Hi Chia-Ping, Adding a new config sounds good to me. Usually in minor releases, we don't accept new features, but for ZK support in v3.9.x, this could be an exception in my opinion. But of course it needs a KIP and community discussion.
@Edoardo, do you think this is acceptable? Thank you, Luke On Fri, Dec 5, 2025 at 8:33 AM Chia-Ping Tsai <[email protected]> wrote: > How about introducing a configuration called > alter.config.policy.kraft.compatibility.enable to control this behavior? > > The default value would be false, meaning nothing changes in 3.9.2. > Conversely, setting it to true would align the behavior with KRaft policy > validation > > > Edoardo Comar <[email protected]> 於 2025年12月4日 晚上10:15 寫道： > > > > Chia-Ping, > > I respectfully disagree with such a quick decision. > > > >> On Thu, 4 Dec 2025 at 02:07, Chia-Ping Tsai <[email protected]> wrote: > >> > >> Long-standing bugs often become features. > >> > >> Let's keep this behavior for 3.9.2. I recommend updating the > documentation > >> to explicitly highlight this distinction. > >> > >> > >> Ismael Juma <[email protected]> 於 2025年12月4日週四 上午6:23寫道： > >> > >>> Thanks for starting the discussion. Given that this behavior has > existed > >>> for so long, I would be reluctant to change it in a patch release for > 3.9.x > >>> unless there is strong demand from the community. > >>> > >>> Ismael > >>> > >>>> On Mon, Dec 1, 2025 at 6:18 AM PoAn Yang <[email protected]> wrote: > >>> > >>>> Hi developers, > >>>> > >>>> I'd like to initiate a discussion regarding the AlterConfigPolicy in > >>>> version 3.9.2. > >>>> https://issues.apache.org/jira/browse/KAFKA-19026 > >>>> > >>>> The key issue is the difference in behavior for OpType.SUBTRACT and > >>>> OpType.APPEND between KRaft and ZK modes. > >>>> > >>>> In KRaft mode, AlterConfigPolicy#validate receives the modified > >>>> RequestMetadata. > >>>> In ZK mode, it receives the original user input. > >>>> > >>>> We can observe this difference by looking at the OpType.SUBTRACT > example > >>>> provided in the attachments: > >>>> > >>>> > >>> > https://issues.apache.org/jira/secure/attachment/13075589/KAFKA19026Test.java > >>>> > >>>> > >>> > https://issues.apache.org/jira/secure/attachment/13075585/KAFKA19026Policy.java > >>>> > >>>> Example Output in KRaft Mode: > >>>> AlterConfigPolicy.RequestMetadata(resource=ConfigResource(type=BROKER, > >>>> name='0'), configs={ssl.cipher.suites=}). > >>>> > >>>> Example Output in ZK Mode: > >>>> AlterConfigPolicy.RequestMetadata(resource=ConfigResource(type=BROKER, > >>>> name='0'), configs={ssl.cipher.suites=foo}). > >>>> > >>>> The ZK behavior has been in place since 2.3.1. Therefore, I want to > check > >>>> if the community wants to align this behavior in 3.9.2. > >>>> > >>>> > >>>> > >>> > https://github.com/apache/kafka/blob/2.3.1/core/src/main/scala/kafka/server/AdminManager.scala#L462-L479 > >>>> > >>>> If this is considered a behavioral change, it might be risky to > include > >>> in > >>>> a patch version (3.9.2). However, if it's classified as a bug, then we > >>>> should proceed with the fix in 3.9.2. > >>>> > >>>> Feel free to share your opinions. Thank you! > >>>> > >>>> Best regards, > >>>> PoAn > >>> >
