Stephane Maarek created KAFKA-14573: ---------------------------------------
Summary: RoundRobinPartitioner doesn't work as expected with topic that has 6 partitions Key: KAFKA-14573 URL: https://issues.apache.org/jira/browse/KAFKA-14573 Project: Kafka Issue Type: Bug Affects Versions: 3.3.1 Reporter: Stephane Maarek Attachments: image-2023-01-04-20-15-43-039.png Create a topic with 6 partitions (that's how the behavior is observed) ``` kafka-topics.sh --bootstrap-server localhost:9092 --topic test_topic --create --partitions 6 ``` Start a consumer ``` kafka-console-consumer --bootstrap-server localhost:9092 --topic test_topic --formatter kafka.tools.DefaultMessageFormatter --property print.timestamp=true --property print.key=true --property print.value=true --property print.partition=true --from-beginning ``` Start a producer using `RoundRobinPartitioner` ``` kafka-console-producer.sh --bootstrap-server localhost:9092 --producer-property partitioner.class=org.apache.kafka.clients.producer.RoundRobinPartitioner --topic test_topic ``` And you will see only 3 partitions get produced to (not 6) This doesn't happen with 3 partitions, 5, 7, 9 partitions (we get the expected behavior). But with 6.... it happens. Verified to be like this on my colleague's computer too. !image-2023-01-04-20-15-43-039.png! -- This message was sent by Atlassian Jira (v8.20.10#820010)