when ai wrote code, we don't allow it to have bug and worst.. we don't allow ai to write at all...
sure, you can argue humans should understand the code... but we stop at first hand, that actually blocks us from learning... When ai wrote the code, people argued that llm comprehension of the code is difficult to understand but isn't that give a different perspective on how a code can be rewritten? On Fri, Sep 25, 2026 at 6:28 PM Benedict Elliott Smith <[email protected]> wrote: > > I think it’s extremely important that large blocks of generated code are > directly annotated as such. It is important to me as a maintainer that I know > if human intention was properly brought to bear on a body of code, as it > changes how I will engage with the code. If the code was broadly > LLM-generated, I am more likely to ask an LLM to maintain it, and I am much > less likely to try to maintain its design or semantic decisions. > > On 2026/09/25 01:26:31 Blake Eggleston wrote: > > Why's that? I'm not really interested in adding something like that to my > > patches. > > > > On Thu, Sep 24, 2026, at 6:21 PM, Caleb Rackliffe wrote: > > > Regardless of what we end up moving forward with, I think we need to use > > > "Assisted-by" just like we use "Co-authored-by". > > > > > > On Thu, Sep 24, 2026 at 7:59 PM Jane H <[email protected]> wrote: > > >> I've been reviewing AI-assisted PRs from new contributors lately. > > >> > > >> The main concern I see is that: committers' review is already the > > >> bottleneck of our delivery speed, but LLM-assisted PRs can make PR > > >> review significantly harder, therefore put even more load on reviewers. > > >> Without clear policy, guidance, and aligned expectations from the > > >> community, I worry that increased use of AI can make our delivery speed > > >> slower rather than faster. > > >> > > >> Sharing several challenges I met when reviewing AI-assisted PRs recently: > > >> > > >> 1. How do we put the principle that "contributors are responsible for > > >> the code they submit" into practice? > > >> 1. How does a contributor know they indeed understand every line of > > >> code in their PR? This can be harder than it sounds. Imagine a new > > >> contributor who vibe-codes a PR, reads through every line, feels that > > >> the code makes sense, and it passes several AI review tools. Is that > > >> enough? I'd say no. For example, if this PR involves sending a new > > >> message to a client, then I think a client and server setup for > > >> end-to-end manual testing is needed. If a PR adds a metric, then I think > > >> spinning up a cluster and watching the metric changes is needed. Such > > >> knowledge isn't necessarily straightforward to new-comers. > > >> 1. I think formal guidance on how to verify (e.g. testing env > > >> setup) and what needs to be verified will be helpful. > > >> 2. If a reviewer suspects that a contributor does not actually > > >> understand their code, what should this reviewer do? In my own > > >> experience, I point out what's wrong in the code, but I don't think it > > >> is helpful to simply blame the contributor for not understanding their > > >> submission. In most cases, I don't have strong evidence that a mistake > > >> came from AI-generated code and from the contributor failing to review > > >> it carefully. Human-written code can make similar mistakes too. And even > > >> if I know for sure it's from AI assistance, what should I do? > > >> 3. As PR review is async, sometimes a PR review will go straight to > > >> contributors' claude. For example, if I ask, “Did you try testing > > >> against X?”, and the contributor asks claude to test against X then > > >> responds, “Yes, I tried it and it works,” I may trust them and approve > > >> the PR. But what if that answer turns out to be claude's hallucination? > > >> How should responsibility work in that situation? > > >> 2. More load on reviewers, more load on verification. Because I don't > > >> currently know how the contributor's responsibility can be enforced in > > >> practice, when I see a PR with LLM content, I have less confidence that > > >> the PR is validated by human. In my own experience, I've had to ask > > >> contributors how they've tested and why they think it's working, and > > >> tell them what manual testing is needed. Often times I need to perform > > >> those tests by myself instead, some are tests that I might not have > > >> needed to perform in the same way in pre-AI era. Therefore I propose: > > >> 1. Formal guidance on verification, as mentioned above. > > >> 2. A PR template section that asks contributors to explain what > > >> testing they've done beyond the unit tests and integration tests > > >> included in the PR. > > >> 3. Disclosure of AI assistance, including which parts of the PR were > > >> AI-assisted. > > >> 3. Potentially misaligned expectation of delivery speed. Consider a > > >> situation where someone comes to me with a new feature consisting of > > >> hundreds of new files generated by LLM in a day saying they verified it > > >> and asks for a review. What am I supposed to do? In my humble opinion, > > >> reviewers should still review line-by-line, and as long as this holds > > >> true, the high productivity of AI can never translate to the high > > >> delivery speed as people wish. Various AI PR review tools can only help > > >> a bit but never resolve the fundamental problem. I'm very open to > > >> different opinions here, but I hope the community can align expectations. > > >> Overall, I think LLM is NOT just "another tool". None of previous tools > > >> like IntelliJ has caused the above challenges. We have real problems to > > >> solve here, and I think we would benefit from aligned expectation and > > >> guidance, in addition to policies. > > >> > > >> > > >> > > >> Jane He > > >> > > >> > > >> On Thu, Sep 24, 2026 at 5:40 PM Caleb Rackliffe > > >> <[email protected]> wrote: > > >>> Blake, I’d support those 3 guidelines. > > >>> > > >>> One hostile reaction to them would, I’m guessing, be that guideline > > >>> number 1 is too weak, and that the burden of quality would continue to > > >>> rest entirely on committer reviewers. I suppose my reply there would be > > >>> that anyone who continually spams the project with patches they do not > > >>> fully understand wound incur a pretty heavy reputational penalty and > > >>> the problem would more or less sort itself out. > > >>> > > >>> > > >>> > On Sep 24, 2026, at 6:07 PM, Benedict Elliott Smith > > >>> > <[email protected]> wrote: > > >>> > > > >>> > For the record Josh, I am including pre-3.0. I was involved in > > >>> > customer support escalations for 1.2, 2.0 and 2.1: the software was > > >>> > shoddy, to put it mildly. 