[LEAPSECS] Google, Amazon, now Microsoft

[Steve Allen]

On Sun 2015-05-31T14:28:59 +0000, Poul-Henning Kamp hath writ:
> >But they have servers in multiple locations, so if they are running on the
> >local time zone they will not leap at the same time...
>
> Welcome to the (probably painful) world of "heuristic handling of
> leap seconds".

And it's not just Microsoft, and not just this next leap.

The APNIC APRICOT 2015 lightning talks were mentioned on LEAPSECS back
in March.  There was a talk about the handling of the 2012 leap second
and the desynch that happened among machines running NTP from
different servers.  Even with NTP the clock behavior in one stratum of
client was different from clocks in another stratum because
knowing "what time is it" is a measurement process.

The slides are at
http://www.slideshare.net/apnic/the-leap-second-is-coming-by-tomonori-takada-apricot-2015
The video of the talk is available on the APNIC channel on Youtube:
https://www.youtube.com/watch?v=E_AMR3ECIxQ&feature=youtu.be&t=51m
Starting at Minute 51.

In the case of Microsoft the disclaimer at the bottom of
https://technet.microsoft.com/en-us/library/cc773013(v=ws.10).aspx
still says W32Time cannot guarantee better than 1 to 2 seconds.

UCO/Lick knows that, even with the best available version of NTP, the
sloppy (or even lack of) hardware clock on some motherboards means
that some Windows systems cannot do better than 1 to 2 seconds.

Applications running on networks with these sorts of machines are
probably already robust against 1 to 2 second offsets because those
happen all the time, but that still means we cannot use the timestamps
from Windows for science.  According to the best rumors, the failure
of Qantas/Amadeus in 2012 was because of the 1 second offset between
machines.  And in 2012 the financial markets were not running, so
as PHK writes, this next leap should be very interesting.

--
Steve Allen                 <sla at ucolick.org>               WGS-84 (GPS)
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