Percentage downloaded is less than sum of uploads

Issues and ideas about I2PSnark
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anikey
Posts: 106
Joined: 30 Nov 2023 20:08

Percentage downloaded is less than sum of uploads

Post by anikey »

The situation goes like this (noticed twice):

There are two seeders in total, i have access to them. (One qbittorrent, and one i2p snark)
There appears a downloader using I2PSnark.

After some time, i sum the amount of bytes uploaded on the two seeds, and get value A.
Then i calculate the amount downloaded by the downloader, based on the percentage shown (formula: Torrent_Total_Size * Percentage / 100), and get value B.

On two separate times, i noticed that value A is much bigger than the value B (almost twice as much, i think).

What could this be? Could i2p snark be requesting the same pieces from two seeds simultaneously, and then throwing away one of them?
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lgillis
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Re: Percentage downloaded is less than sum of uploads

Post by lgillis »

Another way of looking at it.
Assuming your clients are using the same router, which I don't know.
The downloader asks for piece 42 from the torrent.
Your router receives the request and forwards it to client #1 and client #2.
The router is not a switch. No. 1 and No. 2 do not coordinate with each other and both send piece 42.
But I'm just guessing here.
    I2P preserves your right to informal self-determination.
anikey
Posts: 106
Joined: 30 Nov 2023 20:08

Re: Percentage downloaded is less than sum of uploads

Post by anikey »

1. the seeds are on different routers

2. the i2p does not work like that, otherwise that'd be a big flaw (since different destinations are supposed to be isolated)
anikey
Posts: 106
Joined: 30 Nov 2023 20:08

Re: Percentage downloaded is less than sum of uploads

Post by anikey »

I think i'm noticing this again.
There is an i2psnark downloader.
I have 2 uploaders, i2psnark and qbittorrent. There are no other uploaders.

The downloader reports 1.9% progress (as seen on my i2psnark uploader).
My i2psnark uploader says it's uploaded (translated into %) 1.1%.
But when I add qbittorrent's upload to that, it becomes about 5%.
So, more than one half of the traffic gone somewhere.
anikey
Posts: 106
Joined: 30 Nov 2023 20:08

Re: Percentage downloaded is less than sum of uploads

Post by anikey »

I have noticed a pattern:

if the snark downloads slowly (i.e. <20 KB/s), it is more or less fine.

if the snark downloads fast (i.e. 100 KB/s and more), it actually downloads ~4-5x the reported download progress.

Have you also noticed these kind of things?
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zzz
Posts: 228
Joined: 31 Mar 2018 13:15

Re: Percentage downloaded is less than sum of uploads

Post by zzz »

You only download a piece once. You can upload a piece once, never, or many many times.
BlindTraveler
Posts: 13
Joined: 19 Oct 2024 10:18

Re: Percentage downloaded is less than sum of uploads

Post by BlindTraveler »

That pattern does ring a bell.

About a month ago I was the only seeder(qbittorrent) and there was one leach(i2psnark). File was quite big so over few days I observed that the reported upload(by my client) was "consistently" 2X the reported progress by the leach. The upload was 50KiB/sec, I concluded that that kind of resources waste was unacceptable and limited the upload on that torrent to ~10KiB/sec. After that the reported upload and reported progress look like they matched more closely(I would assume 1:1). Since then I was not in similar position(only seeder with a large file). I have also limited all the upload to <30KiB so I don't think I will be able to observe it again.


Back then I did not care about it(since I considered low upload limit a fix) and same can be said now.
That being said I am interested in what is causing it.


Good luck!
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