Interview with Tom Lord of Arch Revision System 334
comforteagle writes "Every revision control system has its supporters and detractors, but none is as polar as Arch. Either you hate it or think it is the best thing in revision control ever. Built more around what our beloved kernel hackers use (BK), Arch is definitely a departure from CVS and Subversion. I've interviewed Tom Lord, Arch's daddy, about the application, and he has some -ahem- interesting answers and opinions."
d00d, ur source management sysemz BLOW (Score:2, Insightful)
'Ever hear of the "zero-block over NFS" problem?' (Score:3, Insightful)
Either way, the solution is "don't run CVS over NFS". Use the client-server protocal - either ext or pserver.
I don't like CVS, Subversion, or Arch (Score:4, Insightful)
CVS is Free and lightweight. I run it on my handheld with no problems.
Subversion is Free, reliable (so far), and very easy to use. In fact the stripped-down CVS-based CLI interface is just slightly different than CVS but much more productive.
Arch is all of the above.. EXCEPT easy to use. Here's the "eye-opener" that Mr. Lord really needs to address:
% svn --help | grep '^ ' | wc -l
28
% tla help | grep ' : ' | wc -l
105
I'm sorry but just watching that scroll by is enough to make me say "well, maybe I'll figure this out later". Which is what I do every time I look at Arch.
What I would like is a RCS that has the ease of use of Subversion, but uses changesets like Arch, and uses a lightweight storage system like Arch. I totally agree with his complaints about Subversion.. it is a bloated toy (using Berkeley DB for versioned tree storage is just the most bizarre decision). But the interface is the best, hands-down...
So.. where's the killer open source RCS?? Open source is supposed to be about good no-frills development tools!
All that and he doesn't explain... (Score:5, Insightful)
Primarily, he has only flamed svn. Even this interview he talked more about svn than arch. Nothing he said raised any interest in me to look at arch.
Also, his criticism of svn's current backend was true 8 months ago. There is another backend that will be available soon. And with that, the sytem will be able to handle additonal backends in good form.
SVK, which Lord mentioned, is a feather in svn's hat since it uses subversion as a base. If distributed mode is a real need I would suggest looking at BK or svk.
Re:Where are the screenshots? (Score:5, Insightful)
The main problemw ith a GUI is that you can't script them (or not trivially anyway). A development tool (which is largely what version control is) that cannot be scripted is useless. The GUI is not the be-all-and-end-all. This is what frustrates me so much about Windows on the server (and why it's not a very good server OS) - it's because many parts of Windows are totally unscriptable out of the box. Don't do this to our version control software too.
The GUI should be separate from the 'business logic' of any tool in any case - therefore there's absolutely nothing wrong with a GUI that drives command line tools underneath, or perhaps provides another interface by linking to a library which provides the heavy lifting parts of the code.
Re:I don't like CVS, Subversion, or Arch (Score:3, Insightful)
Here's a couple to have a look at:
PRCS [sf.net]Superversion [sf.net]
Of the two I use PRCS all the time for production code. Superversion's still a very new project but I think it shows a lot of promise, and well worth a periodic look.
Re:No people skills. (Score:1, Insightful)
Re:All that and he doesn't explain... (Score:3, Insightful)
As to the merge capabilities, I agree there is room for improvement. However, I believe that developers/project managers are more comfortable with evolutionary change as opposed to revolutionary. In that light, I predict that svn has a bright future.
svn already has a number of front ends HTTP, SVN:// and webdav. And now, mulitple backends. It is this decoupling that will allow svn to go where cvs could not.
I in no way have any ill-will twoards T. Lord. I would only suggest that he focus on the positive aspects of arch instead of the current ego battle with other version control systems. This is one area where the best will be used. Seasoned Developers/Project managers care about this subject. If a solution is truly head and shoulders above the rest it will be recognized and used.
Re:No people skills. (Score:4, Insightful)
> and as such has no need for people skills.
