[ntp:questions] Any chance of getting bugs 2164 and 1577 moving?

David Lord snews at lordynet.org
Thu Mar 22 21:54:49 UTC 2012


unruh wrote:
> On 2012-03-22, David J Taylor <david-taylor at blueyonder.co.uk.invalid> wrote:
>> "unruh" <unruh at invalid.ca> wrote in message 
>> news:xLHar.38386$IQ1.34248 at newsfe18.iad...
> 
>> []
>>> Measure what? Why do you think that ntp reporting the offset with an
>>> extra three decimal points would allow you to measure anything? What in
>>> your mind would you expect to see in that output that would allow you to
>>> "measure" something that would tell you that the -19 was wrong? Remember
>>> ntpd DID measure something in order to determine that -19. What do you
>>> think the extra decimal places would give you?
>> Most likely I would be looking at a histogram of the reported offsets, and 
>> see whether it was gaussian, flat, or whatever, and how wide.  I might 
>> learn something from that.
> 
> No. Not if it is just noise. 
> 
>> Others have reported precisions better than -19, and also have a need for 
>> greater reporting precision.
> 
> That is a valid issue. 

I have servers currently with precision= of 18, 19, 20 but not
scanned back in history more than today. The value varies, with
temperature and system load which causes local temperature
variations. The precision values vary and are just way points.

With precision 20. I don't really need an extra decimal place
but in a previous life was used to throwing away two results
from five or more if from a greater number of samples.

My standard pc hardware can't do any better.


David


>> There seems to be an impression out there that I'm trying to show 
>> something is wrong - I'm not.  I suggested an enhancement so that the 
>> precision of ntpq matched that of the loopstats.  That's all.
> 
> precision is not accuracy.
> In science we teach students not to report unwarranted precision-- the
> precision should reflect the accuracy of the measurements. We keep
> getting measurements to the mm and reported precision to angstoms
> because that was what the calculator spit out. 
>  I am not averse to reporting with a precion maybe up to a factor of 10
> better than the accuracy, but any more is just silly and misleading (as
> you are demonstrating in believing that a greater precision would convey
> some extra information. 
> 
>> David 
>>



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