Skip to main content

Some thoughts on Git vs complexity


I originally wrote this in the Git For Human Beings mailing list. The thoughts are stolen from Rich Hickey's Simple Made Easy talk. (Matthew McCullough commented the same parallel the same day, but I think his timestamp was a few hours afterwards). I wanted to tweet about it, but it ended up being a whole post, as I'm trying to gather my thoughts on it for my next Git talk.

There's simple stuff, and there's easy stuff.

Simple means the opposite of complex. Easy, on the other hand, means it's very close to the stuff you already know. Git is "simple" but hard. Subversion is "easy", but eventually complex.

Git is *a lot* of features in one tool (think of the 100+ git plumbing commands). Each feature is simple, but learning to use them together is good bit of work. As soon as you've understood the model and you get that Eureka-moment, the tool never fails you, and you find it more and more fun to use the more you learn. (This is why there are so many git enthusiasts, I reckon.)

Subversion has a very limited set of features.It also turns awfully complex when you want to do stuff like merging. Actually the more I learned about Subversion, and the more I used it, the more frustrating I found it.

Why is Subversion complex?

- Because the stuff on the server is something different from what you have locally. Your local checkout is just a thin skin. All the interaction goes over the network with a really thin and crappy API. It’s like reading a book using binoculars. The same information is there, but it’s horrible to get at it.

- Everybody is tangled together using the same repository. People start making mistakes like committing without updating first. Everyone mis-use trunk as their own sandbox. This is complexity too (everything in one bucket).

- It mixes together committing, and pushing the changes to central. A commit should do one thing, and one thing well, and the reasoning should be in the commit message. Some are refactorings, others are feature-changes.

- Because branches are completely disconnected - there’s nothing that ties them together, except being a lot like each other. That’s how merging in Subversion works: “I assume that these two directories will be very similar”, and if they aren’t, BOOM.

Git, on the other hand, is simple: It all boils down to being three kinds of objects in a graph (commits, blobs, trees), and the rest of it are algorithms that work this data-structure.
Labels:

Comments

  1. Christian Schlichtherle18/11/11 18:02

    And then there is Mercurial, which does the same thing as Git, but apparently is a lot easier, which is why I would never use Git unless forced to. ;-)

    ReplyDelete
  2. Thomas Ferris Nicolaisen 18/11/11 23:50

    Hi Christian, thanks for commenting!

    Yeah, I think Mercurial retained a much more user-friendly interface from early on. The last two years it seems like Git has caught up a lot on the user-friendliness, while Mercurial has added a lot of features inspired by git.

    I had a nice discussion with Martin Geisler (Mercurial committer) at a conference earlier this year, and we pretty much arrived at that you can do anything in Mercurial that you can do with Git (minus some features of the git reflog, I think).

    Performance-wise, they're as good as equal.

    I ended up focusing on Git because of the SVN-interoperability being better at what I was trying to do at the time. I wouldn't mind switching to Mercurial if the circumstances were different, but now it seems like Git has the lead "out there".

    Is Mercurial easier than Git? I'd say yes, because the branching model is a bit easier to grok coming from centralized VCS. Is it simpler than Git? I'd say it's about the same..

    ReplyDelete
  3. Sam Livingston-Gray27/11/11 07:37

    Interesting. I ran across this tangentially (I wrote a site based on my experiences trying to learn Git, and was vanity-surfing for links to it, and noticed this at http://coder.io/tag/git). That's a really useful distinction (simple vs. easy) that I'll have to try to incorporate into my own thinking, so thanks for that!

    You're absolutely right to place Git in the "simple but hard" category. I spent my first year or two flailing around, cargo-culting incantations, and generally wasting a lot of time because I didn't grok the model. Unfortunately, while there are a lot of Git enthusiasts, the number of people who seem to be able to effectively teach others how to experience the Git Epiphany is... rather smaller. ;>

    Feel free to steal anything you find useful from my site (http://think-like-a-git.net), and I'd be happy to compare notes sometime.

    Cheers,
    -Sam

    ReplyDelete
  4. Thomas Ferris Nicolaisen 27/11/11 15:17

    Hi Sam, thanks for commenting!

    I'm already a big fan of your Git guide, came across it some time ago. I really appreciate the style of it, and how it's aimed at beginners. Thanks for creating it!

    ReplyDelete
  5. Christoph Baudson1/12/11 10:41

    Thanks for sharing your thoughts, as a git novice I appreciate them. However, I found your use of "simple" versus "complex" somehow confusing. I think Jurgen Appelo has found a helpful interpretation of these terms. Maybe you like it as well :-) http://www.noop.nl/2010/09/simplicity-a-new-model.html

    ReplyDelete
  6. Thomas Ferris Nicolaisen 1/12/11 23:08

    Thanks for commenting Christoph!