I only wish....
Re:I'm left out... (Score:5, Insightful)
I want to thank the Subversion team (Score:5, Insightful)
Re:All that and he doesn't explain... (Score:3, Insightful)
Does he know ANYTHING about Subversion? (Score:4, Insightful)
The BDB backend has it's problems (though none of them nearly as drastic as he seems to think), but has he really never heard of the FSFS [mit.edu] backend?
The rest of the criticism is so vague that it kinda makes it hard to reply to: "it takes too many steps backward in various areas", oh, "various areas" - of course! I've been noticing that.
I'm in the process of moving to Subversion from CVS (which I agree is deeply broken, by todays standards), and I've yet to encounter a single thing that Subversion is worse at than CVS. And a hell of a lot of things that it does much, much better.
Now if that interview presented the tiniest bit of information about what arch does differently (apart from, you know, not being "teh suck") I would be tempted to check it out.
Re:All that and he doesn't explain... (Score:5, Insightful)
Subversion requires a fairly heavyweight server
i run a subversion repository on a FreeBSD system with a Duron 600 and 128Mb of memory, and the upstream link is only 128kbps dsl. subversion runs as smooth as silk, locally and remotely. i do not consider this to be a heavyweight server.
The implementation is too complicated, the use of BDB as the primary back end creates admin hassles... managing database log files and backups
somewhat true. i dont like the fact that subversion is currently tightly bound to BDB and Apache, but this is purely behind the scenes -- subversion's implementation can (and i imagine will) be evolved to support many backends, and issues with BDB are just issues with BDB. i dont think its fair to expect subversion to be fully open and support all sorts of databases and file systems for its backend at 1.06. furthermore, evolution of the implementation can be done so that old repositories still work fine with a new version, the new version has the option to use a dfferent backend, and most importantly, there will be absolutely no difference for user whatsoever.
having to run a recovery process or worse on the server whenever it fail
recovering a corrupted database of filesystem is never fun. nobody looks forward to running fsck. however, Lord makes this sound like a common operation for whenever something fails -- clearly, he has never typed the words svn help cleanup. when user operations go bad, it doesnt corrupt the repository, and recovery isnt necessary. any problems created by an interrupted operation affect only the working copy, and can be fixed with a simple svn cleanup.
the poor merging support
Lord references the poor merging support a few times, but fails to actually detail a complaint. branching as a copy is just a clean intuitive manner to visualize a new branch off of the current line, and one that works with his precious named identifiers instead of version numbers as well. the merging is a little different than cvs, but is as good at worst. if Lord can go off on "Arch is great (you just have to learn all about it and configure your environment in just the right way)", i would think he would leave some leeway for subversion requiring a user to have at least a general birds eye view of its operation.
overall, this interview is like a political campaign that only attacks. i do not see any arguments in the text of "arch is better in this area because...", i only see "XXX is bad for the other guys." i've always taken the same view of these campaigns: if he had substance to support his product, he would have given it to us.
and in finale, he uses the final paragraph to make excuses for arch having most of the same shortcomings he lists for other revision control systems.
in all honesty, i am not familiar with arch. if arch does things better than subversion, i would love to hear it; and i am not claiming here that subversion is better. i can't, since i dont know arch. Lord would have been wise to use this interview as a forum to tell us about arch, and tell us why its good, but he didnt, and he has unfortunately turn my view on arch from neutral to maybe a little negative by virtue of jerkitude.
i take one overall feeling from this interview, due to its lack of content and vitriolic but often uninformed attacks. Tom Lord, who are you trying to fool?
Re:I'm left out... (Score:5, Insightful)
Yeah, it's too bad Linus seems to be so happy with it, because Larry McVoy is a real dick. I posted something here on
IMHO, the man's a complete asshat, which is really a shame, because he seems to have a good product that a lot of developers will never touch because of his childish behavior.
