Hi reviewers, Thank you to everyone who voted.
This candidate received 3 binding votes (Mickael, Josep, and Lucas) and 2 non-binding votes (Jakub and Maros). However, we would like to include two additional Jira issues (KAFKA-19851 and KAFKA-20380), so I have created a new release candidate. Discussion thread: https://lists.apache.org/thread/2xn838tms1vzwg7wltjg9fg8fk9o0lbt New vote thread: https://lists.apache.org/thread/78dx1rv74p0mfzpprvgzjzb29mr77srq Thank you, PoAn Lucas Brutschy via dev <[email protected]> 於 2026年5月7日週四 上午6:40寫道： > +1 (binding) > > Verified on macOS (arm64), JDK 21 (GraalVM CE 21.0.2): > > * GPG signatures and SHA512/SHA1 checksums for source, binary (Scala 2.13), > and site-docs tarballs (signed by PoAn Yang, key D9472951…) > * LICENSE/NOTICE files in source and binary > * Built source with ./gradlew jar — BUILD SUCCESSFUL > * Spot-checked unit tests (clients:KafkaConsumerTest) — pass > * Ran KRaft quickstart from the binary tarball: storage format, broker > start, > topic create/describe, produce/consume, consumer-groups list, version > 4.2.1 > * Ran apache/kafka:4.2.1-rc3 (JVM) and apache/kafka-native:4.2.1-rc3 > (native) > Docker images — both broker up, produce/consume works > * Ran the bundled WordCountDemo with group.protocol=streams (KIP-1071) — > words counted correctly across two rounds; kafka-streams-groups.sh > --list / --describe / --members / --state / --offsets / --verbose / > --reset-offsets all behave correctly against both the live and empty > group > * Documentation, javadoc, protocol, and release notes links accessible > * Maven staging artifacts present (Last-Modified 2026-04-25) > * Git tag 4.2.1-rc3 commit (a7f05858…) matches the binary's > kafka-version.properties > > Thanks PoAn for running the release! > > On Wed, May 6, 2026 at 9:33 PM Josep Prat via dev <[email protected]> > wrote: > > > > Hi, > > I did the following: > > - checked the signatures and checksums > > - built from source > > - ran the tests > > - Tested Docker Images: > > -- can start > > -- can create topics > > - ran quickstart > > - ran sample apps with consumer groups > > - checked Java client interaction from artifacts (admin, producer, > consumer > > and streams) > > - check Tiered Storage offloads to remote storage (with Aiven's plugin) > > - checked Kafka Connect > > > > +1 binding > > > > But as Mickael pointed out, it needs a PR to update the website. > > > > Best, > > > > On Wed, May 6, 2026 at 7:46 PM Maroš Orsák <[email protected]> > wrote: > > > > > Hi, I have checked with the Strimzi test container and did some manual > > > testing on Aarch64. Everything seems to be working fine (+1 > non-binding). > > > Cheers, Maros > > > > > > st 6. 5. 