Hi Vaquar, Thanks for your feedback. Usually the VOTE thread is reserved for casting the votes, while comments about the KIP itself are posted in the DISCUSS thread.
The points you are raising are specific to the current implementation in Aiven’s Inkless repository, which is not the reference implementation of Diskless Topics. For example, Aiven's implementation uses PostgeSQL as the diskless coordinator, but this is not part of the KIP. Any implementation details in that fork should be taken as an example of how things could look like, but changes will be made prior to merging the feature into Apache Kafka. When discussing and voting on KIPs, please focus on the contents of the KIPs themselves as the source of truth. Also, the issues you raise are mostly implementation details, and these are most appropriate to discuss in the PRs themselves rather than in the KIP discussion. We also do not believe that any of these bugs are blockers for voting on KIP-1150. Point 1 is implementation specific, and will be addressed by cleanup logic that can be defined later. Point 2 is a misunderstanding of how transactions work in Kafka and not specific to Inkless or Diskless. Point 3 is not relevant to the KIP discussion as it is about testing practices on a fork on another project. Best, ------------------ Josep Prat Sr. Engineering Director - Streaming Services, Aiven [email protected] | +491715557497 | aiven.io Aiven Deutschland GmbH Alexanderufer 3-7, 10117 Berlin Geschäftsführer: Oskari Saarenmaa, Kenneth Chen Amtsgericht Charlottenburg, HRB 209739 B On Fri, Jan 23, 2026, 19:29 vaquar khan <[email protected]> wrote: > Hi Everyone, > > I have been reviewing the *KIP-1150* proposal and the reference > implementation provided in the aiven/inkless repository > <https://github.com/aiven/inkless/issues>. While the cost-saving goals are > compelling, I have identified three critical architectural flaws in the > current design that directly undermine the KIP's feasibility and > correctness. > > 1.* Unbounded Storage Leaks (Orphaned Segments) *The current > "fire-and-forget" upload logic creates a race condition where a broker > crash after S3 upload (but before metadata commit) results in orphaned > objects that are never garbage collected. In high-churn environments, this > negates the proposed cost benefits and creates an unbounded storage leak. > Issue1 <https://github.com/aiven/inkless/issues/494>: > > 2. EOS Violations in Leaderless Architecture The EndTxnRequest handling > does not strictly synchronize with the Batch Coordinator before advancing > the local LSO. This creates a split-brain scenario where consumers can see > an inconsistent transaction state, effectively breaking Exactly-Once > Semantics (EOS). Issue2 <https://github.com/aiven/inkless/issues/495>: > > 3. Critical Testing Gaps The integration tests rely exclusively on MinIO > (strong consistency) and do not simulate S3's eventual consistency or 503 > throttling. The system is currently unverified against real-world cloud > failure modes, posing a significant risk to production stability. Issue3 > <https://github.com/aiven/inkless/issues/496>: > > Given that these issues affect data integrity and the core economic promise > of the KIP, I strongly suggest we pause the vote until a concrete design > for "Distributed Garbage Collection" and "Coordinator-Synchronized > Transactions" is explicitly added to the proposal. > > Regards, > Viquar Khan > Sr Data Architect > https://www.linkedin.com/in/vaquar-khan-b695577/ > > On Wed, 14 Jan 2026 at 17:04, Ghai, Varun via dev <[email protected]> > wrote: > > > +1 (non-binding) > > > > We (NetApp) have been closely following the changes in this KIP, its > > sub-KIPs and the discussions around diskless in the community. We're > happy > > to see support coalescing around a single path forward to bring diskless > to > > Kafka. In its current state, we support this KIP. > > > > On 2026/01/13 20:29:14 Stanislav Kozlovski wrote: > > > +1 (binding) > > > > > > Thank you so much for this effort. Seeing you reach consensus with the > > competing KIP-1176 is very promising as well. I'm excited to work with > you > > on closing design for the rest of the KIPs and ultimately merging this. I > > agree wholeheartedly on the motivational aspect - this is a necessary > > feature if we wish for Kafka to remain competitive in the industry. > > > > > > On 2026/01/12 12:33:37 Andrew Mills wrote: > > > > +1 (non-binding) > > > > > > > > As a long time Kafka use and member of a team who provides management > > for > > > > Apache Kafka, I'm excited to see this KIP move forward. It will help > to > > > > keep Kafka cost competitive in the face of many cloud-first > > alternatives. > > > > > > > > -- Andrew > > > > > > > > On Fri, Jan 9, 2026, 7:49 PM Henry Haiying Cai via dev < > > [email protected]> > > > > wrote: > > > > > > > > > +1 (non-binding) > > > > > > > > > > As the author of competing KIP (KIP-1176: Tiered Storage for Active > > Log > > > > > Segment), I am supporting KIP-1150 as KIP-1150 represents the right > > > > > long-term architecture for Kafka in the cloud. > > > > > > > > > > Henry Cai > > > > > > > > > > > > > > > On Friday, January 9, 2026 at 04:08:03 AM PST, Anatolii Popov via > > dev < > > > > > [email protected]> wrote: > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > Hi all, > > > > > > > > > > We are restarting the vote for KIP-1150: Diskless Topics. > > > > > > > > > > Since the previous vote, the KIP has been substantially updated to > > address > > > > > community feedback. > > > > > > > > > > As a reminder, KIP-1150 is a motivational KIP intended to establish > > the > > > > > architectural direction for diskless topics. The specific > > implementation > > > > > details are delegated to separate sub-KIPs, which will be discussed > > and > > > > > voted on individually. > > > > > > > > > > To give you a concrete idea of the path forward, KIP-1163 is > already > > in an > > > > > almost-ready-for-review state, so you can see where we are heading > > after > > > > > this. > > > > > > > > > > KIP-1150: > > > > > > > > > > > > > https://cwiki.apache.org/confluence/display/KAFKA/KIP-1150%3A+Diskless+Topics > > > > > KIP-1163 > > > > > < > > > https://cwiki.apache.org/confluence/display/KAFKA/KIP-1150%3A+Diskless+TopicsKIP-1163 > > > > > > > > : > > > > > > > > https://cwiki.apache.org/confluence/display/KAFKA/KIP-1163%3A+Diskless+Core > > > > > > > > > > Best, > > > > > Anatolii > > > > > -- > > > > > Anatolii Popov > > > > > Senior Software Developer, *Aiven OY* > > > > > m: +358505126242 > > > > > w: aiven.io e: [email protected] > > > > > <https://www.facebook.com/aivencloud> > > > > > <https://www.linkedin.com/company/aiven/> < > > https://twitter.com/aiven_io> > > > > > > > > > > > > > > > > -- > Regards, > Vaquar Khan >
