apache/kafka ? reverse-engineered prompt

I want to build a distributed event streaming platform, something like a central nervous system for a bunch of apps to communicate. The idea is to have a system that can ingest huge amounts of real-time data from different sources into 'topics'. Then, other services can subscribe to these topics to process the data as it comes in.

This needs to be super high-performance and reliable, something you could use for things like streaming analytics, data integration pipelines, or just connecting mission-critical microservices. It should be built mainly in Java, but can also use Scala for some parts. Please include the core server/broker logic, client libraries for sending and receiving messages, and also a library for stream processing. It should be a Gradle project, and it would be great if you could also set up a Docker configuration to make it easy to run.