Hi Yishun, I was actually not suggesting we should immediately make such dramatic change on the AbstractRequest APIs which will affect all requests types, just clarifying if it is your intent or not, since your code snippet in the KIP has "@Override" :)
I think an alternative way is to add such a function for for FindCoordinator only, i.e. besides the overridden `public FindCoordinatorRequest build(short version)` we can have one more function (note the function name need to be different since Java type erasure caused it to not able to differentiate these two otherwise, but we can consider a better name: buildMulti is only for illustration) public List<FindCoordinatorRequest> buildMulti(short version) It does mean that we now need to special-handle FindCoordinatorRequestBuilder in all callers from other requests, which is also a bit "ugly and dirty", but the change scope may be smaller. General changes on the AbstractRequestBuilder could be delayed until we realize this is a common usage for some other requests in their newer versions as well. Guozhang On Sun, Sep 2, 2018 at 4:10 PM, Yishun Guan <gyis...@gmail.com> wrote: > Hi Guozhang, > > Yes, you are right. I didn't notice T build() is bounded to <T extends > AbstractRequest>. > I was originally thinking T could be an AbstractedRequest or List<> > but I was wrong. Now the return type has to change from T build() to > List<T> build > where <T extends AbstractRequest>. As you mentioned, > this required a change for all the requests, probably need > a new KIP too, do you think. I will update this KIP accordingly first. > > However, do you see other benefits of changing the return type for build()? > The original improvement that we want is this: > https://issues.apache.org/jira/browse/KAFKA-6788. > It seems like we have to make a lot of structural changes for this > small improvement. > I think changing the return type might benefit the project in the future, > but I don't know the project enough to say so. I would love to keep > working on this, > but do you see all these changes are worth for this story, > and if not, is there another way out? > > Thanks, > Yishun > On Sat, Sep 1, 2018 at 11:04 AM Guozhang Wang <wangg...@gmail.com> wrote: > > > > Hello Yishun, > > > > Thanks for the updated KIP. I think option 1), i.e. return multiple > > requests from build() call is okay. Just to clarify: you are going to > > change `AbstractRequest#build(short version)` signature, and hence all > > requests need to be updated accordingly, but only FindCoordinator for may > > return multiple requests in the list, while all others will return > > singleton list, right? > > > > > > Guozhang > > > > > > On Fri, Aug 31, 2018 at 10:51 AM, Yishun Guan <gyis...@gmail.com> wrote: > > > > > @Guozhang Wang Could you review this again when you have time? Thanks! > > > -Yishun > > > On Wed, Aug 29, 2018 at 11:57 AM Yishun Guan <gyis...@gmail.com> > wrote: > > > > > > > > Hi, because I have made some significant changes on this design, so I > > > > want to reopen the discussion on this KIP: > > > > https://cwiki.apache.org/confluence/x/CgZPBQ > > > > > > > > Thanks, > > > > Yishun > > > > On Thu, Aug 16, 2018 at 5:06 PM Yishun Guan <gyis...@gmail.com> > wrote: > > > > > > > > > > I see! Thanks! > > > > > > > > > > On Thu, Aug 16, 2018, 4:35 PM Guozhang Wang <wangg...