I'm very interested in looking into the code as a sample of real-world distributed system implementation, much more informative than our university's distributed systems course, I guess.
Are there any guide available for the source code, besides src/README ?
Unfortunately, there isn't a good guide yet (but hopefully there will be one soon).
Studying RethinkDB source code may not be the best way to study distributed systems, though. There is an enormous gap between a working system and a production quality product, and most of the code in that gap has to do with relatively mundane issues like error checking/error reporting, monitoring tools/APIs, lots of polish, edge case handling, etc.
It's a lot of fun to get into the guts of the system, but it's fairly large, so it's a non-trivial undertaking. If you do decide to do it, we'd love to help you out on IRC (#rethinkdb on freenode), and would appreciate if you documented your experience so we could make the process easier for others in the community!
