I understand that using Postgres without WAL is quite fault-INtolerant (although considerably more performant). But what about the setups of YDB and CockroachDB, are they comparable to Postgres' setup in terms of fault tolerance?
Well it is an in-house tool that just got opensourced, so it is natural that docs and other materials are lacking. There are videos from C++/HighLoad meetups that shed light on internals, but mostly in russian as of now. Give it time.