@gmail.com> > > > wrote: > > > > >> > > > > >> It is not implemented, but should not be hard to do so (and again > you > > > do > > > > >> NOT have to do that in this KIP, I'm bringing this up so that you > can > > > help > > > > >> thinking about the process). > > > > >> > > > > >> Quoting from Colin's comment: > > > > >> > > > > >> " > > > > >> The pattern is that you would try to send a request for more than > one > > > > >> group, and then you would get an UnsupportedVersionException > (nothing > > > would > > > > >> be sent on the wire, this is purely internal to the code). > > > > >> Then your code would handle the UVE by creating requests with an > older > > > > >> version that only had one group each. > > > > >> " > > > > >> > > > > >> > > > > >> Guozhang > > > > >> > > > > >> > > > > >> On Wed, Aug 15, 2018 at 4:44 PM, Yishun Guan <gyis...@gmail.com> > > > wrote: > > > > >> > > > > >> > Hi, I am looking into AdminClient.scala and AdminClient.java, > and > > > also > > > > >> > looking into ApiVersionRequest.java and ApiVersionResponse.java, > > > but I > > > > >> > don't see anywhere contains to logic of the one-to-one mapping > from > > > version > > > > >> > to version, am i looking at the right place? > > > > >> > > > > > >> > On Mon, Aug 13, 2018 at 1:30 PM Guozhang Wang < > wangg...@gmail.com> > > > wrote: > > > > >> > > > > > >> > > Regarding 3): Today we do not have this logic with the > existing > > > client, > > > > >> > > because defer the decision about the version to use (we always > > > assume > > > > >> > that > > > > >> > > an new versioned request need to be down-converted to a > single old > > > > >> > > versioned request: i.e. an one-to-one mapping), but in > principle, > > > we > > > > >> > should > > > > >> > > be able to modify the client make it work. > > > > >> > > > > > > >> > > Again this is not necessarily need to be included in this KIP, > > > but I'd > > > > >> > > recommend you to look into AdminClient implementations around > the > > > > >> > > ApiVersionRequest / Response and think about how that logic > can be > > > > >> > modified > > > > >> > > in the follow-up PR of this KIP. > > > > >> > > > > > > >> > > > > > > >> > > > > > > >> > > Guozhang > > > > >> > > > > > > >> > > On Mon, Aug 13, 2018 at 12:55 PM, Yishun Guan < > gyis...@gmail.com> > > > wrote: > > > > >> > > > > > > >> > > > @Guozhang, thank you so much! > > > > >> > > > 1. I agree, fixed. > > > > >> > > > 2. Added. > > > > >> > > > 3. I see, that is something that I haven't think about. How > > > does Kafka > > > > >> > > > handle other api's different version problem now? So we > have a > > > specific > > > > >> > > > convertor that convect a new version request to a old > version > > > one for > > > > >> > > each > > > > >> > > > API (is this what the ApiVersionsRequest supposed to do, > does > > > it only > > > > >> > > > handle the detection or it should handle the conversion > too)? > > > What will > > > > >> > > be > > > > >> > > > the consequence of not having such a transformer but the > > > version is > > > > >> > > > incompatible? > > > > >> > > > > > > > >> > > > Best, > > > > >> > > > Yishun > > > > >> > > > > > > > >> > > > On Sat, Aug 11, 2018 at 11:27 AM Guozhang Wang < > > > wangg...@gmail.com> > > > > >> > > wrote: > > > > >> > > > > > > > >> > > > > Hello Yishun, > > > > >> > > > > > > > > >> > > > > Thanks for the proposed KIP. I made a pass over the wiki > and > > > here are > > > > >> > > > some > > > > >> > > > > comments: > > > > >> > > > > > > > > >> > > > > 1. "DESCRIBE_GROUPS_RESPONSE_MEMBER_V0", why we need to > > > encode the > > > > >> > full > > > > >> > > > > schema for the "COORDINATOR_GROUPIDS_KEY_NAME" field? > Note it > > > > >> > includes > > > > >> > > a > > > > >> > > > > lot of fields such as member id that is not needed for > this > > > case. I > > > > >> > > > think a > > > > >> > > > > "new ArrayOf(String)" for the group ids should be > sufficient. > > > > >> > > > > > > > > >> > > > > 2. "schemaVersions" of the "FindCoordinatorRequest" needs > to > > > include > > > > >> > > > > FIND_COORDINATOR_REQUEST_V3 