Google turns on free public NTP servers that SMEAR TIME Google's turned on a set of public network time protocol (NTP) servers. You'll find the servers at time.google.com – which resolves to 216.239.35.0, a rather less pretty IP address than the 8.8.8.8 and 8.8.4.4 Google uses for its public domain-name system (DNS) servers. There's also time2.google.com at 216.239.35.4, time3. at …
I read about Google's approach some time ago, and for non-sub-second-critical apps it's a better solution than stepping by 1 sec. If you do need the sub-second stuff then TAI is the way to go. Of course, even things like HFT need to ultimately tie to real-world time but it's much more important to have a unique time ordering of transactions (no, relativity doesn't (yet) apply!) and the reference back to real-world time can be done after the fact from logs, e.g. when litigation requires it.
I've configured my home network now to have two internal NTP servers referenced to the Google ones & then everything else talks to them. I'll see what happens at New Year, probably set up a client with logging on & talking to NPL or Linx.
The article reads as if its a "new Google thing", which it isn't.
As long as its done to the standards and everyone follows the same standard, then there should be no problem here. RFC5905 defines NTP4 which includes handling of leap time.
I agree with the other posts stating that this should come from the reference clocks out,
This is a bad idea. Google are free to use whatever system they like internally, but all public-facing NTP servers should agree. Google is deliberately making its servers give the wrong time for 20 hours. If someone uses a mix of Google and non-Google NTP servers for their time then the results will depend on which version of time is in the majority in their list.
Our Linux servers encountered synchronization issues during the last leap second. We were using NTP to sync to the NTP pooled servers as well as google smeared servers. Needless to say on the day, Linux rejected both time sources. Moral of the tale - do not sync to both at the same time! See:
http://timetoolsltd.com/information/public-ntp-server/
The problem is we are using an artificial time constant, the second, to measure a variable time activity, the Earth year.
Just go back to the old system of defining a second based on a fraction of a year. Then all that needs to be done is agree annually the length of the second that will be used next year to keep us on track.
It's that old computing problem of using a data index pointer as a real world definer.
Problem is, the second has transcended the year, and an exact measurement of the second is necessary for various scientific and non-scientific purposes. Like it or not, the second is not relative to the year anymore. It's now relative to the speed of light, which IS constant in a vacuum and can apply extraterrestrially as well.
The Register 
Biting the hand that feeds IT
Copyright. All rights reserved © 1998–2024