8099 was a symptom, not the disease. > > >>> > > > >>> > The project had a culture of doing stuff without sufficient care or > > >>> > consideration. This is by no means a simple matter of needing more > > >>> > testing or less timeline pressure, nor is it easy to define a "bar" > > >>> > to ensure it does not regress. If we had simple metrics, we would > > >>> > have settled it a long time ago. > > >>> > > > >>> > You can still see customer scars crop up on forum discussions > > >>> > periodically. > > >>> > > > >>> > > > >>> > On 2026/09/24 19:01:02 Josh McKenzie wrote: > > >>> >>> Apache Cassandra was fundamentally undeployable for four years > > >>> >>> between Nov 2015 - 2019. > > >>> >> CASSANDRA-8099 was a maximal manifestation of a specific approach to > > >>> >> engineering and calendar constraints we've seen time and again on > > >>> >> the project; I don't want us to conflate things here. That was a > > >>> >> herculean monolithic body of work performed in inhuman conditions > > >>> >> (in vim!) that was ultimately so invasive, all the unit tests in the > > >>> >> code-base were commented out and Jake and I spent a grueling 1.5-2 > > >>> >> months hand-rewriting basically all the unit tests in that code-base > > >>> >> to get things to even build and run, much less pass. > > >>> >> > > >>> >> Massive blast radius changes that are un-sustainably complex, > > >>> >> under-tested, where we don't property, fuzz, check coverage, check > > >>> >> complexity, or A/B compare against a known good system (i.e. > > >>> >> pre/post) correctness testing are going to destabilize the database > > >>> >> at any time under any regime of tooling. We certainly could > > >>> >> speed-run our way back into destabilization with LLM's as they are a > > >>> >> force multiplier for both the good and the bad of one's engineering > > >>> >> practices, but that's a solvable problem by better defining what our > > >>> >> bars of quality are (Definition of Done anyone?) and holding > > >>> >> ourselves accountable to delivering at that bar. > > >>> >> > > >>> >> On Thu, Sep 24, 2026, at 2:40 PM, David Capwell via dev wrote: > > >>> >>>> > > >>> >>>> > > >>> >>>> if you really want to pursue it I would ask that we do it offline > > >>> >>>> to avoid polluting an already busy conversation > > >>> >>>> > > >>> >>> People are directly responding saying that they feel discrimination > > >>> >>> currently and that the policy tries to codify that discrimination, > > >>> >>> so I feel its 100% on topic. This thread has presented 0 evidence > > >>> >>> that LLM usage has lowered the quality of contributions merged and > > >>> >>> has so far been vibes and feeling; I have yet to see any evidence > > >>> >>> to justify such discrimination so I will keep pushing back until > > >>> >>> such evidence is presented so we can have a informed debate. > > >>> >>> > > >>> >>>> namely how we handle shallow and localised bug fixes. I would be > > >>> >>>> happy adding a clear entry to the “Permitted” section for this. No > > >>> >>>> doubt there are many refinements needed to the Restricted text as > > >>> >>>> well, that might also capture some of your concerns. > > >>> >>>> > > >>> >>> I will not sign off on cherry picking areas where "safe" to use a > > >>> >>> tool; so no it does not capture my concerns. > > >>> >>> > > >>> >>> > > >>> >>> > > >>> >>>> I don't know if everyone remembers, but ten years ago Cassandra > > >>> >>>> was full of serious correctness and stability issues. Despite > > >>> >>>> developing it, I would not have run it myself or recommend that > > >>> >>>> anyone use it. We have dug ourselves out of that hole, but it took > > >>> >>>> years of discipline and effort, and we're still (deservedly) > > >>> >>>> recovering our reputation. > > >>> >>>> > > >>> >>>> Let's use this new technology to improve the quality of our > > >>> >>>> contributions, not squander our hard-earned gains in the name of > > >>> >>>> speed. It will be hard to recover our reputation a second time. > > >>> >>>> > > >>> >>> I do recall the 3.x line and put in a significant amount of effort > > >>> >>> to harden it. There were behaviors I noticed after joining > > >>> >>> Cassandra that I feel directly contributed to 3.0 and the decade of > > >>> >>> catch up; behaviors that still linger in parts of the community > > >>> >>> today. > > >>> >>> > > >>> >>> As I look on trunk and look at committed code and trace back to PRs > > >>> >>> and JIRA I see the following: > > >>> >>> > > >>> >>> • large patches approved without comments > > >>> >>> • 0 evidence that tests were run > > >>> >>> I then look at our CI and see tests failing for months. As you > > >>> >>> start to triage you start to see some of them show real issues; yet > > >>> >>> they linger for months not being addressed... when CI is unstable > > >>> >>> it takes a lot of effort to triage "did my patch break the test", > > >>> >>> and I have seen time and time again people do not put in that > > >>> >>> effort, and shrug off as "its just a flakey test"; then our CI > > >>> >>> failure rate grows. > > >>> >>> > > >>> >>> Non of this has anything to do with LLMs but LLMs running in this > > >>> >>> environment is far more dangerous as there are not checks in place > > >>> >>> to "hold the bar". I am all for raising the bar universally; > > >>> >>> expecting both humans and LLMs to match that bar. > > >>> >>> > > >>> >>>> `I’d support something that boils down to roughly this: > > >>> >>>> > > >>> >>>> 1.) 2 committers must understand an LLM-assisted change before it > > >>> >>>> commits. (Perhaps separately we can explore the question of why we > > >>> >>>> haven’t added any new committers to the core project for about a > > >>> >>>> year. I’m also still not entirely sure if it’s acceptable within > > >>> >>>> our guidelines for a committer to +1 a patch after delegating > > >>> >>>> review.) > > >>> >>>> > > >>> >>>> 2.) Patch authors must demonstrate enough understanding to discuss > > >>> >>>> their own patch, whether or not parts of it are generated by an > > >>> >>>> LLM. > > >>> >>>> > > >>> >>>> 3.) The “Assisted-by” tag should be used to indicate any > > >>> >>>> non-trivial LLM usage in the generation of a patch, just like we > > >>> >>>> have used Co-authored-by historically. > > >>> >>>> > > >>> >>>> 4.) Comments and other things that aren't the actual code (but > > >>> >>>> could sow confusion) should be held to the same standard we'd > > >>> >>>> expect from a human writer. If we don’t yet agree on that > > >>> >>>> standard, we can formalize enough of it to guide both humans and > > >>> >>>> LLMs. > > >>> >> ` > > >>> >>> I can get behind this proposal but i would tweak it as 1/2 i don't > > >>> >>> think really need to special case LLM usage > > >>> >>> > > >>> >>> 1. 