How To optimize seeding of new torrent?

[CupCrazy]

I have a torrent I've posted that's gonna take quite a while to seed. It's almost 8gb and in the first 6hours I've had almost 50 people start downloading. My max upload rate is about 40K/s so I need to do whatever I can to optimize the seeding of this torrent.

With my initial utorrent settings, I noticed that I had >20 pe6ers connected with an average DL speed per peer of only 2K/s...that would take FOREVER to get out to everybody, and it was getting worse.

So I dropped the max number of uploads / peers pr torrent to only 4...this increased the average upload speed per peer to about 10K/s. My theory was that if I focused more data to a small group of peers, they would better be able to seed that data to others.

Unortunately, as I watched the progress, I frequently noticed people with 10% download completion not receiving any data at aall, while people with 0.5% or less were receiving 10-15K/s. So the people that I wanted to receive "higher priority" on this torrent weren't getting any data, while people who'd just hopped on board were getting a major chunk.

I've read a number of other threads here and saw a few discussions about prioritizing peers, but it looks like the feature was never added.

Is there any way to "focus" the seeding of this torrent so that the people who have the highest percent downloaded aren't losing slots to lower percentage DLers?

I strongly suggest that a "Prioritize Peer based on % of completion" option be added. So that someone who's already downloaded 15-20% of a torrent does not get bumped off by someone who's only download 1%...this should at least be available to people who doing an initial seed of a torrent to get more seeders out there as quickly as possible.

Thanks!

[DreadWingKnight]

Such micromanaging features don't actually improve the speeds of the swarm as much as you'd think they would.

Peer preferencing by completion has been rejected before because it doesn't actually help speeds or piece distribution as much as people think it would have.

It was never added because it doesn't work.

[CupCrazy]

Okay, I guess I misunderstand the nature of torrent swarms then because I always thought that the overall transfer of the torrent would go much faster if, for example, I could get 4 peers to 100% ASAP, then the 5 of us could more quickly distribute the bits to the rest...hence the frequent comments I see about "building up seeds" before posting a torrent to a larger group of people.

At this point, there are 50+ people trying to DL my torrent, about a quarter of them have >15% completion but out of the 6 slots I have available for download, only 1 of them is even close to 10%, the other 5 are <5%...so the people who are near 15% completion aren't even receiving any bits from me and I apparently have no way to change that.

Seems counter-productive, but the bits are flowing and it'll reach 100% eventually.

Thanks for the response.

[DreadWingKnight]

Seems counter-intuitive until you realize that the faster speeds come from trading relationships, not from having a high number of seeds.

[Switeck]

Ideally, you want almost everyone to have at least 1 completed piece of the torrent...but for them to all have DIFFERENT parts of the file. A fast peer with nothing to share is bad!

Keep upload slots low so average upload speed per upload slot is ~5-10 KB/sec while seeding.

This is even MORE important with larger piece sizes of 1, 2, or 4 MB!

With 20 upload slots, 20 peers each with 75% of separate 4 MB pieces represents 60 MB of uploading by you...but even at that point 20 peers still have nothing to share with each other. 10 upload slots would possibly achieve 10 completed pieces to peers and be working on 5-20 more in the same amount of time.

Initial seeding mode should switch which peer/s it's uploading to until ALL the torrent's pieces are uploaded at least once to someone.

[CupCrazy]

Switeck: So what you're saying is that the people with low completion percentages could be downloading pieces from me that no other peer has yet?

My assumption was that the torrent pieces are being sent out linearly, so the peer that is at 10% of a 100 piece torrent is receiving piece #10 and the peer that's only at 1% is receiving part #1. I figured, why I am sending the 1% guy piece #1 when I've already sent it to a bunch of other people. Sounds like this assumption is completely wrong.

Thanks for helping to clear things up. I've stopped micro-managing the torrent and it seems to flowing a little more smoothly without my meddling.

[Switeck]

"Switeck: So what you're saying is that the people with low completion percentages could be downloading pieces from me that no other peer has yet?"

YES! Almost a guarantee in initial seeding mode. Even regular seeding mode has some variation and ONLY Sequential downloaders (and those who put first/last pieces at high priority) will be dumb enough to request the same piece from the only seed as other peers have.

[CupCrazy]

Cool, thanks for the explanation! That makes sense and would definitely negate the need for a peer prioritization system.

[Switeck]

Sadly...4th link in my signature.