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> Google probably only provides stats about growth (like "500 hours of video are uploaded to YouTube every minute") because the total number of videos is so lar
by slver 5y ago
> Google probably only provides stats about growth (like "500 hours of video are uploaded to YouTube every minute") because the total number of videos is so large, it's an unknowable amount.
I can totally see it being non-trivial to count your videos, which is a funny problem to have. But I doubt it's unknowable. More like they don't care/want us to know that.
- nine_k 5y agoQuite likely they have a good approximate number. But knowing the exact number can indeed be hard. It would take stopping the entire uploading and deletion activity. Of course they may have counters of uploads and deletions on every node which handles them, but the notion of 'the same instant' is tricky in distributed systems, so the exact number still remains elusive.
- iainmerrick 5y agoIt’s not just tricky and elusive, I think it’s literally unknowable -- not a well-defined question. Like asking about the simultaneity of disconnected events in special relativity.
- zodiac 5y agoYou can modify the question to be well-defined and not suffer those measurement problems, eg "the total number of videos uploaded before midnight UTC on 2021-04-29"
- suprfsat 5y agoInteresting, I wonder if a distributed database could be developed to consistently answer queries phrased in this way.
- hderms 5y agoSeems like it would either need to be append only or have some kind of snapshot isolation
- mmcconnell1618 5y agoGoogle Developed Spanner which is a globally distributed database that uses atomic clocks to keep things synchronized: https://static.googleusercontent.com/media/research.google.com/en//archive/spanner-osdi2012.pdf https://static.googleusercontent.com/media/research.google.c...
- zodiac 5y agoI think the Chandy-Lamport snapshot algorithm tries to do something like this for all distributed systems (in their model, and it tries to get any consistent snapshot, not allowing you to specify the "time"); not sure if it's actually useful IRL though
- nine_k 5y agoAll these nodes are in the same light cone, so we theoretically can stop all mutation and wait for the exact final state to converge to a precise number of uploaded videos. But the question of the precise number of videos before that moment is indeed ill-defined.
- iainmerrick 5y agoYou can theoretically stop all mutation, but the users might start to complain!
- saalweachter 5y agoI read "an unknowable amount" as "a meaninglessly large number to our monkey brains". It's like knowing the distance to the Sun is 93 million miles. The difficulty there isn't that measuring the distance from the Sun to the Earth exactly is hard, although it is, or that the distance is constantly changing, although it is, or that the question is ill-defined, because the Earth is an object 8000 miles across and the Sun is 100 times bigger, and what points are you measuring between? The distance is "unknowable" because while we know what "93 million miles" means, it's much harder to say we know what it "means". Even when we try to rephrase it to smaller numbers like "it's the distance you could walk in 90 human lifetimes" is still hard to really feel beyond "it's really really far." Likewise, does it matter if YouTube has 100, 1000, or 10,000 millennia of video content? Does that number have any real meaning beyond back-of-the-envelope calculations of how much storage they're using? Or is "500 years per minute" the most comprehensible number they can give?