Hey Robert, Apologies for coming back with a delay! I observed the same things as you during the qualification of the first release candidate (RC0), so thank you very much for confirming!
I filed a fix and have cherry-picked it to 4.2. I think this is important enough that it necessitates another release candidate. Hence, I am closing this vote and will be opening a new one tomorrow. If anybody is running qualification tests, I hope this gives some time for you to flush any other problems out! Best, Christo On Mon, 26 Jan 2026 at 13:54, Christo Lolov <[email protected]> wrote: > > Hello Jun, > > The PR for the documentation/javadocs and protocol is accessible > https://github.com/apache/kafka-site/pull/785, thanks for catching > this! > My understanding is that once the RC passes and we merge the PR it > will be available on the originally mentioned URLs, but let me know if > I am wrong! > > Best, > Christo > > On Fri, 23 Jan 2026 at 19:53, Jun Rao via dev <[email protected]> wrote: > > > > Hi, Christo, > > > > Thanks for preparing the RC. The links to documentation and protocol are > > inaccessible. Are they ready? > > > > Jun > > > > On Mon, Jan 19, 2026 at 8:28 AM Christo Lolov <[email protected]> > > wrote: > > > > > Hello Kafka users, developers and client-developers, > > > > > > This is the RC1 candidate for release of Apache Kafka 4.2.0. > > > > > > This release has many exciting changes: > > > * Kafka Queues (Share Groups) is now production-ready with new > > > features like the RENEW acknowledgement type for extended processing > > > times, adaptive batching for coordinators, and comprehensive lag > > > metrics. > > > * Kafka Streams brings the server-side rebalance protocol to GA with a > > > limited feature set, adds dead letter queue support in exception > > > handlers, introduces anchored wall-clock punctuation for deterministic > > > scheduling, and gives users full control over whether to send a leave > > > group request on closing. > > > * This release also delivers significant improvements to consistency > > > and observability: CLI tools now feature standardized arguments like > > > --bootstrap-server across all tools, metric naming has been corrected > > > to follow the kafka.COMPONENT convention, and new idle ratio metrics > > > provide better visibility into controller and MetadataLoader > > > performance. > > > * Security is enhanced with a new allowlist connector client > > > configuration override policy, while thread-safety improvements to > > > RecordHeader eliminate concurrency risks. > > > * Additional highlights include external schema support in > > > JsonConverter for reduced message sizes, dynamic configuration for > > > remote log manager thread pools, and rack ID exposure in the Admin API > > > for consumer and share group members. > > > > > > Release notes for the 4.2.0 release: > > > https://dist.apache.org/repos/dist/dev/kafka/4.2.0-rc1/RELEASE_NOTES.html > > > > > > *** Please download, test and vote by Monday, January 26, 10am UTC > > > > > > Kafka's KEYS file containing PGP keys we use to sign the release: > > > https://kafka.apache.org/KEYS > > > > > > * Release artifacts to be voted upon (source and binary): > > > https://dist.apache.org/repos/dist/dev/kafka/4.2.0-rc1/ > > > > > > * Docker release artifacts to be voted upon: > > > apache/kafka:4.2.0-rc1 > > > apache/kafka-native:4.2.0-rc1 > > > > > > * Maven artifacts to be voted upon: > > > https://repository.apache.org/content/groups/staging/org/apache/kafka/ > > > > > > * Javadoc: > > > https://dist.apache.org/repos/dist/dev/kafka/4.2.0-rc1/javadoc/index.html > > > > > > * Tag to be voted upon (off 4.2 branch) is the 4.2.0 tag: > > > https://github.com/apache/kafka/releases/tag/4.2.0-rc1 > > > > > > * Documentation: > > > https://kafka.apache.org/42/documentation.html > > > > > > * Protocol: > > > https://kafka.apache.org/42/protocol.html > > > > > > * Successful CI builds for the 4.2 branch: > > > Unit/integration tests: The build for the 4.2.0-rc1 tag can be found > > > at > > > https://github.com/apache/kafka/actions/runs/21135565337/job/60779418474 > > > There is a single failing test which I have since retried. > > > > > > System tests: I have setup my E2E environment and will share test > > > results in the next ~24 hours. > > > Chia-Ping has been very generous and helpful and is also running a > > > parallel environment at > > > https://jenkins.opensource4you.tw/job/kafka-e2e/636/ > > > > > > * Successful Docker Image Github Actions Pipeline for 4.2 branch: > > > Docker Build Test Pipeline (JVM): > > > https://github.com/apache/kafka/actions/runs/21135593072 > > > Docker Build Test Pipeline (Native): > > > https://github.com/apache/kafka/actions/runs/21136272782 > > > > > > Thanks, > > > Christo > > > > > > -- > > > You received this message because you are subscribed to the Google Groups > > > "kafka-clients" group. > > > To unsubscribe from this group and stop receiving emails from it, send an > > > email to [email protected]. > > > To view this discussion visit > > > https://groups.google.com/d/msgid/kafka-clients/CANF%2Ba5c5USZr9TG1YrXcg9zuy2tnZdgC4MyW6QYtJ30eR_5VvQ%40mail.gmail.com > > > . > > >
