Low seeders -> torrent dies, stop/start -> magically revives? Wtf?

[Sakura90]

Hi nice ppl

I'm having a little issue with torrents. As I download obscure Jpn movies and music (that means if I get more than 5 seeders I throw a party) I always have a hard time downloading from crappy seeders. I don't mind the speed at all, even 30 kb/s makes my day happier.

But for some time I'm seeing a weird issue. It always seems to happen from the overwhelming number of 1 to 3 or 4 seeders. I begin downloading peacefully till the download speed drops to zero (it can be suddenly or slowly decreasing to 0). I can leave it for a day or two and it'll stay dead. But as soon as I stop and start the torrent, I get bits flowing again, sometimes even at amazing speeds of >100 kb/s.

It never happens with properly seeded torrents or even with 2 [apparently good] seeders. But it happens more often than I'd like to. With different trackers, different torrents, different seeders. I guess it's a problem with them and not me. Any idea what causes the stop/start action for them to become active again? Is it something because how the torrent system works? Not always stopping/starting makes the download start rolling again, but it usually does.

And more importantly, is there any way to automate the action? I mean, if a torrent download idles for x time and seeders > 0, it would stop and start again by itself. I use lastest uTorrent but I'm not picky, if there's a way to do that with any client I'll buy.

[Xycolian2332]

Pretty sure your problem stems from the interval at which your torrent application updates the trackers.

I'm not an expert though, so your problem might be something entirely different.

[Sakura90]

Currently I have a torrent with two seeders, always the same 2. They die randomly and the tracker updates every 30 min, there *seems* to be no relation between them. If the torrent is dead, even if the time when the tracker update comes (or if I force update) nothing changes. Only if I manually stop/start the torrent.

Does it really matter then, when it's always the same 2 IPs to connect to? I thought the tracker matters to give you the swarm information, IPs to connect and that sort of thing. But there's nothing new to update here.

Currently I'm on a winning streak it seems. It doesn't last more than 20 mins running, but I get speeds of 80 kb/s. Sometimes it dies and starts on it's own, often I need to intervene.

[megido-rev.M]

It somewhat sounds like a problem with the two peers you're connecting to.

[Dhruv]

Usually happens with those badly/low seeded torrents. Mostly because they client isn't able to receive any data from the peers and hence reports it as having 'Zero' seeders.

I'm not sure if this topic belongs to this board or not.

[megido-rev.M]

Actually, it would seeing it's not related to this particular tracker.

[Sakura90]

Actually, it would seeing it's not related to this particular tracker.

Indeed, it's a question regarding the torrent protocol.

And I think I just found why. I was looking at the peers tab and I noticed the "flags". I looked for them and found them in uTorrent's FAQ. Interesting. It seems whenever the download stops the peers show the "DS" flag. More searching and I found out about the "snubbing" and "choking" here. And a problem similar to mine here.

I think it I understand it more or less, and it makes sense for a healthy swarm. But nothing makes sense when there are SO LITTLE peers. When there are 2 seeders and 1 leecher, why in hell stupid uTorrent snubs them? It's the ONLY source of data. As far as I understand then it's a problem on my client "banning" them until they decide to send the data. But once snubbed it looks like the seeds never send data again and only a start/stop fixes it. I'm kinda lost here. What to do? Why clients are made to keep that behavior with poor swarms of very few ppl, it should be much more forgiving before snubbing someone. And in case there's 1 or 2 seeders never snub at all.

Ideas? I'll read more tomorrow, I'm kinda tired now and all this is a bit... obscure. To sleep >_<

[Freedom Kira]

Pretty sure your problem stems from the interval at which your torrent application updates the trackers.

Shouldn't be, nope. The update interval is set by the tracker, not by the client. Any client that overrides that and just updates whenever the heck it wants is a bad client.

And I think I just found why. I was looking at the peers tab and I noticed the "flags". I looked for them and found them in uTorrent's FAQ. Interesting. It seems whenever the download stops the peers show the "DS" flag. More searching and I found out about the "snubbing" and "choking" here. And a problem similar to mine here.

