A change in "Rarest First"

[mcaspi]

uT implements "Rarest First" when it comes to downloading pieces, but it's disadvantage, in my opinion, is that the decision, which piece to download, is based only on the current condition of the swarm.

What I recommend is that each peer and seed in the swarm will have an "image" (or availability) of it from the last 24 hours. When a new peer or seed is connected to another peer or seed, the image of the swarm will be transferred to it during the handshake. Now, the peer will request rarest pieces in the swarm from the last 24 hours and not only the current rarest pieces. This way, downloading torrents, especially with small swarms, will be faster in my opinion.

As an example, peer A downloads X% of a torrent and disconnects. Later comes peer B. Seeds send it the image of the swarm (including what peer A has) and peer B downloads Y% that peer A doesn't have. Both peers can later download (A+% of the torrent (as opposed to less than that today) without the help of seeds.

[ktetch]

You've overlooked a few things.

First you're wanting to add a whole new set of data processing. That's never a good idea in the first place.

Second, You want to take a subjective observation (the rarest piece available) and try and timeline it, and then distribute it. That doesn't make any sense. Whose rarest piece takes precedence? what you can see, or what some random peer you've no idea about has said you should get? If you can't see how this can be abused, you're not thinking straight.

Third, you seem to believe that whatever condition the swarm was in 10 hours ago has any relevance to the swarms state now. It doesn't.

The Whole point of rarest-first is to try and create as many distributed copies as it can, AT THAT TIME. Doesn't matter if 6 hours ago there were eleventy-billion seeds and one leecher. If right her, right now, there's 1.999 distributed copies you can see, whatever pieces that hours-ago leecher needed has no relevance on what you need to get now, to maximise the number of distributed copies.

And THAT is why I think your idea is a silly one.