kafka Performance Reduced when adding more consumer or producer

Question

I have 3 server with 10GB connection between them and run a Kafka cluster on 2 servers and generate some test in third server...

when I run a single java producer (in third server that is not in Kafka cluster) sending 1 million messages take 3 seconds, but when I run another java producer (with different topic) both of producers take 6 seconds for sending messages.

I sure network connection is not bottleneck (it is 10GB)

so why this problem happened and how can I solve this (I want both producers take 3 seconds) ?

Answer 1

Sounds like you are getting a consistent 333,333 messages/sec performance out of a two node kafka cluster, with zookeeper running on the same 2 machines as your 2 kafka brokers. You don’t say what size these messages are or what kind of disks you are using, or how much memory, or if you are publishing with acks=all, or what programming language you are using (I assume java) but that actually sounds like good consistent results that are probably disk IO bound on the brokers or cpu bound on your single client machine.