All staff members, in preparation for leap second 2015, should watch a brief training on the other problems with time & timezones[1].
[1] https://www.youtube.com/watch?v=-5wpm-gesOY On Thu, Jun 25, 2015 at 12:05 PM Gabriel Wicke <gwi...@wikimedia.org> wrote: > Alex and Moritz, > > thank you for taking care of this. These leap seconds are a real pain in > the butt for time-based distributed systems, and I'm glad that we have a > plan in place. I hope the movement to abolish leap seconds > < > https://en.wikipedia.org/wiki/Leap_second#Proposal_to_abolish_leap_seconds > > > wins out in the end! > > On Thu, Jun 25, 2015 at 7:27 AM, Moritz Mühlenhoff <mor...@wikimedia.org> > wrote: > > > > * On the 1st of July we'll re-enable NTP in batches. System clocks will > > move forward by a second once NTP is started again, > > > > To clarify: By default, system time will move *backwards* one second. > > We just talked about this on IRC, so just for other's benefit: With NTP's > -x option we should be able to smear the adjustment (by slowing down the > system clock temporarily) until the leap second is incorporated into the > system time. This avoids non-monotonicity, which is important for systems > that use time to capture causality. It would be great to apply the > adjustment to all nodes of the cassandra cluster at once, so that their > clocks are being slewed in lock-step. > > Gabriel > _______________________________________________ > Wikitech-l mailing list > Wikitech-l@lists.wikimedia.org > https://lists.wikimedia.org/mailman/listinfo/wikitech-l _______________________________________________ Wikitech-l mailing list Wikitech-l@lists.wikimedia.org https://lists.wikimedia.org/mailman/listinfo/wikitech-l
