I updated the wiki to include both results along with their average. Thank you, Crispin
On Mon, Jul 24, 2023 at 10:58 AM Ismael Juma <m...@ismaeljuma.com> wrote: > Hi Crispin, > > One additional question, the wiki says "The results are averaged over 2 > runs.". Can you please provide some measure of variance in the > distribution, i.e. were both results similar to each other for both cases? > > Ismael > > On Fri, Jul 21, 2023 at 11:31 AM Ismael Juma <m...@ismaeljuma.com> wrote: > > > Thanks for the update Crispin - very helpful to have actual performance > > data. 2-5% for the default configuration is a bit on the low side for > this > > kind of proposal. > > > > Ismael > > > > On Thu, Jul 20, 2023 at 11:33 PM Crispin Bernier > > <cbern...@confluent.io.invalid> wrote: > > > >> Benchmark numbers have been posted on the KIP, please review. > >> > >> On 2023/07/20 13:03:00 Mayank Shekhar Narula wrote: > >> > Jun > >> > > >> > Thanks for the feedback. > >> > > >> > Numbers to follow. > >> > > >> > If we don't plan to > >> > > bump up the FetchResponse version, we could just remove the > reference > >> to > >> > > version 16. > >> > > >> > Fixed. > >> > > >> > On Thu, Jul 20, 2023 at 1:28 AM Jun Rao <ju...@confluent.io.invalid> > >> wrote: > >> > > >> > > Hi, Mayank, > >> > > > >> > > Thanks for the KIP. I agree with others that it would be useful to > >> see the > >> > > performance results. Otherwise, just a minor comment. If we don't > >> plan to > >> > > bump up the FetchResponse version, we could just remove the > reference > >> to > >> > > version 16. > >> > > > >> > > Jun > >> > > > >> > > On Wed, Jul 19, 2023 at 2:31 PM Mayank Shekhar Narula < > >> > > mayanks.nar...@gmail.com> wrote: > >> > > > >> > > > Luke > >> > > > > >> > > > Thanks for the interest in the KIP. > >> > > > > >> > > > But what if the consumer was fetching from the follower? > >> > > > > >> > > > We already include `PreferredReadReplica` in the fetch response. > >> > > > > Should we put the node info of PreferredReadReplica under this > >> case, > >> > > > > instead of the leader's info? > >> > > > > > >> > > > > >> > > > PreferredReadReplica is the decided on the leader. Looking at the > >> Java > >> > > > client code, AbstractFetch::selectReadReplica, first fetch request > >> goes > >> > > to > >> > > > Leader of the partition -> Sends back PreferredReadReplica -> Next > >> fetch > >> > > > uses PreferredReadReplica. So as long as leader is available, > >> > > > PreferredReadReplica would be found in subsequent fetches. > >> > > > > >> > > > Also, under this case, should we include the leader's info in the > >> > > response? > >> > > > > >> > > > > >> > > > In this case, I think the follower would fail the fetch if it > knows > >> a > >> > > > different leader. If the follower knows a newer leader, it would > >> return > >> > > new > >> > > > leader information in the response, for the client to act on. > >> > > > > >> > > > > >> > > > Will we include the leader/node info in the response when having > >> > > > > `UNKNOWN_LEADER_EPOCH` error? > >> > > > > >> > > > > >> > > > My understanding is UNKNOWN_LEADER_EPOCH when a request from a > >> client > >> > > has a > >> > > > newer epoch than the broker. So the client is already up to date > on > >> new > >> > > > leader information, it's the broker that has the catching up to > do. > >> I > >> > > think > >> > > > there might be some optimisations to make sure the broker > refreshes > >> its > >> > > > metadata quickly, so it can quickly recover to handle requests > that > >> > > > previously returned UNKNOWN_LEADER_EPOCH. But this work is outside > >> the > >> > > > scope of this KIP, as for now this KIP focusses on client-side > >> > > > optimisations. > >> > > > > >> > > > Mayank > >> > > > > >> > > > On Tue, Jul 18, 2023 at 8:51 AM Luke Chen <sh...