2 committers must understand the change before it commits. > > >>> >>> 2. Patch authors must demonstrate enough understanding to discuss > > >>> >>> their own patch > > >>> >>> Nothing about those 2 need to be scoped to LLM usage and honestly > > >>> >>> matches most PMCs I have talked to understanding of our bar (as > > >>> >>> Benedict pointed out, the actual wording could be interpreted to > > >>> >>> allow rubber stamping from committer) > > >>> >>> > > >>> >>> As for 3 I am cool with this. ASF recommends the same (it says > > >>> >>> `Generated-by` but that discount's the human's effort) as its > > >>> >>> useful for audits and tooling. Having `Assisted-by` tag should not > > >>> >>> imply anything about the committed patch as it should have gone > > >>> >>> through the same bar we all expect; its just for tools auditing. > > >>> >>> > > >>> >>> > > >>> >>>> On Sep 24, 2026, at 10:37 AM, Aleksey Yeshchenko via dev > > >>> >>>> <[email protected]> wrote: > > >>> >>>> > > >>> >>>> Meant "doing away with", sorry. Non-native speaker with a headache > > >>> >>>> here. Thanks Caleb for spotting. > > >>> >>>> > > >>> >>>>> On 24 Sep 2026, at 17:35, Aleksey Yeshchenko via dev > > >>> >>>>> <[email protected]> wrote: > > >>> >>>>> > > >>> >>>>> P.S. I assume it's obvious from the text above that I don't > > >>> >>>>> believe that getting away with human code review is a viable > > >>> >>>>> option. > > >>> >>>> > > >>> >>>> > > >>> >>>>> On 24 Sep 2026, at 17:37, Štefan Miklošovič > > >>> >>>>> <[email protected]> wrote: > > >>> >>>>> > > >>> >>>>> Good call on checkerframework, we even have a patch for it. Work > > >>> >>>>> of > > >>> >>>>> Jacek Lewandowski. We might just drive it to completion. Using AI > > >>> >>>>> for > > >>> >>>>> finishing it would be quite ironic. > > >>> >>>>> > > >>> >>>>> (1) https://github.com/apache/cassandra/pull/2370 > > >>> >>>>> > > >>> >>>>> On Thu, Sep 24, 2026 at 6:19 PM Jon Haddad > > >>> >>>>> <[email protected]> wrote: > > >>> >>>>>> > > >>> >>>>>> There are some really good points being brought up about > > >>> >>>>>> stability of the codebase, maintainability, quality of reviews, > > >>> >>>>>> correctness bugs, and I agree with all of them. I think it > > >>> >>>>>> would be helpful to take a step back and consider how those bugs > > >>> >>>>>> got there in the first place, how they were fixed, and what we > > >>> >>>>>> could do to further advance the codebase so they don't creep > > >>> >>>>>> back. LLMs can be used either with very tight guardrails, or in > > >>> >>>>>> what's effectively YOLO mode, and there's a big difference in > > >>> >>>>>> the quality of the results you get. > > >>> >>>>>> > > >>> >>>>>> One thing to keep in mind, a lot of the initial code in C* was > > >>> >>>>>> added without comprehensive testing. I hope we can all agree > > >>> >>>>>> that it's a lot easier to break code that doesn't have high > > >>> >>>>>> quality tests. During the code freeze, a lot of people people > > >>> >>>>>> spent several years relentlessly finding and fixing bugs. This > > >>> >>>>>> was probably a pretty frustrating time for anyone who was > > >>> >>>>>> focused on fixing other people's bugs when they wanted to build > > >>> >>>>>> features. I think we should recognize the effort here and > > >>> >>>>>> appreciate the foundation that the project stands on now. I can > > >>> >>>>>> understand how anyone involved with this effort would be > > >>> >>>>>> apprehensive about seeing years of their life swept away by an > > >>> >>>>>> agent that was driven by goal seeking to remove all the tests > > >>> >>>>>> that it broke instead of fixing them. > > >>> >>>>>> > > >>> >>>>>> When I picked up the work to improve cursor compaction, the > > >>> >>>>>> first thing I asked myself was how can I make sure I don't break > > >>> >>>>>> this? How do I even know it works properly? There were some > > >>> >>>>>> tricky parts to the code, and I really didn't want to come in > > >>> >>>>>> and immediately break stuff. That's why I started with an > > >>> >>>>>> entire patch dedicated to adding test infra to it. 90% of the > > >>> >>>>>> patch was tests, and in my other cursor patches, it remains *at > > >>> >>>>>> least* 80% of my patches. It was a *lot* faster to add almost > > >>> >>>>>> 10K lines of tests that handled a byte for byte differential > > >>> >>>>>> testing paired with harry to find over 30 bugs that caused > > >>> >>>>>> cursor to corrupt results. Range tombstones alone were at least > > >>> >>>>>> a dozen bugs, but I also found issues with static columns, > > >>> >>>>>> reverse ordering, etc. Randomizing schemas and data in burn > > >>> >>>>>> tests to generate different shapes of data, to ensure they all > > >>> >>>>>> result in the same output at the end. JMH tests to ensure there > > >>> >>>>>> weren't performance regressions, hours of profiling. These were > > >>> >>>>>> all a *lot* easier to do with the LLM helping me out. In the > > >>> >>>>>> process I've found bugs that have been lingering in the codebase > > >>> >>>>>> for years. > > >>> >>>>>> > > >>> >>>>>> That's a long story, but hopefully we all agree that having > > >>> >>>>>> comprehensive tests is a great way to ensure that both humans > > >>> >>>>>> and LLMs don't break things that are working. > > >>> >>>>>> > > >>> >>>>>> The lesson: we need to keep improving our testing. Everything > > >>> >>>>>> that we touch, should be left in a better state than how we > > >>> >>>>>> found it with regard to test coverage. > > >>> >>>>>> > > >>> >>>>>> Test coverage isn't everything though, there's always little > > >>> >>>>>> subtle bugs that don't get found in testing, that can slip in > > >>> >>>>>> despite our best efforts. It's debatable if humans will be as > > >>> >>>>>> good as agents for coding in the long term, for spotting small > > >>> >>>>>> defects. I sincerely doubt it. For the time being though, we > > >>> >>>>>> still have people involved. It's probably a good time to start > > >>> >>>>>> using more static analysis tools to identify problematic code > > >>> >>>>>> and to add this to CI. Dmitry had a suggestion recently for > > >>> >>>>>> checkerframework to detect leaking contexts, a problem he > > >>> >>>>>> spotted when reviewing my branch. It would be great to have > > >>> >>>>>> that integrated into our CI and dev workflow so we can simply > > >>> >>>>>> avoid an entire class of bugs. > > >>> >>>>>> > > >>> >>>>>> There's also PMD, which is excellent for finding code that can > > >>> >>>>>> be hard to understand. I *highly* suggest you all run PMD to > > >>> >>>>>> analyze for cognitive complexity and high npath scores. This > > >>> >>>>>> was made popular by the folks at Sonar and I've found it to be > > >>> >>>>>> an excellent feedback mechanism for structuring code. The > > >>> >>>>>> default max they set is 15, which is the point where it starts > > >>> >>>>>> to become difficult to verify something works without making a > > >>> >>>>>> massive investment. We've got areas in the codebase that are in > > >>> >>>>>> the hundreds, and some parts even higher. These have been > > >>> >>>>>> contributed by humans, and are all high risk points for both > > >>> >>>>>> humans and agents to start messing around with. They're also in > > >>> >>>>>> some fairly critical areas that are very likely to break, so I > > >>> >>>>>> understand why people would not want an agent anywhere near it. > > >>> >>>>>> > > >>> >>>>>> Unfortunately, it's not an easy problem to address. There's so > > >>> >>>>>> many places where the code is structured in a way that has so > > >>> >>>>>> many branches, so many conditions, that it's effectively > > >>> >>>>>> impossible for a human to understand, creating a fear of messing > > >>> >>>>>> around in it. There's plenty of areas that deserve extreme > > >>> >>>>>> scrutiny, and we should be careful of what we add, whether it's > > >>> >>>>>> human or agent. > > >>> >>>>>> > > >>> >>>>>> The codebase today requires a high degree of internal knowledge > > >>> >>>>>> to navigate. There's land mines everywhere. We should be > > >>> >>>>>> looking to make conscious improvements by moving the code > > >>> >>>>>> forward, so it's easier to make changes to small, well tested > > >>> >>>>>> components with minimal side effects. Not