[ntp:questions] Flash 400 on all peers; can't get ntpd to be happy
ralph at depth.net
Sat Mar 12 05:24:51 UTC 2011
I appreciate the offer to help.
I've been thinking about this problem a while and here are my thoughts... It
seems to me that ntpd has the goal of keeping extremely accurate time - which
is important for many obvious reasons. However there are those of us that
don't need time accurate to the millisecond and / or don't need time to be
perfectly in sync with the rest of the world.
With that in mind, it would be nice if there was something out there that
operated in a slightly different mode than ntpd does... It appears that the
problem that ntpd has is that because the distance between ticks on the local
machine are variable and therefore calculating the time between a transmission
and receipt is 'impossible'. But why not have something that assumes that
the local ticks simply can't be trusted? Keep track of how far off the local
clock is from the ntp sources (averaged over numerous queries) and adjust the
clock based on the average adjustment that is needed. Don't mess with trying
to calculate the time taken for the round trip and all that, if the replies
back from servers are within a certain amount of time of one another, then just
average them out.
If you do something similar to what I suggest, you will end up running further 'behind' than a ntpd server that has consistent ticks, but you ought to
at least be able to have something that disciplines the clock into running
fairly close to real time on average and stays within a handful of seconds
within 'real' time.
As I said, this probably is a completely different solution than ntpd, but it
seems like it would be really useful for people that are more concerned with
making time consistent / realistic than they are with making it ultra-accurate.
And this could also be very useful for people that have hardware clocks that
don't seem to run consistently enough for ntpd - the people whom I've seen been
told to replace their motherboard in order to get a clock that can keep time.
I'm no time expert, so feel free to explain where I've lost my mind if I'm not
thinking through this all the way...
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