Hi Team, I need some guidance related to Kafka Consumer Incremental Rebalance Protocol.
I was following the below KIP and understood the upgrade path, But a bit confused with the downgrade procedure. *KIP:* https://cwiki.apache.org/confluence/display/KAFKA/KIP-429%3A+Kafka+Consumer+Incremental+Rebalance+Protocol I am currently using Kafka consumer 2.3.0 and trying to update it to 2.6.2. Let's say, I switched to CooperativeStickyAssignor, and due to some reason, I may need to roll back my build from production to 2.3.0. Also please note, we are using ECS Blue-Green deployment. As per KIP, and also tested this locally, If we try to rollback to 2.3.0, new consumers will not be able to join the group and will be kicked out with the following error: ----------- org.apache.kafka.common.errors.InconsistentGroupProtocolException: The group member's supported protocols are incompatible with those of existing members or the first group member tried to join with empty protocol type or empty protocol list. ------------- I saw the below line in KIP, but could not find `rebalance.protocol` config in ConsumerConfig. `*The right way to downgrade is first rolling bounce the instances while setting "rebalance.protocol" to "compatible", and then a second rolling bounce to set the rebalance protocol to "eager" if necessary.`* Can somebody please point me in the right direction regarding how to downgrade is needed? Regards, Vipul
