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 > > >>> > > >> > > > > >