making it harder for > > >>> >>>>>> people to use the tools that aid in that process. > > >>> >>>>>> > > >>> >>>>>> Here's what we could do to achieve the underlying goal of not > > >>> >>>>>> breaking the DB: > > >>> >>>>>> > > >>> >>>>>> Add cognitive complexlity and npath via PMD as a feedback > > >>> >>>>>> mechanism. > > >>> >>>>>> > > >>> >>>>>> Code that's hard to understand is hard to review. It's also > > >>> >>>>>> hard to test. Let's break down the complex code so more people > > >>> >>>>>> can contribute, safely. > > >>> >>>>>> > > >>> >>>>>> Add checkerframework to our tooling, > > >>> >>>>>> > > >>> >>>>>> Properly annotate the codebase for it and reduce the surface > > >>> >>>>>> area that things can break. Less brittle codebase = we can move > > >>> >>>>>> faster. > > >>> >>>>>> > > >>> >>>>>> Use jacoco to find areas of the codebase with poor testing. > > >>> >>>>>> > > >>> >>>>>> Let's improve the test coverage there, LLMs are great for this. > > >>> >>>>>> We have a ton of static tests, these can become more dynamic, > > >>> >>>>>> parameterized, and leverage harry. > > >>> >>>>>> > > >>> >>>>>> Refactor parts of the codebase that have high cognitive > > >>> >>>>>> complexlity and NPath scores. > > >>> >>>>>> > > >>> >>>>>> This should be lowered over time to meet some high watermark, > > >>> >>>>>> say 25 maximum, although I'd prefer 15 which is where the Sonar > > >>> >>>>>> folks settled. > > >>> >>>>>> > > >>> >>>>>> Move forward moving the codebase to a more modular structure > > >>> >>>>>> > > >>> >>>>>> We've talked about Gradle on and off - but it can really be a > > >>> >>>>>> huge help with incremental, modular builds. This is pretty easy > > >>> >>>>>> to do with an agent and we could have it done in a couple days. > > >>> >>>>>> > > >>> >>>>>> Enforce boundaries with ArchUnit > > >>> >>>>>> > > >>> >>>>>> If we want to enforce certain code boundaries, this is the way > > >>> >>>>>> to do it. Should not be part of manual review. > > >>> >>>>>> > > >>> >>>>>> Add LLM review for all incoming PRs before a human > > >>> >>>>>> > > >>> >>>>>> The goal here is to automate the initial part of the review > > >>> >>>>>> process that reviewers should spot, and raise the bar for the > > >>> >>>>>> initial contribution. When the code gets reviewed by a human, > > >>> >>>>>> it should already have passed a large variety of initial checks. > > >>> >>>>>> This should shorten the review cycle and result in higher > > >>> >>>>>> quality patches. I've had Claude reviewing all my PRs in my > > >>> >>>>>> personal projects for a while now and it consistently gives > > >>> >>>>>> great feedback that I almost always incorporate. > > >>> >>>>>> > > >>> >>>>>> In my ideal world, we'd also auto-format all code > > >>> >>>>>> > > >>> >>>>>> Consistent formatting throughout the codebase would be amazing, > > >>> >>>>>> but that's just one man's dream. > > >>> >>>>>> > > >>> >>>>>> Hopefully there's at least a couple things in this list we could > > >>> >>>>>> move forward with in the short term, as it'll help improve the > > >>> >>>>>> code quality regardless of how it's created. > > >>> >>>>>> > > >>> >>>>>> Jon > > >>> >>>>>> > > >>> >>>>>> https://checkerframework.org/manual/#aliasing-leaking-contexts > > >>> >>>>>> https://www.sonarsource.com/docs/CognitiveComplexity.pdf > > >>> >>>>>> https://pmd.github.io/pmd/pmd_rules_java_design.html > > >>> >>>>>> > > >>> >>>>>> > > >>> >>>>>> > > >>> >>>>>> > > >>> >>>>>> > > >>> >>>>>> On Thu, Sep 24, 2026 at 7:38 AM C. Scott Andreas > > >>> >>>>>> <[email protected]> wrote: > > >>> >>>>>>> > > >>> >>>>>>> From Benedict: > > >>> >>>>>>> > > >>> >>>>>>> “I don't know if everyone remembers, but ten years ago > > >>> >>>>>>> Cassandra was full of serious correctness and stability issues. > > >>> >>>>>>> Despite developing it, I would not have run it myself or > > >>> >>>>>>> recommend that anyone use it. We have dug ourselves out of that > > >>> >>>>>>> hole, but it took years of discipline and effort, and we're > > >>> >>>>>>> still (deservedly) recovering our reputation.” > > >>> >>>>>>> > > >>> >>>>>>> Expanding on this point for those who may not have been active > > >>> >>>>>>> in the project at this time — > > >>> >>>>>>> > > >>> >>>>>>> Apache Cassandra was fundamentally undeployable for four years > > >>> >>>>>>> between Nov 2015 - 2019. The database literally lost data if > > >>> >>>>>>> you ran a read-only SELECT query ordered descending (C-14513, > > >>> >>>>>>> C-14515). If you haven’t read these tickets before, please take > > >>> >>>>>>> a moment to do so. > > >>> >>>>>>> > > >>> >>>>>>> It took years of careful work via property-based testing, > > >>> >>>>>>> fuzzing, and deterministic simulation to restore Cassandra’s > > >>> >>>>>>> status as a usable system of record. Once 14513 and 14515 were > > >>> >>>>>>> identified, nearly 30 additional critical data loss and > > >>> >>>>>>> incorrect response bugs were identified. > > >>> >>>>>>> > > >>> >>>>>>> It is essential for the project’s future that we don’t regress > > >>> >>>>>>> to this state chasing AI-generated features motivated by fear. > > >>> >>>>>>> The fact that examples cited in this thread which boast shiny > > >>> >>>>>>> features but have critical shortcomings unknown to their author > > >>> >>>>>>> supports this argument. > > >>> >>>>>>> > > >>> >>>>>>> The most common path for large corpuses of AI-generated > > >>> >>>>>>> software is elation and reveling in a feature matrix, followed > > >>> >>>>>>> by abandonment. > > >>> >>>>>>> > > >>> >>>>>>> I endorse this point: > > >>> >>>>>>> > > >>> >>>>>>> “Let's use this new technology to improve the quality of our > > >>> >>>>>>> contributions, not squander our hard-earned gains in the name > > >>> >>>>>>> of speed. It will be hard to recover our reputation a second > > >>> >>>>>>> time.” > > >>> >>>>>>> > > >>> >>>>>>> Patrick, I don’t want your note regarding a TCM issue to go > > >>> >>>>>>> unaddressed. Please file a Jira ticket and the patch if you > > >>> >>>>>>> like. I can’t comment on the patch as I haven’t seen it, but > > >>> >>>>>>> together we will solve the problem. > > >>> >>>>>>> > > >>> >>>>>>> – Scott > > >>> >>>>>>> > > >>> >>>>>>>> On Sep 24, 2026, at 4:01 AM, Benedict Elliott Smith > > >>> >>>>>>>> <[email protected]> wrote: > > >>> >>>>>>>> > > >>> >>>>>>>> Hi Patrick, > > >>> >>>>>>>> > > >>> >>>>>>>> As I mentioned in my reply to David, I would be happy to > > >>> >>>>>>>> create a carve out for shallow and localised bug fixes in the > > >>> >>>>>>>> "Permitted" section. Would this alleviate some of your > > >>> >>>>>>>> concerns regarding your ability to contribute to the project? > > >>> >>>>>>>> > > >>> >>>>>>>> I appreciate your pointing out Ferrosa's Accord implementation > > >>> >>>>>>>> however, as it is a *great* example of the problems we're > > >>> >>>>>>>> leaping into. I took a look, and within about 30s found that > > >>> >>>>>>>> the protocol is fundamentally incorrect, having failed to > > >>> >>>>>>>> address CASSANDRA-18365. This is despite claiming to be tested > > >>> >>>>>>>> with Jepsen that should in principle find this fault. I > > >>> >>>>>>>> followed up by using Claude to interrogate the implementation > > >>> >>>>>>>> further, and immediately