[LEAPSECS] How good could civil timekeeping be?
seaman at noao.edu
Fri Feb 15 08:35:46 EST 2008
> 3.The only thing worse than generalizing from one example
> is generalizing from no examples at all.
Right. Which is why you invest time and money in seeking out (or
eliminating) possible examples. I have access to examples of
astronomical software (and also have experience from having performed
our Y2K inventory). As we've discussed far too many times, changing
UTC will definitely require changing astronomical software extensively.
Will there be similar extensive changes required to most communities'
software or system assets? Unlikely. Will subtle changes (the sort
that show up dramatically when least expected) be required? Unknown
until an inventory is performed. I don't have access to software
systems for air traffic control, or airframe platforms themselves, or
for railroads (the ancient poster child for synchronizing time), or
pipelines (with similar timezone spanning networks), or communications
(the poster child for ooh! those 'orrible leap seconds), or...
Has anybody attempted an inventory for any of these classes of
systems? Or did the apparent non-event of Y2K wrongly convince
managers and technologists that nothing could possibly go wrong? Do
the folks agitating to change UTC even know comp.risks exists?
What about risks emergent from diverging interpretation of the new
standard? Will all carriers and vendors be on the same page regarding
UTC as static offset from TAI and the current meaning of UTC as an
approximation of mean solar time?
A few of us have also been following the NTP saga. NTP should be
blind to a cessation of leap seconds. Should be. Has anyone tested a
sizable subnetwork of diverse servers? For Y2K I set a server's clock
forward by eleven years for several years before the gratifyingly
undramatic event. What tests at all have been done to show that
modifying the UTC standard behind nearly every clock on the planet
(many predating NTP still in operation in industries like - say -
nuclear energy) - that making such a modification won't break
Please don't tell me again how good system engineering practices
aren't needed here. Please, with this change looming, please tell me
someone, anyone, has grepped for the string "DUT1" in the source for
any one of the systems mentioned above.
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