hi Xiang
> 1. Which version(s) is the most proper version to go to if I want to get
> the core design and implementation of Kafka so that it won’t be too old and
> not too new either.
The code in the trunk branch is the best choice if you want to understand
Kafka's most up-to-date architecture :
If you want to understand the architecture, I think you probably want to start
with reading a book like "Kafka: The Definitive Guide."
If you understand the architecture, you can learn the source code with time. I
would suggest always reading the newest source code, since that is what people
wi