found other serious correctness > > >>> >>>>>>>> issues. > > >>> >>>>>>>> > > >>> >>>>>>>> I use LLMs daily now to help facilitate Accord development, > > >>> >>>>>>>> and while they are powerful they are NOT able to author the > > >>> >>>>>>>> code themselves, even when building upon a strong > > >>> >>>>>>>> human-authored foundation. > > >>> >>>>>>>> > > >>> >>>>>>>> I don't know if everyone remembers, but ten years ago > > >>> >>>>>>>> Cassandra was full of serious correctness and stability > > >>> >>>>>>>> issues. Despite developing it, I would not have run it myself > > >>> >>>>>>>> or recommend that anyone use it. We have dug ourselves out of > > >>> >>>>>>>> that hole, but it took years of discipline and effort, and > > >>> >>>>>>>> we're still (deservedly) recovering our reputation. > > >>> >>>>>>>> > > >>> >>>>>>>> Let's use this new technology to improve the quality of our > > >>> >>>>>>>> contributions, not squander our hard-earned gains in the name > > >>> >>>>>>>> of speed. It will be hard to recover our reputation a second > > >>> >>>>>>>> time. > > >>> >>>>>>>> > > >>> >>>>>>>> > > >>> >>>>>>>>> On 2026/09/23 19:16:17 Patrick McFadin wrote: > > >>> >>>>>>>>> I was waiting for this moment to hit our project and I'm glad > > >>> >>>>>>>>> we're here. I > > >>> >>>>>>>>> am deeply concerned for our project and its future, as we > > >>> >>>>>>>>> have increasingly > > >>> >>>>>>>>> made it difficult to contribute. I had hoped that this new > > >>> >>>>>>>>> era of > > >>> >>>>>>>>> software tools powered by AI would expand the project's reach > > >>> >>>>>>>>> and bring > > >>> >>>>>>>>> more diverse thoughts and ideas. This policy proposal is the > > >>> >>>>>>>>> exact opposite > > >>> >>>>>>>>> of what we need. We have been sitting on a Cassandra 6 > > >>> >>>>>>>>> release alpha for > > >>> >>>>>>>>> months. We need to accelerate and embrace new ways of being > > >>> >>>>>>>>> or be left > > >>> >>>>>>>>> behind. As I read that policy, my first and gut level > > >>> >>>>>>>>> reactions: > > >>> >>>>>>>>> - It comes across as elitist and class protectionism. > > >>> >>>>>>>>> Committer should not > > >>> >>>>>>>>> be special but this proposal makes that designation even more > > >>> >>>>>>>>> sacred. > > >>> >>>>>>>>> - It signals that our project is so fragile that only a few > > >>> >>>>>>>>> people "Really > > >>> >>>>>>>>> understand it" That's some SQLite vibes right there. > > >>> >>>>>>>>> - Trying to fix a problem that doesn't exist > > >>> >>>>>>>>> Sadly, i think this policy change would also exclude a lot of > > >>> >>>>>>>>> comitters. > > >>> >>>>>>>>> We aren't alone in this moment. The Linux project just went > > >>> >>>>>>>>> through > > >>> >>>>>>>>> this. You can find the thread with a simple Google, but > > >>> >>>>>>>>> similar hard > > >>> >>>>>>>>> feelings were being expressed "AI is going to ruin our > > >>> >>>>>>>>> project!", "The > > >>> >>>>>>>>> unwashed masses are going to contribute terrible code!", "We > > >>> >>>>>>>>> have to > > >>> >>>>>>>>> protect our precious status as Linux maintainers!" Linus > > >>> >>>>>>>>> being Linus, was > > >>> >>>>>>>>> deeply invloved and they adopted a super simple statement > > >>> >>>>>>>>> that covers all > > >>> >>>>>>>>> bases. Human or Human using AI. “You are expected to > > >>> >>>>>>>>> understand and to be > > >>> >>>>>>>>> able to defend everything you submit.” Love that. > > >>> >>>>>>>>> In the larger picture, I'll restate. I'm worried for our > > >>> >>>>>>>>> project. In late > > >>> >>>>>>>>> 2025(Opus 4.5 IYKYK), early 2026, AI coding LLMs turned a > > >>> >>>>>>>>> real corner and > > >>> >>>>>>>>> in the hands of somebody that knows how to build software, > > >>> >>>>>>>>> this tool is > > >>> >>>>>>>>> like jet fuel. Here's some examples of new projects being > > >>> >>>>>>>>> hyper fueled by > > >>> >>>>>>>>> AI coding tools. > > >>> >>>>>>>>> Apache Iggy - Complete rust replacement of kafka. Crazy fast > > >>> >>>>>>>>> velocity > > >>> >>>>>>>>> Turso - Rust re-write of SQLite > > >>> >>>>>>>>> Bun - Rust re-write of itself from Zig. > > >>> >>>>>>>>> Think this couldn't happen to us? Already has: > > >>> >>>>>>>>> https://github.com/ferrosadb/ferrosa. Ben is using it to > > >>> >>>>>>>>> power his own > > >>> >>>>>>>>> startup, but it was him alone using a ton of local AI coding > > >>> >>>>>>>>> agents. He > > >>> >>>>>>>>> even implemented Accord. Yeah... > > >>> >>>>>>>>> The cracks are already starting to show. There is a black > > >>> >>>>>>>>> market economy of > > >>> >>>>>>>>> Cassandra patches happening now. Not going to name names or > > >>> >>>>>>>>> call people > > >>> >>>>>>>>> out, but there are fixes and optimizations living in > > >>> >>>>>>>>> branches outside of > > >>> >>>>>>>>> the Cassandra project. Why? I'll use myself as an example. I > > >>> >>>>>>>>> fixed a nasty > > >>> >>>>>>>>> bug I ran into with TCM a few weeks ago. Wrote the tests. It > > >>> >>>>>>>>> passes CI and > > >>> >>>>>>>>> lives in my personal branch. I'm sitting here really > > >>> >>>>>>>>> wondering if I want to > > >>> >>>>>>>>> go through the ritual humiliation of being roasted for using > > >>> >>>>>>>>> AI to fix it. > > >>> >>>>>>>>> Me. I am worried about contrinuting code the Cassandra. What > > >>> >>>>>>>>> the hell does > > >>> >>>>>>>>> that say? > > >>> >>>>>>>>> I have my CQLite project that I've been doing a release > > >>> >>>>>>>>> around once a > > >>> >>>>>>>>> month. I would love to donate that to the Cassandra project > > >>> >>>>>>>>> but I wouldn't > > >>> >>>>>>>>> if it essentially killed any progress. > > >>> >>>>>>>>> My larger counter proposal would be to: > > >>> >>>>>>>>> - Adopt the “You are expected to understand and to be able to > > >>> >>>>>>>>> defend > > >>> >>>>>>>>> everything you submit.” approach the Linux project has > > >>> >>>>>>>>> adopted. > > >>> >>>>>>>>> - Loosen up the contributor process and our worry on trunk. > > >>> >>>>>>>>> Let 1000 > > >>> >>>>>>>>> flowers bloom and bring it in. > > >>> >>>>>>>>> - And finally, to give some people more peace of mind and > > >>> >>>>>>>>> open more doors, > > >>> >>>>>>>>> adopt what other projects have done and provide more > > >>> >>>>>>>>> pluggability. Let new > > >>> >>>>>>>>> ideas have an easy place to connect. > > >>> >>>>>>>>> We are at a fork in the road. What are we going to do? And > > >>> >>>>>>>>> then I have to > > >>> >>>>>>>>> ask myself, what am I going to do as a contributor? > > >>> >>>>>>>>> Patrick > > >>> >>>>>>>>> On Wed, Sep 23, 2026 at 6:16 AM Blake Eggleston > > >>> >>>>>>>>> <[email protected]> > > >>> >>>>>>>>> wrote: > > >>> >>>>>>>>>> I’m not necessarily opposed to having a policy, but so far > > >>> >>>>>>>>>> we have some > > >>> >>>>>>>>>> specific proposals addressing a problem statement that’s > > >>> >>>>>>>>>> very nebulous. > > >>> >>>>>>>>>> What is the community failing to do on its own that we’re > > >>> >>>>>>>>>> trying to correct > > >>> >>>>>>>>>> with policy? What outcomes are we trying to create or > > >>> >>>>>>>>>> prevent? Having some > > >>> >>>>>>>>>> examples and specific problems to discuss would help focus > > >>> >>>>>>>>>> the conversation. > > >>> >>>>>>>>>>> On Wed, Sep 23, 2026, at 4:34 AM, Shailaja Koppu via dev > > >>> >>>>>>>>>>> wrote: > > >>> >>>>>>>>>> Benedict, > > >>> >>>>>>>>>> Thanks for clarifying. My concern still remains. This > > >>> >>>>>>>>>> criteria would be > > >>> >>>>>>>>>> difficult to define and apply consistently. What counts as > > >>> >>>>>>>>>> “similar” scope > > >>> >>>>>>>>>> or area, “mostly correct,” or sufficiently independent work? > > >>> >>>>>>>>>> More > > >>> >>>>>>>>>> importantly, how do we prevent such vague criteria from > > >>> >>>>>>>>>> creating an > > >>> >>>>>>>>>> informal hierarchy where some contributors work is routinely > > >>> >>>>>>>>>> accepted while > > >>> >>>>>>>>>> others is routinely rejected? > > >>> >>>>>>>>>> If the intent is to limit AI-assisted code changes to > > >>> >>>>>>>>>> Cassandra > > >>> >>>>>>>>>> contributors, or to contributors who have previously worked > > >>> >>>>>>>>>> in that > > >>> >>>>>>>>>> component without AI, that would at least be clear and > > >>> >>>>>>>>>> enforceable. > > >>> >>>>>>>>>>> On Sep 23, 2026, at 12:01 PM, Benedict Elliott Smith < > > >>> >>>>>>>>>> [email protected]> wrote: > > >>> >>>>>>>>>>> Core code changes > > >>> >>>>>>>>>>> Chris: Do you object to the first or second line you quote? > > >>> >>>>>>>>>>> Because the > > >>> >>>>>>>>>> first line is effectively motivation for the second line, > > >>> >>>>>>>>>> and can be > > >>> >>>>>>>>>> removed (or more clearly combined). If it’s the second line, > > >>> >>>>>>>>>> then I do not > > >>> >>>>>>>>>> think this is an unreasonable expectation, and we can get > > >>> >>>>>>>>>> into a proper > > >>> >>>>>>>>>> debate about it. > > >>> >>>>>>>>>>> Shailaja, since you only snipped the first sentence, your > > >>> >>>>>>>>>>> concerns might > > >>> >>>>>>>>>> also be mostly answered by this clarification? “Minimal > > >>> >>>>>>>>>> third-party > > >>> >>>>>>>>>> guidance” implies you have some concerns about the second > > >>> >>>>>>>>>> line, but all of > > >>> >>>>>>>>>> our policies have some ambiguity because legalese is even > > >>> >>>>>>>>>> worse. I don’t > > >>> >>>>>>>>>> think the ambiguity here would be challenging to navigate > > >>> >>>>>>>>>> though we can > > >>> >>>>>>>>>> certainly refine it. This specific snippet is meant to > > >>> >>>>>>>>>> convey an > > >>> >>>>>>>>>> expectation that a contributor has autonomously produced > > >>> >>>>>>>>>> patches of similar > > >>> >>>>>>>>>> scope that were mostly correct, so that they have > > >>> >>>>>>>>>> demonstrated the level of > > >>> >>>>>>>>>> understanding necessary to guide another party to a > > >>> >>>>>>>>>> successful patch (i.e. > > >>> >>>>>>>>>> an LLM in this case). > > >>> >>>>>>>>>>> On 2026/09/23 10:54:16 Benedict Elliott Smith wrote: > > >>> >>>>>>>>>>>> Thanks everyone for your input so far. I’ll respond in > > >>> >>>>>>>>>>>> brief to the > > >>> >>>>>>>>>> main themes, in (mostly) separate emails so they can each > > >>> >>>>>>>>>> have their own > > >>> >>>>>>>>>> debate chain. > > >>> >>>>>>>>>>>> Should we have a policy (Blake/Josh*/Jon/Dinesh) > > >>> >>>>>>>>>>>> I think we would all agree that LLMs represent the biggest > > >>> >>>>>>>>>>>> change to > > >>> >>>>>>>>>> this community (and software more generally) since its > > >>> >>>>>>>>>> inception, and we > > >>> >>>>>>>>>> all now have enough experience with the technology to have > > >>> >>>>>>>>>> formed opinions > > >>> >>>>>>>>>> about how it is best managed. We also evidently have not all > > >>> >>>>>>>>>> arrived at the > > >>> >>>>>>>>>> same conclusions. In this situation, it would be an > > >>> >>>>>>>>>> abdication of our > > >>> >>>>>>>>>> responsibilities as a management committee to not agree > > >>> >>>>>>>>>> *some* policy. > > >>> >>>>>>>>>>>> I intend to conduct straw polls as the discussion evolves, > > >>> >>>>>>>>>>>> so if you > > >>> >>>>>>>>>> prefer an alternative policy - or modifications to this > > >>> >>>>>>>>>> policy - I would > > >>> >>>>>>>>>> encourage you to make those alternative proposals. > > >>> >>>>>>>>>>>> *Veto/Consensus (Josh) > > >>> >>>>>>>>>>>> It was fair to call out my poor use of language on this > > >>> >>>>>>>>>>>> topic, so let > > >>> >>>>>>>>>> me rephrase a little. The community is built on consensus, > > >>> >>>>>>>>>> and work should > > >>> >>>>>>>>>> not be merged when there are outstanding concerns to > > >>> >>>>>>>>>> address. The explicit > > >>> >>>>>>>>>> -1 should only be used rarely, because the prior expectation > > >>> >>>>>>>>>> should prevent > > >>> >>>>>>>>>> it ever being needed. I (and others) have outstanding > > >>> >>>>>>>>>> concerns on LLM > > >>> >>>>>>>>>> generated work that can only be addressed through this > > >>> >>>>>>>>>> process right here, > > >>> >>>>>>>>>> so to merge such work while maintaining the community’s > > >>> >>>>>>>>>> consensus we must > > >>> >>>>>>>>>> agree some policy. > > >>> >>>>>>>>>>>> On 2026/09/23 09:58:27 Shailaja Koppu via dev wrote: > > >>> >>>>>>>>>>>>> I am strongly -1 on this > > >>> >>>>>>>>>>>>> - Core code changes made by LLM may only be proposed by > > >>> >>>>>>>>>>>>> contributors > > >>> >>>>>>>>>> with demonstrated expertise > > >>> >>>>>>>>>>>>> That creates a new, subjective privileged class of > > >>> >>>>>>>>>>>>> contributors and > > >>> >>>>>>>>>> turns a tool choice into an eligibility test. Who decides > > >>> >>>>>>>>>> whether expertise > > >>> >>>>>>>>>> has been “demonstrated,” what counts as “minimal third-party > > >>> >>>>>>>>>> guidance,” and > > >>> >>>>>>>>>> how could those judgments be applied consistently or fairly? > > >>> >>>>>>>>>>>>> Apache already has a better model, anyone may contribute, > > >>> >>>>>>>>>>>>> trust and > > >>> >>>>>>>>>> additional repository privileges are earned transparently > > >>> >>>>>>>>>> over time. The > > >>> >>>>>>>>>> ASF describes its communities as flat, and says that > > >>> >>>>>>>>>> newcomer ideas have as > > >>> >>>>>>>>>> much input as those from original creators. We should not > > >>> >>>>>>>>>> add a separate, > > >>> >>>>>>>>>> informal hierarchy in which certain people may use common > > >>> >>>>>>>>>> development tools > > >>> >>>>>>>>>> while others may not. > > >>> >>>>>>>>>>>>>> On Sep 23, 2026, at 6:33 AM, Chris Lohfink > > >>> >>>>>>>>>>>>>> <[email protected]> > > >>> >>>>>>>>>> wrote: > > >>> >>>>>>>>>>>>>> - Core code changes made by LLM may only be proposed by > > >>> >>>>>>>>>>>>>> contributors > > >>> >>>>>>>>>> with demonstrated expertise > > >>> >>>>>>>>>>>>>> - Must have produced similar patches in size, scope and > > >>> >>>>>>>>>>>>>> area > > >>> >>>>>>>>>> unassisted and with minimal third-party guidance > > >>> >>>>>>>>>>>>>> I really don't like this one or its wording. Definitely > > >>> >>>>>>>>>>>>>> too "the > > >>> >>>>>>>>>> peasants are getting uppity lets build a wall". Lets not let > > >>> >>>>>>>>>> a subjective > > >>> >>>>>>>>>> thing like demonstrated expertise (who decides that?) be if > > >>> >>>>>>>>>> it's ok or not. > > >>> >>>>>>>>>> Hold the same standards for code quality and process for it > > >>> >>>>>>>>>> all. I don't > > >>> >>>>>>>>>> want this to be: only people on the storage team in Apple > > >>> >>>>>>>>>> can use AI. > > >>> >>>>>>>>>>>>>> Chris > > >>> >>>>>>>>>>>>>> On Wed, Sep 23, 2026 at 12:16 AM <[email