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
