```
commit ec37eb538b (HEAD ->
KAFKA-19719-cherry-pick-41, origin/KAFKA-19719-cherry-pick-41)
Author: Kevin Wu <kevin.wu2412@gmail.com>
Date: Thu Sep 25 11:56:16 2025 -0500
KAFKA-19719: --no-initial-controllers should not assume
kraft.version=1 (#20551)
Just because a controller node sets --no-initial-controllers flag
does not mean it is necessarily running kraft.version=1. The more
precise meaning is that the controller node being formatted does not
know what kraft version the cluster should be in, and therefore it
is only safe to assume kraft.version=0. Only by setting
--standalone,--initial-controllers, or --no-initial-controllers AND
not specifying the controller.quorum.voters static config, is it
known kraft.version > 0.
For example, it is a valid configuration (although confusing) to run
a static quorum defined by controller.quorum.voters but have all
the controllers format with --no-initial-controllers. In this
case, specifying --no-initial-controllers alongside a metadata
version that does not support kraft.version=1 causes formatting to
fail, which is does not support kraft.version=1 causes formatting
to fail, which is a regression.
Additionally, the formatter should not check the kraft.version
against the release version, since kraft.version does not actually
depend on any release version. It should only check the
kraft.version against the static voters config/format arguments.
This PR also cleans up the integration test framework to match the
semantics of formatting an actual cluster.
Reviewers: TengYao Chi <kitingiao@gmail.com>, Kuan-Po Tseng
<brandboat@gmail.com>, Chia-Ping Tsai <chia7712@gmail.com>, José Armando
García Sancio <jsancio@apache.org> Conflicts:
core/src/main/scala/kafka/tools/StorageTool.scala Minor conflicts. Keep
changes from cherry-pick.
core/src/test/java/kafka/server/ReconfigurableQuorumIntegrationTest.java
Remove auto-join tests, since 4.1 does not support it. docs/ops.html
Keep docs section from cherry-pick.
metadata/src/test/java/org/apache/kafka/metadata/storage/FormatterTest.java
Minor conflicts. Keep cherry-picked changes.
test-common/test-common-runtime/src/main/java/org/apache/kafka/common/test/KafkaClusterTestKit.java
Conflicts due to integration test framework changes. Keep new changes.
commit 02d58b176c (upstream/4.1)
```
Reviewers: Chia-Ping Tsai <chia7712@gmail.com>
012e4ca6d8