[Monotone-devel] Re: monotone CVS import failed.

[Markus Schiltknecht]

Hi,

Jon Smirl wrote:
> I have been trying with cvs2svn for three months now and progress
> isn't happening. You at least seem interested in making things work
> right for Mozilla.

I don't think so. The graph algorithm is just very new and we still have 
to experiment with it. I don't know about the details why cvs2svn (graph 
based) fails with importing Mozilla, though.

But for sure the cvs2svn people are more experienced with CVS 
repositories and I'm very much basing my work on their experience. To be 
honest, I'm unsure if monotone will give you better results than cvs2svn 
anytime soon (or ever at all). Although, monotone is obviously closer to 
git than svn.

> > Jon Smirl wrote:
> > > You can get the Mozilla CVS repository here:
> > > rsync -az cvs-mirror.mozilla.org::mozilla ~/mozilla/cvs-mirror
> > > The import was about 85% through the revs, 1.1M total.
> >
> > Why do you think it's 85%? Are you expecting more than 894,279 versions?
> > How did you count them? I'm sure there's a difference in counting or a
> > bug in my code ;-)
>
> cvs2svn reports somewhere between 1.0 and 1.1M revisions.

Can anybody here quickly explain how cvs2svn counts? Does it count tags, 
branch identifiers?

I'll check how monotone cvs_import counts. I didn't write that portion 
of the code myself. But certainly these numbers should match (or we 
should know why they don't.)

> Let me know as soon as your code is ready. I know where most of the
> tricky cases are located in the Mozilla repo. We can work together to
> get me a good import and you some debugged code.

Sure, but as I told you, the cvs2svn people are probably more 
knowledgeable than me WRT strangeness in CVS.

> > Did you watch memory consumption?
>
> Around 1.2GB when it died.

That's good to know. IMHO it's the main difference between my monotone 
cvs_import rewrite and cvs2svn's graph based approach: the 'in-memory' 
vs. 'on-disk' issue.

It convinces me that spilling to disk is not necessary, because it looks 
like the whole mozilla repository with all its blobs and its 
dependencies fits into 1.2 GB of memory (this is of course excluding the 
files and its deltas itself).

Regards

Markus