > > > > > > > >> >>>>>>> On 6/27/17 1:35 PM, Jeyhun Karimov wrote: > > > > > > > > >> >>>>>>>> Hi all, > > > > > > > > >> >>>>>>>> > > > > > > > > >> >>>>>>>> I updated the KIP w.r.t. discussion and comments. > > > > > > > > >> >>>>>>>> Basically I eliminated overloads for particular > > > method > > > > if > > > > > > > they > > > > > > > > >> >> are > > > > > > > > >> >>>>> more > > > > > > > > >> >>>>>>>> than 3. > > > > > > > > >> >>>>>>>> As we can see there are a lot of overloads (and > > more > > > > will > > > > > > > come > > > > > > > > >> >>> with > > > > > > > > >> >>>>>> KIP-149 > > > > > > > > >> >>>>>>>> :) ) > > > > > > > > >> >>>>>>>> So, is it wise to > > > > > > > > >> >>>>>>>> wait the result of constructive DSL thread or > > > > > > > > >> >>>>>>>> extend KIP to address this issue as well or > > > > > > > > >> >>>>>>>> continue as it is? > > > > > > > > >> >>>>>>>> > > > > > > > > >> >>>>>>>> Cheers, > > > > > > > > >> >>>>>>>> Jeyhun > > > > > > > > >> >>>>>>>> > > > > > > > > >> >>>>>>>> On Wed, Jun 14, 2017 at 11:29 PM Guozhang Wang < > > > > > > > > >> >>> wangg...@gmail.com> > > > > > > > > >> >>>>>> wrote: > > > > > > > > >> >>>>>>>> > > > > > > > > >> >>>>>>>>> LGTM. Thanks! > > > > > > > > >> >>>>>>>>> > > > > > > > > >> >>>>>>>>> > > > > > > > > >> >>>>>>>>> Guozhang > > > > > > > > >> >>>>>>>>> > > > > > > > > >> >>>>>>>>> On Tue, Jun 13, 2017 at 2:20 PM, Jeyhun Karimov > < > > > > > > > > >> >>>>> je.kari...@gmail.com> > > > > > > > > >> >>>>>>>>> wrote: > > > > > > > > >> >>>>>>>>> > > > > > > > > >> >>>>>>>>>> Thanks for the comment Matthias. After all the > > > > > discussion > > > > > > > > >> >>> (thanks > > > > > > > > >> >>>> to > > > > > > > > >> >>>>>> all > > > > > > > > >> >>>>>>>>>> participants), I think this (single method that > > > > passes > > > > > > in a > > > > > > > > >> >>>>>> RecordContext > > > > > > > > >> >>>>>>>>>> object) is the best alternative. > > > > > > > > >> >>>>>>>>>> Just a side note: I think KAFKA-3907 [1] can > also > > > be > > > > > > > > >> >> integrated > > > > > > > > >> >>>> into > > > > > > > > >> >>>>>> the > > > > > > > > >> >>>>>>>>>> KIP by adding related method inside > RecordContext > > > > > > > interface. > > > > > > > > >> >>>>>>>>>> > > > > > > > > >> >>>>>>>>>> > > > > > > > > >> >>>>>>>>>> [1] > > > https://issues.apache.org/jira/browse/KAFKA-3907 > > > > > > > > >> >>>>>>>>>> > > > > > > > > >> >>>>>>>>>> > > > > > > > > >> >>>>>>>>>> Cheers, > > > > > > > > >> >>>>>>>>>> Jeyhun > > > > > > > > >> >>>>>>>>>> > > > > > > > > >> >>>>>>>>>> On Tue, Jun 13, 2017 at 7:50 PM Matthias J. > Sax < > > > > > > > > >> >>>>>> matth...@confluent.io> > > > > > > > > >> >>>>>>>>>> wrote: > > > > > > > > >> >>>>>>>>>> > > > > > > > > >> >>>>>>>>>>> Hi, > > > > > > > > >> >>>>>>>>>>> > > > > > > > > >> >>>>>>>>>>> I would like to push this discussion further. > It > > > > seems > > > > > > we > > > > > > > > got > > > > > > > > >> >>>> nice > > > > > > > > >> >>>>>>>>>>> alternatives (thanks for the summary Jeyhun!). > > > > > > > > >> >>>>>>>>>>> > > > > > > > > >> >>>>>>>>>>> With respect to RichFunctions and allowing > them > > to > > > > be > > > > > > > > >> >>> stateful, I > > > > > > > > >> >>>>>> have > > > > > > > > >> >>>>>>>>>>> my doubt as expressed already. From my > > > > understanding, > > > > > > the > > > > > > > > >> >> idea > > > > > > > > >> >>>> was > > > > > > > > >> >>>>> to > > > > > > > > >> >>>>>>>>>>> give access to record metadata information > only. > > > If > > > > > you > > > > > > > want > > > > > > > > >> >> to > > > > > > > > >> >>>> do > > > > > > > > >> >>>>> a > > > > > > > > >> >>>>>>>>>>> stateful computation you should rather use > > > > > #transform(). > > > > > > > > >> >>>>>>>>>>> > > > > > > > > >> >>>>>>>>>>> Furthermore, as pointed out, we would need to > > > switch > > > > > to > > > > > > a > > > > > > > > >> >>>>>>>>>>> supplier-pattern introducing many more > > overloads. > > > > > > > > >> >>>>>>>>>>> > > > > > > > > >> >>>>>>>>>>> For those reason, I advocate for a simple > > > interface > > > > > > with a > > > > > > > > >> >>> single > > > > > > > > >> >>>>>>>>> method > > > > > > > > >> >>>>>>>>>>> that passes in a RecordContext object. > > > > > > > > >> >>>>>>>>>>> > > > > > > > > >> >>>>>>>>>>> > > > > > > > > >> >>>>>>>>>>> -Matthias > > > > > > > > >> >>>>>>>>>>> > > > > > > > > >> >>>>>>>>>>> > > > > > > > > >> >>>>>>>>>>> On 6/6/17 5:15 PM, Guozhang Wang wrote: > > > > > > > > >> >>>>>>>>>>>> Thanks for the comprehensive summary! > > > > > > > > >> >>>>>>>>>>>> > > > > > > > > >> >>>>>>>>>>>> Personally I'd prefer the option of passing > > > > > > RecordContext > > > > > > > > as > > > > > > > > >> >>> an > > > > > > > > >> >>>>>>>>>>> additional > > > > > > > > >> >>>>>>>>>>>> parameter into he overloaded function. But > I'm > > > also > > > > > > open > > > > > > > to > > > > > > > > >> >>>> other > > > > > > > > >> >>>>>>>>>>> arguments > > > > > > > > >> >>>>>>>>>>>> if there are sth. that I have overlooked. > > > > > > > > >> >>>>>>>>>>>> > > > > > > > > >> >>>>>>>>>>>> Guozhang > > > > > > > > >> >>>>>>>>>>>> > > > > > > > > >> >>>>>>>>>>>> > > > > > > > > >> >>>>>>>>>>>> On Mon, Jun 5, 2017 at 3:19 PM, Jeyhun > Karimov > > < > > > > > > > > >> >>>>>> je.kari...@gmail.com > > > > > > > > >> >>>>>>>>>> > > > > > > > > >> >>>>>>>>>>> wrote: > > > > > > > > >> >>>>>>>>>>>> > > > > > > > > >> >>>>>>>>>>>>> Hi, > > > > > > > > >> >>>>>>>>>>>>> > > > > > > > > >> >>>>>>>>>>>>> Thanks for your comments Matthias and > > Guozhang. > > > > > > > > >> >>>>>>>>>>>>> > > > > > > > > >> >>>>>>>>>>>>> Below I mention the quick summary of the > main > > > > > > > alternatives > > > > > > > > >> >> we > > > > > > > > >> >>>>>> looked > > > > > > > > >> >>>>>>>>>> at > > > > > > > > >> >>>>>>>>>>> to > > > > > > > > >> >>>>>>>>>>>>> introduce the Rich functions (I will refer > to > > it > > > > as > > > > > > Rich > > > > > > > > >> >>>>> functions > > > > > > > > >> >>>>>>>>>>> until we > > > > > > > > >> >>>>>>>>>>>>> find better/another name). Initially the > > > proposed > > > > > > > > >> >>> alternatives > > > > > > > > >> >>>>> was > > > > > > > > >> >>>>>>>>> not > > > > > > > > >> >>>>>>>>>>>>> backwards-compatible, so I will not mention > > > them. > > > > > > > > >> >>>>>>>>>>>>> The related discussions are spread in > KIP-149 > > > and > > > > in > > > > > > > this > > > > > > > > >> >> KIP > > > > > > > > >> >>>>>>>>>> (KIP-159) > > > > > > > > >> >>>>>>>>>>>>> discussion threads. > > > > > > > > >> >>>>>>>>>>>>> > > > > > > > > >> >>>>>>>>>>>>> > > > > > > > > >> >>>>>>>>>>>>> > > > > > > > > >> >>>>>>>>>>>>> 1. The idea of rich functions came into the > > > stage > > > > > with > > > > > > > > >> >>> KIP-149, > > > > > > > > >> >>>>> in > > > > > > > > >> >>>>>>>>>>>>> discussion thread. As a result we extended > > > KIP-149 > > > > > to > > > > > > > > >> >> support > > > > > > > > >> >>>>> Rich > > > > > > > > >> >>>>>>>>>>>>> functions as well. > > > > > > > > >> >>>>>>>>>>>>> > > > > > > > > >> >>>>>>>>>>>>> 2. To as part of the Rich functions, we > > > provided > > > > > init > > > > > > > > >> >>>>>>>>>>> (ProcessorContext) > > > > > > > > >> >>>>>>>>>>>>> method. Afterwards, Dammian suggested that > we > > > > should > > > > > > not > > > > > > > > >> >>>> provide > > > > > > > > >> >>>>>>>>>>>>> ProcessorContext to users. As a result, we > > > > separated > > > > > > the > > > > > > > > >> >> two > > > > > > > > >> >>>>>>>>> problems > > > > > > > > >> >>>>>>>>>>> into > > > > > > > > >> >>>>>>>>>>>>> two separate KIPs, as it seems they can be > > > solved > > > > in > > > > > > > > >> >>> parallel. > > > > > > > > >> >>>>>>>>>>>>> > > > > > > > > >> >>>>>>>>>>>>> - One approach we considered was : > > > > > > > > >> >>>>>>>>>>>>> > > > > > > > > >> >>>>>>>>>>>>> public interface ValueMapperWithKey<K, V, > VR> > > { > > > > > > > > >> >>>>>>>>>>>>> VR apply(final K key, final V value); > > > > > > > > >> >>>>>>>>>>>>> } > > > > > > > > >> >>>>>>>>>>>>> > > > > > > > > >> >>>>>>>>>>>>> public interface RichValueMapper<K, V, VR> > > > extends > > > > > > > > >> >>>> RichFunction{ > > > > > > > > >> >>>>>>>>>>>>> } > > > > > > > > >> >>>>>>>>>>>>> > > > > > > > > >> >>>>>>>>>>>>> public interface RichFunction { > > > > > > > > >> >>>>>>>>>>>>> void init(RecordContext recordContext); > > > > > > > > >> >>>>>>>>>>>>> void close(); > > > > > > > > >> >>>>>>>>>>>>> } > > > > > > > > >> >>>>>>>>>>>>> > > > > > > > > >> >>>>>>>>>>>>> public interface RecordContext { > > > > > > > > >> >>>>>>>>>>>>> String applicationId(); > > > > > > > > >> >>>>>>>>>>>>> TaskId taskId(); > > > > > > > > >> >>>>>>>>>>>>> StreamsMetrics metrics(); > > > > > > > > >> >>>>>>>>>>>>> String topic(); > > > > > > > > >> >>>>>>>>>>>>> int partition(); > > > > > > > > >> >>>>>>>>>>>>> long offset(); > > > > > > > > >> >>>>>>>>>>>>> long timestamp(); > > > > > > > > >> >>>>>>>>>>>>> Map<String, Object> appConfigs(); > > > > > > > > >> >>>>>>>>>>>>> Map<String, Object> > > > > appConfigsWithPrefix(String > > > > > > > > >> >> prefix); > > > > > > > > >> >>>>>>>>>>>>> } > > > > > > > > >> >>>>>>>>>>>>> > > > > > > > > >> >>>>>>>>>>>>> > > > > > > > > >> >>>>>>>>>>>>> public interface ProcessorContext extends > > > > > > RecordContext > > > > > > > { > > > > > > > > >> >>>>>>>>>>>>> // all methods but the ones in > > RecordContext > > > > > > > > >> >>>>>>>>>>>>> } > > > > > > > > >> >>>>>>>>>>>>> > > > > > > > > >> >>>>>>>>>>>>> As a result: > > > > > > > > >> >>>>>>>>>>>>> * . All "withKey" and "withoutKey" > interfaces > > > can > > > > be > > > > > > > > >> >>> converted > > > > > > > > >> >>>> to > > > > > > > > >> >>>>>>>>>> their > > > > > > > > >> >>>>>>>>>>>>> Rich counterparts (with empty init() and > > close() > > > > > > > methods) > > > > > > > > >> >>>>>>>>>>>>> *. All related Processors will accept Rich > > > > > interfaces > > > > > > in > > > > > > > > >> >>> their > > > > > > > > >> >>>>>>>>>>>>> constructors. > > > > > > > > >> >>>>>>>>>>>>> *. So, we convert the related "withKey" or > > > > > > "withoutKey" > > > > > > > > >> >>>>> interfaces > > > > > > > > >> >>>>>>>>> to > > > > > > > > >> >>>>>>>>>>> Rich > > > > > > > > >> >>>>>>>>>>>>> interface while building the topology and > > > > initialize > > > > > > the > > > > > > > > >> >>>> related > > > > > > > > >> >>>>>>>>>>> processors > > > > > > > > >> >>>>>>>>>>>>> with Rich interfaces only. > > > > > > > > >> >>>>>>>>>>>>> *. We will not need to overloaded methods > for > > > rich > > > > > > > > >> >> functions > > > > > > > > >> >>> as > > > > > > > > >> >>>>>> Rich > > > > > > > > >> >>>>>>>>>>>>> interfaces extend withKey interfaces. We > will > > > just > > > > > > check > > > > > > > > >> >> the > > > > > > > > >> >>>>> object > > > > > > > > >> >>>>>>>>>> type > > > > > > > > >> >>>>>>>>>>>>> and act accordingly. > > > > > > > > >> >>>>>>>>>>>>> > > > > > > > > >> >>>>>>>>>>>>> > > > > > > > > >> >>>>>>>>>>>>> > > > > > > > > >> >>>>>>>>>>>>> > > > > > > > > >> >>>>>>>>>>>>> 3. There was some thoughts that the above > > > approach > > > > > > does > > > > > > > > not > > > > > > > > >> >>>>> support > > > > > > > > >> >>>>>>>>>>> lambdas > > > > > > > > >> >>>>>>>>>>>>> so we should support only one method, only > > > > > > > > >> >>> init(RecordContext), > > > > > > > > >> >>>>> as > > > > > > > > >> >>>>>>>>>> part > > > > > > > > >> >>>>>>>>>>> of > > > > > > > > >> >>>>>>>>>>>>> Rich interfaces. > > > > > > > > >> >>>>>>>>>>>>> This is still in discussion. Personally I > > think > > > > Rich > > > > > > > > >> >>> interfaces > > > > > > > > >> >>>>> are > > > > > > > > >> >>>>>>>>> by > > > > > > > > >> >>>>>>>>>>>>> definition lambda-free and we should not > care > > > much > > > > > > about > > > > > > > > >> >> it. > > > > > > > > >> >>>>>>>>>>>>> > > > > > > > > >> >>>>>>>>>>>>> > > > > > > > > >> >>>>>>>>>>>>> 4. Thanks to Matthias's discussion, an > > > alternative > > > > > we > > > > > > > > >> >>>> considered > > > > > > > > >> >>>>>> was > > > > > > > > >> >>>>>>>>>> to > > > > > > > > >> >>>>>>>>>>>>> pass in the RecordContext as method > parameter. > > > > This > > > > > > > might > > > > > > > > >> >>> even > > > > > > > > >> >>>>>>>>> allow > > > > > > > > >> >>>>>>>>>> to > > > > > > > > >> >>>>>>>>>>>>> use Lambdas and we could keep the name > > > > RichFunction > > > > > as > > > > > > > we > > > > > > > > >> >>>>> preserve > > > > > > > > >> >>>>>>>>> the > > > > > > > > >> >>>>>>>>>>>>> nature of being a function. > > > > > > > > >> >>>>>>>>>>>>> "If you go with `init()` and `close()` we > > > > basically > > > > > > > > >> >>>>>>>>>>>>> allow users to have an in-memory state for a > > > > > function. > > > > > > > > >> >> Thus, > > > > > > > > >> >>> we > > > > > > > > >> >>>>>>>>> cannot > > > > > > > > >> >>>>>>>>>>>>> share a single instance of RichValueMapper > > (etc) > > > > > over > > > > > > > > >> >>> multiple > > > > > > > > >> >>>>>> tasks > > > > > > > > >> >>>>>>>>>> and > > > > > > > > >> >>>>>>>>>>>>> we would need a supplier pattern similar to > > > > > > > #transform(). > > > > > > > > >> >> And > > > > > > > > >> >>>>> this > > > > > > > > >> >>>>>>>>>> would > > > > > > > > >> >>>>>>>>>>>>> "break the flow" of the API, as > > > > > > > (Rich)ValueMapperSupplier > > > > > > > > >> >>> would > > > > > > > > >> >>>>> not > > > > > > > > >> >>>>>>>>>>>>> inherit from ValueMapper and thus we would > > need > > > > many > > > > > > new > > > > > > > > >> >>>> overload > > > > > > > > >> >>>>>>>>> for > > > > > > > > >> >>>>>>>>>>>>> KStream/KTable classes". (Copy paste from > > > > Matthias's > > > > > > > > email) > > > > > > > > >> >>>>>>>>>>>>> > > > > > > > > >> >>>>>>>>>>>>> > > > > > > > > >> >>>>>>>>>>>>> Cheers, > > > > > > > > >> >>>>>>>>>>>>> Jeyhun > > > > > > > > >> >>>>>>>>>>>>> > > > > > > > > >> >>>>>>>>>>>>> > > > > > > > > >> >>>>>>>>>>>>> On Mon, Jun 5, 2017 at 5:18 AM Matthias J. > > Sax < > > > > > > > > >> >>>>>>>>> matth...