as well. > > > > >> > > > > > > > > >> > > > > 3. One thing you may need to consider is that, in the > > > adminClient to > > > > >> > > > handle > > > > >> > > > > broker compatibility, how to transform a new (v3) request > to > > > a bunch > > > > >> > of > > > > >> > > > > (v2) requests if it detects the broker is still in old > > > version and > > > > >> > > hence > > > > >> > > > > cannot support v3 request (this logic is already > implemented > > > via > > > > >> > > > > ApiVersionsRequest in AdminClient, but may need to be > > > extended to > > > > >> > > handle > > > > >> > > > > one-to-many mapping of different versions). > > > > >> > > > > > > > > >> > > > > This is not sth. that you need to implement under this > KIP, > > > but I'd > > > > >> > > > > recommend you think about this earlier than later and see > if > > > it may > > > > >> > > > affect > > > > >> > > > > this proposal. > > > > >> > > > > > > > > >> > > > > > > > > >> > > > > Guozhang > > > > >> > > > > > > > > >> > > > > > > > > >> > > > > On Sat, Aug 11, 2018 at 10:54 AM, Yishun Guan < > > > gyis...@gmail.com> > > > > >> > > wrote: > > > > >> > > > > > > > > >> > > > > > Hi, thank you Ted! I have addressed your comments: > > > > >> > > > > > > > > > >> > > > > > 1. Added more descriptions about later optimization. > > > > >> > > > > > 2. Yes, I will implement the V3 later when this KIP gets > > > accepted. > > > > >> > > > > > 3. Fixed. > > > > >> > > > > > > > > > >> > > > > > Thanks, > > > > >> > > > > > Yishun > > > > >> > > > > > > > > > >> > > > > > On Fri, Aug 10, 2018 at 3:32 PM Ted Yu < > yuzhih...@gmail.com > > > > > > > > >> > wrote: > > > > >> > > > > > > > > > >> > > > > > > bq. this is the foundation of some later possible > > > > >> > > > optimizations(enable > > > > >> > > > > > > batching in *describeConsumerGroups ...* > > > > >> > > > > > > > > > > >> > > > > > > *Can you say more why this change lays the foundation > for > > > the > > > > >> > > future > > > > >> > > > > > > optimizations ?* > > > > >> > > > > > > > > > > >> > > > > > > *You mentioned **FIND_COORDINATOR_REQUEST_V3 in the > wiki > > > but I > > > > >> > > don't > > > > >> > > > > see > > > > >> > > > > > it > > > > >> > > > > > > in PR.* > > > > >> > > > > > > *I assume you would add that later.* > > > > >> > > > > > > > > > > >> > > > > > > *Please read your wiki and fix grammatical error such > as > > > the > > > > >> > > > > following:* > > > > >> > > > > > > > > > > >> > > > > > > bq. that need to be make > > > > >> > > > > > > > > > > >> > > > > > > Thanks > > > > >> > > > > > > > > > > >> > > > > > > On Wed, Aug 8, 2018 at 3:55 PM Yishun Guan < > > > gyis...@gmail.com> > > > > >> > > > wrote: > > > > >> > > > > > > > > > > >> > > > > > > > Hi all, > > > > >> > > > > > > > > > > > >> > > > > > > > I would like to start a discussion on: > > > > >> > > > > > > > > > > > >> > > > > > > > KIP-347: Enable batching in FindCoordinatorRequest > > > > >> > > > > > > > https://cwiki.apache.org/confluence/x/CgZPBQ > > > > >> > > > > > > > > > > > >> > > > > > > > Thanks @Guozhang Wang <wangg...@gmail.com> for his > > > help and > > > > >> > > > > patience! > > > > >> > > > > > > > > > > > >> > > > > > > > Thanks, > > > > >> > > > > > > > Yishun > > > > >> > > > > > > > > > > > >> > > > > > > > > > > >> > > > > > > > > > >> > > > > > > > > >> > > > > > > > > >> > > > > > > > > >> > > > > -- > > > > >> > > > > -- Guozhang > > > > >> > > > > > > > > >> > > > > > > > >> > > > > > > >> > > > > > > >> > > > > > > >> > > -- > > > > >> > > -- Guozhang > > > > >> > > > > > > >> > > > > > >> > > > > >> > > > > >> > > > > >> -- > > > > >> -- Guozhang > > > > > > > > > > > -- > > -- Guozhang > -- -- Guozhang
