[Tarantool-patches] [RFC] Quorum-based synchronous replication

[Konstantin Osipov]

* Sergey Ostanevich <sergos at tarantool.org> [20/04/30 17:51]:

A few more issues:

- the spec assumes there is a full mesh. In any other
  topology electing a leader based on the longest wal can easily
  deadlock. Yet it provides no protection against non-full-mesh
  setups. Currently the server can't even detect that this is not
  a full-mesh setup, so can't check if the precondition for this
  to work correctly is met.

- the spec assumes that quorum is identical to the
  number of replicas, and the number of replicas is stable across
  cluster life time. Can I have quorum=2 while the number of
  replicas is 4? Am I allowed to increase the number of replicas
  online? What happens when a replica is added,
  how exactly and starting from which transaction is the leader
  required to collect a bigger quorum?

- the same goes for removing a replica. How is the quorum reduced?

-- 
Konstantin Osipov, Moscow, Russia