My first positive structural change to NTP

Eric S. Raymond esr at
Sun Jun 26 12:57:26 UTC 2016

Hal Murray <hmurray at>:
> Stromeko at said:
> > I think that's still perpetuating a mistake.  This whole business of having
> > to specify two servers (or refclocks) for the same thing should go away.
> There is a fundamental issue.  With a PPS, there really are two sources of 
> time.  Internally, ntpd needs two different handles so you can see both sets 
> of info on ntpq -peers and clockstats.

Agreed.  This is a specialization of my case that the declaration language
should be channel-focused, not deviced-focused.

> Normally, each PPS has an associated serial stream.  It would be good if 
> there were a clean way to specify that rather than using the prefer kludge.

I'm open to proposals.  I love designing minilanguages and DSLs, so I
am totally up for a friendly technical wrangle about this. :-)

The current new syntax has just these changes:

1. Magic driver-type numbers are replaced by driver shortnames

2. server 127.127.{t}.{u} -> refclock {typename} unit {u}

3. fudge ceases to be a separate command; its option grammar is glued
   to the end of the refclock part.

This is a pretty minimal change. It has the dual advantage that it is (a) easy
to explain to people familiar with the old syntax, and (b) significantly
simpler for newbies.  I think it is therefore at a sweet spot that we
shouldn't wander away from without good reason.

That said, I'm totally willing to hear good reasons.
		<a href="">Eric S. Raymond</a>

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