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by withinboredom 796 days ago
That’s a rather specific edge case and I can’t think of any sync that handles it relatively well except for BitTorrent. At that point you are limited by so many things, it’s not worth optimizing for because all the error cases you have to handle (inode exhaustion, network limits, etc).

99.99% of the time only a single file changes at a time, which is the use case here.
2 comments
al_borland 796 days ago
Is it really an edge case these days? A user’s very first sync is likely to be the largest one, to seed all the data into the could. That could easily be thousands of files.

Installing on a desktop, laptop, and mobile device would bring 3 clients into the mix right away.

So the user’s first use is likely to be one of the more complex operations, and the one they absolutely needs to work, as a failure here will lead to the user looking elsewhere for a solution.

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withinboredom 796 days ago
> A user’s very first sync is likely to be the largest one, to seed all the data into the could.

You are almost guaranteed that the first sync results in zero conflicts. It's just a mass-upload. Even if you bring other clients in, there is still a very low chance and "last-one-wins" is a pretty decent policy for who gets the original filename and then other gets a " (copy)" suffix or something. Doesn't really matter as long as it's documented and intuitive.

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imclaren 796 days ago
FWIW having built a sync service I can tell you that this is an issue in practice, and you have to test for these differences in any event.
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withinboredom 796 days ago
My point is that for a weekend PoC that you want to use for yourself… it’s rather a non-issue. Further, you need to create a lot of primitives before you can even tackle the problem correctly, so initially, it is an unsolvable problem until you have those primitives.
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imclaren 796 days ago
Hmm the macOS photos folders have this many files so I’m not sure it’s an edge case to sync this many files between at least 2 clients. And the issues you mention are real even when syncing relatively static large folders.

But you’re right that there are many such error cases to handle if you want a real iCloud / Dropbox alternative.

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