protected] > > >>> >>>>>>>>>>>>>> <mailto: > > >>> >>>>>>>>>> [email protected]>> wrote: > > >>> >>>>>>>>>>>>>>> I agree with Stefan and think this is both a reasonable > > >>> >>>>>>>>>>>>>>> and > > >>> >>>>>>>>>> thoughtful proposal. > > >>> >>>>>>>>>>>>>>> Here are some things I like about it: > > >>> >>>>>>>>>>>>>>> – It outlines areas where LLM usage is unambiguously > > >>> >>>>>>>>>>>>>>> useful to the > > >>> >>>>>>>>>> project’s developers and users. > > >>> >>>>>>>>>>>>>>> – It defines a spectrum of recommendations and cautions. > > >>> >>>>>>>>>>>>>>> – The only prohibited areas are extremely narrow and > > >>> >>>>>>>>>>>>>>> say nothing > > >>> >>>>>>>>>> about code at all. > > >>> >>>>>>>>>>>>>>> Some in this thread are responding as if this proposal > > >>> >>>>>>>>>>>>>>> seeks to > > >>> >>>>>>>>>> prohibit or sharply limit use of LLMs. In fact, it’s one of > > >>> >>>>>>>>>> the most open > > >>> >>>>>>>>>> and welcoming I’ve seen for an OSS project of our size where > > >>> >>>>>>>>>> many are > > >>> >>>>>>>>>> adopting policies that simply ban them entirely. I’ve > > >>> >>>>>>>>>> re-appended the > > >>> >>>>>>>>>> proposal below my message as it seems to have been lost in > > >>> >>>>>>>>>> threaded > > >>> >>>>>>>>>> replies, and would encourage folks to give it a second read. > > >>> >>>>>>>>>>>>>>> Some brief thoughts based on my own use of LLMs: > > >>> >>>>>>>>>>>>>>> – I find them fantastically useful for reviewing and > > >>> >>>>>>>>>>>>>>> identifying > > >>> >>>>>>>>>> problems that have slipped through review - primarily via > > >>> >>>>>>>>>> Alex Petrov’s > > >>> >>>>>>>>>> /deep-review skill, which I have running in a VM in a loop > > >>> >>>>>>>>>> executing over > > >>> >>>>>>>>>> every new commit in the project as of a few days ago. I will > > >>> >>>>>>>>>> be posting a > > >>> >>>>>>>>>> few hand-authored Jira tickets based on findings that appear > > >>> >>>>>>>>>> legitimate to > > >>> >>>>>>>>>> me. For now, the loop is posting them as issue drafts for my > > >>> >>>>>>>>>> own review on > > >>> >>>>>>>>>> my personal fork which you can find here: > > >>> >>>>>>>>>> https://github.com/cscotta/cassandra/issues?q=is%3Aissue%20state%3Aopen%20label%3Abug > > >>> >>>>>>>>>>>>>>> – They’re great for enabling use of model checkers and > > >>> >>>>>>>>>>>>>>> formal > > >>> >>>>>>>>>> methods where such work would have previously been > > >>> >>>>>>>>>> prohibitively expensive, > > >>> >>>>>>>>>> such as Blake’s work on a TLA+ proof of aspects of Mutation > > >>> >>>>>>>>>> Tracking and > > >>> >>>>>>>>>> Benedict/Fedor’s work on a machine-checkable proof of the > > >>> >>>>>>>>>> Accord protocol > > >>> >>>>>>>>>> in Lean. > > >>> >>>>>>>>>>>>>>> – They are stunning for allowing me to experiment with > > >>> >>>>>>>>>>>>>>> ideas that > > >>> >>>>>>>>>> would have otherwise been a summer internship’s scope of > > >>> >>>>>>>>>> work. Some > > >>> >>>>>>>>>> examples include an io_uring prototype, exploring the impact > > >>> >>>>>>>>>> of > > >>> >>>>>>>>>> page-aligned compressed chunk sizes, an API shim bridging > > >>> >>>>>>>>>> the 3.x and 4.x > > >>> >>>>>>>>>> Java Drivers, and potential enhancements to Zstandard. > > >>> >>>>>>>>>>>>>>> – And they shine when given grunt-work that is critical > > >>> >>>>>>>>>>>>>>> to the > > >>> >>>>>>>>>> project but a miserable labor for humans, such as triaging, > > >>> >>>>>>>>>> reproducing, > > >>> >>>>>>>>>> and root-causing flaky tests, which David Capwell now has > > >>> >>>>>>>>>> running in a loop > > >>> >>>>>>>>>> to help us improve CI stability in the project. > > >>> >>>>>>>>>>>>>>> I never thought I’d be so positive on what’s possible > > >>> >>>>>>>>>>>>>>> via language > > >>> >>>>>>>>>> models a year ago. At the same time, I also agree that they > > >>> >>>>>>>>>> present > > >>> >>>>>>>>>> challenges and risks that can be managed through thoughtful > > >>> >>>>>>>>>> discussion and > > >>> >>>>>>>>>> policy. Some of the concerns that I think are important to > > >>> >>>>>>>>>> guard against > > >>> >>>>>>>>>> include: > > >>> >>>>>>>>>>>>>>> – Asymmetry of effort between author and reviewers: As > > >>> >>>>>>>>>> token-generating machines, LLMs can generate diffs of > > >>> >>>>>>>>>> extraordinary size > > >>> >>>>>>>>>> very rapidly. /deep-review is great for chewing through > > >>> >>>>>>>>>> diffs and > > >>> >>>>>>>>>> identifying defects. But it should be used by the > > >>> >>>>>>>>>> contributor themselves to > > >>> >>>>>>>>>> identify issues – not to replace the role of the reviewer > > >>> >>>>>>>>>> with more > > >>> >>>>>>>>>> electricity. The role of the reviewers extends beyond > > >>> >>>>>>>>>> identifying and > > >>> >>>>>>>>>> highlighting defects. It encompasses architecture, harmony > > >>> >>>>>>>>>> with the > > >>> >>>>>>>>>> existing codebase, thinking ahead to future evolution of the > > >>> >>>>>>>>>> project, and > > >>> >>>>>>>>>> replicates context on the project as new code is committed. > > >>> >>>>>>>>>> These functions > > >>> >>>>>>>>>> cannot be automated away. > > >>> >>>>>>>>>>>>>>> – Hesitancy of authors to engage manually with code > > >>> >>>>>>>>>>>>>>> they have > > >>> >>>>>>>>>> generated: This is not specific to Cassandra, but it is a > > >>> >>>>>>>>>> behavior that I > > >>> >>>>>>>>>> have seen in several “highly-electric” projects. There’s a > > >>> >>>>>>>>>> bimodal tendency > > >>> >>>>>>>>>> toward code that is entirely generated or entirely > > >>> >>>>>>>>>> human-authored - but it > > >>> >>>>>>>>>> is rare for someone to prepare an AI-authored patch to take > > >>> >>>>>>>>>> an offramp and > > >>> >>>>>>>>>> spend a significant amount of time refining the work by hand > > >>> >>>>>>>>>> in an IDE. > > >>> >>>>>>>>>> This hesitancy toward human participation in authorship of > > >>> >>>>>>>>>> LLM-generated > > >>> >>>>>>>>>> code is very concerning to me. > > >>> >>>>>>>>>>>>>>> – Harmony with the existing codebase: Due to the > > >>> >>>>>>>>>>>>>>> tunnel-vision of > > >>> >>>>>>>>>> context windows, LLMs are generally unaware of conventions > > >>> >>>>>>>>>> and norms > > >>> >>>>>>>>>> present in codebases and very frequently reinvent concepts > > >>> >>>>>>>>>> in a generation > > >>> >>>>>>>>>> turn to suit a goal without view of the project’s overall > > >>> >>>>>>>>>> architecture. > > >>> >>>>>>>>>> This results in a profusion of messy and duplicated concepts > > >>> >>>>>>>>>> that gradually > > >>> >>>>>>>>>> sprawl about a codebase. > > >>> >>>>>>>>>>>>>>> Again, none of these are grounds for prohibition of > > >>> >>>>>>>>>>>>>>> usage of > > >>> >>>>>>>>>> language models in developing the project. They’re just > > >>> >>>>>>>>>> problems we need to > > >>> >>>>>>>>>> bear in mind and guard against – and I think the proposal is > > >>> >>>>>>>>>> designed to do > > >>> >>>>>>>>>> just that. > > >>> >>>>>>>>>>>>>>> I’m thrilled by the potential of LLMs to improve Apache > > >>> >>>>>>>>>>>>>>> Cassandra > > >>> >>>>>>>>>> and we already see it happening through a vast number of > > >>> >>>>>>>>>> issues that are > > >>> >>>>>>>>>> being reported and fixed. But there’s also danger in taking > > >>> >>>>>>>>>> ATVs down a > > >>> >>>>>>>>>> hiking trail full of people. > > >>> >>>>>>>>>>>>>>> Regarding