This version is still in development and is not considered stable yet. For the latest stable version, please use spring-cloud-stream 4.1.3!

Concurrency

When using reactive functions with the reactive Kafka binder, if you set concurrency on the consumer binding, then the binder creates as many dedicated KafkaReceiver objects as provided by the concurrency value. In other words, this creates multiple reactive streams with separate Flux implementations. This could be useful when you are consuming records from a partitioned topic.

For example, assume that the incoming topic has at least three partitions. Then you can set the following property.

spring.cloud.stream.bindings.lowercase-in-0.consumer.concurrency=3

That will create three dedicated KafkaReceiver objects that generate three separate Flux implementations and then stream them to the handler method.