[ntp:questions] frequency of updation

David J Taylor david-taylor at blueyonder.co.not-this-bit.nor-this-part.uk
Wed Nov 29 10:18:12 UTC 2006


lulu wrote:
> Actually I want to know how frequently a system's time get get updated
> by any NTP server.
> I didn't found in man pages that it can be done with user
> interference. So I think this is something done by deamon itself. And
> the frequency is hardcoded inside its source code.
>
> If it is so it may happen that it will over load the cpu. Because it
> must be updating itself with some
> transmission and recepton of packets from server.
>
> So how to know that how frequently a system get itself updated with
> that of a NTP server and is it uniform ?
>
> Is there any chance of getting a cpu overloaded due to this updation
> or due to any operation of xntpd deamon  ?
>
> thanks in advance.

[simple explanation]

An NTP client (by default) will ask each server for a new time every 64 
seconds when it starts up.  As the client time becomes correct, the 
interval between requests will gradually lengthen until it reaches 1024 
seconds.  It is not hard-coded, but dynamic and adaptive, and will reduce 
again if needed.

There is no chance of CPU overload.

David 





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