i’m confused when i have read this doc Storage Architecture
as i know
first apache kafka do not using RocksDB and also not a database management system. known as Message Queue.
second CockroachDB only supports one type of storage engine called Pebble now.
May be this doc need update?
Thank you for your question!
Regarding Apache Kafka, Kafka Streams utilizes RocksDB internally as a local embedded key-value cache store. For more information on how to utilize RocksDB with Kafka for cache, I recommend checking out Kafka Streams Memory Management documentation.
Regarding CockroachDB, CockroachDB was originally built on RocksDB (source) and has switched to an internal alternative, Pebbles, which is heavily inspired by RocksDB. It is not a complete replacement for RocksDB as Pebbles only has a fraction of the code size of RocksDB. More details on the differences & similarities between the two can be found in CockroachDB Pebbles press release.