> We just make sure the builds don't break. To ensure builds don't break across all projects using utils, we'd need to integrate a basic build of all GA supported branches of Cassandra and all ecosystem projects as a CI gate for the cassandra-utils project. That would foist needing to fix all dependents up to the workflow of committing an API breaking change, onto the person making the change to utils or onto the delegates they find at that time. This is predicated on the "one branch to rule them all" model though.
The alternative (existing API endpoints are static but you can add new ones) decouples that need to update all dependents to whenever they want to integrate that new API and takes that burden off the person making the change to utils. In theory we'd get to have our cake and eat it too (i.e. frictionless iteration on an API endpoint flagged @BETA, users have stable APIs they can rely on with @STABLE), at the risk / cost of having a proliferation of @DEPRECATED APIs littered behind us. My intuition is that the latter is actually significantly less work for anyone that wants to modify utils vs. the former and the risk of that long tail of deprecated API proliferation isn't that high. > I’m against creating any API boundaries we need to maintain for any external > users 100% agree. I think we get this as a free side-effect of a model where we have STABLE flagged APIs and BETA, since it defers that integration cost to *any* consumer's timeline. i.e. someone could iterate on an API they need a change for in cassandra-analytics and core cassandra can keep trucking with a now @DEPRECATED endpoint until such time as it wants to integrate the new structure. One other point that's come up in conversation offline is around bug-fixing; being able to fix bugs in implementation w/out consumers having to also refactor to new API endpoints is just good hygiene for limiting blast radius of changes. On Tue, Aug 18, 2026, at 4:25 AM, Benedict Elliott Smith wrote: > I’m hard -1 on this the > > I’m very pro code sharing between Cassandra projects, but these do not need > any special handling - we just make sure the builds don’t break. I’m against > creating any API boundaries we need to maintain for any external users > > On 2026/08/17 20:33:32 David Capwell wrote: > > > They're all internal, this is a convenience to improve code sharing. > > > > Once they go into utils they are not “internal” (whatever that means). Why > > I started this effort in the first place is that the test utilities have > > been requested to be used in projects like Cassandra-ecosystem, but also > > non-cassandra projects. Both users need to know that a hot fix doesn’t > > break their build hence why I propose basic properties you would expect: > > major versions might have breaking changes, minor / patch won’t. For the > > classes anyone has talked about moving here, non of them should have issues > > with this; we are free to add new methods over time, but removing causes > > issues for consumers. > > > > > to improve code sharing. > > > > Even if you think about this only for cassandra ecosystem, if I depend on > > version 0.1.0 and we find a bug so get that fixed and now we depend on > > 0.1.10… I shouldn’t expect to deal with breaking changes. The mentality of > > “They’re all internal” as a justification to not document these assumptions > > causes me concern as breaking changes explicitly make it harder for parties > > to depend on these classes; breaking changes make is so much harder to > > “share code”. > > > > > We only care about versioning to ensure we don't break any builds > > > > What do you mean by this? Major versions I am ok with breaking changes; > > minor / patch is what I want to avoid. We can add new APIs without issue, > > the concern is only on removal. > > > > > and even decide when we upgrade the jar so can spot and fix any breakages. > > > > If we are upgrading to enable a new JDK change, I wouldn’t expect users to > > have to rewrite all their tests, redo all their collections, etc…. You > > shouldn’t have to worry about upgrading the version cross minor / patch > > versions, as that should impose a no breaking change rule. > > > > > > > On Aug 14, 2026, at 3:06 PM, Benedict Elliott Smith <[email protected]> > > > wrote: > > > > > > Why are we defining this at all? They're all internal, this is a > > > convenience to improve code sharing. We only care about versioning to > > > ensure we don't break any builds, and we have all the builds, and even > > > decide when we upgrade the jar so can spot and fix any breakages. > > > > > > Let's not overcomplicate things, or bind our future selves in red tape > > > and regret. > > > > > > On 2026/08/14 17:57:40 Josh McKenzie wrote: > > >> While I read your email I found myself wondering "To what are we > > >> referring to when we say 'API'"? ;) > > >> > > >> Are you talking about a public interface? Or are you talking about "any > > >> class that's public and any public method within a public class"? > > >> > > >> If the latter, my primary theoretical concern is that if we pull in code > > >> that has components that are scoped public for cross-package > > >> accessibility within-project, promoting those to "public by default" > > >> immediately calcifies their interface whether we intend for that to be > > >> consumed or not. Basically, we don't have an interim scope layer between > > >> "package private" and "public" that corresponds to "project public". In > > >> theory the post JDK9 modularity kind of provides that but then everyone > > >> just add-opens bulldozes across things (the joys of legacy code...). > > >> > > >> I think "Any interface that's public