[arch-d] Centralization or diversity

["Martin Thomson" <[e-mail]>]

Having just read draft-arkko-arch-infrastructure-centralisation, I was struck by an observation.

The draft specifically calls out the notion of a single point of failure being a problem.  But my experience with centralized services is that they aren't centralized in the fault tolerance sense.  If I look at the big services, that scale is only achieved with careful distributed systems design.  Name any modern service of even modest scale and you generally find excellent fault tolerance.

This draft really wants to say something less negative: that it values diversity on multiple axes.  The draft covers:

* fault domains
* geopolitical
* organizational

To which I might add:

* geographic
* implementation
* infrastructure (power, network, hardware)

There are probably areas of diversity that are less valuable.  Protocol diversity has the effect of forcing divisions.  I tend to think that cryptographic diversity divides the limited resources available for protecting and assuring system integrity.  And diversifying where standardization happens is almost certainly bad [RFC5704].

Finally, I don't like the emphasis on DNS in this document.  It only serves to sensationalize.