bazaar performance with single large project and a comparison with?git / mercurial

[Talden]

>  The unfortunate thing here is not so much Bazaar's performance per
>  se in my option.  Before Git, nobody really cared about benchmarking
>  VCS'es.  Well, at least this has become *much* more popular since
>  then.  Fact is that even Bazaar is fast enough for >90% of the
>  projects out there.

We were benchmarking before we were even aware of the impressive
performance of git.  CVS is painfully slow and although not the only
significant motivator for migrating away it certainly is one of the
major ones.

Bazaar resolves so many of the other issues we've had with CVS (and
admittedly introduces a few caveats) that we're currently banking on
Bazaars performance improving.

>  However, its performance is problematic nevertheless because it
>  makes advocacy more difficult.  People tend to look at the Big
>  Projects when they choose between VCS'es.  These projects are in a
>  phase of switching to DVCS currently but they can't use Bazaar.
>  They won't switch twice so easily though.  Eric Raymond is writing
>  an essay comparing DVCS'es.  Thus, Bazaar scaling so badly at the
>  moment is unfortunate timing.

This is definitely true.  We've recently been acquired and though we
were considering a CVS to Subversion migration we're now faced with
the new corporate policy of using ClearCase unless we can tick enough
of the right boxes to convince them to give us the latitude to choose
another tool.

Bazaar currently looks the most likely to do this.  I am ever hopeful.

Some numbers (unfortunately from memory as I don't have my documents
available at the moment).

Working tree:
- 650MB of file content, 10% of the files represent well over half of
this volume.
- 20,000 files in 3,500 folders

CVS repo = 2GB
SVN repo = 1.5GB (~22,000 change-sets after a cvs2svn migration)

We'd get about an additional 2,000 change-sets a year in 5-10 release
branches - naturally this will be much higher with us using feature
branches in Bazaar and all of the merge revisions.

Our developers are a mix of Windows, Cygwin and likely to soon also
include linux users.  The users are located in three different
continents with two of the three teams using CVS over a WAN with some
fairly severe latency, bandwidth and unfortunately reliability issues.

CVS branching and merging inconvenience combined with its lack of
merge-tracking is so bad that we don't feature branch.

We look forward to moving from CVS, many don't want to touch
ClearCase, a few are apathetic.

I'm still hopeful that Bazaar makes some improvements to help us get
approval for Bazaar...

Better Windows support (defensive warnings to protect from producing
broken branches on case-insensitive file-systems).

More GUI tools and, if not IDE integration (Intellij IDEA and
Eclipse), then OS integration (EG TortoiseBzr).

More performance improvements.

Many users are happy with Bazaar as it stands (though noone will
bemoan improvement) however failing to improve these areas gives
management ammunition to exclude Bazaar as an option.

--
Talden