Kafka Replication factor increase post issue

Question

I am using a 3 broker Kafka cluster in prod. Earlier the replication factor was 2 . Now I want to increase the replication factor to 3. I have executed the kafka-reassignment-partions.sh file and it go executed successfully. Post execution when I am executing the describe command it is showing 3 brokers in the ISR list , but for all partions , I am having the same leader (Broker 1 as the Leader).

Please suggest

Answer 1

As far as I know the order you put in the "replicas" field reflect which broker will be the leader for that partition so have the same [1,2,3] sequence for all the partitions and broker 1 is always in the same first position so it will be the leader for that partition. You should change that order putting in the first position the broker-id you want being the leader for the corresponding partition. After that you have to run the preferred replica election tool.