[ntp:questions] More Granularity in the US in the NTP Pool

Danny Mayer mayer at ntp.isc.org
Fri Sep 14 03:36:49 UTC 2007


Brian Utterback wrote:
> Unfortunately, neither poolcasting nor preempt does what is being
> requested, at least I know that preempt does not and poolcasting
> doesn't if I understand it correctly.  The problem with preempt (at
> least) is that it only subtracts or replaces, it never incrementally
> improves. By this I mean it picks some subset of the original
> servers and throws away the rest. So, if the original set is
> sub-optimal, the final result will likewise be sub-optimal, that
> is, it only gets you the best of what could be a very bad set.
> 
> Poolcasting as described by Dave, allows NTP to throw away all
> the current servers and get a new set. This is an improvement in
> that you at least get a new set to work with if the previous one
> was poor, but your chances of getting a good set are still
> the same as the first time around.
> 

I don't think that Dave said that he was throwing anything away except
for falsetickers from the pool. Nothing was mentioned about retrying.
One of the things that could be implemented is to fetch additional lists
of addresses if there aren't sufficient truechimer servers in the
current set. That's a suggested addition right now.

> What Henk has described is just the first step in a  facility that I
> have been thinking about for quite some time. The idea is to allow a
> much more extensive level of self-organizing emergent NTP behavior.
> But the ability of get this type of incremental behavior is
> crucial to getting it to work.
> 

Please explain more about what you are suggesting.

Danny
> Brian Utterback
> 




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