Very good description with pictures in the book Kafka: The Definitive Guide
https://www.oreilly.com/library/view/kafka-the-definitive/9781491936153/ch04.html -hans > On Mar 26, 2020, at 12:00 PM, sunil chaudhari <sunilmchaudhar...@gmail.com> > wrote: > > Again.... > A consumer can have one or more consumer thread. > The analogy of 12 partitions and 4 consumer is true when each consumer has > 3 consumer threads. > Please don’t skip the important factor “consumer thread” in this matter. > > If you run each consumer with threads then you may need max 3 consumers for > that consumer group. > > If you have 12 partitions and you run 4 consumers with 4 consumer threads > then 4 threads will be idle at any time T1. > > I hope this is clear. > > Thanks, > Sunil. > > On Thu, 26 Mar 2020 at 7:52 PM, Hans Jespersen <h...@confluent.io> wrote: > >>> As per my understanding, in Apache Kafka a single consumer from a >> consumer >>> group can consume messages from one partition only. >> >> Not correct. A single consumer from a consumer group can consume from many >> partitions. For example if you had a topic with 12 partitions and 4 >> consumers in a consumer group, each consumer in the group would consume >> from 3 partitions. >> >> -hans
