Expected lifetime of software?

[Hal Murray]

esr at thyrsus.com said:
> I'm not pulling this estimate out of a hat.  "It will last about as long  as
> it already has" is, as it turns out, a pretty good heuristic for systems
> that evolve under selection. 

I don't think that is the question I was trying to ask.

The case I was interested in is user takes a snapshot, then never updates.  
(Let's assume there are no major security issues.)


> Apparently you don't understand the solution Dave Mills already embedded in
> the design. This surprises me.

> Here's how I think it works:

> Instances of ntpd with different pivot points can synchronize because
> maximum time skew between servers is much smaller than the modulus of the
> NTP calendar.  Above certain skew, the code says "uh oh, looks like I'm
> hearing from a server with an epoch other that mine. That means I need to do
> calendar aithmetic to figure out which epoch assuption will minimze the
> skew". 

I think we are on the same wavelength.  Or close enough.

I think your "calendar aithmetic" is misleading.  It's epoch arithmetic, a 
simple add.

The reason I got started on this line of thought is that I haven't found the 
code that deals with the pivot point.

Yes, if we had working pivot point code things would keep working forever as 
long as it was updated occasionally.



-- 
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