Comments on: Linus Torvalds explains distributed source control

By: Mark

Mark — Wed, 06 Jun 2007 08:07:57 +0000

Bzr (“bazaar”) is the revision control system we chose for the Ubuntu project, because of its perfect support for renames. By “perfect” I mean that you cannot break Bzr no matter how aggressively your community renames files and directories. One contributor can rename a directory, someone else can rename a subdirectory, and other people can rename files *and add* files in both directories, and then you can merge from all of them, and It Just Works.

Bzr was designed for multiplatform work, so it has the best support for Windows too (not a big issue for Ubuntu, but definitely an issue for upstreams).

Early versions of Bzr were slower than Git or Mercurial, but the performance is improving constantly, and Bzr now takes less than a second (“heartbeat time”) to do a status on a project of up to 5,000 files. I think the team is confident they will match Mercurial in performance without losing their advantages on renaming robustness. Commit is still slower on Bzr, but status is the key performance item from a usability perspective.

So, please add Bzr to your list of things people shoudl check out. bazaar-vcs.org.

By: Alec the Geek

Alec the Geek — Sun, 03 Jun 2007 20:18:46 +0000

Linux Poster Boy Talks about SCM…

Códice Software: Linus Torvalds on GIT and SCM
speech Linus Torvalds gave some days ago at Google, basically talking about GIT and Source Control Management
Codice Software have a nice blog entry about Linus’ presentation on Source Control Mana…

By: Nathan Neff

Nathan Neff — Wed, 23 May 2007 18:22:28 +0000

I’ve been checking out darcs, which is also a distributed source control tool, and it was easy to set up and work with.

I had a bit of a problem with the overzealous default filter (it didn’t import .class files, and I wasn’t able to get it to allow .class files). There was talk of it being slow. I tested darcs on a smaller “project”, it works fine for smaller projects.

Has anyone else experimented with darcs?

By: Alex Miller

Alex Miller — Sun, 20 May 2007 03:18:38 +0000

Also, I should mention that you will find links in Mark’s post to an evaluation that was done prior for Open Solaris, where Mercurial was chosen over bzr and git.

By: Alex Miller

Alex Miller — Sun, 20 May 2007 03:14:25 +0000

This is an interesting topic and I don't think you should miss the ruminations that have been going on in the Java world in the process of open-sourcing the JDK. Several key people have been blogging on the selection and conversion process for moving from Sun's internal TeamWare system to Mercurial (a distributed SCM). Most recently, check out: Mark Reinhold's recent entry and also the blogs from Kelly O'Hair and Martin Englund. Certainly, there has been some outcry from the Java public about not choosing Subversion but apparently Sun did not feel that it met the basic requirements. So, I would suspect that Mercurial (which I can't type for anything...arrghg) is going to be receiving a lot of attention in the near future. Maybe another one to consider. The blogs linked above contain a bunch more interesting links, The authors have other blog entries on these topics as well.

By: Todd Jordan

Todd Jordan — Sun, 20 May 2007 03:04:32 +0000

Best quote:
There are important differences between source control tools. I have heard it said that these are all “just tools” which don’t matter, you simply use whatever the local management felt like buying. That is wrong: making better tool choices will make your project better (cheaper, faster, more fun, etc.), making worse tool choices will make your project worse (more expensive, slower, painful, higher turnover, etc.)

The inertia of our current shops will carry us even past the newness and best practices being found today, until they are replaced by even better tools. Many shops won’t know the joy of tools like Git until it’s old news.

But I see hope against this inertia as the ‘old skoolrz’ age out and move up, and the next generation want to experiment more.
Thanks for the excellent and well thought out post.

By: Kyle Cordes

Kyle Cordes — Sat, 19 May 2007 16:48:00 +0000

I don’t have a recommendation, though I expect to have one eventually, after we have substantial experience on real projects.

SVK appears to be the most closely suited at being used as a better SVN client, though of course it’s much more than that. I have personally tested cloning an SVN project then committed changes back, with git and SVK. I am using bzr for another project, and it supports that kind of using with an svn plugin, but I haven’t tried that plugin yet.

By: Craig Buchek

Craig Buchek — Sat, 19 May 2007 16:33:15 +0000

I’m looking to move from Subversion to SVK or Bazaar (bzr) myself. Do you have any advice on which one to choose? I want to keep my Subversion mainline repositories on the web, but do offline development on my notebook.

By: Brian Gilstrap

Brian Gilstrap — Thu, 17 May 2007 15:16:07 +0000

I look forward to viewing the talk. But I also really like your statement about tools not being 'just tools'.

By: Dan Miser

Dan Miser — Thu, 17 May 2007 15:10:54 +0000

Thanks for that very complete post (and link), Kyle. You are always finding a way to push the envelope!

By: Mark Volkmann

Mark Volkmann — Thu, 17 May 2007 14:52:02 +0000

Maybe it’s just paranoia from using not distributed source control tools, but I think I wouldn’t feel like I had really checked in a change unless I checked it into a remote repository. Checking it into my local repository still leaves me open to losing code when my harddrive crashes. For this reason, the arguments that distributed tools are better because they “work offline” and “are much faster because they don’t have to go over the network very often” aren’t very appealing or comforting to me. However, the idea that my changes can be committed to a replicated repository is very appealing.

Adoption of distributed source control tools may be slow because most developers probably don’t perceive that there is a problem with their current tool.

I’d be interested in learning more about git. Hopefully someone will do a presentation on this at a local user group meeting soon.