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Ismael Juma commented on KAFKA-3827: ------------------------------------ [~ecomar], 1) We tweaked the instructions in Git a while back to make this clearer. I have just pushed the changes to the website as well. The answer is that you can do them at the same time, but typically you would want to change log.message.format.version after most consumers have been upgraded. 2) Some inter-broker communication would fail, yes. The specifics depends on the particular version. In theory, it should be OK if a short outage is tolerated, but we haven't tested it, so no guarantees. You'd want to test it yourself to verify. > log.message.format.version should default to inter.broker.protocol.version > -------------------------------------------------------------------------- > > Key: KAFKA-3827 > URL: https://issues.apache.org/jira/browse/KAFKA-3827 > Project: Kafka > Issue Type: Improvement > Affects Versions: 0.10.0.0 > Reporter: Jun Rao > Assignee: Manasvi Gupta > Labels: newbie > > Currently, if one sets inter.broker.protocol.version to 0.9.0 and restarts > the broker, one will get the following exception since > log.message.format.version defaults to 0.10.0. It will be more intuitive if > log.message.format.version defaults to the value of > inter.broker.protocol.version. > java.lang.IllegalArgumentException: requirement failed: > log.message.format.version 0.10.0-IV1 cannot be used when > inter.broker.protocol.version is set to 0.9.0.1 > at scala.Predef$.require(Predef.scala:233) > at kafka.server.KafkaConfig.validateValues(KafkaConfig.scala:1023) > at kafka.server.KafkaConfig.<init>(KafkaConfig.scala:994) > at kafka.server.KafkaConfig$.fromProps(KafkaConfig.scala:743) > at kafka.server.KafkaConfig$.fromProps(KafkaConfig.scala:740) > at > kafka.server.KafkaServerStartable$.fromProps(KafkaServerStartable.scala:28) > at kafka.Kafka$.main(Kafka.scala:58) > at kafka.Kafka.main(Kafka.scala) -- This message was sent by Atlassian JIRA (v6.3.4#6332)