is a public API" is pretty obvious > > >> to maintainers and users and good. I'm also good with "anything public > > >> is an API unless otherwise documented" and we add a simple annotation > > >> like @INTERNAL > > >> <https://github.com/apiguardian-team/apiguardian/blob/main/src/main/java/org/apiguardian/api/API.java#L87> > > >> from API Guardian to basically say "yeah, this is public, but it's not > > >> intended for public consumption" (I think we should roll our own to > > >> match our proposed lifecycles but that's a clear example of the idea). > > >> > > >> I'm worried about the approach of "Any public method in a public class > > >> is considered public API and you can't change it". I'd prefer we start > > >> with a more constrained surface area we commit to as being an API and > > >> widen it later if we find there's a need; it's much harder to go in the > > >> other direction. > > >> > > >> On Fri, Aug 14, 2026, at 1:24 PM, David Capwell wrote: > > >>> Josh and I talked about this offline and not perfectly in-sync so would > > >>> be good to get other peoples views > > >>> > > >>> My take is that if you are adding the API to this shared repo we need > > >>> to care about backwards compatibility so things should be PUBLIC by > > >>> default (anything that is java public is part of the public interface > > >>> and breaking changes are not allowed without a long enough deprecation > > >>> window similar to Cassandra’s.). I think Josh is in favor of using a > > >>> annotation to mark that a API is public, but without custom tooling I > > >>> don’t think anyone will notice and then we will get to a effectively > > >>> public state and breaking changes will be a nightmare to deal with for > > >>> the community. So if you want to post the API here, it should be > > >>> stable and we shouldn’t be putting APIs that have not been fleshed out > > >>> first. > > >>> > > >>>> On Aug 7, 2026, at 8:16 AM, Josh McKenzie <[email protected]> wrote: > > >>>> > > >>>> One thing worth immediately calling out that we might want to split > > >>>> out: we *could* do this work in Ant. > > >>>> > > >>>> It would be somewhat more imperative and brittle: we'd explicitly > > >>>> orchestrate the build ordering in Ant, while relying on the Gradle > > >>>> build inside Accord for its cassandra-utils dependency resolution / > > >>>> source substitution. That leaves us with a somewhat more complicated > > >>>> mixed Ant/Gradle build relationship but it's entirely workable for an > > >>>> interim time. > > >>>> > > >>>> So if the Gradle migration is a sticking point, we can break that out > > >>>> into a separate discussion and CEP rather than making it part of > > >>>> CEP-65. > > >>>> > > >>>> Doing so would mean retaining and extending some of the complexity in > > >>>> our existing build system that a future migration could remove, but > > >>>> it's not a crushing amount of additional complexity. The benefit of > > >>>> doing that work here with this CEP is that we have one more concrete > > >>>> build need providing a reason to move toward a unified build stack, > > >>>> and it fits the "clean things up and refactor as you're working on > > >>>> things that could benefit from that work" approach many have argued > > >>>> for in the past on the project. > > >>>> > > >>>> On Fri, Aug 7, 2026, at 10:58 AM, Josh McKenzie wrote: > > >>>>> As per the previous ML thread: [DISCUSS] Forking Cassandra utilities > > >>>>> into a separately released library > > >>>>> <https://lists.apache.org/thread/7kllp45vvonsg7ggzxpz39c5kdcy7r6g>, > > >>>>> David and I put together a draft of what we discussed and worked > > >>>>> through some implications and requirements that came up as we tried > > >>>>> to nail things down. > > >>>>> > > >>>>> The goal here is to provide a material backstop to continue our > > >>>>> discussion and version it. As with all CEP DISCUSS threads, this is > > >>>>> very fluid and none of it should be taken as settled or an implicit > > >>>>> mandate. Let's see if we can make some progress on this long-standing > > >>>>> pain point in our ecosystem. > > >>>>> > > >>>>> CEP-65 DRAFT: link > > >>>>> <https://cwiki.apache.org/confluence/spaces/CASSANDRA/pages/446071230/CEP-65+cassandra-utils+-+A+shared+utility+library+for+the+cassandra+ecosystem+DRAFT> > > >>>>> > > >>>>> *Why You Should Read This Draft:* > > >>>>> 1. Build system impact: we need a parent project and one of its > > >>>>> submodule to depend on another submodule. We're proposing freezing > > >>>>> ant's API surface area, maintaining that into perpetuity, and moving > > >>>>> to gradle going forward. > > >>>>> 2. Branching model: read the draft to see what "One Branch to Rule > > >>>>> Them All" means. > > >>>>> 3. API Lifecycle: Is @BETA/@STABLE/@DEPRECATED enough? Do we need a > > >>>>> @PRIVATE? > > >>>>> 4. To Release or Not To Release: we're proposing consumers embed this > > >>>>> as a submodule initially to minimize friction in moving shared code > > >>>>> into a shared space. > > >>>>> We have 1 outstanding unanswered question we didn't come up with an > > >>>>> opinionated proposal for: > > >>>>> > > >>>>> What should unannotated methods and classes in the library be > > >>>>> considered by potential consumers? @PRIVATE? @PUBLIC? Should we lint > > >>>>> and fail on any class without a top-level annotation forcing us to > > >>>>> make a choice on our dev list [DISCUSS] threads whenever we bring in > > >>>>> new things? > > >>>>> > > >>>>> There's no timeline on this thread; let's keep turning the crank on > > >>>>> this until we've hit our pareto-polish frontier. ;) > > >>>>> > > >>>>> ~Josh > > >>>>> > > >>>>> > > >>>> > > >> > > > > >
