Thanks Andor, Christopher and Enrico. I will be happy to review the PRs too.
Best, Li On Fri, Jan 9, 2026 at 2:02 PM Enrico Olivelli <[email protected]> wrote: > +1 to move to jdk17 both for client and server > > I would use 3.10 as there are no breaking changes in any protocol or sisk > format. > We have always been pretty good at keeping backward and forward > compatibility. > > Upgrading to 4.x may seem a big leap for users, and you usually are very > afraid of touching foundational libraries and services like ZK. > > Upgrading the required jdk is not enough for such a big bump > > > I will be happy to review the PRs > > Enrico > > Il Ven 9 Gen 2026, 06:47 Christopher <[email protected]> ha scritto: > > > Yes, I did offer. I'm sorry I haven't had time to work on it yet. I > > think I may have time next week to help, if somebody else doesn't do > > it first. > > > > On Thu, Jan 8, 2026 at 7:30 PM Andor Molnár <[email protected]> wrote: > > > > > > Personally I’m waiting for somebody who has experience with Maven to > put > > together a patch against the master branch with the proposed JDK/JRE > > changes. > > > > > > As far as I remember Christopher has offered help. > > > > > > Regards, > > > > > > Andor > > > > > > > > > > > > > > > > On Jan 8, 2026, at 15:59, Li Wang <[email protected]> wrote: > > > > > > > > Happy New Year! > > > > > > > > Just wonder if there is any update on the target date/timeframe for > > the new > > > > 4.0.0/3.10 release? > > > > > > > > Thanks, > > > > > > > > Li > > > > > > > > > > > > On Tue, Sep 23, 2025 at 12:31 AM Andor Molnar <[email protected]> > > wrote: > > > > > > > >> Thanks Christopher, would you please open a PR with the proposed > > changes > > > >> for the master branch? > > > >> > > > >> > > > >> > > > >> > > > >>> On Sep 19, 2025, at 19:50, Christopher <[email protected]> > wrote: > > > >>> > > > >>> Sounds good to me. I can help with the maven changes, too. > > > >>> > > > >>> On Fri, Sep 19, 2025, 11:54 Andor Molnar <[email protected]> wrote: > > > >>> > > > >>>> Hi all, > > > >>>> > > > >>>> Since our household chores have been finished with recent 3.9 and > > 3.8 > > > >>>> version, I think we can get back to this topic. > > > >>>> > > > >>>> Looking at the tremendous amount of work that Kezhu is doing on > > master > > > >>>> with client jar separations, I tend to cut 4.0.0 from master once > > > >>>> everything is done. If that’d be the case we could make a leap and > > make > > > >> JDK > > > >>>> 17 the minimum runtime and compile versions for the master branch. > > wdyt? > > > >>>> > > > >>>> Once the change is merged to master, we'll backport it to > > branch-3.9 as > > > >>>> follows: > > > >>>> > > > >>>> * minimum JDK for building: 17 > > > >>>> * minimum JRE for running: 8 (no change) > > > >>>> > > > >>>> This is completely aligned with Christopher’s suggestion except we > > won’t > > > >>>> touch the branch-3.8 as it’s going to be EoL’d in 6 months after > the > > > >>>> release of 4.0.0. > > > >>>> > > > >>>> Regards, > > > >>>> Andor > > > >>>> > > > >>>> p.s. Due to my little Maven experience I won’t be able to make the > > PRs > > > >>>> myself, so I’ll ask sb to volunteer. > > > >>>> > > > >>>> > > > >>>> > > > >>>> > > > >>>>> On Aug 20, 2025, at 20:59, Christopher <[email protected]> > > wrote: > > > >>>>> > > > >>>>> It looks like