KafkaListener partition mapping within instance for concurrency > 1

Issue

I have a simple kafka listener annotated method and spring.kafka.listener.concurrency = 5

My topic has 100 partitions, and there are 5 instances of the application running. The topic has partition keys set, so the consumer level partition affinity exists. I would like to understand if its possible for multiple threads of the consumer to receive messages from the same partition.

Solution

No; with concurrency = 5, each instance has 5 distinct consumers; only one consumer in a group can consume from a partition.

Answered By - Gary Russell