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June 30th Leap Second Could Trigger Unexpected Issues
dkatana writes: On January 31, 2013, approximately 400 milliseconds before the official release of the EIA Natural Gas Report, trading activity exploded in Natural Gas Futures. It is believed that was the result of some fast computer trading systems being programmed to act, and have a one-second advance access to the report. On June 30th a leap second will be added to the Network Time Protocol (NTP) to keep it synchronized with the slowly lengthening solar day. In this article, Charles Babcock gives a detailed account of the issues, and some disturbing possibilities: The last time a second needed to be added to the day was on June 30, 2012. For Qantas Airlines in Australia, it was a memorable event. Its systems, including flight reservations, went down for two hours as internal system clocks fell out of synch with external clocks.
The original author of the NTP protocol, Prof. David Mills at the University of Delaware, set a direct and simple way to add the second: Count the last second of June 30 twice, using a special notation on the second count for the record. Google will use a different approach: Over a 20-hour period on June 30, Google will add a couple of milliseconds to each of its NTP servers' updates. By the end of the day, a full second has been added. As the NTP protocol and Google timekeepers enter the first second of July, their methods may differ, but they both agree on the time.
But that could also be problematic. In adding a second to its NTP servers in 2005, Google ran into timekeeping problems on some of its widely distributed systems. The Mills sleight-of-hand was confusing to some of its clusters, as they fell out of synch with NTP time. Does Google's smear approach make more sense to you, or does Mills's idea of counting the last second twice work better? Do you have a better idea of how to handle this?
The original author of the NTP protocol, Prof. David Mills at the University of Delaware, set a direct and simple way to add the second: Count the last second of June 30 twice, using a special notation on the second count for the record. Google will use a different approach: Over a 20-hour period on June 30, Google will add a couple of milliseconds to each of its NTP servers' updates. By the end of the day, a full second has been added. As the NTP protocol and Google timekeepers enter the first second of July, their methods may differ, but they both agree on the time.
But that could also be problematic. In adding a second to its NTP servers in 2005, Google ran into timekeeping problems on some of its widely distributed systems. The Mills sleight-of-hand was confusing to some of its clusters, as they fell out of synch with NTP time. Does Google's smear approach make more sense to you, or does Mills's idea of counting the last second twice work better? Do you have a better idea of how to handle this?
I understand the desire to change things, but putting some social media Share link in place of the Read More link goes against the kind of website Slashdot is.
Please restore the original layout. Thanks.
I understand the desire to change things, but putting some social media Share link in place of the Read More link goes against the kind of website Slashdot is.
Please restore the original layout. Thanks.
+1 - Mod parent up.
+2. In a Slashdot comment, we must add links and formatting by typing HTML by hand. You would therefore think we know how to copy and paste a web address from Slashdot to Facebook, if that's what we really want to do. We don't need an icon to do it for us.
If you're going to add icons, switch the places for Share and Comments. Put the Share link to the right of the heading. Put the Comments link at the bottom. To me it seems more logical that way, it puts the Comments link back where it was.
If the POSIX standards people had bothered to actually follow the existing SI and ITU standards back in 1988 when they were setting up their standard, this would not be an issue.
The ITU-R has outlined 4 methods for the future of UTC. Methods A1, A2, B, C1, C2, and D are from various delegations of the international assembly, and they are in serious disagreement with each other.
That's silly. There's no reason for it. Let's just sit down and come up with a new standardized method that covers all of these use cases.
#DeleteChrome
The way they changed the design is clickbait of sorts.
People trained their muscle memory to click that area to load more of the story or comments. Now they click and yell in frustration.
That's a really shitty way of luring people. Shame on you, Dice!
...gis sdrawkcab (usually not responding to ACs; don't bother posting as AC)
What's nonsense is locking civil time to atomic time. There would be no need for leap seconds if civil time simply remained linked to astronomical time, as it was for millenia.
Oh, and NIST - at least the person responsible for the leap second file they distribute (Judah Levine) - really has a very poor understanding of how leap seconds work. He's actually stated that "In the legal definition of UTC, a leap second is "forgotten" once it happens." That is, of course, completely incorrect. No wonder NIST wants to drop them, they don't understand them.
"National Security is the chief cause of national insecurity." - Celine's First Law