Re:Where are the screenshots? (Score:3, Insightful)
Okay, this is a pet peve of mine and (surprise) it does relate to arch, subversion, et al. The problems Tom Lord mentions are found everywhere in open source, and that is why X.org, arch and other 'duplicative works' or 'hateful forkings' exist.
It is very trivial to script a properly built GUI. Now the deifintion of a 'properly built GUI' goes beyond being able to be scripted, but does include this feature.
How? Why? From HCI and study of disability access we know that every action possible in a GUI should be performable with out a mouse. On Microsoft Certified Software this usually means everything has a contextually unique hotkey.
Windows 3.1 included a nifty tool called Recorder. Recorder is a lot like UNIX typescript, i.e. type 'script' and it records all the stuff in your command line session until ^D, except it only recorded your inputs to the computer. ALL GUI. No Terminal. Using the run box and keyboard (hot-key) only commands you could record a fairly portable script to automate your task. Given that the script (macro) was in textual format (IIRC) basic text editing skill was all you needed to turn a simple script into whatever you wanted (including being driven by command line scripts.)
The utter lack of standards compliance in Linux GUIs contrasts with the impresively standards-compliant command line applications (that are often definitive or reference implementations.) Let alone the lack of support for something like uniform contextual keyboard hot-keys.
A GUI for arch or CVS or subversion could be made with scripting in mind. And not just via embedding LUA or another 'lighweight' language. However, proper GUI scripting would take a project on the order of the Ximian Desktop to make it work even as well as a cheesy under-utilized program from 1980's Microsoft.
(Oh, and scripted GUI + decent version control GUI + automation tool = 100% developer envrionment matched automated test setup. Which can potentially be very cool if a bug is due to how a naughty newbie code monkey setup his little development cage. It's happened. And I've had to clean that monkey's cage one time too many.)
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Ugh. That's two pointless rants in one day. I need caffine.
Re:Design and License (Score:3, Insightful)
How is this model any different than the history of Linux kernel development? The packet filter portion of Linux comes to mind immediately.
It's not always a bad thing to strive toward production ready code. It can be a good and necessary counterbalance to the "think forever" reflex that takes hold in projects that go too far in the other direction.
Concerning the tone of the interview, I wouldn't be at all surprised that the best source-code revision system comes from a Theo-like development camp. Some projects can handle a "let's all get along and not say anything too combative" and some projects do much better at the other extreme.
Personally, I'll download my firewall, my filesystem, and my source control system from the crabbiest ubertard I can find.
CVS: another answer to the same old problem (Score:3, Insightful)
Why can't we see that CVS is just another version of the solution for the same problem? that problem is distributed information management. There are numerous places that this problem pops up: distributed filesystems, distributed databases, e-mails sharing between applications, source code sharing, etc.
It should be the role of the operating system to provide distributed information management. It would render a whole class of applications unneccessary and it would make programming much easier.
It is a great chance for open source software to provide this solution at open source level and gain a great technological, economical and social lead over propriatery software.
Re:I'm left out... (Score:1, Insightful)
Clearmake deps do not work for Sun C++, Java (Score:1, Insightful)
Proof of correctness (Score:3, Insightful)
In my view, the biggest barrier to adoption of new source code control systems is the confidence level. CVS suffers from lots of problems, but they are well understood due to the age of the system. Similarly I only trust Clearcase for my commerical development as it has been around so long (although BK is progressing well with gathering a bigger user base)
For any new system to be a contender it needs to have either a large existing user base (chicken and egg problem) or a very comprehensive test suite with code and problem domain coverage figures. If I am going to trust my (assumed valuable) source code to an SCM system, then I need to know that it behaves correctly. DARCS scores lots of points for being based on a semi-formal proof of correctness, but that only proves the algorithms not the implementation.
I've discussed this on Shlomi Fish's mailing list "Better SCM", but the real opportunity for all of the open source SCM projects is to collaborate on collating normal and pathalogical examples of SCM problems and building a common test suite.
Asmo