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About merging (I'll get back to the other bit later): if I want to push my change, I already regularly encounter the situation where git tells me: you are not u

About merging (I'll get back to the other bit later): if I want to push my change, I already regularly encounter the situation where git tells me: you are not up to date, even if I pulled say 15 minutes ago. So I have to fetch and rebase before I can push. Even if that doesn't require manually solving any merge conflicts (and I think I have to in about 1/4th of the cases), it takes a bit of time. In that bit of time another developer can push a commit. If that already happens on occasion with 10 developers, I imagine it becomes very problematic with 1000 developers on the same repo. Of course you effectively organise your repos in a 'tree' like e.g. happens with the Linux kernel, but, well, then you again have many repos. One per component that has someone responsible for signing off on them. It reduces the amount of people committing to each specific repo, but in the end, it's still many repos. So that's not 'one monolithic repo' in my book.

teraflop 11y ago
Still, that's a limitation of the specific tools and the way you're using them, not a fundamental problem with monolithic repositories. You're running into problems because you have multiple people all trying to push to the same branch, and Git errs on the side of extreme caution rather than creating a merge that you didn't specifically request. If you use merge requests instead, as supported by Github/Gitlab, you don't get blocked by other people's commits. (Actual merge conflicts are an orthogonal problem. They'll happen whenever you have multiple people editing the same code, regardless of what VCS you use or how it's organized.) The Linux kernel example is a bit of a tricky one. Yes, kernel.org hosts a lot of repos, but they're all different versions of the same codebase. They have a common commit ancestry, and commits get merged from one to another. So they're not really separate modules in the sense that we're talking about; they're more like namespaces that each contain a set of branches.
- Confusion 11y ago
  I guess it comes down to organisational style. Using merge requests requires some benevolent dictator (poor sod?) to perform the merges. For us, if your commit is approved in Gerrit, it's your task to merge it. If some other commit was merged in between, you have to rebase, possibly solving merge conflicts. So guess that with a monolithic repo, that wouldn't scale, but it could be made to scale by appointing someone to perform the merge requests. I'm not sure I would like to be that person...
  - Mathiasdm 11y ago
    I helped set up such a system for a few hundred developers. We had an 'automated Linus Torvalds', which did the merge, and aborted whenever a file was changed on both sides of the merge. In the good case (almost every time), there were no conflicts, and the merge went fine (we had unittests, builds and regression tests as extra checks in our CI system). In the bad case, the developer request was rejected and the developer was told to rebase or merge his code on his own, so the merge issues would be handled.

teraflop 11y ago

Still, that's a limitation of the specific tools and the way you're using them, not a fundamental problem with monolithic repositories. You're running into problems because you have multiple people all trying to push to the same branch, and Git errs on the side of extreme caution rather than creating a merge that you didn't specifically request. If you use merge requests instead, as supported by Github/Gitlab, you don't get blocked by other people's commits. (Actual merge conflicts are an orthogonal problem. They'll happen whenever you have multiple people editing the same code, regardless of what VCS you use or how it's organized.) The Linux kernel example is a bit of a tricky one. Yes, kernel.org hosts a lot of repos, but they're all different versions of the same codebase. They have a common commit ancestry, and commits get merged from one to another. So they're not really separate modules in the sense that we're talking about; they're more like namespaces that each contain a set of branches.

Confusion 11y ago
I guess it comes down to organisational style. Using merge requests requires some benevolent dictator (poor sod?) to perform the merges. For us, if your commit is approved in Gerrit, it's your task to merge it. If some other commit was merged in between, you have to rebase, possibly solving merge conflicts. So guess that with a monolithic repo, that wouldn't scale, but it could be made to scale by appointing someone to perform the merge requests. I'm not sure I would like to be that person...
- Mathiasdm 11y ago
  I helped set up such a system for a few hundred developers. We had an 'automated Linus Torvalds', which did the merge, and aborted whenever a file was changed on both sides of the merge. In the good case (almost every time), there were no conflicts, and the merge went fine (we had unittests, builds and regression tests as extra checks in our CI system). In the bad case, the developer request was rejected and the developer was told to rebase or merge his code on his own, so the merge issues would be handled.