@confluent.io > > > > > > > > >> >>>>>>>>>>> > > > > > > > > >> >>>>>>>>>>>>> wrote: > > > > > > > > >> >>>>>>>>>>>>> > > > > > > > > >> >>>>>>>>>>>>>> Yes, we did consider this, and there is no > > > > > consensus > > > > > > > yet > > > > > > > > >> >>> what > > > > > > > > >> >>>>> the > > > > > > > > >> >>>>>>>>>> best > > > > > > > > >> >>>>>>>>>>>>>> alternative is. > > > > > > > > >> >>>>>>>>>>>>>> > > > > > > > > >> >>>>>>>>>>>>>> @Jeyhun: the email thread got pretty long. > > > Maybe > > > > > you > > > > > > > can > > > > > > > > >> >>> give > > > > > > > > >> >>>> a > > > > > > > > >> >>>>>>>>> quick > > > > > > > > >> >>>>>>>>>>>>>> summary of the current state of the > > discussion? > > > > > > > > >> >>>>>>>>>>>>>> > > > > > > > > >> >>>>>>>>>>>>>> > > > > > > > > >> >>>>>>>>>>>>>> -Matthias > > > > > > > > >> >>>>>>>>>>>>>> > > > > > > > > >> >>>>>>>>>>>>>> On 6/4/17 6:04 PM, Guozhang Wang wrote: > > > > > > > > >> >>>>>>>>>>>>>>> Thanks for the explanation Jeyhun and > > > Matthias. > > > > > > > > >> >>>>>>>>>>>>>>> > > > > > > > > >> >>>>>>>>>>>>>>> I have just read through both KIP-149 and > > > > KIP-159 > > > > > > and > > > > > > > am > > > > > > > > >> >>>>>> wondering > > > > > > > > >> >>>>>>>>>> if > > > > > > > > >> >>>>>>>>>>>>> you > > > > > > > > >> >>>>>>>>>>>>>>> guys have considered a slight different > > > approach > > > > > for > > > > > > > > rich > > > > > > > > >> >>>>>>>>> function, > > > > > > > > >> >>>>>>>>>>>>> that > > > > > > > > >> >>>>>>>>>>>>>> is > > > > > > > > >> >>>>>>>>>>>>>>> to add the `RecordContext` into the apply > > > > > functions > > > > > > as > > > > > > > > an > > > > > > > > >> >>>>>>>>> additional > > > > > > > > >> >>>>>>>>>>>>>>> parameter. For example: > > > > > > > > >> >>>>>>>>>>>>>>> > > > > > > > > >> >>>>>>>>>>>>>>> --------------------------- > > > > > > > > >> >>>>>>>>>>>>>>> > > > > > > > > >> >>>>>>>>>>>>>>> interface RichValueMapper<V, VR> { > > > > > > > > >> >>>>>>>>>>>>>>> > > > > > > > > >> >>>>>>>>>>>>>>> VR apply(final V value, final > RecordContext > > > > > > context); > > > > > > > > >> >>>>>>>>>>>>>>> > > > > > > > > >> >>>>>>>>>>>>>>> } > > > > > > > > >> >>>>>>>>>>>>>>> > > > > > > > > >> >>>>>>>>>>>>>>> ... > > > > > > > > >> >>>>>>>>>>>>>>> > > > > > > > > >> >>>>>>>>>>>>>>> // then in KStreams > > > > > > > > >> >>>>>>>>>>>>>>> > > > > > > > > >> >>>>>>>>>>>>>>> <VR> KStream<K, VR> > mapValues(ValueMapper<? > > > > super > > > > > > V, ? > > > > > > > > >> >>>> extends > > > > > > > > >> >>>>>> VR> > > > > > > > > >> >>>>>>>>>>>>>> mapper); > > > > > > > > >> >>>>>>>>>>>>>>> <VR> KStream<K, VR> > > > > > > > mapValueswithContext(RichValueMapper > > > > > > > > >> >> <? > > > > > > > > >> >>>>> super > > > > > > > > >> >>>>>>>>>> V, ? > > > > > > > > >> >>>>>>>>>>>>>>> extends VR> mapper); > > > > > > > > >> >>>>>>>>>>>>>>> > > > > > > > > >> >>>>>>>>>>>>>>> ------------------------------- > > > > > > > > >> >>>>>>>>>>>>>>> > > > > > > > > >> >>>>>>>>>>>>>>> The caveat is that it will introduces more > > > > > > overloads; > > > > > > > > >> >> but I > > > > > > > > >> >>>>> think > > > > > > > > >> >>>>>>>>>> the > > > > > > > > >> >>>>>>>>>>>>>>> #.overloads are mainly introduced by 1) > > serde > > > > > > > overrides > > > > > > > > >> >> and > > > > > > > > >> >>>> 2) > > > > > > > > >> >>>>>>>>>>>>>>> state-store-supplier overides, both of > which > > > can > > > > > be > > > > > > > > >> >> reduced > > > > > > > > >> >>>> in > > > > > > > > >> >>>>>> the > > > > > > > > >> >>>>>>>>>>> near > > > > > > > > >> >>>>>>>>>>>>>>> future, and I felt this overloading is > still > > > > > > > worthwhile, > > > > > > > > >> >> as > > > > > > > > >> >>>> it > > > > > > > > >> >>>>>> has > > > > > > > > >> >>>>>>>>>> the > > > > > > > > >> >>>>>>>>>>>>>>> following benefits: > > > > > > > > >> >>>>>>>>>>>>>>> > > > > > > > > >> >>>>>>>>>>>>>>> 