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Comment by dmoy | Hacker News Reader

Google doesn't use perforce anymore. It's been replaced with Piper, you can read about it in articles from about 2015 or so. Perforce didn't scale enough. I guess it's not clear to what extent Piper is a layer of infrastructure on top of perforce or actually a complete rewrite? I was never super sure. The articles appear to imply way more than a layer on top...

You are exactly right that git doesn't scale though, go see the posts on git that Facebook's engineers made while trying, only to be met with replies to the extent of "you're holding it wrong, go away, no massive monorepo here", at which point they made it work with mercurial instead. Good read though, lot of good technical details. Can't find the link at the moment though :(, but it was from somewhere around 2012-13 ish.

Edit: here, looks like the original thread is deleted but here's the hn pointer: https://news.ycombinator.com/item?id=3548824

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There's nothing wrong with saying "you're holding it wrong" if they're holding it in a way clearly contrary to the solution design. I don't fit in a toddler's car seat and if I tried, it's clearly my fault and not the seat engineer's. I doubt they'd want to accept my changes that would make it work worse for toddlers either.

Sure, if you don't care about people actually using your stuff you can ignore their requests. But Facebook and Google are now working on Mercurial rather than git, and Mercurial actually cares about ease of use (whereas git seems to revel in its obtuseness) and the Mercurial folks are looking at rewriting it, or parts of it in Rust to improve performance, which has always been the major issue.

If all those things continue I think the only reason to use git over hg would be github. How long until they decide to support Mercurial too and people abandon git?

> Sure, if you don't care about people actually using your stuff you can ignore their requests.

Yes. End of story. People will abandon things that don't support them for things that do and those that want to continue using something that fits their application will do so. Nothing to see here; we get it, you don't like git -- don't use it if it doesn't fit your needs. However, don't expect those who do like it to go out of their way in a way they don't want to please you. Just because there is a community developed around something and that something is open source does not mean they are required to accept whatever patches come their way -- often the best projects know what to keep out as much as what to let in. In this case, the git community has decided it doesn't want to do those things; more power to them.

>> Sure, if you don't care about people actually using your stuff you can ignore their requests.

I think you nailed the problem with Git here: it was created by one guy to support his pet project and as long as it works well for him all the other feature requests are low priority.

Agree completely, git is just not the tool for the job, the original thread (which I still can't find, gah), makes that pretty clear.

Working gmane link: http://permalink.gmane.org/gmane.comp.version-control.git/18...

Edit: scratch that, that works but has no threading. Take two.

These work:

http://git.661346.n2.nabble.com/Git-performance-results-on-a...

http://www.spinics.net/lists/git/msg173931.html

Google replaced piper with mercurial

https://opensource.googleblog.com/2017/03/dispatches-from-la...

That article doesn't claim that. It only claims that mercurial is used within Google.

Actually that says they are working on improving Mercurial to the point where they can use it.

Mercurial (with lots of extensions) sits on top of Piper at Google. It doesn't replace it.

I thought it was Facebook that did the mercurial thing: https://code.facebook.com/posts/218678814984400/scaling-merc...

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