Kafka did lose a lot of data in the Jepsen test, as it will by design to preserve availability under some specific circumstances. The behavior in question will

Kafka did lose a lot of data in the Jepsen test, as it will by design to preserve availability under some specific circumstances. The behavior in question will be configurable from Kafka 0.8.2, by setting "unclean.leader.election.enable" to false. See https://issues.apache.org/jira/browse/KAFKA-1028 https://issues.apache.org/jira/browse/KAFKA-1028