1) still allow lambda expressions. > > > > > > > > >> >>>>>>>>>>>>>>> 2) clearer code path (do not need to > > "convert" > > > > > from > > > > > > > > >> >>> non-rich > > > > > > > > >> >>>>>>>>>> functions > > > > > > > > >> >>>>>>>>>>>>> to > > > > > > > > >> >>>>>>>>>>>>>>> rich functions) > > > > > > > > >> >>>>>>>>>>>>>>> > > > > > > > > >> >>>>>>>>>>>>>>> > > > > > > > > >> >>>>>>>>>>>>>>> Maybe this approach has already been > > discussed > > > > > and I > > > > > > > may > > > > > > > > >> >>> have > > > > > > > > >> >>>>>>>>>>>>> overlooked > > > > > > > > >> >>>>>>>>>>>>>> in > > > > > > > > >> >>>>>>>>>>>>>>> the email thread; anyways, lmk. > > > > > > > > >> >>>>>>>>>>>>>>> > > > > > > > > >> >>>>>>>>>>>>>>> > > > > > > > > >> >>>>>>>>>>>>>>> Guozhang > > > > > > > > >> >>>>>>>>>>>>>>> > > > > > > > > >> >>>>>>>>>>>>>>> > > > > > > > > >> >>>>>>>>>>>>>>> > > > > > > > > >> >>>>>>>>>>>>>>> On Thu, Jun 1, 2017 at 10:18 PM, Matthias > J. > > > > Sax < > > > > > > > > >> >>>>>>>>>>>>> matth...@confluent.io> > > > > > > > > >> >>>>>>>>>>>>>>> wrote: > > > > > > > > >> >>>>>>>>>>>>>>> > > > > > > > > >> >>>>>>>>>>>>>>>> I agree with Jeyhun. As already mention, > > the > > > > > > overall > > > > > > > > API > > > > > > > > >> >>>>>>>>>> improvement > > > > > > > > >> >>>>>>>>>>>>>>>> ideas are overlapping and/or > contradicting > > > each > > > > > > > other. > > > > > > > > >> >> For > > > > > > > > >> >>>>> this > > > > > > > > >> >>>>>>>>>>>>> reason, > > > > > > > > >> >>>>>>>>>>>>>>>> not all ideas can be accomplished and > some > > > Jira > > > > > > might > > > > > > > > >> >> just > > > > > > > > >> >>>> be > > > > > > > > >> >>>>>>>>>> closed > > > > > > > > >> >>>>>>>>>>>>> as > > > > > > > > >> >>>>>>>>>>>>>>>> "won't fix". > > > > > > > > >> >>>>>>>>>>>>>>>> > > > > > > > > >> >>>>>>>>>>>>>>>> For this reason, we try to do those KIP > > > > > discussion > > > > > > > with > > > > > > > > >> >>> are > > > > > > > > >> >>>>>> large > > > > > > > > >> >>>>>>>>>>>>> scope > > > > > > > > >> >>>>>>>>>>>>>>>> to get an overall picture to converge to > an > > > > > overall > > > > > > > > >> >>>> consisted > > > > > > > > >> >>>>>>>>> API. > > > > > > > > >> >>>>>>>>>>>>>>>> > > > > > > > > >> >>>>>>>>>>>>>>>> > > > > > > > > >> >>>>>>>>>>>>>>>> @Jeyhun: about the overloads. Yes, we > might > > > get > > > > > > more > > > > > > > > >> >>>> overload. > > > > > > > > >> >>>>>> It > > > > > > > > >> >>>>>>>>>>>>> might > > > > > > > > >> >>>>>>>>>>>>>>>> be sufficient though, to do a single > > > > > > xxxWithContext() > > > > > > > > >> >>>> overload > > > > > > > > >> >>>>>>>>> that > > > > > > > > >> >>>>>>>>>>>>> will > > > > > > > > >> >>>>>>>>>>>>>>>> provide key+value+context. Otherwise, if > > > might > > > > > get > > > > > > > too > > > > > > > > >> >>> messy > > > > > > > > >> >>>>>>>>> having > > > > > > > > >> >>>>>>>>>>>>>>>> ValueMapper, ValueMapperWithKey, > > > > > > > > ValueMapperWithContext, > > > > > > > > >> >>>>>>>>>>>>>>>> ValueMapperWithKeyWithContext. > > > > > > > > >> >>>>>>>>>>>>>>>> > > > > > > > > >> >>>>>>>>>>>>>>>> On the other hand, we also have the > > "builder > > > > > > pattern" > > > > > > > > >> >> idea > > > > > > > > >> >>>> as > > > > > > > > >> >>>>> an > > > > > > > > >> >>>>>>>>>> API > > > > > > > > >> >>>>>>>>>>>>>>>> change and this might mitigate the > overload > > > > > > problem. > > > > > > > > Not > > > > > > > > >> >>> for > > > > > > > > >> >>>>>>>>> simple > > > > > > > > >> >>>>>>>>>>>>>>>> function like map/flatMap etc but for > joins > > > and > > > > > > > > >> >>>> aggregations. > > > > > > > > >> >>>>>>>>>>>>>>>> > > > > > > > > >> >>>>>>>>>>>>>>>> > > > > > > > > >> >>>>>>>>>>>>>>>> On the other hand, as I mentioned in an > > older > > > > > > email, > > > > > > > I > > > > > > > > >> >> am > > > > > > > > >> >>>>>>>>>> personally > > > > > > > > >> >>>>>>>>>>>>>>>> fine to break the pure functional > > interface, > > > > and > > > > > > add > > > > > > > > >> >>>>>>>>>>>>>>>> > > > > > > > > >> >>>>>>>>>>>>>>>> - interface WithRecordContext with > method > > > > > > > > >> >>>>>> `open(RecordContext)` > > > > > > > > >> >>>>>>>>>> (or > > > > > > > > >> >>>>>>>>>>>>>>>> `init(...)`, or any better name) -- but > not > > > > > > > `close()`) > > > > > > > > >> >>>>>>>>>>>>>>>> > > > > > > > > >> >>>>>>>>>>>>>>>> - interface > ValueMapperWithRecordContext > > > > > extends > > > > > > > > >> >>>>> ValueMapper, > > > > > > > > >> >>>>>>>>>>>>>>>> WithRecordContext > > > > > > > > >> >>>>>>>>>>>>>>>> > > > > > > > > >> >>>>>>>>>>>>>>>> This would allow us to avoid any > overload. > > Of > > > > > > course, > > > > > > > > we > > > > > > > > >> >>>> don't > > > > > > > > >> >>>>>>>>> get > > > > > > > > >> >>>>>>>>>> a > > > > > > > > >> >>>>>>>>>>>>>>>> "pure function" interface and also > > sacrifices > > > > > > > Lambdas. > > > > > > > > >> >>>>>>>>>>>>>>>> > > > > > > > > >> >>>>>>>>>>>>>>>> > > > > > > > > >> >>>>>>>>>>>>>>>> > > > > > > > > >> >>>>>>>>>>>>>>>> I am personally a little bit undecided > what > > > the > > > > > > > better > > > > > > > > >> >>>> option > > > > > > > > >> >>>>>>>>> might > > > > > > > > >> >>>>>>>>>>>>> be. > > > > > > > > >> >>>>>>>>>>>>>>>> Curious to hear what other think about > this > > > > trade > > > > > > > off. > > > > > > > > >> >>>>>>>>>>>>>>>> > > > > > > > > >> >>>>>>>>>>>>>>>> > > > > > > > > >> >>>>>>>>>>>>>>>> -Matthias > > > > > > > > >> >>>>>>>>>>>>>>>> > > > > > > > > >> >>>>>>>>>>>>>>>> > > > > > > > > >> >>>>>>>>>>>>>>>> On 6/1/17 6:13 PM, Jeyhun Karimov wrote: > > > > > > > > >> >>>>>>>>>>>>>>>>> Hi Guozhang, > > > > > > > > >> >>>>>>>>>>>>>>>>> > > > > > > > > >> >>>>>>>>>>>>>>>>> It subsumes partially. Initially the > idea > > > was > > > > to > > > > > > > > >> >> support > > > > > > > > >> >>>>>>>>>>>>> RichFunctions > > > > > > > > >> >>>>>>>>>>>>>>>> as a > > > > > > > > >> >>>>>>>>>>>>>>>>> separate interface. Throughout the > > > discussion, > > > > > > > > however, > > > > > > > > >> >>> we > > > > > > > > >> >>>>>>>>>>> considered > > > > > > > > >> >>>>>>>>>>>>>>>> maybe > > > > > > > > >> >>>>>>>>>>>>>>>>> overloading the related methods (with > > > > > RecodContext > > > > > > > > >> >> param) > > > > > > > > >> >>>> is > > > > > > > > >> >>>>>>>>>> better > > > > > > > > >> >>>>>>>>>>>>>>>>> approach than providing a separate > > > > RichFunction > > > > > > > > >> >>> interface. > > > > > > > > >> >>>>>>>>>>>>>>>>> > > > > > > > > >> >>>>>>>>>>>>>>>>> Cheers, > > > > > > > > >> >>>>>>>>>>>>>>>>> Jeyhun > > > > > > > > >> >>>>>>>>>>>>>>>>> > > > > > > > > >> >>>>>>>>>>>>>>>>> On Fri, Jun 2, 2017 at 2:27 AM Guozhang > > > Wang < > > > > > > > > >> >>>>>>>>> wangg...@gmail.com> > > > > > > > > >> >>>>>>>>>>>>>> wrote: > > > > > > > > >> >>>>>>>>>>>>>>>>> > > > > > > > > >> >>>>>>>>>>>>>>>>>> Does this KIP subsume this ticket as > > well? > > > > > > > > >> >>>>>>>>>>>>>>>>>> https://issues.apache.org/ > > > > > jira/browse/KAFKA-4125 > > > > > > > > >> >>>>>>>>>>>>>>>>>> > > > > > > > > >> >>>>>>>>>>>>>>>>>> On Sat, May 20, 2017 at 9:05 AM, Jeyhun > > > > > Karimov < > > > > > > > > >> >>>>>>>>>>>>> je.kari...