This implies the reason most sparsely seeded torrents
have chunk availability is because the transient leechers
just happen to arrive consistently in time to hand off to
one another.
No. I'm not sure where you got that idea.This is a pathological and unrealistic example but please try to extrapolate to more realistic scenarios. Imagine a file with three pieces. 200 torrent users have zero pieces, 100 torrent users have the first piece, 50 have the first and second piece, and "Joe" is the sole seeder that has all three. Obviously, assuming Joe doesn't have godlike bandwidth, there are 350 users who want that third piece and only a single Joe and there is going to be contention.
In this pathological situation things will work itself out as soon as supply of the third piece increases, assuming people don't kill their clients as soon as they hit 100%, but things will be slower than they need to be at first. What I think you're trying to point out is that there are situations where sequential torrent downloads aren't harmful to download speed or overall availability. Yes, that is true. If seeder bandwidth for a given piece is more than sufficient for leecher demand for that piece then... yes, no harm done. As another user posted, http://bittorrent.org/bittorrentecon.pdf section 2.4.2 "Rarest first" You're free to disagree with the design of bittorrent, obviously. |