Re: blobs (once more)

From: Johannes Schindelin <johannes.schindelin@gmx.de>
Date: Apr 7, 2011, 06:45 UTC
Message-ID: <alpine.DEB.1.00.1104070836590.2040@bonsai2>
In-Reply-To: <buo4o6abpsg.fsf@dhlpc061.dev.necel.com>

Hi,

On Thu, 7 Apr 2011, Miles Bader wrote:

Show 15 quoted lines

> Pau Garcia i Quiles <pgquiles@elpauer.org> writes:
> > The usual answer to the "I need to put binaries in the repository" 
> > question has been "no, you do not". Well, we do. We are in heavy 
> > development now, therefore today's version may depend on a certain 
> > version of a third-party shared library (DLL) which we only can get in 
> > binary form, and tomorrow's version may depend on the next version of 
> > that library, and you cannot mix today's source with yesterday's 
> > third-party DLL. I. e. to be able to use the code from 7 days ago at 
> > 11.07 AM you need "git checkout" to "return" our source AND the 
> > binaries we were using back then. This is something ClearCase manages 
> > satisfactorily.
> 
> If it were me, I'd just store the huge binaries in some sort of separate 
> remote filesystem, and then store the remote-file-system _paths_ to them 
> in git (in a simple text file).

That fails for a number of reasons:

- it does not pass the 30,000-feet-high test

- integrity is not guaranteed (anybody can edit the files on the remote 
  file system, and nobody would realize that a "git checkout HEAD~2000" 
  ends up being something different from before)

- you would have to reinvent an efficient transfer (e.g. taking into 
  account all the data we have already)

- storage is no longer efficient, especially if you have multiple versions 
  of the same file.

- it is no longer decentralized anymore. Just think about yourself sitting 
  in the middle of antarctica, desperately needing to match a penguin 
  against a database of known penguins. You definitely want to have the 
  database local instead of leeching it down the non-existing wire all the 
  time. Likewise, if you and your group sit, say, on Viti Levu, and 
  develop software with people from New York, Texas, you definitely want
  a repository-in-the-middle, making it one person's duty to synchronize, 
  say, once per day.

I am sure you can think of more reasons.

Ciao, Johannes