[ntp:questions] chrony as a server

Terje Mathisen terje.mathisen at tmsw.no
Mon Feb 16 14:12:27 UTC 2015


William Unruh wrote:
> On 2015-02-16, David Taylor <david-taylor at blueyonder.co.uk.invalid> wrote:
>> On 16/02/2015 07:59, William Unruh wrote:
>> []
>>> ?? There are chonyc which is its own monitoring. chrony is not ntpd, so
>>> why would you expect ntpc monitoring commands to work?
>> []
>>
>> As I already said, compatibility with the installed base would greatly
>> increase the acceptance on different software.
>
> I think, but am not sure, that the biggest problem with porting chrony
> to windows is that windows does not have a good way of having the kernel
> discipline the clock-- the equivalent of adjtimex on Linux.

If this is the biggest problem, then it would already be running there!

GetSystemTimeAdjustment()
SetSystemTimeAdjustment()

The only "hard" part is that you have to manually convert the adjustment 
rate to an absolute value:

Call Get* to retrieve the amount the system clock is incremented by on 
each timer tick/basic clock interval, then scale this value by the 
adjustment rate, i.e. to add 5.6ppm you would take the base value and 
multiply by 1.0000056.

Finally you call Set* to program the new clock frequency.

Obviously you have call the Set* function once more to turn off or 
modify the adjustment.

The only way to make it much simpler is to have something like the 
Netware clock, where you got a pointer to the clock data:

Basic increment per timer tick
Current increment per tick
Current additional increment/decrement
Nr of timer ticks when that additional adjustment should be applied
Final extra adjustment.

The last variable was in order to make it easier to get an exact 
adjustment by taking the total adjustment and dividing by the number of 
ticks to spread it over, with the remainder to go in that final field.

Terje
>
>>
>> Let's hope that ntimed is usable with Windows, otherwise it too will be
>> out of the window.
>>


-- 
- <Terje.Mathisen at tmsw.no>
"almost all programming can be viewed as an exercise in caching"



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