MIroslav,
The select algorithm was changed in a very minor way to conform
precisely to the formal assassin quoted in my previous message. It
probably has very little practical significance. After all, the old
algorithm has been going strong for nineteen years.
Dave
Miroslav Lichvar wrote:
On Wed, Jan 05, 2011 at 09:23:59AM +0100, Terje Mathisen wrote:
Two servers which don't overlap, and a third which overlaps (partly)
both of them:
<----> <----> server A and B
<---> server C
In this particular situation C must be a survivor, but since it
overlaps both A and B with an identical amount, there is no way to
determine if (A^C) or (B^C) is the best interval to pick.
The select algorithm doesn't care how much they overlap. Recent
ntp-dev versions work as described on the select.html web page, so the
intersection interval will be equal to C and all three sources will
pass. Older versions worked also with centers of the intervals and as
the centers of A and B are lying outside the intersection interval, C
would be the only truechimer.
I'd be curious to hear why that approach was dropped.
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