I finally got around to playing around with Paulo's 5.0 backport branch as well and added some review feedback. I agree with Jaydeep that it looks great, nice work Paulo!
The write up on the PR in NEWS.txt ( https://github.com/apache/cassandra/pull/4558/changes#diff-95c20d744db732cdbca24c3e0406c10005ecf7fe8b5719c2fdf2b8af3fcedc79) does a great job describing how to opt into the feature and how it mitigates any risk. I'm hopeful that the approach taken here makes a giving a +1 to a possible backport vote an easier choice for folks! Thanks! Andy On Sun, Feb 8, 2026 at 8:03 PM Jaydeep Chovatia <[email protected]> wrote: > I have looked at the PR. Overall, it looks great. Added a few comments. > > Jaydeep > > On Fri, Jan 30, 2026 at 8:20 PM Jaydeep Chovatia < > [email protected]> wrote: > >> I will take a look at it. Happy to see AutoRepair in 5.0. >> Thank you for the patch, Paulo! >> >> Jaydeep >> >> On Fri, Jan 30, 2026 at 3:27 PM Tolbert, Andy <[email protected]> >> wrote: >> >>> I'd be happy to take a look at reviewing this as well as I would be >>> excited to see Auto Repair in 5.0. Thank you for the patch, Paulo! >>> >>> Andy >>> >>> On Fri, Jan 30, 2026 at 5:13 PM Paulo Motta <[email protected]> wrote: >>> >>>> I have submitted a patch porting AutoRepair to 5.0 on >>>> CASSANDRA-21138[1] and tagged Jaydeep Chovatia for review. I would greatly >>>> appreciate other sets of eyes, especially those involved with the original >>>> CEP-37 effort. >>>> >>>> The feature is disabled by default and no schema changes are made >>>> unless a JVM flag is enabled to reduce upgrade risk to users who do not >>>> intend to enable this feature. >>>> >>>> Please let us know if you have any questions or concerns about having >>>> this merged in 5.0. >>>> >>>> [1] - https://issues.apache.org/jira/browse/CASSANDRA-21138 >>>> >>>> On Mon, Jan 12, 2026 at 8:34 PM Jaydeep Chovatia < >>>> [email protected]> wrote: >>>> >>>>> Sure, I am happy to review it whenever it's ready, Paulo. Please let >>>>> me know. >>>>> >>>>> Jaydeep >>>>> >>>>> On Mon, Jan 12, 2026 at 8:32 AM Paulo Motta <[email protected]> wrote: >>>>> >>>>>> I agree with Scott. I don't think we should backport this to 4.1 due >>>>>> to the compatibility issues raised plus this branch has already been >>>>>> stabilized for a while. >>>>>> >>>>>> I think backporting auto-repair to 5.0 would be more appropriate as >>>>>> it would encourage users to adopt this version and get closer to trunk, >>>>>> rather than encouraging users to stick to an older version. >>>>>> >>>>>> I decided to take a stab at backporting auto-repair + >>>>>> additional fixes to 5.0 on this preliminary PR: >>>>>> https://github.com/apache/cassandra/pull/4558 >>>>>> >>>>>> It's not ready for review yet since I need to gate the schema changes >>>>>> under a feature flag, but I think I can get it ready by the end of week. >>>>>> >>>>>> If there's no opposition against shipping this in 5.0 maybe I can >>>>>> create a JIRA and have Jaydeep review it ? >>>>>> >>>>>> On Mon, Jan 12, 2026 at 11:15 AM C. Scott Andreas < >>>>>> [email protected]> wrote: >>>>>> >>>>>>> For the purpose of a quick straw poll, I’m not opposed to >>>>>>> backporting to 5.x, but I don’t support backporting to 4.x-series >>>>>>> releases >>>>>>> for the compatibility and upgrade complexity reasons previously >>>>>>> discussed. >>>>>>> >>>>>>> - Scott >>>>>>> >>>>>>> > On Jan 12, 2026, at 1:27 AM, Štefan Miklošovič < >>>>>>> [email protected]> wrote: >>>>>>> > >>>>>>> > Hi everybody, >>>>>>> > >>>>>>> > I want to refresh this thread after the holidays. Is there an >>>>>>> > agreement we reached? Is everybody on board with backporting to >>>>>>> 4.1+? >>>>>>> > How are we going to do this concretely? I guess Jaydeep would be >>>>>>> > involved in the backporting as he just said. I honestly do not >>>>>>> think >>>>>>> > there is anybody else better suited to make it happen