Download corrupt

[DrByte]

They are running PHP 5 and have customized their Apache for highest efficiency and stability. Not sure what that means about what they've done or how it would affect Zen Cart.

This is Siteground, btw.

Perhaps you might ask them for a detailed list of changes they've made since around the time you first started getting complaints.

The goal is to find out what's suddenly caused downloads to no longer be delivered reliably since they made the changes.

[freya]

I was going to update from 1.3.2 to 1.3.7, but decided to do a new install instead as it seemed easier and less problematic, so that is what I did.

[freya]

I was having some problems in the beginning, but then they fixed the symlink issue, so that's not a problem. They upgraded their servers, but it didn't affect my downloads. In any case, I have gone to streaming, but now people are getting errors that the files are not found when they are on the server, in the correct folder, and it shows in admin that they are there, AND I still have the corrupt file problem. I have zipped my files, although that really shouldn't be necessary as people download pdf files off the internet without a problem all of the time.

Should I reinstall Zen Cart? (Gah! Thinking about it makes me shudder. LOL) I'll do it if it might fix this mess.

Thanks,

Marci

[DrByte]

I'm not optimistic that a re-install will make much difference, since I suspect the problem is a server thing.

However, you could test the theory by installing into a subdirectory, with a fresh set of files, and using a separate new temporary database. Then set up a couple products with downloads, and test. If the problem "does" go away, then maybe it's worth the re-install. Or at least worth doing a careful comparison of all your settings, etc.

[freya]

If it is an issue with the server translating Zen Cart, what do I do? Query them?

Marci

[DrByte]

There are too many unknowns to be able to know exactly what's causing it.

You said it used to work reliably.

Your hosting company says they've changed some things.
But they won't tell you *what*. Most likely they don't even know *exactly what*.

So, they're just going to "pass the buck" and blame your software ... ie: Zen Cart.

If we knew what exactly they changed, we might have an idea of what to tell them to undo, or maybe even a way to write code to override the mess their changes have caused.

Since I doubt they're going to help you at all, any resolution is going to require a lot of research, including trial-and-error.

And, since the problem seems to be intermittent and cannot be repeated consistently "on demand", it's going to be a very tough one to solve.

But, if you can find a pattern, or narrow it down to certain specific conditions during which the downloads fail, there might be some hope.

[DrByte]

Some of the things we'll need to know are:

- *how* is the file corrupted? -- ie: is it too short? or too long?
- does it contain any extra characters, either at the top or the bottom?
- does it happen with *any* file, or just specific ones?
- what's common with respect to the failures? file sizes similar? file type? file extension?
- is there any pattern to the browsers used?

You already mentioned earlier that you were:

I have been querying customers who've had download problems to see what browser, OS and internet speed they have to see if there is any correlation between these and the download issue.

What sort of observations have you made?

[DrByte]

Do you have GZip compression enabled in Admin->Configuration->GZip ?
Is there any difference if you change the setting there?
Turning it off might be a help.

What is your setting in Admin->Tools->Server Info for "output_buffering" ? (go to that screen, and search for output_buffering, and report the values shown beside it).

[freya]

Okay. I have at least found why the file is said to be corrupt: There is HTML inserted at the end. For some reason, some computers can open it fine where others can't. The original files do not have HTML in them. What would cause a file to have HTML inserted into it?

I have informed my server about what is happening.

This still does not explain why some times files are not found.

Marci

[freya]

Alright, this is what I have learned from my server:

As I am on a shared server, Apache is set to time out at after a certain time. I find this a bit upsetting as we have very few files larger than 1 MB. Even if someone buys say five books at a time that are 1 MB/book, you are only looking at a 5 MB download. Say a few other people are buying and downloading at the same time, this still shouldn't be that much of an issue. I never exceed my daily limit. We have decent sales, but nothing that should overtax the server or go past our limit (5000 GB/mo). It looks as if I will need a new host if this cannot be resolved. (sigh) I am not going to pay $89/month for a virtual private server when the file sizes are so small. We do not have enough product to warrant a private server.

Breathe, Marci. Breathe.

Marci