[Joker_vD]

Oh, you just run two instances of those and point them at each other.

[jasongill]

And then a third instance in case those both go down at the same time, and a fourth just in case there's a major worldwide outage.... it's monitoring instances all the way down

[hinkley]

Even number so that everything is symmetrical.

[Temporary_31337]

You want odd numbers (n+1) so you can have a quorum in case of network partition.

[hinkley]

I think you're missing the vibe (sarcasm).