and your >>>>>>> > willingness to do that is really appreciated. >>>>>>> > >>>>>>> > Regards >>>>>>> > >>>>>>> >> On Tue, Dec 23, 2025 at 5:38 AM Jaydeep Chovatia >>>>>>> >> <[email protected]> wrote: >>>>>>> >> >>>>>>> >> FYI—regardless of the outcome, you can count on me to port CEP-37 >>>>>>> in whatever form the community agrees on. As mentioned earlier, I’m >>>>>>> already >>>>>>> maintaining a private 4.1.6 fork ( >>>>>>> https://github.com/apache/cassandra/pull/3367). >>>>>>> >> Thank you! >>>>>>> >> >>>>>>> >> Jaydeep >>>>>>> >> >>>>>>> >>> On Mon, Dec 22, 2025 at 7:43 AM Micah Green <[email protected]> >>>>>>> wrote: >>>>>>> >>> >>>>>>> >>> I'm really interested in this thread, but don't see an update on >>>>>>> where we landed in terms of backporting and also the amount of work >>>>>>> involved. I'm all for backporting to 5.x minimally! I'm planning our >>>>>>> 2026 >>>>>>> work and where this discussion goes will really help me optimally plan, >>>>>>> which is why I'm asking. >>>>>>> >>> Thanks! >>>>>>> >>> >>>>>>> >>> On Sun, Dec 7, 2025 at 4:44 PM Ekaterina Dimitrova < >>>>>>> [email protected]> wrote: >>>>>>> >>>> >>>>>>> >>>> Seems like the 4.1 branch would still require some work to >>>>>>> cover everything raised on this thread? Have anyone evaluated how much >>>>>>> work >>>>>>> that can be? >>>>>>> >>>> >>>>>>> >>>> I agree porting to 4.1, but not 4.0 is kind of weird. Then >>>>>>> probably we better have it only in 5.0? >>>>>>> >>>> >>>>>>> >>>> Do people think it makes sense to create some kind of user >>>>>>> survey around this work, too? Posted in @user >>>>>>> >>>> >>>>>>> >>>> On Fri, 5 Dec 2025 at 9:00, Josh McKenzie <[email protected]> >>>>>>> wrote: >>>>>>> >>>>> >>>>>>> >>>>> Otherwise it feels weird backporting to 4.1 but not 4.0, and >>>>>>> backporting to both would increase the risk and maintenance burden. >>>>>>> >>>>> >>>>>>> >>>>> It would but by how much? >>>>>>> >>>>> >>>>>>> >>>>> 2 things jump out to me re: risk and maintenance: >>>>>>> >>>>> >>>>>>> >>>>> Risk: We kind of need to tackle the "version straddle w/schema >>>>>>> table diffs is currently Bad and makes rollbacks manual and brittle" >>>>>>> broadly; this feature is just one more example of that though it's a >>>>>>> little >>>>>>> exacerbated by discussing doing something like this in a patch release. >>>>>>> The >>>>>>> ergonomics of the "one-way-door without a human manually deleting >>>>>>> columns" >>>>>>> part holds true cross-MAJOR too. "Progress" here seems like it's either >>>>>>> we >>>>>>> handle this on a case-by-case basis w/flags to remove those schema >>>>>>> entries >>>>>>> on rollback (kinda ew), or more durably with an elegant solution in the >>>>>>> long term, i.e. capabilities framework, though that doesn't answer the >>>>>>> "we >>>>>>> explode when schemas don't match" bit. >>>>>>> >>>>> >>>>>>> >>>>> Maintenance: maintaining this across 4 branches is clearly >>>>>>> more toil than across 2. >>>>>>> >>>>> >>>>>>> >>>>> I'm personally kind of keen for us to tackle that Risk bit; >>>>>>> I'd like all of us to be able to more freely consider making changes to >>>>>>> schema tables w/out the complexity burden we have right now and the >>>>>>> operator toil and risk that comes along with it. >>>>>>> >>>>> >>>>>>> >>>>> The maintenance toil bit - I have less opinions on. Kind of >>>>>>> depends on how many people are on 4.0/4.1 right now that we'd expect to >>>>>>> be >>>>>>> on 4.1 for another year until 7.0 hits and whether we think they'd >>>>>>> benefit >>>>>>> from the feature (and contribute to bettering it) during that year I >>>>>>> guess. >>>>>>> >>>>> >>>>>>> >>>>> On Thu, Dec 4, 2025, at 5:57 PM, Paulo Motta wrote: >>>>>>> >>>>> >>>>>>> >>>>> Otherwise it feels weird backporting to 4.1 but not 4.0, and >>>>>>> backporting to both would increase the risk and maintenance burden. >>>>>>> >>>>> >>>>>>> >>>>> >>>>>>> >>>>>>