that Confluence page is pretty close to Semver > 2.0's > > > >>>>> definition (semver.org). > > > >>>>> I was confused by the use of the word "major" to refer to 3.10 > > earlier > > > >> in > > > >>>>> this thread. By the definition there, it'd be a "minor" release. > > > >>>>> > > > >>>>> Since the version numbering is based on API changes, and not > > dependency > > > >>>>> requirements, it is permissible to update dependencies > > substantially, > > > >>>>> without breaking any documented goal. However, I still think > going > > to > > > >> 17 > > > >>>> in > > > >>>>> a 3.x minor release is a bit too much for existing 3.x users who > > are > > > >>>> trying > > > >>>>> to stay up-to-date on 3.x. I think 11 is less disruptive for a > > minor > > > >>>>> version bump. But, I also think it would be okay to release 4.0 > > from > > > >> the > > > >>>>> master branch instead of 3.10, and make bigger, more disruptive > > > >> changes. > > > >>>> My > > > >>>>> main concern is whether users on 3.x will be properly prepared > for > > the > > > >>>>> risks of disruptive changes. If the version is called 3.10, they > > may > > > >>>> think > > > >>>>> it to be low-risk, but if it is called 4.0, they will recognize > it > > as > > > >>>>> riskier and can prepare for it. Users tend to infer a lot about > the > > > >> risk > > > >>>>> level from the name of the version, and a major version number > > change > > > >>>>> communicates bigger risk that users may need to prepare for. > > > >>>>> > > > >>>>> In any case, I certainly don't feel too strongly about it. > > Although my > > > >>>>> preference would be to have 11 as the runtime minimum for 3.10, I > > would > > > >>>>> prefer 17 rather than staying on 8. My preferences are: > > > >>>>> > > > >>>>> * minimum JDK for building all active branches (3.9 and later): > 17 > > > >>>>> * minimum JRE for running 3.9: 8 (no change) > > > >>>>> * minimum JRE for running 3.10: 11 > 17 > 8 > > > >>>>> * minimum JRE for running a future 4.x: 17 > > > >>>>> > > > >>>>> On Wed, Aug 20, 2025 at 6:38 PM Patrick Hunt <[email protected]> > > wrote: > > > >>>>> > > > >>>>>> FYI here's what documented for the project: > > > >>>>>> > > > >>>>>> > > > >>>> > > > >> > > > https://cwiki.apache.org/confluence/pages/viewpage.action?pageId=24193438#Roadmap-ReleaseNumbering > > > >>>>>> I personally think about it along these lines: "Upgrading > between > > > >> major > > > >>>>>> releases will generally require changes to user code". > > > >>>>>> The "annually" - I guess that was aspirational. :-) > > > >>>>>> > > > >>>>>> Regards, > > > >>>>>> > > > >>>>>> Patrick > > > >>>>>> > > > >>>>>> On Tue, Aug 19, 2025 at 5:24 PM Christopher < > [email protected]> > > > >>>> wrote: > > > >>>>>> > > > >>>>>>> I think most people interpret Java/maven version numbers > (x.y.z) > > as: > > > >>>>>>> x = major > > > >>>>>>> y = minor > > > >>>>>>> z = patch/bugfix > > > >>>>>>> > > > >>>>>>> I think it's confusing when you say 3.10 is a "major" version. > > What > > > >>>> would > > > >>>>>>> you call 4.0.0? A "supremely major" release, perhaps? It's fine > > to > > > >>>> treat > > > >>>>>> a > > > >>>>>>> minor release as a substantial change, but for communication, I > > think > > > >>>>>> it's > > > >>>>>>> still a minor release unless you bump the "major" portion of > the > > > >>>> version. > > > >>>>>>> > > > >>>>>>> I like the changes that you're planning, but I think they might > > be > > > >>>>>>> significant enough to call it a "major" version and bump to > > 4.0.0. > > > >>>> There > > > >>>>>>> doesn't need to be a 3.10... you can just rename it anytime > > before it > > > >>>> is > > > >>>>>>> released. > > > >>>>>>> > > > >>>>>>> > > > >>>>>>> On Tue, Aug 19, 2025 at 2:46 PM Andor Molnar <[email protected] > > > > > >> wrote: > > > >>>>>>> > > > >>>>>>>> We agreed on that we cut 3.10.0 from the master branch as new > > major > > > >>>>>>>> release of ZooKeeper. There’s no plan for 4.0.0 right now. > > > >>>>>>>> > > > >>>>>>>> Bumping minimum JDK version to JDK 17 is for 3.10.0 only. > > > >>>>>>>> > > > >>>>>>>> I suggested JDK 17, because I’d like to do a major refactoring > > to > > > >>>>>> upgrade > > > >>>>>>>> Jetty to the latest (12.1) version and it requires Java 17 in > > the > > > >>>>>>> runtime. > > > >>>>>>>> I know it sounds like a big jump, but consider that Java 11 is > > > >> already > > > >>>>>>>> outdated. (EoS was Sept 2023) > > > >>>>>>>> > > > >>>>>>>> Every version of Jetty including and earlier than 11 is > already > > EoL, > > > >>>> so > > > >>>>>>> we > > > >>>>>>>> don’t benefit too much from a JDK 11 upgrade. > > > >>>>>>>> > > > >>>>>>>> ZooKeeper 3.9.x will be supported and stay the stable version > of > > > >>>> Apache > > > >>>>>>>> ZooKeeper for a long long time, so people running on Java 8 > and > > 11 > > > >> are > > > >>>>>>>> still covered. > > > >>>>>>>> > > > >>>>>>>> Best, > > > >>>>>>>> Andor > > > >>>>>>>> > > > >>>>>>>> > > > >>>>>>>> > > > >>>>>>>> > > > >>>>>>>> > > > >>>>>>>>> On Aug 19, 2025, at 13:18, Christopher <[email protected]> > > > >> wrote: > > > >>>>>>>>> > > > >>>>>>>>> I have reservations about bumping the minimum runtime Java > > version > > > >> to > > > >>>>>>>>> 17, because I have applications that use ZooKeeper client > code > > that > > > >>>>>>>>> run Java 11. I think a more modest change would be to bump > the > > > >>>>>>>>> required build version to 17, but keep the target version at > > 11. If > > > >>>>>>>>> this is being considered for 4.0.0 only, then I'm okay with > > just > > > >>>>>> going > > > >>>>>>>>> to 17 for the runtime version as well. I think my existing > > > >>>>>>>>> applications that run on java 11 can continue to use 3.x. > > > >>>>>>>>> > > > >>>>>>>>> On Mon, Aug 18, 2025 at 8:44 AM Kezhu Wang < > [email protected]> > > > >>>>>> wrote: > > > >>>>>>>>>> > > > >>>>>>>>>> Hi all, > > > >>>>>>>>>> > > > >>>>>>>>>> +1 to upgrade to JDK 17 > > > >>>>>>>>>> > > > >>>>>>>>>> Ideally, I would suggest using different jdk versions for > > client > > > >> and > > > >>>>>>>>>> server to not push client usage just like kafka[1] and > > pulsar[2]. > > > >>>>>> But > > > >>>>>>>>>> given the fact that we don't have a slim client jar[3], so > +1 > > to > > > >>>>>> this. > > > >>>>>>>>>> > > > >>>>>>>>>> +1 to call next release from master as 3.10.0 > > > >>>>>>>>>> > > > >>>>>>>>>> I think most of the code changes in master since 3.9 were > > expected > > > >>>>>> to > > > >>>>>>>>>> be shipped in 3.10.0. One can confirm this in > > zookeeperAdmin.md. I > > > >>>>>>>>>> don't think it is worth bumping to 4.x near its release. > > > >>>>>>>>>> > > > >>>>>>>>>> I expect 4.x to be a planned version to do