Kafka

Hello Kafka Community, We are investigating a recurring Kafka broker startup failure on Windows Server and would appreciate guidance from the Kafka maintainers and community. Environment * Apache Kafka: 4.0.1 * Operating system: Windows Server * Java: Eclipse Temurin JDK 17.0.18 * Metadata mode: KRaft, single-node combined broker/controller * Service management: NSSM * Kafka storage directory: D:\KafkaStorage * Configuration: D:\Kafka\config\kraft\server.properties Problem description Kafka repeatedly fails during startup while recovering KRaft metadata snapshots. The service manager reports the Windows service as Running or restarts the Java process, but Kafka does not successfully start its listeners. Ports 9092 and 9093 remain unavailable. The recurring exception is: java.nio.file.AccessDeniedException: D:\KafkaStorage\__cluster_metadata-0\00000000000004062214-0000001671.checkpoint.deleted The stack trace indicates that the exception occurs dur...

Hi Kafka community, Two weeks ago, I got a reply from the community that our steps for an in-place KRaft topology change from dedicated controllers (static quorum) to combined broker/controller nodes is feasible, but we have some further questions. Let's say we currently have a 6-broker + 3-dedicated-controller KRaft Kafka cluster, and we want to eventually sunset controllers 101, 102, 103 and use 1, 2, 3 as mixed-role (broker + controller) nodes. Current dedicated-controller topology: - Controllers: 101, 102, 103 with process.roles=controller - Brokers: 1, 2, 3, 4, 5, 6 with process.roles=broker - Current quorum: controller.quorum.voters=101@host1:9093,102@host2:9093,103@host3:9093 Target mixed-role topology: - Mixed-role nodes: 1, 2, 3 with process.roles=broker,controller - Broker nodes: 4, 5, 6 with process.roles=broker - Target quorum: controller.quorum.voters=1@host1:9093,2@host2:9093,3@host3:9093 Our questions: 1. Is stopping the whole Kafka clust...

+1 (non-binding). I used the staged binaries and Maven artifacts to run my smoke tests & the Strimzi tests. All seems to work fine. Thanks for running the release. Thanks & Regards Jakub On Sun, Oct 11, 2026 at 4:07 PM 黃竣陽 <s7133700@gmail.com> wrote: > Hello Kafka users, developers and client-developers, > > This is the fourth candidate for release of Apache Kafka 4.3.2. > > This is a bugfix release in 4.3 line. > > Release notes for the 4.3.2 release: > https://dist.apache.org/repos/dist/dev/kafka/4.3.2-rc3/RELEASE_NOTES.html > <https://dist.apache.org/repos/dist/dev/kafka/4.3.2-rc/RELEASE_NOTES.html> > > Please download, test and vote by Wednesday, October 14th, 9am PT > > Kafka's KEYS file containing PGP keys we use to sign the release: > https://downloads.apache.org/kafka/KEYS > > * Release artifacts to be voted upon (source and binary): > https://dist.apache.org/repos/dist/dev/ka...

Thanks David for spotting this will raise RC4 with a fix > On 2 Oct 2026, at 09:56, David Jacot <david.jacot@gmail.com> wrote: > > Hi Omnia, > > Thanks again for running the release. > > While verifying RC3, I found an issue with the signatures of the Maven > artifacts. The source and binary artifacts are fine, as Bill reported, > but most of the Maven artifacts cannot be verified with gpg. Here is how > to reproduce it. > > Setup: > > curl -sO https://downloads.apache.org/kafka/KEYS > gpg --import KEYS > D=https://dist.apache.org/repos/dist/dev/kafka/4.4.0-rc3 > M=https://repository.apache.org/content/groups/staging/org/apache/kafka > > 1) Binary tarball (dist): OK > > curl -sO $D/kafka_2.13-4.4.0.tgz > curl -sO $D/kafka_2.13-4.4.0.tgz.asc > gpg --verify kafka_2.13-4.4.0.tgz.asc kafka_2.13-4.4.0.tgz > > gpg: Signature made Tue Sep 29 14:24:00 2026 CEST > gpg...

Thanks to David for pointing out this issue. I opened https://issues.apache.org/jira/browse/KAFKA-21208 to improve our release flow. On 2026/10/02 08:56:23 David Jacot wrote: > Hi Omnia, > > Thanks again for running the release. > > While verifying RC3, I found an issue with the signatures of the Maven > artifacts. The source and binary artifacts are fine, as Bill reported, > but most of the Maven artifacts cannot be verified with gpg. Here is how > to reproduce it. > > Setup: > > curl -sO https://downloads.apache.org/kafka/KEYS > gpg --import KEYS > D=https://dist.apache.org/repos/dist/dev/kafka/4.4.0-rc3 > M=https://repository.apache.org/content/groups/staging/org/apache/kafka > > 1) Binary tarball (dist): OK > > curl -sO $D/kafka_2.13-4.4.0.tgz > curl -sO $D/kafka_2.13-4.4.0.tgz.asc > gpg --verify kafka_2.13-4.4.0.tgz.asc kafka_2.13-4.4.0.tgz > > gpg: Signature m...

I used the staged binaries and Maven artifacts to run my smoke tests & the Strimzi tests. All seems to work fine. So +1 non-binding from me. Thanks for running the release. Thanks & Regards Jakub On Tue, Sep 29, 2026 at 2:23 PM 黃竣陽 <s7133700@gmail.com> wrote: > Hello Kafka users, developers and client-developers, > > This is the first candidate for release of Apache Kafka 4.3.2. > > This is a bugfix release in 4.3 line. > > Release notes for the 4.3.2 release: > https://dist.apache.org/repos/dist/dev/kafka/4.3.2-rc0/RELEASE_NOTES.html > > Please download, test and vote by Friday, October 2nd, 9am PT > > Kafka's KEYS file containing PGP keys we use to sign the release: > https://downloads.apache.org/kafka/KEYS > > * Release artifacts to be voted upon (source and binary): > https://dist.apache.org/repos/dist/dev/kafka/4.3.2-rc0/ > > * Docker release artifacts to be voted upon: > apach...

Hi Omnia, Thanks again for running the release. While verifying RC3, I found an issue with the signatures of the Maven artifacts. The source and binary artifacts are fine, as Bill reported, but most of the Maven artifacts cannot be verified with gpg. Here is how to reproduce it. Setup: curl -sO https://downloads.apache.org/kafka/KEYS gpg --import KEYS D=https://dist.apache.org/repos/dist/dev/kafka/4.4.0-rc3 M=https://repository.apache.org/content/groups/staging/org/apache/kafka 1) Binary tarball (dist): OK curl -sO $D/kafka_2.13-4.4.0.tgz curl -sO $D/kafka_2.13-4.4.0.tgz.asc gpg --verify kafka_2.13-4.4.0.tgz.asc kafka_2.13-4.4.0.tgz gpg: Signature made Tue Sep 29 14:24:00 2026 CEST gpg: using RSA key 1817905E3B2708B11A24B88E9AFA6F66CC8C3534 gpg: Good signature from "Omnia Ibrahim <omnia@apache.org>" [unknown] gpg: Signature notation: manu=2,2.5+1.12,0,3 gpg: WARNING: This key is not certified with a...