[vox-tech] bittorrent - no seeds but distributed copies increase

[Peter Jay Salzman]

On Mon 26 Jul 04,  2:37 PM, Samuel N. Merritt <spam at andcheese.org> said:
> On Mon, Jul 26, 2004 at 02:08:22PM -0700, Peter Jay Salzman wrote:
> > Question:
> > 
> > How does the "distributed copies" get larger when there are no seeds?
> 
> I think that "distributed copies" measures how many complete copies of
> the file you could get if you took all the pieces that everyone has and
> assembled them. 
> 
> For example, consider a five-part file.
> Alice has: 1 2 3 4
> Bob has:       3 4 5 
> Carol has: 1 2   4 
> 
> You could make one complete copy of the file from all this, so there'd
> be 1 distributed copy. If Carol got piece 5 from Bob, then you could
> assemble two complete copies. 
> 
> That's the integer part of distributed copies; I'm not sure where the
> fractional part comes from. Maybe it's the size of the largest
> distributed incomplete subfile divided by size of file, but that's just
> a shot in the dark. 
  
ok.  this was my understanding.

> > Does the tracker ever inject packets into the torrent when needed (like
> > when seeds == 0 and distributed copies < 1.0)?
> 
> No. The tracker doesn't have a local copy of the file. If there are no
> seeds and < 1 distributed copy, everyone's download will stall before
> finishing 

this was also my understanding.  but my question still stands: how does
the distributed copies increase if there are no seeds?

i'm looking at a bittorrent right now.  it's remained constant at:

   seeds: 0 seen now, plus 0.983 distributed copies
   peers: 19 seen now, 98.4% done at 0.2 kB/s

that ".983 distributed copies" has been creeping upwards.  last i looked
at it, about 15 minutes ago, it was at .97.   i've noticed this happen
before too.

how exactly does that number increase when there are no seeds?

pete

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