dns and software, was Re: Reliable Cloud host ?

Joe Greco jgreco at ns.sol.net
Thu Mar 1 08:53:02 CST 2012


> On Thu, Mar 1, 2012 at 8:25 AM, Joe Greco <jgreco at ns.sol.net> wrote:
> > "If three people died and the building burned down then the sprinkler
> > system didn't work. It may have sprayed water, but it didn't *work*."
> >
> > That's not true. =A0If it sprayed water in the manner it was designed to,
> > then it worked.
> 
> That's like the old crack about ICBM interceptors. Why yes, our system
> performed swimmingly in the latest test achieving nine out of the ten
> criteria for success. Which criteria didn't it achieve? It missed the
> target.

Difference: the fire suppression system worked as designed, the ICBM 
didn't.

That's kind of the whole point here.  If you have something like an
automobile that's designed to protect you against certain kinds of
accidents, it isn't a failure if it does not protect you against an
accident that is not reasonably within the protection envelope.

For example, cars these days are designed to protect against many
different types of impacts and provide survivability.  It is a failure
if my car is designed to protect against a head-on crash at 30MPH by
use of engineered crumple zones and deploying air bags, and I get into
such an accident and am killed regardless.  However, if I fly my car
into a bridge abutment at 150MPH and am instantly pulverized, I am not
prepared to consider that a failure of the car.  Likewise, if a freeway
overpass slab falls on my car and crushes me as I drive underneath it,
I am not going to consider that a failure of the car.

There's a definite distinction between a system that fails when it is
deployed and used in the intended manner, and a system that doesn't
work as you'd like it to when it is used in some incorrect manner, which
is really not a failure as the word is normally used.

... JG
-- 
Joe Greco - sol.net Network Services - Milwaukee, WI - http://www.sol.net
"We call it the 'one bite at the apple' rule. Give me one chance [and] then I
won't contact you again." - Direct Marketing Ass'n position on e-mail spam(CNN)
With 24 million small businesses in the US alone, that's way too many apples.



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