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

[Sergey Ostanevich]

On 06 мая 22:10, Konstantin Osipov wrote:
> * Konstantin Osipov <kostja.osipov at gmail.com> [20/05/06 21:55]:
> > 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.
> 
> Come to think of it, it's a special case of network partitioning.
> A replica with the longest WAL can be reachable by the external
> coordinator but partitioned away from the majority, so never able to
> make progress.

So the answer from this replica on it's appointment will be 'I have no
quorum'. Hence, the orchentration should pick the next-length WAL.
What's the problem?

> 
> 
> -- 
> Konstantin Osipov, Moscow, Russia
> https://scylladb.com