[ntp:hackers] How many servers for a pool config line?

Hal Murray hmurray at megapathdsl.net
Thu Nov 12 05:02:34 UTC 2009


tglassey at glassey.com said:
> He is saying that you may want to be able to set other controls like a
> maximum number of servers that a POOL can select from. The problem
> there is DNS I think but hey... if you are going this far you also
> may want to do something like set controls as far as distance or
> number of hops to the time servers in the pool that also would make
> sense. 

What I'd like to see is something like:
  the pool command does a DNS lookup and selects N+1 servers
  every N hours:
    the system scans those servers and kicks out the worst one
    then does another DNS lookup and grabs a new one.

There are two ideas in here.
  If you take a server out of the pool and it stops responding,
    it will get de-selected by clients.  So you can remove a system
    from the pool without it getting hammered forever.
  The clients end up using servers that are good for them.

Of course, this assumes we can figure out some way to measure goodness.  Some 
combination of jitter and root dispersion will probably work.  But how bad is 
a dropped packet?


-- 
These are my opinions, not necessarily my employer's.  I hate spam.





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