[alfalfasprout]

It is a philosophical one when you design around scaling out at a high rate. You incur significant additional complexity in many cases along with increased overhead.

It's fallacious to think that relying on "n" things is strictly safer than "3" things where n is large. That's not quite true due to the significant complexity increases when dealing with large "n" and accompanying overhead.

For web applications (which I suspect the majority of HN readers work on) then sure, but plenty of realtime or safety critical applications are perfectly ok with three-way redundancy.

[Bad_CRC]

I work a lot with voip systems and it's much much easier to have one big machine that trying to make it work distributed...