Julian Bergner created KAFKA-19148:
--------------------------------------
Summary: Potential Unclean Leader Election in KRaft Despite
unclean.leader.election.enable=false
Key: KAFKA-19148
URL: https://issues.apache.org/jira/browse/KAFKA-19148
Project: Kafka
Issue Type: Bug
Components: controller
Affects Versions: 3.9.0, 4.0.0
Reporter: Julian Bergner
Attachments: Readme_Kraft.md, Readme_Zookeeper.md,
docker-compose_kraft.yml, docker-compose_zookeeper.yml
*Issue Summary:*
We're observing unclean leader election even though
{{{}unclean.leader.election.enable=false{}}}.
*Scenario:*
During a partition reassignment, if we promote a non-ISR broker to leader and
simultaneously remove the current leader from the ISR, Kafka still elects a new
leader from outside the ISR. This behavior contradicts the expected behavior
when unclean leader election is explicitly disabled.
*Details:*
* *Original ISR:* [1, 2]
* *New ISR after reassignment:* [3, 2]
* *Kafka Versions Tested:*
** Kafka 4.0.0 (KRaft mode)
** Kafka 3.9.0 (Kraft mode)
** Kafka 3.9.0 (Zookeeper mode)
* *Observation:*
** The behavior differs between the two modes.
** In Kraft, unclean leader election occurred, which should not happen with
the config set to {{{}false{}}}.
** In Zookeeper no unclean leader election occurred.
*Attachments:*
Docker Compose files and reproduction steps for both:
* Kafka 4.0.0 (KRaft)
* Kafka 3.9.0 (Zookeeper)
--
This message was sent by Atlassian Jira
(v8.20.10#820010)
