+1 (binding) Verified on macOS arm64, JDK 17:
* GPG signatures and SHA512 checksums for source, binary (Scala 2.13), and site-docs tarballs * LICENSE/NOTICE present in source and binary * Built source with ./gradlew jar — BUILD SUCCESSFUL * git tag 4.2.1-rc5 commit (18d5ecd939c8d510fdd72d0abb1f7099659dcd58) matches the shipped binary jar's kafka-version.properties commitId * Confirmed KAFKA-20572 (Connect REST server NPE on startup with listener-prefixed SSL configs) is included in the rc5 commit history * KRaft quickstart: format --standalone, broker start, topic/produce/consume * KIP-1071 streams group: enabled group.coordinator.rebalance.protocols=classic,consumer,streams and group.streams.enable=true; kafka-features.sh reports streams.version FinalizedVersionLevel: 1. Ran WordCountDemo with group.protocol=streams; logs show StreamsGroupHeartbeatRequestManager and counts aggregate correctly across multiple produce rounds. Exercised kafka-streams-groups.sh --list/--describe/--members/ --state/--offsets/--verbose; --reset-offsets correctly rejected while Stable, accepted (dry-run) once Empty * Docker images apache/kafka:4.2.1-rc5 and apache/kafka-native:4.2.1-rc5: both start, produce/consume works against each, commitId in container logs matches the rc5 tag * Documentation, javadoc, protocol, release-notes, and GitHub tag URLs all reachable * Maven staging artifacts present (kafka-clients, kafka_2.13, kafka-streams, connect-api) with Last-Modified consistent with the rc5 build date * Did not rerun the full test suite locally; relied on the linked Apache CI run Thanks PoAn for running the release! On Wed, May 20, 2026 at 12:19 PM Mickael Maison <[email protected]> wrote: > > Hi, > > I did the following: > - verified signatures and checksums > - ran quickstart with Java 21 and both docker images > - built from source > > +1 (binding) > I've not seen a PR yet in kafka-site for the 4.2.1 docs. > > Thanks, > Mickael > > On Thu, May 14, 2026 at 12:41 PM PoAn Yang <[email protected]> wrote: > > > > Hello Kafka users, developers and client-developers, > > > > This is the third candidate for release of Apache Kafka 4.2.1. > > > > This is the first bug fix release for Apache Kafka 4.2 with fixes as > > described in the release notes. In the third candidate, it adds KAFKA-20572. > > > > Release notes for the 4.2.1 release: > > https://urldefense.com/v3/__https://dist.apache.org/repos/dist/dev/kafka/4.2.1-rc5/RELEASE_NOTES.html__;!!Ayb5sqE7!tdkj2XYwnben6I5hhh5L3dwznOlN9tuEKJAcTxesDF-wDuApVTdazSW3l-OrkNi8U8nht5Vy4yS59bzyRiQG67k1mFgr8A$ > > > > Please download, test and vote by Thursday, May 20, 9pm PT. > > > > Kafka's KEYS file containing PGP keys we use to sign the release: > > https://urldefense.com/v3/__https://kafka.apache.org/KEYS__;!!Ayb5sqE7!tdkj2XYwnben6I5hhh5L3dwznOlN9tuEKJAcTxesDF-wDuApVTdazSW3l-OrkNi8U8nht5Vy4yS59bzyRiQG67ll_YK1Eg$ > > > > * Release artifacts to be voted upon (source and binary): > > https://urldefense.com/v3/__https://dist.apache.org/repos/dist/dev/kafka/4.2.1-rc5/__;!!Ayb5sqE7!tdkj2XYwnben6I5hhh5L3dwznOlN9tuEKJAcTxesDF-wDuApVTdazSW3l-OrkNi8U8nht5Vy4yS59bzyRiQG67nunoBBtg$ > > > > * Docker release artifacts to be voted upon: > > apache/kafka:4.2.1-rc5 > > apache/kafka-native:4.2.1-rc5 > > > > * Maven artifacts to be voted upon: > > https://urldefense.com/v3/__https://repository.apache.org/content/groups/staging/org/apache/kafka/__;!!Ayb5sqE7!tdkj2XYwnben6I5hhh5L3dwznOlN9tuEKJAcTxesDF-wDuApVTdazSW3l-OrkNi8U8nht5Vy4yS59bzyRiQG67nkNiVG9A$ > > > > * Javadoc: > > https://urldefense.com/v3/__https://dist.apache.org/repos/dist/dev/kafka/4.2.1-rc5/javadoc/index.html__;!!Ayb5sqE7!tdkj2XYwnben6I5hhh5L3dwznOlN9tuEKJAcTxesDF-wDuApVTdazSW3l-OrkNi8U8nht5Vy4yS59bzyRiQG67n9zeL-iw$ > > > > * Tag to be voted upon (off 4.2 branch) is the 4.2.1 tag: > > https://urldefense.com/v3/__https://github.com/apache/kafka/releases/tag/4.2.1-rc5__;!!Ayb5sqE7!tdkj2XYwnben6I5hhh5L3dwznOlN9tuEKJAcTxesDF-wDuApVTdazSW3l-OrkNi8U8nht5Vy4yS59bzyRiQG67kUzuYr8w$ > > > > * Documentation: > > https://urldefense.com/v3/__https://kafka.apache.org/42/documentation.html__;!!Ayb5sqE7!tdkj2XYwnben6I5hhh5L3dwznOlN9tuEKJAcTxesDF-wDuApVTdazSW3l-OrkNi8U8nht5Vy4yS59bzyRiQG67lHGRq__Q$ > > > > * Protocol: > > https://urldefense.com/v3/__https://kafka.apache.org/42/design/protocol/__;!!Ayb5sqE7!tdkj2XYwnben6I5hhh5L3dwznOlN9tuEKJAcTxesDF-wDuApVTdazSW3l-OrkNi8U8nht5Vy4yS59bzyRiQG67m37ABVvw$ > > > > * Successful CI builds for the 4.2 branch: > > Unit/integration tests: > > https://urldefense.com/v3/__https://github.com/apache/kafka/actions/runs/25801189532__;!!Ayb5sqE7!tdkj2XYwnben6I5hhh5L3dwznOlN9tuEKJAcTxesDF-wDuApVTdazSW3l-OrkNi8U8nht5Vy4yS59bzyRiQG67lmFxAl9w$ > > System tests: > > https://urldefense.com/v3/__https://jenkins.opensource4you.tw/job/kafka-e2e/756/__;!!Ayb5sqE7!tdkj2XYwnben6I5hhh5L3dwznOlN9tuEKJAcTxesDF-wDuApVTdazSW3l-OrkNi8U8nht5Vy4yS59bzyRiQG67mphIk09Q$ > > , > > https://urldefense.com/v3/__https://jenkins.opensource4you.tw/job/kafka-e2e/757/__;!!Ayb5sqE7!tdkj2XYwnben6I5hhh5L3dwznOlN9tuEKJAcTxesDF-wDuApVTdazSW3l-OrkNi8U8nht5Vy4yS59bzyRiQG67lAKsqAtA$ > > , > > https://urldefense.com/v3/__https://jenkins.opensource4you.tw/job/kafka-e2e/758/__;!!Ayb5sqE7!tdkj2XYwnben6I5hhh5L3dwznOlN9tuEKJAcTxesDF-wDuApVTdazSW3l-OrkNi8U8nht5Vy4yS59bzyRiQG67kobIPTug$ > > > > * Successful Docker Image Github Actions Pipeline for 4.2 branch: > > Docker Build Test Pipeline (JVM): > > https://urldefense.com/v3/__https://github.com/apache/kafka/actions/runs/25800098270__;!!Ayb5sqE7!tdkj2XYwnben6I5hhh5L3dwznOlN9tuEKJAcTxesDF-wDuApVTdazSW3l-OrkNi8U8nht5Vy4yS59bzyRiQG67le2BVdeA$ > > Docker Build Test Pipeline (Native): > > https://urldefense.com/v3/__https://github.com/apache/kafka/actions/runs/25800112759__;!!Ayb5sqE7!tdkj2XYwnben6I5hhh5L3dwznOlN9tuEKJAcTxesDF-wDuApVTdazSW3l-OrkNi8U8nht5Vy4yS59bzyRiQG67nvPJiZ4g$ > > > > Thanks, > > PoAn > > > > -- > > 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://urldefense.com/v3/__https://groups.google.com/d/msgid/kafka-clients/CAL6fUMRnZLWC7VdoHh7nkr6Oi4K3*3D9hghvZ8MdvO*3DaqhJJb3oA*40mail.gmail.com__;JSUl!!Ayb5sqE7!tdkj2XYwnben6I5hhh5L3dwznOlN9tuEKJAcTxesDF-wDuApVTdazSW3l-OrkNi8U8nht5Vy4yS59bzyRiQG67mgV1y1OA$ > > .
