torrent stuck on file

[Bannerdog]

Hello,

Let's say I'm downloading a torrent "containing" 30 files.

I make one of the files "high priority".

The remaining files are "normal" or "low" priority.

Quite often, the high priority file reaches 99.8% or 99.8% complete, and then won't "budge".

In order to "force" the file to complete, I must change the status of all other files to "don't download", then change them back once the stuck file finishes.

However, doing this can cause my download rate to drop to zero once the high priority file finishes, and then take some time to go back up after I change the other files from "don't download" to "do download" (high, normal, or low).

So, the question is, why does the (only) high priority file often "get stuck" at 99.8%?

This could conceivably be

1) Caused by the uTorrent client.

2) Caused by a torrent server.

3) A consequence of the torrent protocol.

Does anyone know the details of why this occurs?

I wouldn't think that it's by design.

And it doesn't seem like it would be difficult to fix.

Thanks

[DreadWingKnight]

It's a consequence of downloading outside of the normal "rarest first then random" piece order.

Forcing sequential downloading like you're likely doing does NOT help you get the files faster.

[Bannerdog]

It's a consequence of downloading outside of the normal "rarest first then random" piece order.

Forcing sequential downloading like you're likely doing does NOT help you get the files faster.

A) It is NOT a consequence of failing to download the rarest piece first.

That makes no sense.

Certainly not an implicit consequence. It could only be a consequence if a client, server, or protocol was deliberately designed to hold back the final pieces of a file selected for high priority download (possibly to discourage such downloads, but if so, why even allow priority to be specified?).

In such cases, the final piece or two (to complete the 99.8% file) is readily available.

In fact, I can finish off the "stuck" file almost instantly, by placing all other files into "skip" status, as I indicated in my original post.

Whether or not forcing sequential downloading helps me get files faster was not the issue.

C) Utilizing download priority can be very useful in some circumstances, and my use of it often has minimal impact on download speed, mine or my peers.

I tend to use the following approach:

First, I check availability. If availability is low (less than perhaps 8), I rarely prioritize, because I want the rarest pieces to become the highest priority (that is, I want to increase overall availability, and I hope and presume that the default logic will do so, at least when availability is low).

Next, I visually inspect the availability bar to see whether availability of pieces seems to be uniform, or whether there are dense areas in a pattern indicating that some peers have downloaded some intact files.

The next thing I check for, after downloading for a while, is the percentage of my data that is coming from seeders, as well as the ratio of seeders to non-seeders.

In an extreme case, in which all peers are seeders, there's no point at all in not downloading sequentially (other than the possibility that a non-seeder will show up).

In any event...

If the sole goal is to minimize the time needed to obtain all desired files of a torrent (which is often the entire torrent), the "best" approach is to not prioritize,

However, that is not always the sole goal.

Sometimes I want to:

A) Watch one or two videos of a series to determine whether I am interested in the series.

Watch one of the videos sooner, rather than later.

C) Maximize the odds that I will get at least some complete files.

If availability is high, and distribution is uniform, I usually prioritize sequentially.

If availability is high, and distribution is non-uniform, I often prioritize a file that is least-available.

----------

There was a case in which a torrent had about 15 files.

There were NO seeders, but about 10 peers, and availability was just BARELY over 1.00.

Amongst us we had it all, though no one had the whole thing.

One guy had in the 90's.

Clearly, a very high priority is to get at least two copies of every piece "out there", and then at least three copies of every piece, etc (i.e, to increase availability).

On the other hand, it's better to get some complete files than to get none.

Will the 90's guy seed if he finishes?

Piece availability was basically uniform.

I selected my file with the highest completion percentage, and made it high priority.

When it finished, I selected the next highest completion percentage, etc.

After 4 files completed, the guy with the most got the full torrent, he went to 99.9%, then disappeared.

What a jerk.

At that point, availability was something like 98%.

However, only the 4 files that I had selected for high priority were completely available.