2026 o 12:26 Mickael Maison <[email protected]> > > > napísal(a): > > > > > > > Hi, > > > > > > > > I did the following: > > > > - checked the checksums and signatures > > > > - ran the quickstart with the binaries and both docker images > > > > - built from source and ran the tests with Java 21 > > > > > > > > +1 binding > > > > > > > > It looks like the website has note been updated yet and I don't see > a PR > > > > open. > > > > > > > > Thanks, > > > > Mickael > > > > > > > > > > > > On Sat, May 2, 2026 at 4:34 PM Jakub Scholz <[email protected]> wrote: > > > > > > > > > > I used the staged binaries and Maven artifacts ... and did some > manual > > > > > smoke testing and tested it with Strimzi tests as well. > > > > > > > > > > All seems to work fine, so +1 (non-binding). > > > > > > > > > > Thanks for running the release. > > > > > > > > > > Jakub > > > > > > > > > > On Sun, Apr 26, 2026 at 7:31 AM PoAn Yang <[email protected]> > wrote: > > > > > > > > > > > Hello Kafka users, developers and client-developers, > > > > > > > > > > > > This is the 1st 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. > > > > > > > > > > > > Release notes for the 4.2.1 release: > > > > > > > > > > > > > > https://urldefense.com/v3/__https://dist.apache.org/repos/dist/dev/kafka/4.2.1-rc3/RELEASE_NOTES.html__;!!Ayb5sqE7!sOQ2WUmb_pbM8Gca9anURMjGkPygmQPAfOm1oBbVKf_CE6AOGsFx7NRYx6siVEdKjgnD-kk0mpOpkFSbwLVvxg$ > > > > > > > > > > > > Please download, test and vote by Friday, May 1, 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!sOQ2WUmb_pbM8Gca9anURMjGkPygmQPAfOm1oBbVKf_CE6AOGsFx7NRYx6siVEdKjgnD-kk0mpOpkFTtUXtapg$ > > > > > > > > > > > > * Release artifacts to be voted upon (source and binary): > > > > > > > https://urldefense.com/v3/__https://dist.apache.org/repos/dist/dev/kafka/4.2.1-rc3/__;!!Ayb5sqE7!sOQ2WUmb_pbM8Gca9anURMjGkPygmQPAfOm1oBbVKf_CE6AOGsFx7NRYx6siVEdKjgnD-kk0mpOpkFT8qg32AA$ > > > > > > > > > > > > * Docker release artifacts to be voted upon: > > > > > > apache/kafka:4.2.1-rc3 > > > > > > apache/kafka-native:4.2.1-rc3 > > > > > > > > > > > > * Maven artifacts to be voted upon: > > > > > > > > > > https://urldefense.com/v3/__https://repository.apache.org/content/groups/staging/org/apache/kafka/__;!!Ayb5sqE7!sOQ2WUmb_pbM8Gca9anURMjGkPygmQPAfOm1oBbVKf_CE6AOGsFx7NRYx6siVEdKjgnD-kk0mpOpkFSQHUK-zw$ > > > > > > > > > > > > * Javadoc: > > > > > > > > > > > > > > https://urldefense.com/v3/__https://dist.apache.org/repos/dist/dev/kafka/4.2.1-rc3/javadoc/index.html__;!!Ayb5sqE7!sOQ2WUmb_pbM8Gca9anURMjGkPygmQPAfOm1oBbVKf_CE6AOGsFx7NRYx6siVEdKjgnD-kk0mpOpkFSSGPFVBw$ > > > > > > > > > > > > * 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-rc3__;!!Ayb5sqE7!sOQ2WUmb_pbM8Gca9anURMjGkPygmQPAfOm1oBbVKf_CE6AOGsFx7NRYx6siVEdKjgnD-kk0mpOpkFRVuqd7ZQ$ > > > > > > > > > > > > * Documentation: > https://urldefense.com/v3/__https://kafka.apache.org/42/documentation.html__;!!Ayb5sqE7!sOQ2WUmb_pbM8Gca9anURMjGkPygmQPAfOm1oBbVKf_CE6AOGsFx7NRYx6siVEdKjgnD-kk0mpOpkFSxgka5pQ$ > > > > > > > > > > > > * Protocol: > https://urldefense.com/v3/__https://kafka.apache.org/42/design/protocol/__;!!Ayb5sqE7!sOQ2WUmb_pbM8Gca9anURMjGkPygmQPAfOm1oBbVKf_CE6AOGsFx7NRYx6siVEdKjgnD-kk0mpOpkFRulYLQFA$ > > > > > > > > > > > > * Successful