Hi PoAn, The explicit topic creation refers to the topic created through AdminClient#createTopics. In this code path, both num.partitions and default.replication.factor default values are applied on the controller side.
I agree the original sentence was a bit unclear. I’ll update the documentation from: For explicit topic creation and internal streams topic creation to For explicit topic creation via AdminClient#createTopics and internal streams topic creation Thanks, KuanPo Tseng On Mon, Dec 15, 2025 at 4:37 PM PoAn Yang <[email protected]> wrote: > Hi Kuan-Po, > > Thanks for the KIP. > > PoAn_01: both num.partitions and default.replication.factor have sentence > “For explicit topic creation and internal streams topic creation, this > configuration is applied on the controller side.”. > Do you want to mean “implicit” here? > > Thanks, > PoAn > > > On Oct 23, 2025, at 9:34 AM, Kuan Po Tseng <[email protected]> wrote: > > > > Hi all, > > > > If there are no further comments, I plan to start the vote tomorrow. > > > > Best, > > Kuan-Po Tseng > > > > On 2025/10/15 15:57:04 Kuan Po Tseng wrote: > >> Hi all, > >> > >> Sorry for the late reply, and thanks so much for all the feedback — > really appreciated! > >> > >> chia_00: Good point. We can add warnings during broker startup to > notify users about this change. > >> chia_01: Thanks for the reminder — as you mentioned, both configs > should indeed be set to -1. > >> > >> Luke_01: Absolutely, we can make this change in 5.0. > >> Luke_02: Thanks! Agreed, we should update the documentation, as it’s > not very clear at the moment. > >> Luke_03: As you and Ismael suggested, for the 4.x series we can > introduce an override rule: if users explicitly set these two configs in > the broker configuration, we’ll continue applying them for auto topic > creation. This override will eventually be removed in 5.0. I’ve updated the > KIP to reflect this. > >> > >> Best, > >> Kuan-Po Tseng > >> > >> On 2025/09/25 13:37:41 Ismael Juma wrote: > >>> An alternative would be to allow the configs to be set on either > >>> broker.properties or controller.properties. The former would take > >>> precedence over the latter (just like topic configs provided by clients > >>> take precedence over the default server configuration). > >>> > >>> Ismael > >>> > >>> On Thu, Sep 25, 2025 at 12:01 AM Luke Chen <[email protected]> wrote: > >>> > >>>> Hi Kuan-Po, > >>>> > >>>> Thanks for fixing this inconsistency! > >>>> > >>>> Questions: > >>>> 1. The `num.partitions` currently still exists in our example > >>>> broker.properties file. We should update it, too. > >>>> > >>>> 2. "This is a breaking change because it alters where these two > configs are > >>>> applied. The change can only be introduced in the next major release > (i.e., > >>>> 5.0)." > >>>> Does that mean we don't do anything before v5.0? Maybe we can update > the > >>>> doc first to mention this inconsistency? > >>>> > >>>> 3. What about the topic configuration overridden in broker and > controller > >>>> properties file? > >>>> For example: > >>>> Broker sets "log.retention.ms=100" > >>>> Controller sets "log.retention.ms=1000" > >>>> A topic "t" created without setting the "retention.ms". > >>>> In this case, the "retention.ms" for topic "t" is 100 or 1000? > >>>> Does the inconsistency happen in all topic configs? > >>>> > >>>> > >>>> Thank you. > >>>> Luke > >>>> > >>>> > >>>> On Thu, Sep 25, 2025 at 1:40 AM Chia-Ping Tsai <[email protected]> > wrote: > >>>> > >>>>> hi Kuan-Po > >>>>> > >>>>> thanks for this KIP. > >>>>> > >>>>> chia_00: Is it possible to add warning messages to broker to > highlight > >>>> this > >>>>> change? > >>>>> > >>>>> chia_01: Should broker set `-1` explicitly? > >>>>> > >>>>> Best, > >>>>> Chia-Ping > >>>>> > >>>>> Kuan-Po Tseng <[email protected]> 於 2025年9月25日 週四 上午12:20寫道： > >>>>> > >>>>>> Hello everyone, > >>>>>> > >>>>>> I’d like to bring up a small change aimed at aligning the behavior > of > >>>>>> num.partitions and default.replication.factor during topic creation. > >>>>>> > >>>>>> You can find the KIP here: > >>>> https://cwiki.apache.org/confluence/x/WIrHFg. > >>>>>> > >>>>>> Thanks, > >>>>>> Kuan-Po Tseng > >>>>>> > >>>>> > >>>> > >>> > >> > >
