"He was such an iconic element of the early Internet"

January 20, 2024 7:27 AM

Inventor of NTP protocol that keeps time on billions of devices dies at age 85. Dave Mills created NTP, the protocol that holds the temporal Internet together, in 1985.

On Thursday, Internet pioneer Vint Cerf announced that Dr. David L. Mills, the inventor of Network Time Protocol (NTP), died peacefully at age 85 on January 17, 2024. The announcement came in a post on the Internet Society mailing list after Cerf was informed of David's death by Mills' daughter, Leigh.

Dr. Mills was one of the pioneers of the internet, the first chairperson of the Gateway Algorithms and Data Structures Task Force, the precursor to our modern Internet Engineering Task Force, responsible for many of the standards that make the internet interoperable, and, of course, inventor of the Network Time Protocol.

He has previously spoken to The New Yorker about NTP, and given lectures about his own history [yt] during the early days of the net.

If you have an internet thing, and it knows what time it is: that was Dave.

posted by lewiseason (52 comments total)

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posted by Mitheral at 7:41 AM on January 20

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posted by Songdog at 7:43 AM on January 20

Even if your device doesn't use NTP directly, there's a near 100% chance that the server it is getting its time from keeps its time in sync thanks to NTP.

One of the really neat things about the NTP daemon is that it doesn't just correct the current time, but it learns how to correct for your hardware clock's drift. This is very helpful when you lose network connectivity for a while or only have intermittent connectivity as standard. Plus, if the time delta between your local idea of the time and the actual time is small enough, it simply changes the rate at which your local clock ticks so that it gradually comes back into alignment with reality. Much better than just stepping the clock by some arbitrary amount, which can make certain software very unhappy.
posted by wierdo at 7:46 AM on January 20 [16 favorites]

Time sync is one of those things that seems like it shouldn't be that complicated. But when I first had to learn how to setup an NTP server I found out how wrong I was. And it's one of those foundational things that silently makes so much of the modern world possible.

Thank you Dave. Much respect.
posted by DrumsIntheDeep at 7:48 AM on January 20 [13 favorites]

it's one of those foundational things that silently makes so much of the modern world possible.

That is underselling it, I think. Almost every part of the modern connected world depends, often in extremely subtle ways, on his work.
posted by mhoye at 8:12 AM on January 20 [16 favorites]

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posted by jpziller at 8:14 AM on January 20

NTP was such an exciting thing for me when I learned about it in the early 90s. It seemed like magic! The Internet barely worked at all and here was a thing that was setting our clocks to within 100ms of true time. That's only improved over the years, it's easy to get < 1ms accuracy on a basic Linux box running chrony.

Here's the original NTP paper, or at least the one I recall reading.

Mills didn't just do technical work, he created a community. NTP is hugely successful today thanks to that. I interacted briefly with him and that community in 1999 when I did a survey of the NTP network. I remember him being patient and helpful. Also a bit professorly in telling me I would ask better questions if I read the research more carefully first. Advice I probably needed to hear at the time.

RIP, you made the Internet a better place.
posted by Nelson at 8:16 AM on January 20 [12 favorites]

I mean, if you know a veteran systems administrator or anyone I charge of a large, heterogeneous install base, ask them how they feel about legislated DST or timezone changes, and watch their eyes defocus for a moment while the question sinks in. Dr. Mills’ work keeps nightmares at bay that you don’t even realize exist.
posted by mhoye at 8:18 AM on January 20 [13 favorites]

Just don't mention leap seconds.
posted by Nelson at 8:20 AM on January 20

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posted by JoeXIII007 at 9:01 AM on January 20

Requiem aeternam dona ei, Domine, et lux perpetua luceat ei. Requiescat in pace.
posted by ob1quixote at 9:20 AM on January 20

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posted by May Kasahara at 9:21 AM on January 20

I am disappointed that none of the obituaries I could find mention a time of death.
posted by swift at 9:33 AM on January 20 [22 favorites]

I spent the morning diving down the rabbit hole of NTP server abuse by router and other companies, so this is especially poignant.
posted by adamrice at 9:50 AM on January 20 [3 favorites]

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posted by MonsieurPEB at 10:14 AM on January 20

I am disappointed that none of the obituaries I could find mention a time of death.

It’s complicated.
posted by mhoye at 10:14 AM on January 20 [20 favorites]

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posted by the_dreamwriter at 10:21 AM on January 20

Whenever I set up a new Linux install, I'm always happy to make sure it reaches out to the appropriate NTP server regularly. One of those protocols that Just. Works. Alhamdulillah.

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posted by rabia.elizabeth at 10:21 AM on January 20 [2 favorites]

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posted by LobsterMitten at 10:48 AM on January 20

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posted by humbug at 11:09 AM on January 20

One reason NTP Just Works in modern times is the NTP Pool. That's a volunteer project to provide reliable time servers, generally free of cost. I don't think Dave Mills was ever involved with it, but it's a testament to the design of NTP that it was relatively simple to set something like that up and have folks use it sensibly, even if some of the pool servers are unreliable occasionally.

The NTP pool is run by Ask Bjørn Hansen and has been running for 20+ years. It started as a response to the abuse problem adamrice mentions and while I'm sure the pool gets used improperly sometimes, at least there's a clear right way for device manufacturers to get the time now.

Microsoft and Apple also run major NTP servers that are the defaults for their operating systems. They've made a big difference too.
posted by Nelson at 11:20 AM on January 20 [6 favorites]

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posted by Token Meme at 11:57 AM on January 20 [1 favorite]

⏱️
posted by jzb at 12:02 PM on January 20 [6 favorites]

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posted by luckynerd at 12:16 PM on January 20

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posted by Tell Me No Lies at 12:27 PM on January 20

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posted by farlukar at 1:36 PM on January 20

Infrastructure ain't sexy, but it's so, so important. My hat is off to Dr. Mills.
posted by wenestvedt at 1:38 PM on January 20 [5 favorites]

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posted by estherbester at 1:40 PM on January 20

We're all standing on the shoulders of giants.