I think it I understand it more or less, and it makes sense for a healthy swarm. But nothing makes sense when there are SO LITTLE peers. When there are 2 seeders and 1 leecher, why in hell stupid uTorrent snubs them? It's the ONLY source of data. As far as I understand then it's a problem on my client "banning" them until they decide to send the data. But once snubbed it looks like the seeds never send data again and only a start/stop fixes it. I'm kinda lost here. What to do? Why clients are made to keep that behavior with poor swarms of very few ppl, it should be much more forgiving before snubbing someone. And in case there's 1 or 2 seeders never snub at all.

Ideas? I'll read more tomorrow, I'm kinda tired now and all this is a bit... obscure. To sleep >_<

That may well be the reason. Clients usually snub seeds that frequently send bad data or fail to send data within a certain amount of time (note that the snubbed flag indicates that your client snubbed the peer, not the other way around). I would expect this to not reset if you stop and start a torrent, but perhaps clients need some way to refresh their knowledge and this is the best way to do it.

The seed may be temp-banning you for eating up so much of his bandwidth. If you were the seeder, you'd probably do the same to someone who asks for 100 pieces at a time or something. It's probably a safety thing. I'd expect that lowering the max number of connections per torrent in your settings should help with that.

[kitamesume]

i've seen that happen on some buggy download managers, not necessarily torrent manager, but scarce on torrent managers.

download a regular file, pause->continue and see a wooping 300+KB/s on a 2mbps line, it should be impossible really.


ok as for the issue, are you running on default utorrent settings or did you tweak them? same goes for some OS internet tweaks, download managers hates those tweaks.

edit: i think the "maximum connection globally/per torrent" details to how many peers/seeds can connect per torrent at once, not how many pipes/connections per peer or seeds.

[megido-rev.M]

^ Yes. 'Connections' in that context is synonymous with 'connected peers'.

[Freedom Kira]

^ Yes. 'Connections' in that context is synonymous with 'connected peers'.

No, it's not. You can open multiple connections to the same peer.

edit: i think the "maximum connection globally/per torrent" details to how many peers/seeds can connect per torrent at once, not how many pipes/connections per peer or seeds.

No, it is exactly what it says - how many connections the client is allowed to make for each torrent. It's possible to use up your entire allotted number of connections for one torrent on a single peer. If you hammer a single seed with your max number of connections per torrent and that number is set very high, chances are you'll get temp-banned.

[megido-rev.M]

You don't say. I guess I should increase my max global connections then.

[kitamesume]

i cant really say if your claim is fact or not, because with that info it would mean that anything over 10connections is bound to get you snuffed.

also i just checked, the entries in utorrent are as follows:

global maximum number of connections : 200
maximum number of connected peers per torrent : 50
number of upload slot per torrent : 2

• use additional upload slots if upload speed <90%

which means, the middle is nulled, it only pertains to number of peers, and it doesn't say number of connections to peers.
and leaves you with global, so anything over 10 on global is bound to get you snuffed? i don't think so.

edit: simply put, if you enter in 10 on global you can only power up 10torrents at once with only one connection to each, or maybe the other way around of 10connections per torrent. but its still not the case on peers or seeds.
also, with that info in mind, it would suggest that running multiple torrents at once should solve the connection problems, but it doesn't.

edit2: theres also the registry entry of maximum number of connections per server under the TCP/IP registry entry, unless utorrent bypasses the OS's connection constrictions it should limit it down to x number of connections per IP address/server.

[megido-rev.M]

Connections use resources managed by the OS. That much I'm at least sure of.

[Freedom Kira]

i cant really say if your claim is fact or not, because with that info it would mean that anything over 10connections is bound to get you snuffed.

That depends on the seeder's settings.

also i just checked, the entries in utorrent are as follows:

global maximum number of connections : 200
maximum number of connected peers per torrent : 50
number of upload slot per torrent : 2

• use additional upload slots if upload speed <90%

I guess uTorrent uses different settings. I get max connections per torrent in KTorrent. Is there a setting somewhere for max connections per peer?

[megido-rev.M]

It doesn't, as far as the bandwidth settings show. Can't say for newest versions though.