Hi Daniel, Kafka 4.0 includes a rewrite of the group coordinator with a new batching mechanism. The batching interval defaults to 5 ms and is controlled by the `group.coordinator.append.linger.ms` broker config option. Could you try lowering this config and rerunning the benchmarks?
Thanks, Sean On 2025/08/21 15:50:58 Daniel Germon wrote: > Hi Greg, > > I have changed the linger.ms configuration on the producer and yes it > explains the difference in client version latencies, but I am still seeing > the broker latency differences with this configuration. > > Kafka broker 3.9.1, client 4.0.0, linger.ms = 0 > > 50th percentile: 310us > 90th percentile: 414us > 99th percentile: 825us > 99.9th percentile: 9813us > > Kafka broker 4.0.0, client 4.0.0, linger.ms = 0 > > 50th percentile: 8193us > 90th percentile: 10373us > 99th percentile: 11109us > 99.9th percentile: 13812us > > > Regards, > Dan > > This message and its attachments are confidential, may not be disclosed or > used by any person other than the addressee and are intended only for the > named recipient(s). If you are not the intended recipient, please notify the > sender immediately and delete any copies of this message. > > LMAX Group is the holding company of LMAX Exchange, LMAX Global and LMAX > Digital. Our registered address is Yellow Building, 1A Nicholas Road, London > W11 4AN.