@gmail.com> > wrote: > >> > > > > >> > > > > Hi Mayank, > >> > > > > > >> > > > > Thanks for the KIP! > >> > > > > > >> > > > > Some questions: > >> > > > > 1. I can see most of the cases we only care about consumer fetch > >> from > >> > > the > >> > > > > leader. > >> > > > > But what if the consumer was fetching from the follower? > >> > > > > We already include `PreferredReadReplica` in the fetch response. > >> > > > > Should we put the node info of PreferredReadReplica under this > >> case, > >> > > > > instead of the leader's info? > >> > > > > Also, under this case, should we include the leader's info in > the > >> > > > response? > >> > > > > > >> > > > > 2. Will we include the leader/node info in the response when > >> having > >> > > > > `UNKNOWN_LEADER_EPOCH` error? > >> > > > > I think it's fine we ignore the `UNKNOWN_LEADER_EPOCH` error > >> since when > >> > > > > this happens, the node might have some error which should > refresh > >> the > >> > > > > metadata. On the other hand, it might also be good if we can > heal > >> the > >> > > > node > >> > > > > soon to do produce/consume works. > >> > > > > > >> > > > > > >> > > > > Thank you. > >> > > > > Luke > >> > > > > > >> > > > > On Tue, Jul 18, 2023 at 2:00 AM Philip Nee <ph...@gmail.com> > >> > > wrote: > >> > > > > > >> > > > > > Hey Mayank: > >> > > > > > > >> > > > > > For #1: I think fetch and produce behave a bit differently on > >> > > metadata. > >> > > > > > Maybe it is worth highlighting the changes for each client in > >> detail. > >> > > > In > >> > > > > > producer did you mean by the metadata timeout before sending > out > >> > > > produce > >> > > > > > requests? For consumer: I think for fetches it requires user > to > >> retry > >> > > > if > >> > > > > > the position does not exist on the leader. I don't have the > >> detail on > >> > > > top > >> > > > > > of my head, but I think we should lay out these behavioral > >> changes. > >> > > > > > > >> > > > > > For #3: Thanks for the clarification. > >> > > > > > > >> > > > > > On Mon, Jul 17, 2023 at 10:39 AM Mayank Shekhar Narula < > >> > > > > > mayanks.nar...@gmail.com> wrote: > >> > > > > > > >> > > > > > > Philip > >> > > > > > > > >> > > > > > > 1. Good call out about "poll" behaviour, my understanding is > >> the > >> > > > same. > >> > > > > I > >> > > > > > am > >> > > > > > > assuming it's about the motivation of the KIP. There with > >> async, my > >> > > > > > > intention was to convey that the client doesn't wait for the > >> > > > > > > metadata-refresh before a subsequent retry of the produce or > >> fetch > >> > > > > > request > >> > > > > > > that failed due to stale metadata(i.e. going to an old > >> leader). The > >> > > > > only > >> > > > > > > wait client has is the configured retry-delay. > >> > > > > > > > >> > > > > > > 2. Yes, in theory other APIs could benefit from this too. > But > >> that > >> > > is > >> > > > > > > outside of the scope of the KIP. > >> > > > > > > > >> > > > > > > 3. Do you mean the response for the Metadata RPC? I think > >> brokers > >> > > > > always > >> > > > > > > have a view of the cluster, although it can be stale,it > would > >> > > always > >> > > > > > return > >> > > > > > > a leader(whether old or new). > >> > > > > > > > >> > > > > > > Mayank > >> > > > > > > > >> > > > > > > On Fri, Jul 14, 2023 at 8:53 PM Philip Nee <ph...@gmail.com > > > >> > > > > wrote: > >> > > > > > > > >> > > > > > > > Hey Mayank, > >> > > > > > > > > >> > > > > > > > Thanks for the KIP. I think this is a great proposal, and > >> I'm in > >> > > > > favor > >> > > > > > > > of this idea. A few comments: > >> > > > > > > > > >> > > > > > > > 1. Claiming metadata refresh is done asynchronously is > >> > > misleading. > >> > > > > The > >> > > > > > > > metadata refresh requires Network Client to be physically > >> polled, > >> > > > > which > >> > > > > > > is > >> > > > > > > > done in a separate thread in Producer and Admin Client > >> (IIRC!) > >> > > but > >> > > > > not > >> > > > > > > > Consumer. > >> > > > > > > > 