On Tue, Jan 3, 2017 at 6:35 AM, Rob Seaman <[email protected]> wrote: > And Steve is discussing a specific legacy telescope.
That rather sums up the situation today with software. We have a specific legacy standard called POSIX that's causing all kinds of issues that pop up when you least expect it (taking out DNS server, that's impressive), but there's no heir apparent to the standard, and no history of willingness to change the standard to allow it to properly model the current reality. Sure, it's just this bizarre interface that we have to cope with, and it should just work by default. But it doesn't. And that's before we get to the unspecified behavior in the SQL standard or any of a large number of other standards and APIs both great and small that punt on the issue entirely. So instead of having this one telescope in the corner that's old and ironically has issues with leap seconds with the rest of the fleet working great and having high confidence the fleet will work great, the situation with software is rather different. Here the bits of software that work right on purpose are rather the rare exception than the rule. The rest of the 'fleet' of software applications may or may not handle the leap second correctly, which may in turn cause problems great or small (or no problems at all). The issue here is that it's hard do audit to know that it all works, hard to detect issues before the failure and extensive testing of every single bit of code across the leap second is prohibitively expensive. So even before we get to "should work" or "should model reality" we are confronted with a situation where we know that they don't, have lots of examples of issues around them and such a general fear of leap seconds causing something to go wonky we paper over it by introducing a frequency error and hoping for the best since it breaks the fewest number of things, at least as studied at Google and other places. Such a permanent and ongoing impedance mismatch can not end in a happy place. So Rob and I can argue about what should happen, but I do know what does happen and will continue to happen unless something radical changes. > There are subtleties to timekeeping. Removing leap seconds wouldn’t remove > the subtleties, rather it would promote them to significantly more > importance, perhaps “breaking” even more software and systems. I suspect strongly, based on two decades of fixing bugs large and small with leap seconds, that vastly more software will behave correctly than badly by simply removing them. Time will no longer go backwards, have a large step, or other weirdness that systems with leap seconds and faulty software experience today. Given the rise of smeared leap seconds to paper over it, I think that lots of people have come to this same conclusion (mostly for reasons that have been discussed at length). Warner _______________________________________________ LEAPSECS mailing list [email protected] https://pairlist6.pair.net/mailman/listinfo/leapsecs
