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Re:Cloud Spanner is now production-ready by hoschicz on Tuesday May 16, 2017 @02:01PM (#14351768)
This is basically impossible: for strong consistency, you need very accurate clocks. Google installs GPS clocks in its data centers.

Also Bigtable, Spanners predecessor, is not open source too.

Re:Cloud Spanner is now production-ready by cormacrelf on Tuesday May 16, 2017 @02:06PM (#14351821)
Well, that's how Spanner's consistency works. CockroachDB uses a hybrid vclock/wall clock solution that's possibly going to be tuneable to just clocks. https://jepsen.io/analyses/cockroachdb-beta-20160829
Re:Cloud Spanner is now production-ready by atemerev on Tuesday May 16, 2017 @02:17PM (#14351948)
Every GPS chip in every GPS-enabled device includes the clock — by design, it can't work without it. So perhaps it is possible to quickly hack something from a cheap Android phone placed somewhere near the window?
Re:Cloud Spanner is now production-ready by timelol on Tuesday May 16, 2017 @03:42PM (#14352626)
Using GPS as your time source is a fabulously good way to trash your entire database during a leap second. See this paper for a discussion on how essentially everybody but Google gets this wrong: http://crin.eng.uts.edu.au/~darryl/Publications/LeapSecond_c...
Re:Cloud Spanner is now production-ready by mastax on Tuesday May 16, 2017 @09:39PM (#14354920)
GPS time does not have leap seconds: http://www.oc.nps.edu/oc2902w/gps/timsys.html

> GPS Time is a uniformly counting time scale ... The word "uniformly" is used above to indicate that there are no "leap seconds" in this time system.

> The GPS message contains information that allows a receiver to convert GPS Time into Universal Time

In fact the article you linked corroborates this, because they used GPS time to show how inaccurate NTP servers are.

Re:Cloud Spanner is now production-ready by nickpsecurity on Tuesday May 16, 2017 @03:07PM (#14352345)
That was sams idea I had. I found that SparkFun even had a guide on it:

https://www.sparkfun.com/pages/GPS_Guide

Re:Cloud Spanner is now production-ready by detaro on Tuesday May 16, 2017 @03:09PM (#14352363)
Better resources: http://www.satsignal.eu/ntp/Raspberry-Pi-NTP.html

https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts (I don't understand a lot discussed there, but many interesting links and info about current deals to be found)

There also are differences between the quality of the timing output of different GPS modules, with some being optimized for timing applications (as opposed to location finding)

Re:Cloud Spanner is now production-ready by nickpsecurity on Tuesday May 16, 2017 @03:46PM (#14352655)
Appreciate it as I am wanting timing-focused ones.