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