some ambitious > > tasks > > > >> and > > > >>>>>>>>>> probably in a not backward compatible way such as > > > >> ZOOKEEPER-233[3], > > > >>>>>>>>>> ZOOKEEPER-835[4] or ZOOKEEPER-22[5]. Also, there is 4.0.0 in > > > >>>>>> jira[6]. > > > >>>>>>>>>> > > > >>>>>>>>>> I do think bumping to JDK 17 could also be considered as a > > > >> breaking > > > >>>>>>>>>> change, but that could be trivial for dependants to solve > and > > not > > > >>>>>>>>>> touching zookeeper related codes. I would prefer new > > > >>>>>> features(probably > > > >>>>>>>>>> along with breaking changes) from our side in major > releases. > > > >>>>>>>>>> > > > >>>>>>>>>> [1]: > > https://kafka.apache.org/40/documentation/compatibility.html > > > >>>>>>>>>> [2]: > > > >>>>>>>> > > > >>>>>>> > > > >>>>>> > > > >>>> > > > >> > > > https://github.com/apache/pulsar?tab=readme-ov-file#pulsar-runtime-java-version-recommendation > > > >>>>>>>>>> [3]: https://issues.apache.org/jira/browse/ZOOKEEPER-233 > > > >>>>>>>>>> [4]: https://issues.apache.org/jira/browse/ZOOKEEPER-835 > > > >>>>>>>>>> [5]: https://issues.apache.org/jira/browse/ZOOKEEPER-22 > > > >>>>>>>>>> [6]: > > > >>>>>>>> > > https://issues.apache.org/jira/projects/ZOOKEEPER/versions/12313382 > > > >>>>>>>>>> > > > >>>>>>>>>> > > > >>>>>>>>>> On Sun, Aug 10, 2025 at 9:34 AM Andor Molnar < > > [email protected]> > > > >>>>>>> wrote: > > > >>>>>>>>>>> > > > >>>>>>>>>>> What tech debt do you mean exactly? > > > >>>>>>>>>>> > > > >>>>>>>>>>> I'm happy either way, don't have strong opinion, we can > stay > > at > > > >>>>>> 3.x.x > > > >>>>>>>>>>> versioning. > > > >>>>>>>>>>> > > > >>>>>>>>>>> Andor > > > >>>>>>>>>>> > > > >>>>>>>>>>> > > > >>>>>>>>>>> > > > >>>>>>>>>>> > > > >>>>>>>>>>> On 8/9/25 06:40, tison wrote: > > > >>>>>>>>>>>> Or instead, from a different perspective, if we call a > 4.0, > > can > > > >> we > > > >>>>>>>> pay back > > > >>>>>>>>>>>> some tech debt just for compatibility? > > > >>>>>>>>>>>> > > > >>>>>>>>>>>> Best, > > > >>>>>>>>>>>> tison. > > > >>>>>>>>>>>> > > > >>>>>>>>>>>> > > > >>>>>>>>>>>> tison <[email protected]>于2025年8月9日 周六18:30写道： > > > >>>>>>>>>>>> > > > >>>>>>>>>>>>> +1 for JDK17 > > > >>>>>>>>>>>>> > > > >>>>>>>>>>>>> -0 for 4.0. Bumping JDK version doesn't break APIs and > > > >> contracts. > > > >>>>>>> So > > > >>>>>>>> I'd > > > >>>>>>>>>>>>> prefer 3.10. 4.0 may give a signal of a big break change > > but it > > > >>>>>>>> isn't. > > > >>>>>>>>>>>>> > > > >>>>>>>>>>>>> Best, > > > >>>>>>>>>>>>> tison. > > > >>>>>>>>>>>>> > > > >>>>>>>>>>>>> > > > >>>>>>>>>>>>> Li Wang <[email protected]>于2025年8月9日 周六08:51写道： > > > >>>>>>>>>>>>> > > > >>>>>>>>>>>>>> That's awesome. Thanks for driving this, Andor! > > > >>>>>>>>>>>>>> > > > >>>>>>>>>>>>>> After releasing 3.9.4 I’d like to announce EoL of the > > 3.8.x > > > >>>>>>> release > > > >>>>>>>> line > > > >>>>>>>>>>>>>>> and create a new minor/major off the master branch. > > > >>>>>>>>>>>>>> > > > >>>>>>>>>>>>>> > > > >>>>>>>>>>>>>> Does this mean the next major version (i.e. > 4.0.0/3.10.0) > > will > > > >>>>>> be > > > >>>>>>>> released > > > >>>>>>>>>>>>>> soon, as we need to have a new current release before > > > >> announcing > > > >>>>>>>> EoL of > > > >>>>>>>>>>>>>> the > > > >>>>>>>>>>>>>> 3.8.x release? > > > >>>>>>>>>>>>>> > > > >>>>>>>>>>>>>> Given the 3.9.4 release is in progress, any