About 8 of us hung on for days, all reaching 98% (or whatever it was), but never going further.

If I had not prioritized, would we have had 100% after the jerk left?

I doubt it, though it's possible.

It didn't appear as if anyone else prioritized, and so I think i rarely downloaded a more common piece at the expense of a rarer one.

Of course, the 4 files that I had gotten became available to the remaining peers.

I suspect we got the 4 files only due to my decision, but I can't be 100% sure we would not have gotten the whole thing had I "left it alone".

I never got the rest of the files.

[areaseg]

Well, first of all, I suppose that the problem is because it has no SEEDs.

I already downloaded a file at 300 KB/s that stucked at 94%, because it had no seeds.

Other time I downloaded a complete MP3 even with no seeders. I suppose that uTorrent got part of one, part of other, and parts of several peers, joined the parts and completed the download, so I become the seeder.

When I wish to download a video file, usually I download first the txt file to see if the video is XVID or Windows Media Encoded. Usually fake videos have this wrote down in a text file. It takes one or two minutes to download first the text file.

I already had a torrent that stucked some minutes after completed because it was hashing. It was a 25 GB Blue Ray video!

Maybe the guy you cited above set the computer to turn off when download was complete.

Unfortunately many people do not seed the torrent after download.

I usually seed for 30 minutes, but there are many people that just download and dont seed nothing.

(leechers)

And remember, I already got a pack of files with 99% complete and I was able to listem to the fine!

It was a pack of MP3 files.

Uncomplete torrents are very frequent in the internet.

Maybe you can try another torrent, for the same file?

[Bannerdog]

Well, first of all, I suppose that the problem is because it has no SEEDs.

I already downloaded a file at 300 KB/s that stucked at 94%, because it had no seeds.

Other time I downloaded a complete MP3 even with no seeders. I suppose that uTorrent got part of one, part of other, and parts of several peers, joined the parts and completed the download, so I become the seeder.

When I wish to download a video file, usually I download first the txt file to see if the video is XVID or Windows Media Encoded. Usually fake videos have this wrote down in a text file. It takes one or two minutes to download first the text file.

I already had a torrent that stucked some minutes after completed because it was hashing. It was a 25 GB Blue Ray video!

Maybe the guy you cited above set the computer to turn off when download was complete.

Unfortunately many people do not seed the torrent after download.

I usually seed for 30 minutes, but there are many people that just download and dont seed nothing.

(leechers)

And remember, I already got a pack of files with 99% complete and I was able to listem to the fine!

It was a pack of MP3 files.

Uncomplete torrents are very frequent in the internet.

Maybe you can try another torrent, for the same file?

The second have of my second post was simply a story, an example where setting file priority was probably very helpful because it allowed us to get at least some of the files in the torrent.

As for being unable to get the remaining files in the torrent, OBVIOUSLY if there had been a seeder, we could have gotten them.

If you are addressing my original post ("stuck file"), it has NOTHING to do with lack of seeders.

1) In the case of stuck files, there are often many seeders from whom I am receiving data.

2) As I have indicated multiple times, if I simply set the remaining files to "skip", the 99.8% file finishes virtually "immediately".

[Bannerdog]

I have a request.

While I appreciate efforts to respond to my post, before doing so, please READ it. Skimming a few words or looking at the subject line isn't sufficient.

[ciaobaby]

@Bannerdog

You seem to be missing the rather important fact, that the bittorrent protocol does NOT download 'files', it download 'pieces' that are parts of the contiguous data payload. Which when re-assembled in the correct order creates what the disc filing system can identify as individual files.

[areaseg]

Well, I intended to pass you some experience I had, more than answer the original question.

[areaseg]

@Bannerdog

You seem to be missing the rather important fact, that the bittorrent protocol does NOT download 'files', it download 'pieces' that are parts of the contiguous data payload. Which when re-assembled in the correct order creates what the disc filing system can identify as individual files.

Well said!