[ntp:questions] Speed of ntp convergence

David Woolley david at ex.djwhome.demon.co.uk.invalid
Wed Nov 5 23:04:13 UTC 2008

Nicola Berndt wrote:

> What really bothers me is that ntp is totally capable of telling me its 
> offset (and so how wrong the time /being served/ is) but not capable of

Careful.  The theory behind ntpd is that, in normal operation, offset 
consists only of measurement error, not of real clock error.  The 
problem with ntpd is that, after startup, or rapid temperature changes, 
that assumption isn't valid, and offset contains a large component of 
real error.  Worse, it is obvious to a human observer, even without 
hindsight, that that is the case.

In these situations, ntpd continues to believe that offset is noise and 
not signal.

(One does have to beware of hindsight.  In judging ntpd, one must only 
look at what has happened before its decisions.)

> reacting to it, due to it's programmed slowness, wich as we prove in 
> some cases leads to the software being unusable.

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