[fomichev3000]

YDB doesn't use Zookeeper. The system is built of tablets, every tablet implements distributed consensus algorithm. There are different types of tablets in the system, say SchemeShard is tablet that stores metadata, table schema for instance. DataShard stores table partition data.

[asadawadia]

Which consensus algorithm? I don't see raft in the codebase

[fomichev3000]

We have consensus protocol over shared log. Some details you can find in a power point presentation at this page https://2019.hydraconf.com/2019/talks/muxomfgqembsb3st7i3ci/