[CentOS] two 2-node clusters or one 4-node cluster?

Sat Jul 7 21:58:54 UTC 2018
Warren Young <warren at etr-usa.com>

On Jul 7, 2018, at 7:54 AM, Gianluca Cecchi <gianluca.cecchi at gmail.com> wrote:
> I have yet to dig sufficiently deep in Warren considerations, but I will do
> it, I promise! Very interesting arguments

Until then, I offer this tl;dr:

A 4-member cluster has distinct advantages over a 2x2 cluster of the same machines *if* the software running that cluster knows how to take the full available advantage of that configuration.

That “if” is key.  By it, I’m telling you I don’t know whether the clustering software you want to run uses a proper distributed consensus algorithm or is something simpler, like a blind mirroring system.  If the latter, then the choice of configuration is purely an operational consideration, something only you can decide.