Speeds "crash"

[bkman]

Odd phenomenon I am experiencing with utorrent. I get incredible speeds for a decent period of time, but periodically the speeds suddenly plummet and utorrent seems to drop quite a few connections. Then the speeds once again climb their way up as it reconnects to the dropped peers.

Is this an acknowledged bug, and will it be fixed next version?

[Firon]

Are you seeing disk overloaded? If so, increase diskio.write_queue_size to a more respectable value (2* to 4* your DL speed, without going over 32000, don't change write delay!)

[bkman]

Yes, I forgot to mention that I am not seeing Disk Overloaded while this is happening. I am quite happy with my I/O settings, although I did change the Write Delay to much lower than the default to enable faster hashing.

[bkman]

This still happens in 1.2 (!!), but seemingly only at fairly high speeds and with a large number of peers.

Here is an illustratory screenshot: http://tinypic.com/fnxvr8.png

And no it is not just a case of a fast uploader leaving.

[DomZ]

Maybe you should try uploading

[bkman]

Maybe you should try uploading

How would that help in this case?

And if you are thinking of criticizing what you percieve of my seeding habits, then forget it.

[Ares]

And if you are thinking of criticizing what you percieve of my seeding habits, then forget it.

Ummm, well, not to criticize, but yeah, your downloading is linked to your uploading. If you'd upload more, according to the Bittorrent protocol, you would indeed receive more. That's kind of how it works. Nothing personal.

Straight from the creator of Bittorrent himself:

"I don't want you stealing my bandwidth! How can I stop it from uploading?"

You could hack the source to not upload, but then your download rate would suck. BitTorrent downloaders engage in tit-for-tat with their peers, so leeches have very little success downloading.

http://www.bittorrent.com/FAQ.html#stopupload

-Ares

[bkman]

Ummm, well, not to criticize, but yeah, your downloading is linked to your uploading. If you'd upload more, according to the Bittorrent protocol, you would indeed receive more. That's kind of how it works. Nothing personal.

Just a look at the swarm stats should make it clear that this doesn't apply to the torrent in question. The large number of seeds and very few leechers means that I am not penalized for not uploading at that moment.

And even if I were, that would not explain the huge dip.

[Animorc]

A few questions:

Does it happen on more than one torrent?

Do you have the possibility to save the torrent to another disk?

Are you downloading anything else in high speeds with another program?

Do you have any other program running, performing heavy disk activity? i.e. Defragmenter, Virusscanner etc.

[Ares]

You know, come to think of it, I have seen µTorrent downloading from a fast peer, only to disconnect from it and others in like 5 minutes. Perhaps it's a bug with the auto-disconnect of non-downloading peers? Maybe after 5 minutes, all peers are cycled?? Just a thought.

Best test would be downloading, say, an Ubuntu torrent. They're always seeded well. If you don't spike on that, you know it's just your torrents.

Try this one: http://us.releases.ubuntu.com/releases/5.10/ubuntu-5.10-live-i386.iso.torrent

I max out on it, and my downloads don't spike. What about you?

-Ares

[Firon]

it disconnects from any peer that's idle for more than 5 minutes. the interval is configurable in the betas, and it's also possible to disable it altogether.

[Ares]

it disconnects from any peer that's idle for more than 5 minutes. the interval is configurable in the betas, and it's also possible to disable it altogether.

Do you think it's cutting off peers that are currently transferring, though? A bug, maybe?

-Ares

[bkman]

A few questions:

Does it happen on more than one torrent? Yes

Do you have the possibility to save the torrent to another disk? Yes, but only a slower one.

Are you downloading anything else in high speeds with another program? Yes. Other BT clients don't seem to suffer these huge dips.

Do you have any other program running, performing heavy disk activity? i.e. Defragmenter, Virusscanner etc. No. Utorrent would tell me my disk was overloaded in that case anyway.

I tried the ubuntu torrent, and saw high speeds and no signs of dips, but that is probably because it is a very "clean" torrent. Ie. many peers have very high upload speeds, so utorrent doesn't need to (want to?) connect to more than ~50 of them. In other torrents I use upload speeds are more evenly distributed and more peers are connected to. This problem usually manifests itself at around 150 - 200 peers. Either utorrent is limiting the speeds inexplicably, or dropping active sources, or I am being snubbed without warning by a large number of seeds at once.

[Firon]

Ares: No, it doesn't do that, ever. That means the peer disconnected itself for some reason (connection dropped, power went out, closed the client, etc), OR your ISP is screwing with you. It's more likely to be the first.

bkman: Is it possible your ISP is screwing with it? You should turn on the logger and see. Also, it might be your modem or router that's taking a dive and can't handle so many connections, I've seen it happen on weak modems and routers.

[bkman]

My ISP recently doubled my upstream (to 256k :-/), and this seems to have resolved the problem. I was getting a steady 750kB/s without dips yesterday.

I'm thinking that previously my upstream was getting choked to the point where utorrent started dropping peers or others were snubbing me.