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How Precision Time Protocol is being deployed at Meta

engineering.fb.com

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Re: How Precision Time Protocol is being deployed at Meta

#31

Post by benlivengood »

throw0101a wrote: post #9
CapmCrackaWaka wrote: post #6

Why do so many tech companies seem to be releasing “secret sauce” for free lately? I see a lot of posts lately detailing how inner production systems work at large companies, and while I’m grateful, I’m curious why the higher ups think it’s worthwhile to release this information.

> Why do so many tech companies seem to be releasing “secret sauce” for free lately? Is it really their "special sauce" though? Do these types of releases actually give away how these companies make money ? In this particular case, telling the world how to get to nanosecond levels of timekeeping doesn't really help any competitors take away Metabook's revenues or profits.

How FB and Google make money isn't secret either. They have a lot of people looking at their web pages and apps, they record a lot of prior interactions with the ads these people see, they train giant models in near-realtime to predict ad quality, serve the ads that maximize expected profits in an ad auction, and record the subsequent clicks, views, and attributed conversions to convince advertisers to keep spending.

Re: How Precision Time Protocol is being deployed at Meta

#32

Post by forrestthewoods »

throw0101a wrote: post #7

So they state: > One could argue that we don’t really need PTP for that. NTP will do just fine. Well, we thought that too. But experiments we ran comparing our state-of-the-art NTP implementation and an early version of PTP showed a roughly 100x performance difference: While I'm not necessarily against more accuracy/precision, what problems specifically are experiencing? They do mention some use cases of course: > Th…

> How many things need to worry the latency of signal travelling ~300mm?

Arguably every program? The slowest part of modern programs is memory access. L1 cache memory access is ~1 nanosecond and RAM is ~50 nanoseconds.

Is 49 nanoseconds a lot? No, if you do it once. Yes, if every line of code pays the price.

Re: How Precision Time Protocol is being deployed at Meta

#33

Post by capableweb »

thatfunkymunki wrote: post #10
epgui wrote: post #2

This is incredible. If I knew I'd be working on things like this (as opposed to optimizing ad revenue or "user engagement" by A/B testing button copy), I'd possibly consider working at Meta.

If this is the only thing stopping you, you should apply and tell the recruiter you would like to work in infra. People that don't want to work on product stuff don't get "roped into it", I know people who have worked at Meta/FB for years and have never touched user-facing code or ads stuff.

> Meta/FB for years and have never touched user-facing code or ads stuff

Does that really matter in the end? If you're against writing code for ads/optimizing for quick dopamine hits, is it really so different to be writing the code that shows the ads vs the code that sets up the infrastructure to serve the ads? Or even infrastructure to support the developers who write the code for the ads?

If you don't want to support the ad-driven internet, don't work for companies who's entire business model is extracting as much data from users as possible in order to show the "right" ads.

Re: How Precision Time Protocol is being deployed at Meta

#34

Post by bombcar »

CapmCrackaWaka wrote: post #6

Why do so many tech companies seem to be releasing “secret sauce” for free lately? I see a lot of posts lately detailing how inner production systems work at large companies, and while I’m grateful, I’m curious why the higher ups think it’s worthwhile to release this information.

It's an effective marketing campaign for "you should work here" - VERY effective.

And lots of this stuff is NOT secret sauce, it's basic business building-blocks that they need. It's not the advertising formulas.

I'm sure FAANG is very VERY happy that they can just run Linux everywhere and don't have to pay Sun or Microsoft a massive per-CPU fee for everything they do.

Re: How Precision Time Protocol is being deployed at Meta

#35

Post by epgui »

capableweb wrote: post #33
thatfunkymunki wrote: post #10

Earlier quoted context omitted.

If this is the only thing stopping you, you should apply and tell the recruiter you would like to work in infra. People that don't want to work on product stuff don't get "roped into it", I know people who have worked at Meta/FB for years and have never touched user-facing code or ads stuff.

> Meta/FB for years and have never touched user-facing code or ads stuff Does that really matter in the end? If you're against writing code for ads/optimizing for quick dopamine hits, is it really so different to be writing the code that shows the ads vs the code that sets up the infrastructure to serve the ads? Or even infrastructure to support the developers who write the code for the ads? If you don't want to supp…

Yeah that's exactly my concern!

I want to contribute to building cool things, and building a really cool component becomes much less inspiring if it's only used to steer nuclear missiles. (dramatic but not unreasonable example)

Re: How Precision Time Protocol is being deployed at Meta

#36

Post by maximinus_thrax »

CapmCrackaWaka wrote: post #6

Why do so many tech companies seem to be releasing “secret sauce” for free lately? I see a lot of posts lately detailing how inner production systems work at large companies, and while I’m grateful, I’m curious why the higher ups think it’s worthwhile to release this information.

There is no 'secret sauce' here. The real 'secret sauce' stays secret. The goal of articles such as this one is mainly recruiting, of the 'look at what we're doing here, you should totally want to work here' variety, and it is very effective.

Re: How Precision Time Protocol is being deployed at Meta

#37

Post by synaesthesisx »

zzixp wrote: post #16

I've been seeing a lot more of these Meta engineering articles on HN - I'm a fan! If you're writing them, keep up the great work!

Yes! I had no idea Meta actually invested in innovation/engineering like this. I always assumed most of their work was just in ad tech & "metaverse".

Re: How Precision Time Protocol is being deployed at Meta

#38

Post by yAak »

throw0101a wrote: post #7

So they state: > One could argue that we don’t really need PTP for that. NTP will do just fine. Well, we thought that too. But experiments we ran comparing our state-of-the-art NTP implementation and an early version of PTP showed a roughly 100x performance difference: While I'm not necessarily against more accuracy/precision, what problems specifically are experiencing? They do mention some use cases of course: > Th…

The way I read it: a larger "Window Of Uncertainty" impacts performance. Having a smaller WOU by using PTP gave them a 100x perf increase in their experiments with the commit-wait solution for "ensuring consistency guarantee."

I'm completely ignorant on the topic in general though... so I'm probably missing something. =)

Re: How Precision Time Protocol is being deployed at Meta

#39

Post by eastbound »

ElevenLathe wrote: post #21
throw0101a wrote: post #9

Earlier quoted context omitted.

> Why do so many tech companies seem to be releasing “secret sauce” for free lately? Is it really their "special sauce" though? Do these types of releases actually give away how these companies make money ? In this particular case, telling the world how to get to nanosecond levels of timekeeping doesn't really help any competitors take away Metabook's revenues or profits.

OTOH if there turns out to be some other way of making money on nanosecond timekeeping, then keeping it secret will help them get into that market before competitors can.

Unless they’re playing 4-D chess and the goal is to make competitors lose time implementing CAP theorem databases, nanosecond precision and React, while they’re pulling ahead.

Re: How Precision Time Protocol is being deployed at Meta

#40

Post by coolestguy »

synaesthesisx wrote: post #37
zzixp wrote: post #16

I've been seeing a lot more of these Meta engineering articles on HN - I'm a fan! If you're writing them, keep up the great work!

Yes! I had no idea Meta actually invested in innovation/engineering like this. I always assumed most of their work was just in ad tech & "metaverse".

That's why they are promoting themselves so much on HN now - to encourage talent to come to Meta
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