Behavioral changes denote a marked change in behavior from the previously released version to this version of software.
New Upgrade Policy for Kafka
Kafka 2.1.0 contains a change to the internal schema used to store consumer offsets (KIP-211).
After you upgrade to Kafka 2.1.0, downgrade to earlier versions of Kafka is strongly discouraged.
Previously, you were able to downgrade to earlier versions of Kafka after the upgrade was complete.
After the introduction of Kafka 2.1.0, once you upgrade to Kafka 2.1.0, downgrade to earlier versions of Kafka might cause data loss.
Expected user action
- If you upgrade both the broker and consumer to 2.1.0, a downgrade might cause data loss.
- If you upgrade the broker to 2.1.0 and the consumer remains at 2.0.0, then you can downgrade the broker to 2.0.0 without any issue.