CI builds for the 4.2 branch: > > > > > > Unit/integration tests: > > > > > > > https://urldefense.com/v3/__https://github.com/apache/kafka/actions/runs/24934069240__;!!Ayb5sqE7!sOQ2WUmb_pbM8Gca9anURMjGkPygmQPAfOm1oBbVKf_CE6AOGsFx7NRYx6siVEdKjgnD-kk0mpOpkFSbt0loBA$ > > > > > > System tests: > https://urldefense.com/v3/__https://jenkins.opensource4you.tw/job/kafka-e2e/736/__;!!Ayb5sqE7!sOQ2WUmb_pbM8Gca9anURMjGkPygmQPAfOm1oBbVKf_CE6AOGsFx7NRYx6siVEdKjgnD-kk0mpOpkFTFyNKeZQ$ > , > > > > > > > https://urldefense.com/v3/__https://jenkins.opensource4you.tw/job/kafka-e2e/737/__;!!Ayb5sqE7!sOQ2WUmb_pbM8Gca9anURMjGkPygmQPAfOm1oBbVKf_CE6AOGsFx7NRYx6siVEdKjgnD-kk0mpOpkFSI15IBZw$ > , > > > > > > > https://urldefense.com/v3/__https://jenkins.opensource4you.tw/job/kafka-e2e/738/__;!!Ayb5sqE7!sOQ2WUmb_pbM8Gca9anURMjGkPygmQPAfOm1oBbVKf_CE6AOGsFx7NRYx6siVEdKjgnD-kk0mpOpkFSN6Q8ZAg$ > > > > > > > > > > > > * 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/24934131423__;!!Ayb5sqE7!sOQ2WUmb_pbM8Gca9anURMjGkPygmQPAfOm1oBbVKf_CE6AOGsFx7NRYx6siVEdKjgnD-kk0mpOpkFSeJCS8HA$ > > > > > > (Native): > https://urldefense.com/v3/__https://github.com/apache/kafka/actions/runs/24934136446__;!!Ayb5sqE7!sOQ2WUmb_pbM8Gca9anURMjGkPygmQPAfOm1oBbVKf_CE6AOGsFx7NRYx6siVEdKjgnD-kk0mpOpkFQ_gEiDNg$ > > > > > > > > > > > > Thanks, > > > > > > PoAn > > > > > > > > > > > > > > > > > > > -- > > [image: Aiven] < > https://urldefense.com/v3/__https://www.aiven.io__;!!Ayb5sqE7!sOQ2WUmb_pbM8Gca9anURMjGkPygmQPAfOm1oBbVKf_CE6AOGsFx7NRYx6siVEdKjgnD-kk0mpOpkFSx8WI6qg$ > > > > *Josep Prat* > > Sr Engineering Director, Streaming Services, *Aiven* > > [email protected] | +491715557497 > > > > aiven.io < > https://urldefense.com/v3/__https://www.aiven.io/__;!!Ayb5sqE7!sOQ2WUmb_pbM8Gca9anURMjGkPygmQPAfOm1oBbVKf_CE6AOGsFx7NRYx6siVEdKjgnD-kk0mpOpkFQPcQOhrA$ > > > > > > [image: LinkedIn] > > < > https://urldefense.com/v3/__https://www.linkedin.com/company/aiven/posts/?feedView=all__;!!Ayb5sqE7!sOQ2WUmb_pbM8Gca9anURMjGkPygmQPAfOm1oBbVKf_CE6AOGsFx7NRYx6siVEdKjgnD-kk0mpOpkFQD--CgBg$ > > [image: X] > > < > https://urldefense.com/v3/__https://x.com/aiven_io__;!!Ayb5sqE7!sOQ2WUmb_pbM8Gca9anURMjGkPygmQPAfOm1oBbVKf_CE6AOGsFx7NRYx6siVEdKjgnD-kk0mpOpkFT7ZLXXBw$ > > [image: GitHub] < > https://urldefense.com/v3/__https://github.com/aiven__;!!Ayb5sqE7!sOQ2WUmb_pbM8Gca9anURMjGkPygmQPAfOm1oBbVKf_CE6AOGsFx7NRYx6siVEdKjgnD-kk0mpOpkFRKaNE5cA$ > > [image: > > YouTube] < > https://urldefense.com/v3/__https://www.youtube.com/@Aiven_io__;!!Ayb5sqE7!sOQ2WUmb_pbM8Gca9anURMjGkPygmQPAfOm1oBbVKf_CE6AOGsFx7NRYx6siVEdKjgnD-kk0mpOpkFRo1o_9xw$ > > [image: Facebook] > > < > https://urldefense.com/v3/__https://www.facebook.com/aivencloud__;!!Ayb5sqE7!sOQ2WUmb_pbM8Gca9anURMjGkPygmQPAfOm1oBbVKf_CE6AOGsFx7NRYx6siVEdKjgnD-kk0mpOpkFSiyQW9bQ$ > > > > *Aiven Deutschland GmbH* > > Rosenthaler Straße 43-45, 10178 Berlin > > Geschäftsführer: Oskari Saarenmaa, Kenneth Chen > > Amtsgericht Charlottenburg, HRB 209739 B >
