On Fri, Sep 6, 2019 at 6:33 PM Boyang Chen <reluctanthero...@gmail.com> wrote:
> Thanks Guozhang, I have polished the design doc to make it sync with > current KIP. As for overriding default timeout values, I guess it's already > stated in the KIP to set txn timeout to 10s, are you suggesting we should > also put down this recommendation on the KIP for non-stream EOS users? > > My comment is not for changing any produce / consumer default config values, but for the Streams configs, to make sure that our overridden config values respect the above rules. That is, we check the actual value used in the config if they are ever overridden by users, and if the above were not true we can log a warning that it may be risky to encounter some unnecessary rebalances. Again, this is not something we need to include in the KIP since it is not part of public APIs, just to emphasize that the internal implementation can have some safety guard like this. Guozhang > Boyang > > On Thu, Sep 5, 2019 at 8:43 PM Guozhang Wang <wangg...@gmail.com> wrote: > > > Hello Boyang, > > > > Just realized one thing about timeout configurations that we should > > consider including in this KIP as well: > > > > 1) In Producer we have: max.block.ms (default value 60sec), > > request.timeout > > (30sec), delivery.timeout.ms (120sec), transaction.timeout (60sec) > > 2) In Consumer we have: session.timeout (10sec), request.timeout (30sec), > > default.api.timeout.ms (60sec). > > > > Within a transaction (i.e. after we've beginTxn), we could potentially > call > > consumer blocking APIs that depend on default.api.timeout.ms, and call > > producer blocking APIs that depend on max.block.ms. Also, if the user is > > following a consumer->producer pattern, then it could be kicked and > fenced > > either by txn or by consumer group session. > > > > So we want to make sure that in the caller, e.g. Kafka Streams: > > > > 1) transaction.timeout < max.block.ms > > 2) transaction.timeout < delivery.timeout.ms > > 3) transaction.timeout < default.api.timeout.ms > > 4) transaction.timeout ~= default.api.timeout.ms (I think this is > already > > mentioned in the KIP, just wanted to bring this up again) > > > > We do not need to override the default since not every users are > following > > the consumer -> producer pattern, but in cases like Streams where it is > > indeed the case, we should override the default values to obey the above > > rules. > > > > Guozhang > > > > > > > > On Thu, Sep 5, 2019 at 5:47 PM Guozhang Wang <wangg...@gmail.com> wrote: > > > > > Thanks Boyang, I'm +1 on the KIP. > > > > > > Could you also update the detailed design doc > > > > > > https://docs.google.com/document/d/1LhzHGeX7_Lay4xvrEXxfciuDWATjpUXQhrEIkph9qRE/edit > > which > > > seems a bit out-dated with the latest proposal? > > > > > > > > > Guozhang > > > > > > On Wed, Sep 4, 2019 at 10:45 AM Boyang Chen < > reluctanthero...@gmail.com> > > > wrote: > > > > > >> Hey all, > > >> > > >> I would like to start the vote for KIP-447 > > >> < > > >> > > > https://cwiki.apache.org/confluence/display/KAFKA/KIP-447%3A+Producer+scalability+for+exactly+once+semantics > > >> >. > > >> This is a very important step to improve Kafka Streams scalability in > > >> exactly-once semantics, by avoiding linearly increasing number of > > >> producers > > >> with topic partition increases. > > >> > > >> Thanks, > > >> Boyang > > >> > > > > > > > > > -- > > > -- Guozhang > > > > > > > > > -- > > -- Guozhang > > > -- -- Guozhang
