This is a breaking change. However this feature hasn't been tested and
allows end-users to break the system too easily. Low-level control over
the SQLite database is better done with PRAGMA commands where possible.
With this change the cluster metadata (arbitrary key-value data associated with each node) is now broadcast across the cluster using the standard consensus mechanism. Specifically the use case for this metadata is to allow all nodes know the HTTP API address of all other nodes, for the purpose of redirecting requests to the leader.
This change removed the need for multiplexing two logical connections
over the single Raft TCP connection, which greatly simplifies the
networking code generally.
Original PR https://github.com/rqlite/rqlite/pull/434
Philip O'Toole