Re: [boost] development branch(es)

From: David A. Greene (greened_at_[hidden])
Date: 2007-07-31 12:29:34

On Thursday 26 July 2007 08:58, Douglas Gregor wrote:

> > What is the timeframe for the migration ?
>
> I'll send out an announcement when we're sure, but I'd like to move over
> early next week. We'll give a couple days notice before we switch, of
> course, so that everyone can get any outstanding work committed to CVS.

I know this is rather late in the game but it's only recently that I've had
extensive experience with Subversion.

My experience has not been good.  I've found that Subversion scales very
poorly, which makes me nervous about moving a large project like Boost
into it.  I've had situations where's it's taken hours and sometimes days to
perform checkouts.  And this is with the most recent version.

I've also encountered issues with Subversion's interaction with http timeouts.
Apparently Subversion sets timeouts low enough that they can expire when
operating on working directories that exist on networked filesystems.  It can 
also happen when checking out or updating very large files.  These timeouts 
are considered a "feature" by the Subversion folks.  See:

http://lists.cs.uiuc.edu/pipermail/llvmdev/2007-July/010066.html

Read the entire thread and the links in it for the whole story.  The bottom 
line is that svn over http and https is very, very broken.

(My comment about no problems with other svn repositories probably has
to do with the fact that those other repositories are much smaller than 
llvm's).

These timeout errors have on occasion resulted in corrupt working directories
where an svn cleanup doesn't fix the problem.  More than once I've had to blow
away a working directory and start over.  Fortunately, I haven't yet had to do
this on a directory with pending changes, but I'm sure it's only a matter of
time.  I'm now VERY careful about when and how I do updates.  More careful 
than I should have to be.

I don't expect Boost to suddenly change course and abandon the plans to more
to Subversion, but I would ask that the community be open to changing to
something else if these problems arise.  Maybe they will, maybe they won't,
but the fact that I've had so many problems and that those problems have
impacted critical work makes me not optimistic.

If we were back at the beginning of discussions about what SCM to use, I
would now strongly, highly, exclusively recommend git.  It's been fabulous
for some other projects I'm working on.

Again, this is just a heads up.  I don't intend to re-open the debate.  But
please be open to suggestions for change if problems crop up.

                                   -Dave