    Yeah, I could have tried to write a clearer message, but this post was a bit more thinking-out-loud-writing :)

    Appelo's model is interesting. Thanks for the pointer!

    ReplyDelete
  7. Hayes Chan26/2/13 05:27

    The last two decades it seems like Git has captured up a lot on the user-friendliness, while Sudden has included a lot of functions motivated by git.

    ReplyDelete

Post a Comment

Popular posts from this blog

Open source CMS evaluations

I have now seen three more or less serious open source CMS reviews. First guy to hit the field was Matt Raible ( 1 2 3 4 ), ending up with Drupal , Joomla , Magnolia , OpenCms and MeshCMS being runner-ups. Then there is OpenAdvantage that tries out a handful ( Drupal , Exponent CMS , Lenya , Mambo , and Silva ), including Plone which they use for their own site (funny/annoying that the entire site has no RSS-feeds, nor is it possible to comment on the articles), following Matt's approach by exluding many CMS that seem not to fit the criteria. It is somewhat strange that OpenAdvantage cuts away Magnolia because it "Requires J2EE server; difficult to install and configure; more of a framework than CMS", and proceed to include Apache Lenya in the full evaluation. Magnolia does not require a J2EE server. It runs on Tomcat just like Lenya does (maybe it's an idea to bundle Magnolia with Jetty to make it seem more lightweight). I'm still sure that OpenAdvant...
6 comments
Read more

Encrypting and Decrypting with Spring

I was recently working with protecting some sensitive data in a typical Java application with a database underneath. We convert the data on its way out of the application using Spring Security Crypto Utilities . It "was decided" that we'd be doing AES with a key-length of 256 , and this just happens to be the kind of encryption Spring crypto does out of the box. Sweet! The big aber is that whatever JRE is running the application has to be patched with Oracle's JCE  in order to do 256 bits. It's a fascinating story , the short version being that U.S. companies are restricted from exporting various encryption algorithms to certain countries, and some countries are restricted from importing them. Once I had patched my JRE with the JCE, I found it fascinating how straight forward it was to encrypt and decrypt using the Spring Encryptors. So just for fun at the weekend, I threw together a little desktop app that will encrypt and decrypt stuff for the given password...
Post a Comment
Read more

The Git Users Mailing List

A year ago or so, I came across the Git-user mailing list (aka. "Git for human beings"). Over the year, I grew a little addicted to helping people out with their Git problems. When the new git-scm.com webpage launched , and the link to the mailing list had disappeared, I was quick to ask them to add it again . I think this mailing list fills an important hole in the Git community between: The Git developer mailing list git@vger.kernel.org  - which I find to be a bit too hard-core and scary for Git newbies. Besides, the Majordomo mailing list system is pretty archaic, and I personally can't stand browsing or searching in the Gmane archives. The IRC channel #git on Freenode, which is a bit out-of-reach for people who never experienced the glory days of IRC. Furthermore, when the channel is busy, it's a big pain to follow any discussion. StackOverflow questions tagged git , these come pretty close, but it's a bit hard to keep an overview of what questio...
Post a Comment
Read more

Git tools for keeping patches on top of moving upstreams

At work, we maintain patches for some pretty large open source repositories that regularly release new versions, forcing us to update our patches to match. So far, we've been using basic Git operations to transplant our modifications from one major version of the upstream to the next. Every time we make such a transplant, we simply squash together the modifications we made in the previous version, and land it as one big commit into the next version. Those who are used to very stringent keeping of Git history may wrinkle their nose at this, but it is a pragmatic choice. Maintaining modifications on top of the rapidly changing upstream is a lot of work, and so far we haven't had the opportunity to figure out a more clever way to do it. Nor have we really suffered any consequences of not having an easy to read history of our modifications - it's a relatively small amount of patches, after all. With a recent boost in team size, we may have that opportunity. Also the need for be...
1 comment
Read more

Managing dot-files with vcsh and myrepos

Say I want to get my dot-files out on a new computer. Here's what I do: # install vcsh & myrepos via apt/brew/etc vcsh clone https://github.com/tfnico/config-mr.git mr mr update Done! All dot-files are ready to use and in place. No deploy command, no linking up symlinks to the files . No checking/out in my entire home directory as a Git repository. Yet, all my dot-files are neatly kept in fine-grained repositories, and any changes I make are immediately ready to be committed: config-atom.git     -> ~/.atom/* config-mr.git     -> ~/.mrconfig     -> ~/.config/mr/* config-tmuxinator.git       -> ~/.tmuxinator/* config-vim.git     -> ~/.vimrc     -> ~/.vim/* config-bin.git        -> ~/bin/* config-git.git               -> ~/.gitconfig config-tmux.git       -> ~/.tmux.conf     config...
Post a Comment
Read more