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NTP at NIST Boulder Has Lost Power

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Re: NTP at NIST Boulder Has Lost Power

#91
post #45
post #37

Earlier quoted context omitted.

Step One of most disaster plans is not to create a second emergency.

But can't NTP server downtime cause a disaster?

If your application is so critical that NTP timing loss causes disaster and your holdover fails in less than a day and you aren't generating your own via gps, you are incompetent, full stop

Re: NTP at NIST Boulder Has Lost Power

#92
post #55

Earlier quoted context omitted.

If your computer was using it as your time server and you didn't have alternatives configured your clock my have drifted a few seconds.

I never checked it, but how much a typical's pc/server's clock does actually drift over a week or a month? I always thought it's well under a second.

I've seen some new ThinkPads lose a minute a month and others (the old ThinkPads) keep within a second of NTP over an entire year. It depends.

Re: NTP at NIST Boulder Has Lost Power

#93
post #39

Of the various internet .+P, NTP is one I never learned about as a student, so now I'm looking at its web page [1] by its creator David L. Mills (1938-2024). I've found one video of him giving a retrospective of his extensive internet work; he talks about NTP at 34:51 [2] and later at 56:26 [3]. [1] https://www.eecis.udel.edu/~mills/ntp.html [2] https://youtu.be/08jBmCvxkv4?si=WXJCV_v0qlZQK3m4&t=2092 [3] https://yout…

In [3] he mentions that one can use NTP to observe frequency deviations and use it as an early warning system for fire and AC failure. That really intrigues me. Can you actually? Has this ever been implemented?

I knew of some experiments in this space back in the late 1980s or early 1990s - but it was specifically with DECstation hardware that had terrible clocks (not used for alerting, just "this graphs nicely against temperature".) https://groups.csail.mit.edu/ana/Publications/PubPDFs/Greg.T... (PDF) 4.2.1 does talk about explaining local clock frequency changes with office temperature changes (because they overwhelm a clock-aging model) but it doesn't have graphs so perhaps they weren't clear enough to include (or just not relevant enough to Time Surveying.)

Re: NTP at NIST Boulder Has Lost Power

#96
post #5

Can anybody expand on the implications of this? Being unfamiliar with it, it's hard to tell if this is a minor blip that happens all the time, or if it's potentially a major issue that could cause cascading errors equal to the hype of Y2K.

I’d say everybody moving off NIST boulder NTP.

Re: NTP at NIST Boulder Has Lost Power

#97
post #5

Can anybody expand on the implications of this? Being unfamiliar with it, it's hard to tell if this is a minor blip that happens all the time, or if it's potentially a major issue that could cause cascading errors equal to the hype of Y2K.

Unix timestamp resets to zero.

Re: NTP at NIST Boulder Has Lost Power

#98
post #44
post #20

Earlier quoted context omitted.

Having clocks synchronized between your servers is extremely useful. For example, having a guarantee that the timestamp of arrival of a packet (measured by the clock on the destination) is ALWAYS bigger than the timestamp recorded by the sender is a huge win, especially for things like database scaling. For this though you need to go beyond NTP into PTP which is still usually based on GPS time and atomic clocks

Actually interesting to think about what UTC actually means and there is seems to be no absolute source of truth [0]. I guess the worry is not that much about the NTP servers (for which people anyways should configure fail overs) but the clocks themselves. [0] https://www.septentrio.com/en/learn-more/insights/how-gps-br...

Could you define an absolute source of truth based on extrinsic features. Something like taking an intrinsic time from atomic sources, pegged to an astronomic or celestial event; then a predicted astronomic event that would allow us to reconcile time in the future.

It might be difficult to generate enough resolution in measurable events that we can predict accurately enough? Like, I'm guessing the start of a transit or alignment event? Maybe something like predicting the time at which a laser pulse will be returnable from a lunar reflector -- if we can do the prediction accurately enough then we can re-establish time back to the current fixed scale.

I think I'm addressing an event that won't ever happen (all precise and accurate time sources are lost/perturbed), and if it does it won't be important to re-sync in this way. But you know...

Re: NTP at NIST Boulder Has Lost Power

#99

Earlier quoted context omitted.

could you list 3 things that you think are more important than the internet? (I know the internet is going to be fine; I just want to understand what you think ranks higher globally...)

I think it wont be affected by this but on the top of my head: - GPS - industrial complex that synchronize operations (we could include trains) - telecoms in general (so a level higher than the internet)

GPS uses the atomic clocks on the satellites though.

(Random search result from space force https://www.ssc.spaceforce.mil/Newsroom/Article/4039094/50-y... claims that cell phone tower-to-tower handoff uses GPS-mediated timing (only microsecond level though.)

Re: NTP at NIST Boulder Has Lost Power

#100
post #89
post #49

Earlier quoted context omitted.

Maybe this is the disaster plan: There's not a smouldering hole where NIST's Boulder facility used to be, and it will be operational again soon enough. There's no present need for important hard-to-replace sciencey-dudes to go into the shop (which is probably both cold, and dark, and may have other problems that make it unsafe: it's deliberately closed ) to futz around with the the time machines. We still have other…

There are many backup clocks/clusters that NIST uses as redundancies all around Boulder too, no need to even go up to Fort Collins. As in, NIST has fiber to a few at CU and a few commercial companies, last I checked. They're used in cases just like this one. Fun facts about The clock: You can't put anything in the room or take anything out. That's how sensitive the clock is. The room is just filled with asbestos. The…

Will the time it takes you to answer depend on the mass of the person asking?
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