Re: git pack/unpack over bittorrent - works!

> On Sat, Sep 04, 2010 at 03:50:29PM +0100, Luke Kenneth Casson Leighton wrote:
> > 
> > :)  the legality or illegality isn't interesting - or is a... red
> > herring, being one of the unfortunate anarchistic-word-associations
> > with the concept of "file sharing".  the robustness and convenience
> > aspects - to developers not users - is where it gets reaaally
> > interesting.
> 
> I ask the question because I think being clear about what goals might
> be are critically important.  If in fact the goals is to evade
> detection be spreading out responsibility for code which is illegal in
> some jurisdictions (even if they are commonly used and approved of by
> people who aren't spending millions of dollars purchasing
> congresscritters), there are many additional requirements that are
> imposed on such a system.
> 
> If the goal is speeding up git downloads, then we need to be careful
> about exactly what problem we are trying to solve.
> 
> >  i do not know of a single free software development tool - not a
> > single one - which is peer-to-peer distributed.  just... none.  what
> > does that say??  and we have people bitching about how great but
> > non-free skype is.  there seems to be a complete lack of understanding
> > of the benefits of peer-to-peer infrastructure in the free software
> > community as a whole, and a complete lack of interest in the benefits,
> > too...

> Maybe it's because the benefits don't exist for many people?  At least
> where I live, my local ISP (Comcast, which is very common internet
> provider in the States) deliberately degrades the transfer of
> peer2peer downloads.  As a result, it doesn't make sense for me to use
> bittorrent to download the latest Ubuntu or Fedora iso image.  It's in
> fact much faster for me to download it from an ftp site or a web site.
> 
> And git is *extremely* efficient about its network usage, since it
> sends compressed deltas --- especially if you already have a base
> responsitory established.  For example, I took a git repository which
> I haven't touched since August 4th --- exactly one month ago --- and
> did a "git fetch" to bring it up to date by downloading from
> git.kernel.org.  How much network traffic was required, after being
> one month behind?  2.8MB of bytes received, 133k of bytes transmitted.

> That's not a lot.  And it's well within the capabilities of even a
> really busy server to handle.  Remember, peer2peer only helps if the
> aggregate network bandwidth of the peers is greater than (a) your
> download pipe, or (b) a central server's upload pipe.  And if we're
> only transmitting 2.8MB, and a git.kernel.org has an aggregate
> connection of over a gigabit per second to the internet --- it's not
> likely that peer2peer would in fact result in a faster download.  Nor
> is it likely that that git updates are likely to be something which
> the kernel.org folks would even notice as a sizeable percentage of
> their usable network bandwidth.  First of all, ISO image files are
> much bigger, and secondly, there are many more users downloading ISO
> files than there are developers downloading git updates, and certainly
> relatively few developers downloading full git repositories (since
> everybody genreally tries really hard to only do this once).