[ntp:questions] Server offset included in served time?

Richard B. Gilbert rgilbert88 at comcast.net
Mon Sep 15 17:11:55 UTC 2008


Brian Utterback wrote:
> Unruh wrote:
> 
>> Just because A has credibility does not mean that B does not. credibility
>> is not an exclusive property. There can be disagreements between 
>> honest men
>> without one having "no credibility".
>>
>> Note that the NTP algorithms are NOT fundamentally flawed. They are 
>> great.
>> They are just, in my opinion and measurements, not the best.
> 
> Of course, a lot of the issue resides with the definition of *best*. 
> Bill has found that in his environment, the algorithms used by chrony 
> preform better than those used by NTP. He has empirical data to back 
> this up. He also believes that his environment is fairly typical, which 
> is his opinion and more speculative. So for him, NTP's algorithms are 
> not the *best*.
> 
> My recent experiments show that the same algorithms that are great in 
> NTP for the long haul, actually hinder its ability to get the offset and 
> frequency right under many typical startup conditions. Dr. Mills isn't 
> really interested in fixing this, not because he denies it, but because 
> he doesn't think it is the best area for his labors. He is more 
> interested in the long-haul.

This may be a problem for those who reboot their systems daily (or more 
frequently).  My NTP server has an uptime of 121 days at the moment.  I 
expect that it will remain up until the next time the power goes out for 
longer than the run time of my UPS.




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