I was just downloading a file and was looking at the amount sent per peer and the amount sent was way over what it should be. The total file was around 353 megs. I enabled logging and see this:

Wed Sep 15 20:18:47 2010: Unnecessary piece, total unnecessary data : 525.91 MiB
Wed Sep 15 20:18:47 2010: Unnecessary piece, total unnecessary data : 525.93 MiB
Wed Sep 15 20:18:47 2010: Unnecessary piece, total unnecessary data : 525.94 MiB
Wed Sep 15 20:18:47 2010: Unnecessary piece, total unnecessary data : 525.96 MiB
Wed Sep 15 20:18:47 2010: Unnecessary piece, total unnecessary data : 525.97 MiB
Wed Sep 15 20:18:47 2010: Unnecessary piece, total unnecessary data : 525.99 MiB
Wed Sep 15 20:18:47 2010: Unnecessary piece, total unnecessary data : 526.01 MiB
Wed Sep 15 20:18:47 2010: Unnecessary piece, total unnecessary data : 526.02 MiB
Wed Sep 15 20:18:47 2010: Unnecessary piece, total unnecessary data : 526.04 MiB
Wed Sep 15 20:18:47 2010: Unnecessary piece, total unnecessary data : 526.05 MiB
Wed Sep 15 20:18:47 2010: Unnecessary piece, total unnecessary data : 526.07 MiB
Wed Sep 15 20:18:47 2010: Unnecessary piece, total unnecessary data : 526.08 MiB
Wed Sep 15 20:18:47 2010: Unnecessary piece, total unnecessary data : 526.10 MiB
Wed Sep 15 20:18:47 2010: Unnecessary piece, total unnecessary data : 526.12 MiB
Wed Sep 15 20:18:47 2010: Unnecessary piece, total unnecessary data : 526.13 MiB
Wed Sep 15 20:18:47 2010: Unnecessary piece, total unnecessary data : 526.15 MiB
Wed Sep 15 20:18:47 2010: Unnecessary piece, total unnecessary data : 526.16 MiB
Wed Sep 15 20:18:47 2010: Unnecessary piece, total unnecessary data : 526.18 MiB
Wed Sep 15 20:18:47 2010: Unnecessary piece, total unnecessary data : 526.19 MiB
Wed Sep 15 20:18:47 2010: Unnecessary piece, total unnecessary data : 526.21 MiB

I don't know what it is. It just seems to keep taking pieces and not banning clients if it is bad data. I looked at the list of peers and it was all coming from seed boxes using deluge if that means anything. The stats reported back to the tracker were ok, but I have seen this happen a few times now and was wondering if there is anything I could do about it. Using Ktorrent 4.03/ kubuntu and newest KDE.

Unnecessary data happens when a piece of a chunk is requested on peer X and then it gets downloaded from peer Y, after which a cancel is sent to peer X, but peer X is already transferring that piece.

So normally you will only see this when 2 or more peers are assigned to the same chunk, typically when a download is nearly finished and there are few chunks remaining. But this should never result in more unnecessary data then there is in the torrent.

It could be that a peer is misbehaving.

How many chunks are left when you see this ?

That was almost at the end of that torrent. On another torrent right now Ktorrent says I have downloaded 295.58 megs of a torrent that is 497.80 megs total. If I go into the peer list and just add up the amount it says is downloaded from just of the 8 of the highest downloaded peers that amount is already over 428.39 megs. Something is just not adding up. I took a screen picture if that helps at all.

What version are you running ?

Sorry. I was away for a while. I am now using 4.04 and this is still happening. I have downloaded over 150 megs of stuff from various seeders but the total shown in the downloaded column is 21 megs. I sent you screen shots before and I took a screen shot again. It is crazy and this is not at all normal. All the seeders are using Deluge.

Can you send me a torrent where you see this behavior ?

George wrote:Can you send me a torrent where you see this behavior ?

I can't because it is a private site, but info has been PM'd to you. Thanks.

Which is not very useful, I need a torrent where you can easily get this behavior. So I can reproduce it, and investigate what is going wrong.

George wrote:Which is not very useful, I need a torrent where you can easily get this behavior. So I can reproduce it, and investigate what is going wrong.

It ONLY occurs when a torrent is first being seeded, when a lot of fast seeders/seedboxes are going. If I sent you a torrent it wouldn't be having the error by the time you got in on the swarm. I sent you a log and a screenshot. Can't you see the amount of data being downloaded, compared to what it should be at? I really guess you can't do anymore then.

Thanks anyways.