[ntp:questions] NTP Support (Was 'What does "Max Distance Exceeded"...')

Joseph Gwinn joegwinn at comcast.net
Tue Mar 17 02:09:11 UTC 2009

In article <49becf09$0$507$5a6aecb4 at news.aaisp.net.uk>,
 David Woolley <david at ex.djwhome.demon.co.uk.invalid> wrote:

> Joseph Gwinn wrote:
> > We have moved from the meaning of status code 9514 to the more general 
> But you should have kept the thread, even if the subject changed.

Opinion varies on this, but why?  It really was a case of topic drift.

> > issue of how NTP shall be supported, so I've collected the relevant 
> > threads below.
> > 
> > More generally, it's hopeless to expect the world's sysadmins to read 
> > NTP code (or any other kind of code).  They just don't have the time, 
> Generally, you only need to read a small bit of code to answer this sort 
> of question, but if you haven't got the time you should pay someone who 
> does have the time.

It's simply not going to happen, especially for random small questions.  
They will just muddle through, and blame NTP.

Hiring outside help isn't just a money problem, it also requires much 
jumping through bureaucratic hoops, which is very time consuming, so it 
never makes sense for non-major issues.

> Historically, open source software was written for use by people who had 
> the ability to support it themselves.  Recently, the relationship has 
> become asymmetric with a lot of people wanting free software and free 
> support.  Whilst some open source software developers may consider it a 
> valuable loss leader to produce a naive user product and support it, may 
> even consider it part of their mission, most open source developers are 
> not that interested in donating that level of free support.

What price success?  Most open-source software would be happy to achieve 
1% of what NTP has achieved.  Only Linux is even in the running, but NTP 
far exceeds Linux.  Given the present scale, for which NTP and its 
community were never designed, what to do?  The single most effective 
thing the community can do is to write good documentation.  Yes, it's 
work, but it's by far the most effective thing one can do, and it's 
really the only practical approach given the immense size of the NTP 
user base.

By the way, when I started digging into the archived NTPv3 
documentation, it said that the peerstats status codes were defined in 
Appendix B of RFC-1305.  OK, I actually knew that. Then, I started 
looking for the corresponding NTPv4 documentation.  The NTPv4 RFC to be 
is innocent of the word "peerstats" and its status field, but the 
current online documentation (which is for NTPv4) at 
<http://www.eecis.udel.edu/~mills/ntp/html/monopt.html> also points to 
the same place in RFC-1305, so it appears that the status code 
definitions did not change.  Unless the documentation is in error.  

If so, the simplest global fix is to update the documentation.  As I 
said in the prior posting, it's a non-starter to try to require a 
hundred million people to either read the source code or pay someone to 
do it for them every time NTP throws an uncommon status code.  It just 
won't happen.  On scale alone, the NTP community would be overwhelmed 
with repeated trivial questions.

I'm reminded of the librarians in the town library when I was in high 
school.  There were lots of hand-written cards in the card file, placed 
there by the librarians when they got tired of hearing the same simple 
or silly question.

> Actually a lot of commercial software, these days, is dumbed down, 
> supported, open source material.

True.  But it can be amusing to figure out which one it is, and start to 
ask uncomfortable questions about how can they be better than free, 
especially if they reduced the usefulness of the code.


More information about the questions mailing list