New method for seeding (less HD space)

[cyber857]

Hello i have been doing some reading latly *gasp, and believe i have stumbeled across a fairly easy way to improve the mu-torrent client. please correct any of my assumptions.

Assuming:

1. a torrent swarm is 'healthy' when there is an avalbility of 1+ (perferably 4-10)

2. Media torrents and installers (apps, games) are seeded well until they lose popularity

3. one reason for loss of popularity in media and games is new episode/ media space (to much room on HD)

My idea arises from the fact that i dont mind sharing my bandwidth, or processor cycles, I mind sharing my HD space. To share the open-source movie elephant's dream (ext link http://www.elephantsdream.org/) I have to keep the whole file (100%) on my harddrive. it seems that for larger files or files that rapidly lose seeders, installers (something you install then delete the installer) or media (something you watch once/ burn to dvd then delete) that seeding becomes a hassel.

I've figured out a very simple method for solving the problem of keeping the whole file(s) on my HD.

I want to share the most rare pieces of a torrent. that is i want to allocate say 50 MB of my HD to help share elephants dream. not the 1 gig for the whole file.

I was wondering if it could be written into utorrent.

the method is simple.

1. download all the files for the torrent. (this is done anyway)

2. allocate a certain size to seed up to 100% (100% is normal seeding)

3. check the swarm and keep the rarest of pieces of the torrent up to the limit specified

4. remove the rest of the downloaded data.

5. continue to check the swarm (at several minute intervals to avoid swamping pieces back and forth between two or more users) swapping the pieces you have with more rarer pieces. i.e:

if the piece size is 1 MB (for easy math) you have 50 pieces. Check the most common piece you have for example lets say its piece 4 with 12 copies out in the swarm look for the rarest piece in the swarm, lets say it finds piece 144 has only one copy out there. switch the two; redownload piece 144 and delete piece 4

6. this will eventually leave you with 50 pieces each of which where you are the only seeder for that piece as primary seeders (the people seeding 100%) die out... BUT if it is a 500 MB file and i host 10% and there are 9 other people willing to share only a fraction of the total storage space i think it not only allows a better way to share but gives seeders more options.

Sure you dont need the partial-share feature on popular items, new tv eps or movies, new games or apps, but if your looking for the fist release of commander keen some other old nerd may be seeding it because its small, but what about the items that are huge, like the complete sg-1 series @56 gigs etc you dl it watch it or burn it then delete it cause it takes up to much room. but if there were 120 people willing to share 500MB of the same torrent i think you would have ALOT more people willing to seed.

This is a metod of distributing the seeders, in a very similar way to how freenet moves its data around.

please feel free to commit on any mistakes i have here (minus spelling) and i will do my best to respond, Also if this is placed in the wrong part of the fourmns please let me know ill move it. Thanks.

I have attemped to have a real-time discussion in irc about this but i run into several arguments, where i believe they arent fully grasping thepartial seed method.

Argument #1: Your method uses selective downloading and that hurts the swarm.

Responce: Selective downloading often referes to a client trying to download a more common piece over a more rare piece, that does hurt the swarm. My method is exactly the opisite. Each client is searching for the rarest of pieces.

Argument #2: When 1 of your 10 people leave (each of who has 10% of the file) the torrent is now broken.

Responce: yes... but... i often come down to the choice of do i keep seeding this torrent which i'm now done with, or delet it and get something else. if i have the option to share a smaller part of media i agree with i would be happy to help the swarm out, remember partial seed > not seeding.

(*Edit many spelling changes, and grammer, added most common arguments)

[DreadWingKnight]

3. check the swarm and keep the rarest of pieces of the torrent up to the limit specified

4. remove the rest of the downloaded data.

You will only get information about a small subset of peers and not the whole swarm. What is rare in your subset may not be rare in another.

Because of this, piece rarity estimates will be horridly inaccurate and you may end up sharing only the most common pieces instead of the most rare.

BitTorrent isn't a traditional p2p network. It is a peer-supplemented download accelleration system. Sharing is only tracked within the torrent, so sharing a stargate torrent won't help you when looking for commander keen.

[cyber857]

You will only get information about a small subset of peers and not the whole swarm. What is rare in your subset may not be rare in another.

Because of this, piece rarity estimates will be horridly inaccurate and you may end up sharing only the most common pieces instead of the most rare.

ok without argueing about if i can get the rarest pieces in the swarm or not lets just take that as a thought experiment. I can only get common pieces. so what. Isn't it better to let me have the option to help seed a more common piece than seed none at all? even if all this method does it allows someone to dl a bit faster isn't it worth building?

BitTorrent isn't a traditional p2p network. It is a peer-supplemented download accelleration system. Sharing is only tracked within the torrent, so sharing a stargate torrent won't help you when looking for commander keen.

I agree/understand. perhaps I had made a bad analogy there, what i meant was this: You may be able to find commander keen BECAUSE it is small and someone doesnt mind having it on their system. It is much harder to find seeders willing to share 50+ gigs of data (the sg-1 example) that they are done with. (in my case if i download video media, i often burn it or delete it after watching it, thus removing the data and not seeding it)

[DreadWingKnight]

All in all, any selective (and I use the term loosely) seeding methods have more flaws than the benefit they generate.

If you can prove the worth of this in an example implementation from another client, I might be more receptive to it, but as it stands now, it's all theory.