A couple of J. van Eyck files fail to download completely

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rud
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A couple of J. van Eyck files fail to download completely

Post by rud »

Files from Preludim (No.1) to De Zoete Zoomertyden (No.41) and Wilhelmus van Nassowen (No.42) to Psalm 150 (No.85) stop downloading at around 9.4 to 9.6 MB. I first tried downloading these some weeks ago and the result was same. I also tried using wget with a direct link but it didn't work either.

The links above are on the page http://imslp.org/wiki/Der_Fluyten_Lust- ... Jacob_van).

These books would be much use to me so any help would be appreciated.

-Janne
Sallen112
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Re: A couple of J. van Eyck files fail to download completely

Post by Sallen112 »

All the links your provided to the files open on my end with no issues. It must either your internet connection speed or your processor of the file is slow to open. Since these files are very big (15-20mbs in size) it might take some time for them to open. Did you try right clicking on the file and save the files directly to your desktop? Opening them in your browser is very slow processing because the images look like they are in color. If they were black and white, the processing would be much quicker. Opening them on your desktop opens them much faster.
rud
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Re: A couple of J. van Eyck files fail to download completely

Post by rud »

Today I tried again (using direct links) and it worked. What was the problem before I don't know.

But I don't think it should be about my internet connection speed, because I frequently download bigger files without problems. It wasn't the file processor either, as I could clearly see that the downloads finished prematurely and the files were smaller in size than they should've been. I tried downloading them multiple times and they always stopped at around the same "spot".

Anyhow, all's well that ends well. :D
Sallen112
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Re: A couple of J. van Eyck files fail to download completely

Post by Sallen112 »

Clearing your cache can reset the downloads to start from the beginning and hopefully it won't run into the hiccup.
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Re: A couple of J. van Eyck files fail to download completely

Post by Choralia »

The logs of the IMSLP-EU server show pretty normal file download times on August 4th, except at 02:15, 07:00, and 16:00 UTC, when the time to download a test file was just a little bit longer (few seconds) than normal. Most likely, the cause of the problem was a minor temporary glitch (probably at the network level) plus the effect of corruputed files stored in the computer's cache being retrieved locally in lieu of the uncorrupted files present on the server.

Small trick to be used in the case of problems: replace imslp.eu with petruccimusiclibrary.eu in the URL. You'll get the same files from an alternative EU server that is ready to backup operations in the case of major problems with the main EU server. This would also bypass the computer's cache because the domain name is different.The domain name petruccilibrary.eu can be also used, which is an alias of the main EU server.

Max
rud
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Re: A couple of J. van Eyck files fail to download completely

Post by rud »

I decided to test a couple of days ago if limiting the download speed would affect whether the download completes or not, and it seems it does. I used this url: http://imslp.eu/files/imglnks/euimg/4/4 ... eus_v3.pdf because it links to a somewhat smaller file (about 8 MB). The first download completed fine at about 80K/s or so (I don't have the logs anymore). The second, with a rate limit of 15K/s failed after 3m 15s. The third, with the same limit, failed after 3m 10s.

I tried again today with the same file and a limit of 20K/s and it failed after 2m 49s. After that I tried without a rate limit and the download succeeded in 98s with an average speed of 86.3 KB/s.

Could it be something in the imslp.eu server configuration that causes this? I tried downloading the same file from petruccimusiclibrary.eu with a rate limit of 20K/s and it succeeded.

I used wget for the downloads. I don't think it uses a local cache, and anyway the retrievals from it would be pretty much instantaneous, wouldn't they?
Choralia
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Re: A couple of J. van Eyck files fail to download completely

Post by Choralia »

rud wrote:Could it be something in the imslp.eu server configuration that causes this?
Yes. A monitoring system runs on the imslp.eu server, which is used both to count the number of downloads, and to trace recurrently failed downloads due to erroneous links (this may reveal that the main IMSLP website invokes the EU server through a wrong URL - tracing these circumstances allows to proactively correct errors). This monitoring system timeouts when the file is very large and the download speed is very low, so that the download time is more than around 3 minutes. The same monitoring system is not active on the petruccimusiclibrary.eu server as it is an offline mirror so there is no reason to strictly monitor it. This is the reason why the download succeeded on it, even when limiting the download speed to 20 KB/s.

I've modified the monitoring system at imslp.eu so that it does not timeout, and therefore large file downloads at a very low speed can be sustained now. I performed tests down to 5 KB/s with the example file that you indicated. The download took almost 30 minutes, however it was successfully completed.

The same monitoring system is used on other regional servers, too. If no problems with imslp.eu are experienced in the next few days, I'll apply the same modification to the other servers.

Thank you for highlighting this problem. It could be only experienced in rather specific conditions, though. It is positive that now we are able to provide the service even in more marginal conditions than before.

Max
rud
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Re: A couple of J. van Eyck files fail to download completely

Post by rud »

Choralia wrote: I've modified the monitoring system at imslp.eu so that it does not timeout, and therefore large file downloads at a very low speed can be sustained now.
Thanks! 8)
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