Upgrade each Kafka node one at a time. You can stop each Kafka broker and upgrade the component without downtime if you have enough replication for your topic.

Shut down the current Kafka daemon, switch to the new version, and start the daemon:

su - kafka -c "/usr/hdp/current/kafka-broker/bin/kafka stop"

hdp-select set kafka-broker 2.2.9.0-$BUILD

su - kafka -c "/usr/hdp/current/kafka-broker/bin/kafka start"

To verify that the Kafka daemon joined the cluster, run the associated validation steps in Appendix A.

If the upgrade process fails, follow the steps in "Downgrading the Cluster," starting with "Downgrade components outside of the cluster." Otherwise, continue with the next upgrade step.