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Performance Tuning Subversion
BlueVoodoo writes "Subversion is one of the few version control systems that can store binary files using a delta algorithm. In this article, senior developer David Bell explains why Subversion's performance suffers when handling binaries and suggests several ways to work around the problem."
putting a toolchain under CM control, so that you can go back to not only an earlier version of your own code, but the version of the toolchain you used to compile the code at that point in time. Absolutely necessary to be able to recreate the full software environment of a past build, without relying on that version of the toolchain still being publicly available (not to mention including any patches/mods you made to the public toolchain).
It's really nice to be able to have your entire product in one place and under version control. Third party DLLs (or .so's or jars), images, your documentation... just about anything that's part of your product.
That way it's all in one place and easily backed up. If you get a new version of the DLL/jar/so you can just drop it into a new branch for testing. If your customer won't upgrade from version 2.2 to version 3.0, you can recreate the entire product to help fix bugs in the old version rather than just saying, "We've lost it, you've got to upgrade."
Basically, by putting your entire project under version control, you know that it's all in one place, no matter what version it is you want. Even if the files don't change, you know how to reconstruct a development installation without having to dig around in multiple locations (source in version control, DLLs in one directory on the server, etc.)
Yeah, so it costs some extra disk to store it. Disk is cheap.
It is still the wave of the future. I've worked in it extensively, and it is still the best version control system I've ever used. Because of its other strengths, it is continuing to expand its user base and gain popularity. You can tell this because Microsoft is now actively attempting to copy Subversion's concepts and ways of doing things. Ever used Team Foundation Server? It is just like Subversion, only buggier (and without a good way to roll back a changeset... you have to download and install Team Foundation Power Tools to do it). I'm a new employee at my company (which uses Microsoft technology), and yet I've been explaining how the TFS system works to seasoned .Net architecture veterans. The reason I can do this? I worked extensively with Subversion, read the Subversion book a few times (the O'Reilly book maintained by the Subversion team), and worked on a project for my previous company that basically had the goal of making versions of the TFS wizards for Subversion on the Eclipse platform. It only took me about one day of using TFS to be able to predict how it would respond, what its quirks would be, etc, because it's technical underpinnings are just like Subversion. So even with performance issues, if even Microsoft is abandoning its years of efforts on Source Safe and jumping all over this, you can know that its strengths still make it worth adopting over the other alternatives. After all, if Microsoft was going to dump source safe, it had its pick of other systems to copy, as well as the option of trying to make something new. What did it pick? Subversion.
Beware of bugs in the above code; I have only proved it correct, not tried it.
For many open source projects, finding good documentation is hard. In the case of Subversion, it couldn't be easier. In fact, the Subversion team has taken documentation to such a level that they should be considered THE model for documentation in the open source community. They have written a book (published in print by O'Reilly, but maintained and posted for free by them on the Internet) that documents their system, and it is very good. My job at the last company I worked for was to write wizards for the Eclipse platform that would automate several of the most common tasks that a Subversion user would try to do, and that book was the only reference I needed. You can find the book on their site here: http://svnbook.red-bean.com/ . They even do nightly builds of the book, so not only is their documentation complete and useful, it is also incredibly thorough and up to date.
If anyone on here hasn't read it, DO IT, because the first half will teach you why you want Subversion rather than CVS or some other alternative, and how to use it and how to get the most out of it (second half is lower level stuff you may not care about). It even includes best practices. Once you really learn how to use Subversion, you won't want to use anything else. And this is the way to get started.
Beware of bugs in the above code; I have only proved it correct, not tried it.
Not just images in the sense of PNGs and JPGs, but original source documents as well (PSD, AI, SVG, etc). We track several large (40MB+) source files and I've seen some slowness but nothing to write home about.
We give our outside designers access to their own SVN repository. When we contract out a design (for a brochure, for instance), I give them the SVN checkout path for the project, along with a user name and password. They don't get paid until they commit the final version along with a matching PDF proof.
This solves several issues:
(a) The tendency for design studios to withhold original artwork. Most of them do this to ensure you have to keep coming back to them like lost puppies needing the next bowl of food. It also eliminates the "I e-mailed it to you already!" argument, removes insecure FTP transfers, and can automatically notify interested parties upon checkin. No checkin? No pay. Period.
(b) Printers have to check out the file themselves using svn. They have no excuse to print a wrong file, and you can have a complete log to cross-check their work. They said it's printing? Look at the checkout/export log and see if they actually downloaded the artwork and how long ago.
(c) The lack of accountability via e-mail and phone. We use Trac in the same setup, so all artwork change requests MUST go through Trac. No detailed ticket? No change.
(d) Keeps all files under one system that is easy to back up.
You may have a little difficulty finding someone at both the design and print companies that can do this, but a 1 page Word document seems to do the trick just fine.