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posted by JoeZydeco at 2:07 PM on January 20 [4 favorites]

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posted by mmascolino at 2:25 PM on January 20

relevant xkcd

relevant tweet

Both, I’m willing to bet, inspired by Dave Mills and NTP.
posted by Ian A.T. at 3:11 PM on January 20 [4 favorites]

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posted by sammyo at 4:06 PM on January 20

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(I love Tom Scot’s “The problem with time and time zones “ for a quick summary of how much complexity is getting hidden away in this area. Computerphile also did a video about NTP and Mills.
posted by rongorongo at 4:07 PM on January 20 [4 favorites]

Time zones are God’s punishment for living on a round earth.
posted by foxfirefey at 4:33 PM on January 20 [1 favorite]

There'd be even more of them if we lived on a flat earth. That would be an NTP problem.
posted by mono blanco at 4:57 PM on January 20 [3 favorites]

With respect to the ntp pool, that is largely possible due to cheap GPS receivers to act as primary reference time sources. When ntp was being invented, GPS was still just a concept, and standard reference time came from atomic clocks. Having a connection to the national bureau of standards was how you got to be a reference ntp server. Now you can hook up with a local GPS receiver and be authoritative.
posted by Aardvark Cheeselog at 5:41 PM on January 20 [1 favorite]

If the timekeeper has died, what sort of gradually degrading reality will we now be living in and how long before complete time chaos has taken over?
posted by hippybear at 7:28 PM on January 20 [8 favorites]

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posted by evilDoug at 8:11 PM on January 20

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posted by detachd at 8:41 PM on January 20

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posted by quazichimp at 9:56 PM on January 20

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posted by oozy rat in a sanitary zoo at 11:04 PM on January 20

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posted by UhOhChongo! at 11:09 PM on January 20

On Thursday, Internet pioneer Vint Cerf announced that Dr. David L. Mills, the inventor of Network Time Protocol (NTP), died peacefully at age 85 on January 17, 2024.

Accessibility note:
* "Cerf and his wife Sigrid both have hearing deficiencies; they met at a hearing aid agent's practice in the 1960s,[18] which led him to becoming an advocate for accessibility." - Wikipedia
* "Mills was born with glaucoma. When he was a child, a surgeon was able to save some of the vision in his left eye, and he has always worked using very large computer displays. Around a decade ago, his vision began to fail, and he is now completely blind. " - The New Yorker
posted by pracowity at 1:59 AM on January 21 [8 favorites]

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posted by drworm at 7:12 AM on January 21 [1 favorite]

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posted by filtergik at 8:50 AM on January 21

Having a connection to the national bureau of standards was how you got to be a reference ntp server

Counterintuitively, the important part about running a time server isn't actually having a good time reference, but having a good frequency reference. A cesium reference standard is still way better than GPS for that. I'm not sure if it's still the case, but back in the late 90s and early 2000s, a surprising number of time servers used CDMA cell networks rather than using GPS directly. Not only is the network clocked using GPS, but they had their own backup rubidium standards at every site, just in case there was a GPS outage. CDMA-based cell networks require an extremely accurate frequency standard of the correlation between sites gets messed up and the network rapidly ceases to function.

Plus, one of the great things about NTP is that which I mentioned above. You only need a few super accurate clocks in the network, the rest of the time servers only need to have reasonably consistent clocks. An ovenized quartz oscillator is perfectly fine since it will be calibrated against a higher stratum server to eliminate whatever error in absolute frequency exists. You just don't want it randomly drifting.
posted by wierdo at 4:29 PM on January 21 [2 favorites]

I caught the DIY-GPS-stratum-1-server obsession a few years ago. Raspberry Pi in a small enclosure with a ublox GPS receiver doing PPS (pulse per second) and a cheap antenna.

Works pretty well, but the Ublox hardware is a real pain to configure (still haven't figured out how to enable the "static hold" filter on an 8th gen using ubxtool, which apparently I would need to patch as this requires editing a specific byte of CFG-NAV5; already set the dynamic model to stationary.) Best TDOP I can achieve on the Pi without that is around 0.5-0.6, but it varies up to 0.9 or so sometimes. It's not as tight as I had hoped, the Pi is certainly not the best tool for this.

Anyway, if I had to do it over I wouldn't bother, it's not got significantly less jitter than just finding a decent, close peer in the pool. Should be able to get within 10ms using the public pool.
posted by Rhomboid at 5:32 PM on January 21 [3 favorites]

That sounds like a fun project Rhomboid. Did you do anything special for an antenna? That's kind of tricky with GPS since it needs a clear view of the sky.
posted by Nelson at 5:42 PM on January 21

The antenna came with a generous length of cable, maybe 10 - 15 feet, but it was not necessary to do anything special to get it to receive. For the first year or so it was coiled up and laying near the Pi enclosure (indoors, on a shelf), not even placed with purpose. At some point I moved it around in the room trying to get a better signal but I have no idea if that actually helped. It's very hard to spot long term trends while waving a little plastic dingus in the air. I've never actually tried it in a window, come to think of it; the placement never worked out.
posted by Rhomboid at 6:02 PM on January 21 [1 favorite]

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posted by Tailkinker to-Ennien at 1:30 PM on January 22

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posted by a non mouse, a cow herd at 6:43 AM on January 23

It's very hard to spot long term trends while waving a little plastic dingus in the air.
I find this to be a universal truth.
posted by pracowity at 8:38 AM on January 23 [3 favorites]