[VOTE] 3.9.0 RC0

Hello Kafka users, developers and client-developers,

This is the first candidate for release of Apache Kafka 3.9.0.
- This is a major release, the final one in the 3.x line. (There may of course be other minor releases in this line, such as 3.9.1.)
- Tiered storage will be considered production-ready in this release.
- This will be the final major release to feature the deprecated ZooKeeper mode.

This release includes the following KIPs:
- KIP-853: Support dynamically changing KRaft controller membership
- KIP-1057: Add remote log metadata flag to the dump log tool
- KIP-1049: Add config log.summary.interval.ms to Kafka Streams
- KIP-1040: Improve handling of nullable values in InsertField, ExtractField, and other transformations
- KIP-1031: Control offset translation in MirrorSourceConnector
- KIP-1033: Add Kafka Streams exception handler for exceptions occurring during processing
- KIP-1017: Health check endpoint for Kafka Connect
- KIP-1025: Optionally URL-encode clientID and clientSecret in authorization header
- KIP-1005: Expose EarliestLocalOffset and TieredOffset
- KIP-950: Tiered Storage Disablement
- KIP-956: Tiered Storage Quotas

Release notes for the 3.9.0 release:
https://home.apache.org/~cmccabe/kafka-3.9.0-rc0/RELEASE_NOTES.html

*** Please download, test and vote by September 23, 2024.

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://home.apache.org/~cmccabe/kafka-3.9.0-rc0/

* Docker release artifacts to be voted upon:
apache/kafka:3.9.0-rc0
apache/kafka-native:3.9.0-rc0

* Maven artifacts to be voted upon:
https://repository.apache.org/content/groups/staging/org/apache/kafka/

* Javadoc:
https://home.apache.org/~cmccabe/kafka-3.9.0-rc0/javadoc/

* Documentation:
https://kafka.apache.org/39/documentation.html

* Protocol:
https://kafka.apache.org/39/protocol.html

* Tag to be voted upon (off 3.9 branch) is the 3.9.0-rc0 tag:
https://github.com/apache/kafka/releases/tag/3.9.0-rc0

I've run several successful junit and ducktape builds. While there were some flaky tests, when re-running them, they passed.

* Successful Docker Image Github Actions Pipeline for 3.8 branch:
Docker Build Test Pipeline (JVM): https://github.com/apache/kafka/actions/runs/10912118987
Docker Build Test Pipeline (Native): https://github.com/apache/kafka/actions/runs/10914303515

Thanks to everyone who helped with this release candidate, either by contributing code, testing, or documentation.

Regards,
Colin