the prohibition on prose, I’ll simply say: I > > >>> >>>>>>>>>>>>>>> recently > > >>> >>>>>>>>>> found myself in a scenario where I found a Claude-authored > > >>> >>>>>>>>>> document so > > >>> >>>>>>>>>> inscrutable that I piped it back into a model, directed it > > >>> >>>>>>>>>> to rewrite it in > > >>> >>>>>>>>>> ASD-STE100, read it myself, and responded based on the > > >>> >>>>>>>>>> summarization. As a > > >>> >>>>>>>>>> humanities grad, this is probably the worst language crime I > > >>> >>>>>>>>>> have > > >>> >>>>>>>>>> committed. But it was in response to language that was > > >>> >>>>>>>>>> itself so > > >>> >>>>>>>>>> idiosyncratic that it was unreadable to me in its original > > >>> >>>>>>>>>> form. I hope > > >>> >>>>>>>>>> this never happens in the Apache Cassandra project. > > >>> >>>>>>>>>>>>>>> I’ll close with a quote from an excellent article > > >>> >>>>>>>>>>>>>>> written by Colin > > >>> >>>>>>>>>> Breck, an engineer who works on large-scale data systems: > > >>> >>>>>>>>>> https://blog.colinbreck.com/i-dont-want-to-read-what-you-didnt-write/ > > >>> >>>>>>>>>>>>>>> Colin wrote: > > >>> >>>>>>>>>>>>>>>> I don’t want to live in a world where you use AI to > > >>> >>>>>>>>>>>>>>>> summarize > > >>> >>>>>>>>>> something important into unreadable text, and then I use AI > > >>> >>>>>>>>>> in an attempt > > >>> >>>>>>>>>> to decipher it. I want to hear you, imperfections and all. I > > >>> >>>>>>>>>> want your > > >>> >>>>>>>>>> interpretation of aesthetics, beauty, quality, relationship, > > >>> >>>>>>>>>> time. I want > > >>> >>>>>>>>>> to know how you feel. I want you to cut through and tell me > > >>> >>>>>>>>>> what really > > >>> >>>>>>>>>> matters. > > >>> >>>>>>>>>>>>>>>> Intentional writing will likely become more valuable. > > >>> >>>>>>>>>>>>>>>> People who > > >>> >>>>>>>>>> write, and write to think, to think deeply and carefully, or > > >>> >>>>>>>>>> to create, to > > >>> >>>>>>>>>> share, or to capture something important without explicitly > > >>> >>>>>>>>>> expressing it > > >>> >>>>>>>>>> will continue to write and produce original work. The people > > >>> >>>>>>>>>> who never were > > >>> >>>>>>>>>> writers will use AI to produce lots of text. > > >>> >>>>>>>>>>>>>>> I hope that our culture can remain one of intentional > > >>> >>>>>>>>>>>>>>> writing and > > >>> >>>>>>>>>> intentional engineering. I enjoy reading the voice of the > > >>> >>>>>>>>>> author in > > >>> >>>>>>>>>> comments, code, and tickets in Cassandra – the different > > >>> >>>>>>>>>> ways we use > > >>> >>>>>>>>>> language based on where we grew up and how we learned > > >>> >>>>>>>>>> English, the > > >>> >>>>>>>>>> translated idioms from our various backgrounds, and terse > > >>> >>>>>>>>>> comments that > > >>> >>>>>>>>>> recognize the difference between code whose function is > > >>> >>>>>>>>>> obvious and what > > >>> >>>>>>>>>> warrants genuine exposition. When I read code in Cassandra, > > >>> >>>>>>>>>> it’s a delight > > >>> >>>>>>>>>> to recognize the author based on their writing style before > > >>> >>>>>>>>>> flipping on > > >>> >>>>>>>>>> `git annotate` to reveal the origin. > > >>> >>>>>>>>>>>>>>> I’d encourage folks to re-read the original proposal > > >>> >>>>>>>>>>>>>>> below. It is > > >>> >>>>>>>>>> very permissive. The guidance strikes me not just as > > >>> >>>>>>>>>> reasonable, but > > >>> >>>>>>>>>> genuinely important to maintaining the health of the project. > > >>> >>>>>>>>>>>>>>> – Scott > > >>> >>>>>>>>>>>>>>> ===== > > >>> >>>>>>>>>>>>>>> Encouraged: > > >>> >>>>>>>>>>>>>>> - Reviewing and otherwise validating human-authored > > >>> >>>>>>>>>>>>>>> patches before > > >>> >>>>>>>>>> submission > > >>> >>>>>>>>>>>>>>> - Debugging, diagnosing etc > > >>> >>>>>>>>>>>>>>> Permitted: > > >>> >>>>>>>>>>>>>>> - Generating or modifying tests, scripts, tooling or > > >>> >>>>>>>>>>>>>>> any other > > >>> >>>>>>>>>> non-user facing changes > > >>> >>>>>>>>>>>>>>> - Minor changes to human-authored patches that are > > >>> >>>>>>>>>>>>>>> carefully > > >>> >>>>>>>>>> reviewed by the author > > >>> >>>>>>>>>>>>>>> Restricted: > > >>> >>>>>>>>>>>>>>> - Core code changes made by LLM may only be proposed by > > >>> >>>>>>>>>>>>>>> contributors > > >>> >>>>>>>>>> with demonstrated expertise > > >>> >>>>>>>>>>>>>>> - Must have produced similar patches in size, scope and > > >>> >>>>>>>>>>>>>>> area > > >>> >>>>>>>>>> unassisted and with minimal third-party guidance > > >>> >>>>>>>>>>>>>>> - Core code changes made by LLM require an additional > > >>> >>>>>>>>>>>>>>> reviewer > > >>> >>>>>>>>>>>>>>> - LLM review is not a substitute for human review, and > > >>> >>>>>>>>>>>>>>> must be used > > >>> >>>>>>>>>> only to augment a complete and independent human > > >>> >>>>>>>>>> understanding of the patch. > > >>> >>>>>>>>>>>>>>> Prohibited: > > >>> >>>>>>>>>>>>>>> - All public prose must be human authored. This > > >>> >>>>>>>>>>>>>>> includes inline > > >>> >>>>>>>>>> comments, docs, posts to Jira etc. > > >>> >>>>>>>>>>>>>>> All LLM generated changes MUST be disclosed: > > >>> >>>>>>>>>>>>>>> - Outlined to any reviewer; > > >>> >>>>>>>>>>>>>>> - Summarised in the commit message; > > >>> >>>>>>>>>>>>>>> - Large blocks or files must be individually marked > > >>> >>>>>>>>>>>>>>> with some agreed > > >>> >>>>>>>>>> message like "created by <some AI>" > > >>> >>>>>>>>>>>>>>> ===== > > >>> >>>>>>>>>>>>>>>> On Sep 22, 2026, at 9:13 PM, Dinesh Joshi > > >>> >>>>>>>>>>>>>>>> <[email protected] > > >>> >>>>>>>>>> <mailto:[email protected]>> wrote: > > >>> >>>>>>>>>>>>>>>> On Tue, Sep 22, 2026 at 3:28 AM Benedict > > >>> >>>>>>>>>>>>>>>> <[email protected] > > >>> >>>>>>>>>> <mailto:[email protected]>> wrote: > > >>> >>>>>>>>>>>>>>>>> Restricted: > > >>> >>>>>>>>>>>>>>>>> - Core code changes made by LLM may only be proposed > > >>> >>>>>>>>>>>>>>>>> by > > >>> >>>>>>>>>> contributors with demonstrated expertise > > >>> >>>>>>>>>>>>>>>>> - Must have produced similar patches in size, scope > > >>> >>>>>>>>>>>>>>>>> and area > > >>> >>>>>>>>>> unassisted and with minimal third-party guidance > > >>> >>>>>>>>>>>>>>>> I am -1 on this. This sounds like gate keeping > > >>> >>>>>>>>>>>>>>>> attempt. It narrowly > > >>> >>>>>>>>>> limits the pool to a few people on the project that have > > >>> >>>>>>>>>> historically > > >>> >>>>>>>>>> contributed to certain parts of the codebase. This policy > > >>> >>>>>>>>>> will prohibit > > >>> >>>>>>>>>> skilled software engineers with domain expertise from > > >>> >>>>>>>>>> proposing LLM > > >>> >>>>>>>>>> assisted changes simply because they have not contributed to > > >>> >>>>>>>>>> the project. > > >>> >>>>>>>>>> This is unrealistic and a net negative for the project to > > >>> >>>>>>>>>> attract talent > > >>> >>>>>>>>>> and grow our community. > > >>> >>>>>>>>>>>>>>>>> - Core code changes made by LLM require an additional > > >>> >>>>>>>>>>>>>>>>> reviewer > > >>> >>>>>>>>>>>>>>>> Can you be more precise what is this in addition to? > > >>> >>>>>>>>>>>>>>>> How many total > > >>> >>>>>>>>>> reviewers do you expect and what is the purpose of > > >>> >>>>>>>>>> additional reviewer? and > > >>> >>>>>>>>>> why? > > >>> >>>>>>>>>>>>>>>> Taking a step back - what are you trying to solve here? > > >>> >>>>>>>>>>>>>>>> Dinesh
