On Thu, Feb 6, 2020, 3:22 AM Tom Van Baak <[email protected]> wrote:
> Hi Hal, > > It's 2020. How on earth can NTP still not implement UTC correctly, in all > cases? Or is it a fundamental NTP design flaw? > Design flaw. NTP time stamps can't encode a leap second. It can therefore never really work in all cases. We are left with what hack do you want to do today. > The Z3801A issue doesn't sound like an NTP problem. This is a known legacy > Z3801A f/w or Motorola Oncore problem, yes? Maybe also affected by one or > even two GPS WNRO problems buy now? > Known past issues are likely future problems. 40 years in software has taught me that we do not always learn and apply the lessons of the past. Every 5-10 years we swap out the coders that learned them for newer, cheaper labor. Or there are new players in a niche that have more hubris than tribal knowledge. This guarantees bugs will repeat. Warner /tvb > > On 2/6/2020 1:41 AM, Hal Murray wrote: > > tvb said: > > There's no ambiguity. Those are just bugs. No software should depend on more > than 1 month notice of a leap second and no software should be fooled if the > notice is months or even years in advance. > > There are plenty of quirks in ntp code along that line. The APIs don't have > an explicit when. The NTP-Kernal API for leap-pending is leap-tonight. You > have most of the next day to turn it off. The leap-pending on the wire is > leap-at-the-end-of-this-month. > > I fixed a bug in the Z3801 driver by ignoring a leap pending unless it was > June or December. It's a hack, but it gets the job done and the code wasn't > setup to ask it when the leap would happen. > > > tvb said: > > If you're writing a FAQ or best practices guide stay in touch. I have a > semi-technical leap second report in the works. UTC is actually very simple; > but it's been complicated by untold levels of bad assumptions, bad > execution, and bad prose. > > Are you going to say anything about POSIX? > > > > > _______________________________________________ > LEAPSECS mailing list > [email protected] > https://pairlist6.pair.net/mailman/listinfo/leapsecs >
_______________________________________________ LEAPSECS mailing list [email protected] https://pairlist6.pair.net/mailman/listinfo/leapsecs
