Kafka is represented as a very unix-friendly message tool, when it is no such thing. Kafka is (one of) the worst of the collection of message bus daemons. It imposes small(3-6mb) message size limits, or else performance goes to hell. Kafka also fails to "do one thing well", and instead tries to provide everything-and-the-kitchen-sink (clustering, compression, etc) built-in, but poorly.

For some contrast, take a language like python, which will allow you to create example programs to test out Kafka VS RabbitMQ VS zeromq. You will quickly find that one of the message bus daemons constantly gets in your way, fails to reliably deliver messages, and consumes a ton of system resources compared to the other two. Hint: It's kafka!

I really can't say enough bad things about kafka. Having used it and unfortunately been forced to implement it at a number of "big"(juniper, cisco, vmware) companies, it has been a horrible and disappointing experience for both the end-users and the developers, every single time.

tldr; don't use Kafka, use a real messaging bus.