@gmail.com > > > > > > > > >> >>>>>>>>>>>>>>> > > > > > > > > >> >>>>>>>>>>>>>>>>>> wrote: > > > > > > > > >> >>>>>>>>>>>>>>>>>> > > > > > > > > >> >>>>>>>>>>>>>>>>>>> Dear community, > > > > > > > > >> >>>>>>>>>>>>>>>>>>> > > > > > > > > >> >>>>>>>>>>>>>>>>>>> As we discussed in KIP-149 [DISCUSS] > > > thread > > > > > > [1], I > > > > > > > > >> >>> would > > > > > > > > >> >>>>> like > > > > > > > > >> >>>>>>>>> to > > > > > > > > >> >>>>>>>>>>>>>>>> initiate > > > > > > > > >> >>>>>>>>>>>>>>>>>>> KIP for rich functions (interfaces) > [2]. > > > > > > > > >> >>>>>>>>>>>>>>>>>>> I would like to get your comments. > > > > > > > > >> >>>>>>>>>>>>>>>>>>> > > > > > > > > >> >>>>>>>>>>>>>>>>>>> > > > > > > > > >> >>>>>>>>>>>>>>>>>>> [1] > > > > > > > > >> >>>>>>>>>>>>>>>>>>> > > > > > > > > >> >>>> > > > http://search-hadoop.com/m/Kafka/uyzND1PMjdk2CslH12?subj= > > > > > > > > >> >>>>>>>>>>>>>>>>>>> > > Re+DISCUSS+KIP+149+Enabling+key+access+in+ > > > > > > > > >> >>>>>>>>>>>>>>>> ValueTransformer+ValueMapper+ > > > > > > > > >> >>>>>>>>>>>>>>>>>>> and+ValueJoiner > > > > > > > > >> >>>>>>>>>>>>>>>>>>> [2] > > > > > > > > >> >>>>>>>>>>>>>>>>>>> > > > > > > > > >> >> https://cwiki.apache.org/confluence/display/KAFKA/KIP- > > > > > > > > >> >>>>>>>>>>>>>>>>>>> 159%3A+Introducing+Rich+ > > > > functions+to+Streams > > > > > > > > >> >>>>>>>>>>>>>>>>>>> > > > > > > > > >> >>>>>>>>>>>>>>>>>>> > > > > > > > > >> >>>>>>>>>>>>>>>>>>> Cheers, > > > > > > > > >> >>>>>>>>>>>>>>>>>>> Jeyhun > > > > > > > > >> >>>>>>>>>>>>>>>>>>> -- > > > > > > > > >> >>>>>>>>>>>>>>>>>>> -Cheers > > > > > > > > >> >>>>>>>>>>>>>>>>>>> > > > > > > > > >> >>>>>>>>>>>>>>>>>>> Jeyhun > > > > > > > > >> >>>>>>>>>>>>>>>>>>> > > > > > > > > >> >>>>>>>>>>>>>>>>>> > > > > > > > > >> >>>>>>>>>>>>>>>>>> > > > > > > > > >> >>>>>>>>>>>>>>>>>> > > > > > > > > >> >>>>>>>>>>>>>>>>>> -- > > > > > > > > >> >>>>>>>>>>>>>>>>>> -- Guozhang > > > > > > > > >> >>>>>>>>>>>>>>>>>> > > > > > > > > >> >>>>>>>>>>>>>>>> > > > > > > > > >> >>>>>>>>>>>>>>>> > > > > > > > > >> >>>>>>>>>>>>>>> > > > > > > > > >> >>>>>>>>>>>>>>> > > > > > > > > >> >>>>>>>>>>>>>> > > > > > > > > >> >>>>>>>>>>>>>> -- > > > > > > > > >> >>>>>>>>>>>>> -Cheers > > > > > > > > >> >>>>>>>>>>>>> > > > > > > > > >> >>>>>>>>>>>>> Jeyhun > > > > > > > > >> >>>>>>>>>>>>> > > > > > > > > >> >>>>>>>>>>>> > > > > > > > > >> >>>>>>>>>>>> > > > > > > > > >> >>>>>>>>>>>> > > > > > > > > >> >>>>>>>>>>> > > > > > > > > >> >>>>>>>>>>> -- > > > > > > > > >> >>>>>>>>>> -Cheers > > > > > > > > >> >>>>>>>>>> > > > > > > > > >> >>>>>>>>>> Jeyhun > > > > > > > > >> >>>>>>>>>> > > > > > > > > >> >>>>>>>>> > > > > > > > > >> >>>>>>>>> > > > > > > > > >> >>>>>>>>> > > > > > > > > >> >>>>>>>>> -- > > > > > > > > >> >>>>>>>>> -- Guozhang > > > > > > > > >> >>>>>>>>> > > > > > > > > >> >>>>>>> > > > > > > > > >> >>>>>> > > > > > > > > >> >>>>>> -- > > > > > > > > >> >>>>> -Cheers > > > > > > > > >> >>>>> > > > > > > > > >> >>>>> Jeyhun > > > > > > > > >> >>>>> > > > > > > > > >> >>>> > > > > > > > > >> >>> -- > > > > > > > > >> >>> -Cheers > > > > > > > > >> >>> > > > > > > > > >> >>> Jeyhun > > > > > > > > >> >>> > > > > > > > > >> >> > > > > > > > > >> > > > > > > > > >> -- > > > > > > > > > -Cheers > > > > > > > > > > > > > > > > > > Jeyhun > > > > > > > > > > > > > > > > > -- > > > > > > > > -Cheers > > > > > > > > > > > > > > > > Jeyhun > > > > > > > > > > > > > > > > > > > > > -- > > > > > > -Cheers > > > > > > > > > > > > Jeyhun > > > > > > > > > > > > > > > > > > > > > > > > > > > -- > > > -- Guozhang > > > > > >