Downloads working, but corrupt...sometimes

[bugfreek1]

Hello, All.

I've been operating a live Zen Cart store at http://www.thespacereport.org/store for the last three days...though the site was extensively tested over the past month on development servers and the current production server. My company owns the servers and has complete control over all installs. Since Monday, we've experienced ridiculous traffic from all over the world due to ad campaigns online and in the New York Times.

Yesterday, we were made aware that <<some>> .pdf downloads are being corrupted during the download process, while many also download just fine. We've tested the problem extensively, getting it to appear on seemingly any computer, connection, or OS at least some of the time. Nobody has seemed to be able to pinpoint why the corrupt files are occuring, though one guess is that Zen Cart is having difficulty serving up any more than one download at a time.

Has anyone else experienced this issue? Is there a workaround?

Supporting Info:
Download Dir Permissions: 777
Redirects: off
File type: .pdf
File size: 8.3mb

Thank you in advance.

Ben Peterson
Interactive Media Developer
Space Foundation

[Ajeh]

More than likely your server is setup with an 8meg limit and that file is too big ...

Speak to your hosting site about increasing the limits for your site so that you do not have these issues ...

[rambo]

I have seen problems with corrupt pdfs (that particular filetype). I would recommend zipping the files and delivering the zipped file if possible. I also notice that some pdfs are reading as corrupt when authored in one version and opened in another of adobe acrobat.

"This type of problem is most likely to occur when attempting to load a PDF document which is larger than .5 MB, OR when attempting to load a newer PDF document with an older Acrobat® viewer -- i.e. when attempting to load a PDF created with the version 3.x tools, with a version 2.x Reader.

NOTE: It is extremely rare for the source PDF document (the file from the server) to be corrupt. Once the originals are created and tested (and placed on the server), the only corruptions which are likely to occur, would be due to physical hardware problems (bad sectors, etc.) on the storage system itself. THE SERVER simply sends files requested by the user - it does NOT contol how the document is saved, stored, viewed or otherwise manipulated on the local PC.

Most PDF file corruptions occur ON THE USER's LOCAL PC, as a result of a failure in the Browser/Plug-In Applet. "

[Ajeh]

NOTE: /download should be 755 not 777

[wildchilded]

What if you create the file in the latest version but make it compatible for earlier versions? Does that cause a problem too? I am having the same problem with corrupt files, although it doesn't happen often.

Thanks,

Marci

[NZerSean]

I have a similar problem with html code being added at the end of a 7Mb .exe file. You can see it with a hex editor.
Happens on some products, but not all. (we sell software, so it is a big problem).

Thanks,
Using ZC 1.3.6

[sywp]

Im having same problems

When someone download a zip with mp3s sometimes one of the mp3s is corrupt or even the whole zip

[DrByte]

Try the update attached to this post:
http://www.zen-cart.com/forum/showth...190#post439190

[sywp]

I tried it and my download didnt work at all

When u click download it sends you to this address

http://www.sywp.co.uk/shop/index.php...order=37&id=21


which doesnt work. Seems to not exist IE says page cannot display this webpage