Based on the design[1], it has a leader / follower pattern (although you should have multiple leaders with Raft consensus to avoid having a single point of failure), where the leader is called "nameserver" and decides where to put each piece of data and metadata among a set of chunk servers and metadata servers.

That design is very reminiscent of CephFS's cluster monitors, metadata servers, object storage devices.

[1]: https://github.com/baidu/bfs/blob/master/docs/design.md, https://github.com/baidu/bfs/blob/master/docs/BFS_design.md