Hi Anton, Thanks for the KIP. It closes a real gap for 3.9 migrations. I have a couple of minor comments.
mb0 - My understanding is this can only ship on 3.9.x since ZK migration is removed on 4.0+. Maybe worth adding it to the KIP in the scope/target section. mb1 - Is there a possibility of misusing the flag `--zk-rollback-compatible` (for ex, applying it on a non-migration cluster or after finalization, then we see V0 meta props.) It may be better to add some guidance in the KIP. Thanks, Murali On Thu, Jul 9, 2026 at 12:18 PM Anton Agestam via dev <[email protected]> wrote: > Hi everyone, > > I would like to start the discussion for KIP-1362: Add a > rollback-compatible storage format option for KRaft migration. > > KIP: > > https://cwiki.apache.org/confluence/spaces/KAFKA/pages/440303727/KIP-1362+Add+a+rollback-compatible+storage+format+option+for+KRaft+migration > Jira: https://issues.apache.org/jira/browse/KAFKA-20762 > PR/reference implementation: https://github.com/apache/kafka/pull/22751 > > In summary: this KIP proposes closing a current gap, where the ability to > do rollback of an ongoing KRaft migration breaks when cluster member nodes > are replaced. The proposed solution is to add a CLI flag to the storage > formatting tool that causes the resulting storage to not break when rolled > back. > > I'm looking forward to feedback on this proposal. > > Thanks, > Anton > > -- > [image: Aiven] <https://www.aiven.io/> > *Anton Agestam* (he/him or they/them) > Software Engineer, *Aiven* > [email protected] | +46 704 486 289 > aiven.io <https://www.aiven.io/> | > <https://www.facebook.com/aivencloud> > <https://www.linkedin.com/company/aiven/> <https://twitter.com/aiven_io > > >
