I'm relative new to Kafka and probably I'd have a miss understand on how rebalancing works, in my case I've created a topic with 4 partition and then I've publish some data.
To test our product we start to consume data with 4 clients with the same consumer group. For increase consumer throughput we extends our topic with 8 partition, after restart clients we noticed that that only 4 clients continues to consume instead what I waiting was that all 8 clients start to consume. The official Kafka resource says "partitioning will potentially be shuffled by adding partitions but Kafka will not attempt to automatically redistribute data in any way", is there a way to redistribuite data (already present in Kafka) on all partition topic ? Thanks for help Andrea