yet another dvcs shootout (this time python-devel)

[Matthieu Moy]

"Arne Bab." <Arne_Bab at web.de> writes:

> Von: "TK Soh" <teekaysoh at gmail.com>
>> On Wed, Nov 5, 2008 at 3:15 AM, Neal Becker <ndbecker2 at gmail.com> wrote:
>> > In case anyone knowledgeable would like to participate, there is now a discussion of choosing a dvcs (hg, bzr, git) for python-devel.
>> 
>> Where can I find the discussions?
>
> Here's some data for the discussion: 

(note: this is meant to be an informative post, not evangelisation of
whatever)

> -----------------------------------------------------------------------------------
> $ time bzr branch http://code.python.org/python/3.0

This seems to be using plain HTTP protocol, that is : no bzr-related
software on the server, just apache and files. AFAIK, Mercurial is not
able to do this and requires hg to be running on the server even for
http. For sure, there's no hope to get something really fast without a
smart server running on the server.

Also, according to
http://code.python.org/python/3.0/.bzr/branch/format, this repository
uses an old format (good for compatibility with old clients, bad for
performance), so event in the "plain HTTP" senario, performance could
be better.

(on this particular issue, the point against bzr is not performance,
but too frequent format change)

To do a fair comparison, you should compare "bzr protocol tunneled
into HTTP" (i.e. bzr+http://blabla URLs) with "hg protocol tunneled
through HTTP".

I wouldn't be surprised if hg remains faster, but it should at least
be much better for bzr.

> $ bzr --version
> No handlers could be found for logger "bzr"
> Bazaar (bzr) 1.5

You should mention also "bzr info | grep format" here.

Bzr's repository format has changed many times in history. The pack
format introduced a few months ago (inspired form what Git does)
brought quite a lot of performance improvements.

Still, clearly, bzr remains really slow for some operations, some of
which are relatively common ones (for example, "bzr log" on the Emacs
repository took around 1 minute _before_ starting to print anything).

-- 
Matthieu