RocksDB is one of the popular open source embedded key value database used by several other popular systems. It is built based on LevelDB code which is developed by Google. More and more opensource as wells as commercial systems started using RocksDB due to its high performance, flexibility and tuning features. Also there are may other Databases improved or customized RocksDB based on their needs.
I am going to write posts which can help in reviewing RocksDB code. Some of the posts which I already published are here below.
Please let me know if you need to know any particular area of RocksDB. Also let me know if any updates are needed to above posts.