[ https://issues.apache.org/jira/browse/KAFKA-19148?page=com.atlassian.jira.plugin.system.issuetabpanels:all-tabpanel ]
Julian Bergner updated KAFKA-19148: ----------------------------------- Description: *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) was: *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) > 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: 4.0.0, 3.9.0 > Reporter: Julian Bergner > Priority: Critical > 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)