rough idea > on > > when > > > >>>>>> the > > > >>>>>>>> next > > > >>>>>>>>>>>>>> major version will be? > > > >>>>>>>>>>>>>> > > > >>>>>>>>>>>>>> what if we rather call the new release 4.0.0 > > > >>>>>>>>>>>>>> > > > >>>>>>>>>>>>>> +1 for calling it 4.0.0. Looks like we have been on 3.x > > for > > > >>>>>> about > > > >>>>>>>> 17 years > > > >>>>>>>>>>>>>> already. > > > >>>>>>>>>>>>>> > > > >>>>>>>>>>>>>> what if we make two steps forward instead of one and let > > Java > > > >> 17 > > > >>>>>>> to > > > >>>>>>>> be the > > > >>>>>>>>>>>>>>> minimum requirement > > > >>>>>>>>>>>>>> > > > >>>>>>>>>>>>>> +1 for Java 17 > > > >>>>>>>>>>>>>> > > > >>>>>>>>>>>>>> Best, > > > >>>>>>>>>>>>>> > > > >>>>>>>>>>>>>> Li > > > >>>>>>>>>>>>>> > > > >>>>>>>>>>>>>> > > > >>>>>>>>>>>>>> On Fri, Aug 8, 2025 at 2:38 PM Patrick Hunt < > > [email protected] > > > >>> > > > >>>>>>>> wrote: > > > >>>>>>>>>>>>>> > > > >>>>>>>>>>>>>>> Thanks for driving this Andor! I think what you are > > saying > > > >>>>>> makes > > > >>>>>>>> sense, > > > >>>>>>>>>>>>>>> will be interested to see what other ppl think. > > > >>>>>>>>>>>>>>> > > > >>>>>>>>>>>>>>> Regards, > > > >>>>>>>>>>>>>>> > > > >>>>>>>>>>>>>>> Patrick > > > >>>>>>>>>>>>>>> > > > >>>>>>>>>>>>>>> On Fri, Aug 8, 2025 at 2:27 PM Andor Molnar < > > > >> [email protected]> > > > >>>>>>>> wrote: > > > >>>>>>>>>>>>>>> > > > >>>>>>>>>>>>>>>> Hi Li, > > > >>>>>>>>>>>>>>>> > > > >>>>>>>>>>>>>>>> The topic comes up every so often on the Dev list, so > > let’s > > > >>>>>>> bring > > > >>>>>>>> it > > > >>>>>>>>>>>>>> up > > > >>>>>>>>>>>>>>>> again. After releasing 3.9.4 I’d like to announce EoL > > of the > > > >>>>>>> 3.8.x > > > >>>>>>>>>>>>>>> release > > > >>>>>>>>>>>>>>>> line and create a new minor/major off the master > > branch. I’d > > > >>>>>>> like > > > >>>>>>>> to > > > >>>>>>>>>>>>>> drop > > > >>>>>>>>>>>>>>>> Java 8 support in that release and make Java 11 as > > minimum > > > >>>>>>>> requirement > > > >>>>>>>>>>>>>>> for > > > >>>>>>>>>>>>>>>> ZooKeeper. > > > >>>>>>>>>>>>>>>> > > > >>>>>>>>>>>>>>>> * In which case, what if we rather call the new > release > > > >> 4.0.0? > > > >>>>>>>>>>>>>>>> * Additionally what if we make two steps forward > > instead of > > > >>>>>> one > > > >>>>>>>> and > > > >>>>>>>>>>>>>> let > > > >>>>>>>>>>>>>>>> Java 17 to be the minimum requirement? With that, we > > could > > > >>>>>>> upgrade > > > >>>>>>>>>>>>>> Jetty > > > >>>>>>>>>>>>>>> to > > > >>>>>>>>>>>>>>>> the latest actively supported version. > > > >>>>>>>>>>>>>>>> > > > >>>>>>>>>>>>>>>> Please share your thoughts. > > > >>>>>>>>>>>>>>>> > > > >>>>>>>>>>>>>>>> Andor > > > >>>>>>>>>>>>>>>> > > > >>>>>>>>>>>>>>>> > > > >>>>>>>>>>>>>>>> > > > >>>>>>>>>>>>>>>> > > > >>>>>>>>>>>>>>>>> On May 7, 2025, at 13:16, Li Wang <[email protected] > > > > > >> wrote: > > > >>>>>>>>>>>>>>>>> > > > >>>>>>>>>>>>>>>>> Hello, > > > >>>>>>>>>>>>>>>>> > > > >>>>>>>>>>>>>>>>> Does anyone know when 3.10.0 is planned to be > released? > > > >>>>>>>>>>>>>>>>> > > > >>>>>>>>>>>>>>>>> Thanks > > > >>>>>>>>>>>>>>>>> > > > >>>>>>>>>>>>>>>>> Li > > > >>>>>>>>>>>>>>>> > > > >>>>>>>>>>>>>>>> > > > >>>>>>>>>>>>>>> > > > >>>>>>>>>>>>>> > > > >>>>>>>>>>>>> > > > >>>>>>>>>>>> > > > >>>>>>>>>>> > > > >>>>>>>> > > > >>>>>>>> > > > >>>>>>> > > > >>>>>> > > > >>>> > > > >>>> > > > >> > > > >> > > > > > >