2. There are other API calls that might result in > >> > > > > > NOT_LEADER_OR_FOLLOWER > >> > > > > > > > response, but it seems like this KIP only wants to update > on > >> > > fetch > >> > > > > and > >> > > > > > > > produce. Do we want to make the leader information > >> available for > >> > > > > other > >> > > > > > > API > >> > > > > > > > calls? > >> > > > > > > > 3. Do you know what would happen during a leader election? > >> I'm > >> > > not > >> > > > > sure > >> > > > > > > > about this process and I wonder if the current metadata > >> response > >> > > > uses > >> > > > > > the > >> > > > > > > > old leader or null as the leader isn't readily available > >> yet. > >> > > > > > > > > >> > > > > > > > Thanks, > >> > > > > > > > P > >> > > > > > > > > >> > > > > > > > On Fri, Jul 14, 2023 at 11:30 AM Kirk True < > >> ki...@kirktrue.pro> > >> > > > > wrote: > >> > > > > > > > > >> > > > > > > > > Hi Mayank, > >> > > > > > > > > > >> > > > > > > > > > On Jul 14, 2023, at 11:25 AM, Mayank Shekhar Narula < > >> > > > > > > > > mayanks.nar...@gmail.com> wrote: > >> > > > > > > > > > > >> > > > > > > > > > Kirk > >> > > > > > > > > > > >> > > > > > > > > > > >> > > > > > > > > >> Is the requested restructuring of the response > >> “simply” to > >> > > > > > preserve > >> > > > > > > > > bytes, > >> > > > > > > > > >> or is it possible that the fetch response > >> could/should/would > >> > > > > > return > >> > > > > > > > > >> leadership changes for partitions that we’re > >> specifically > >> > > > > > requested? > >> > > > > > > > > >> > >> > > > > > > > > > > >> > > > > > > > > > Moving endpoints to top-level fields would preserve > >> bytes, > >> > > > > > otherwise > >> > > > > > > > the > >> > > > > > > > > > endpoint-information would be duplicated if included > >> with the > >> > > > > > > > > > partition-data in the response. Right now, the > top-level > >> > > field > >> > > > > will > >> > > > > > > > only > >> > > > > > > > > be > >> > > > > > > > > > set in case leader changes for any requested > >> partitions. But > >> > > it > >> > > > > can > >> > > > > > > be > >> > > > > > > > > > re-used in the future, for which Jose has a use-case > in > >> mind > >> > > > > shared > >> > > > > > > up > >> > > > > > > > in > >> > > > > > > > > > the thread. KIP is now upto date with endpoint info > >> being at > >> > > > > > > top-level. > >> > > > > > > > > > >> > > > > > > > > > >> > > > > > > > > I didn’t catch before that there was a separate section > >> for the > >> > > > > full > >> > > > > > > node > >> > > > > > > > > information, not just the ID and epoch. > >> > > > > > > > > > >> > > > > > > > > Thanks! > >> > > > > > > > > > >> > > > > > > > > >>> 3. In the future, I may use this information in the > >> > > > > > KRaft/Metadata > >> > > > > > > > > >>> implementation of FETCH. In that implementation not > >> all of > >> > > > the > >> > > > > > > > > >>> replicas are brokers. > >> > > > > > > > > >> > >> > > > > > > > > >> Side point: any references to the change you’re > >> referring > >> > > to? > >> > > > > The > >> > > > > > > idea > >> > > > > > > > > of > >> > > > > > > > > >> non-brokers serving as replicas is blowing my mind a > >> bit :) > >> > > > > > > > > >> > >> > > > > > > > > >> > >> > > > > > > > > > Jose, I missed this as well, would love to know more > >> about > >> > > > > > non-broker > >> > > > > > > > > > serving as replica! > >> > > > > > > > > > -- > >> > > > > > > > > > Regards, > >> > > > > > > > > > Mayank Shekhar Narula > >> > > > > > > > > > >> > > > > > > > > > >> > > > > > > > > >> > > > > > > > >> > > > > > > > >> > > > > > > -- > >> > > > > > > Regards, > >> > > > > > > Mayank Shekhar Narula > >> > > > > > > > >> > > > > > > >> > > > > > >> > > > > >> > > > > >> > > > -- > >> > > > Regards, > >> > > > Mayank Shekhar Narula > >> > > > > >> > > > >> > > >> > > >> > -- > >> > Regards, > >> > Mayank Shekhar Narula > >> > > > > > >
