Symbolic link folder permissions

[Debra_in_MO]

I'm running ZC 1.3.8a, Linux. My host uses suphp. I have and use SSL (my own, not shared).

I was told that no folders were to have 777 permissions. Instead I am to use 755.

I have been having a variety of "sporadic" download issues over the past month especially with larger files (greater than say 20MB). Downloads have I/O errors, corrupt errors, etc. Webhost has no idea what the problem is and I've researched the forums and haven't found an answer either.

I use download by redirect and have "pub" & "download" folders set to 755. Mostly, I am NOT able to reproduce the download errors that my customers have and neither can my webhost. Customers have all different internet connections, some even DSL. My max_execution_time is set to 900, so I do not suspect any issues with that either. My largest downloads are about 50-60MB and download fine with a direct link.

While doing some testing today, I noticed that the symbolic link folders always have 777 permissions. (Webhost says this should be okay even with suphp.) However, when I made some changes from download by redirect to streaming (redirect=false & streaming=true), I received an "IE cannot display this webpage error" when I clicked on the download link and when I checked my Cpanel error log, it said "Symbolic link not allowed or link target not accessible: /home/.../public_html/store/pub/.vhbgpytsbobpds/...".

Any ideas as to what causes this error?

There are so many variables for me here. I changed to this webhost in July and have had problem after problem with downloads. I came from a freeBSD(?) server with shared SSL and was running ZC1.3.6 using download by redirect. I didn't have all of these download problems then. I'm stumped as to what is causing so many problems now. I have a new cart and what seems to be better host as well as my own SSL - should be in better hands now I'd think.

Any thoughts on where to begin my troubleshooting? I'm also having some trouble with downloads from the CMS side of my site for files as small as 12MB. Maybe that gives me some kind of hint? Webhost insists it's not them.

[DrByte]

I was told that no folders were to have 777 permissions. Instead I am to use 755.

With suphp, that's fine.

Mostly, I am NOT able to reproduce the download errors that my customers have and neither can my webhost.

That's puzzling.

Customers have all different internet connections, some even DSL. My max_execution_time is set to 900, so I do not suspect any issues with that either. My largest downloads are about 50-60MB and download fine with a direct link.

With direct or redirected downloads, the max-execution time shouldn't make any difference.
If using download-by-streaming, then the max-execution time does play a part.

While doing some testing today, I noticed that the symbolic link folders always have 777 permissions. (Webhost says this should be okay even with suphp.) However, when I made some changes from download by redirect to streaming (redirect=false & streaming=true), I received an "IE cannot display this webpage error"

If it was truly in streaming mode at that point, that suggests that somehow the streaming isn't starting properly, whether a timeout or a lag in processing, or unexpected page headers are being sent, etc.

when I clicked on the download link and when I checked my Cpanel error log, it said "Symbolic link not allowed or link target not accessible: /home/.../public_html/store/pub/.vhbgpytsbobpds/...".

If you were in streaming mode, you shouldn't be getting any new symbolic link errors, because symlinks aren't used when streaming.
Symlinks are only used in redirect mode.

I changed to this webhost in July and have had problem after problem with downloads.

... I'm also having some trouble with downloads from the CMS side of my site ... Maybe that gives me some kind of hint? Webhost insists it's not them.

I'm inclined to suggest it's something amuck with the host.

[Website Rob]

I would also agree that the problem probably stems from the Hosting side of things.

The problems stated are not the norm but can happen on an overloaded Server.

You should monitor by using:

Admin > Tools > Server/Version Info
- look at the line that states "Server Up Time" (near top of page) and see what it shows for "load average"

The first set of numbers is most important and hopefully, it will always be under or close to 1.0 but even 3.0 can be acceptable in certain situations. If any higher and on a regular basis, you know the Server is overloaded which will cause all cause of problems.

[Debra_in_MO]

If you were in streaming mode, you shouldn't be getting any new symbolic link errors, because symlinks aren't used when streaming.
Symlinks are only used in redirect mode.


I'm inclined to suggest it's something amuck with the host.

What should a streaming link look like? The link that takes me to the "IE cannot display this webpage" looks like this:
http://www.mydomain.com/store/index....=XXXX&id=XXXXX (X's are numbers)

I tried this also in Firefox and the page just hangs and doesn't do anything.

I have redirect set to false and streaming set to true. Are there other settings I should be changing in order to make the switch from one to the other?

[Debra_in_MO]

I would also agree that the problem probably stems from the Hosting side of things.

The problems stated are not the norm but can happen on an overloaded Server.

You should monitor by using:

Admin > Tools > Server/Version Info
- look at the line that states "Server Up Time" (near top of page) and see what it shows for "load average"

The first set of numbers is most important and hopefully, it will always be under or close to 1.0 but even 3.0 can be acceptable in certain situations. If any higher and on a regular basis, you know the Server is overloaded which will cause all cause of problems.

I'll keep an eye on this. Thanks for that info. At first glance the first number was 1.4, but it's steadily decreased throughout the evening. I'll check it during the day tomorrow when things are busier.

[DrByte]

What should a streaming link look like? The link that takes me to the "IE cannot display this webpage" looks like this:
http://www.mydomain.com/store/index....=XXXX&id=XXXXX (X's are numbers)

That's a normal link when in streaming mode.

I have redirect set to false and streaming set to true. Are there other settings I should be changing in order to make the switch from one to the other?

Not usually.

[Debra_in_MO]

If it was truly in streaming mode at that point, that suggests that somehow the streaming isn't starting properly, whether a timeout or a lag in processing, or unexpected page headers are being sent, etc.

I assume that "timeout" and "lag in processing" would be something for the webhost to take a look at. What about the "unexpected page headers being sent"? How do I check this?

[Debra_in_MO]

I would also agree that the problem probably stems from the Hosting side of things.

The problems stated are not the norm but can happen on an overloaded Server.

You should monitor by using:

Admin > Tools > Server/Version Info
- look at the line that states "Server Up Time" (near top of page) and see what it shows for "load average"

The first set of numbers is most important and hopefully, it will always be under or close to 1.0 but even 3.0 can be acceptable in certain situations. If any higher and on a regular basis, you know the Server is overloaded which will cause all cause of problems.

Most current load numbers right now (11:49 CST) are 2.75, 1.92, 1.54
Session-Total:597-8621 (if that helps any)
I run an educational site, so our busier time for traffic is during the day.

I am now also receiving download errors (by redirect, streaming not working for some reason).

[Website Rob]

Two suggestions I can offer are:

- check your Hosting account Error logs to see if they provide any insight
- contact your Hoster to see if they can help with live troubleshooting of the problem

[Debra_in_MO]

Webhost says I should mention to you all that my pdf downloads have upwards of 800 pages. I would think what matters is the overall size of the pdf which in this case is about 50-60MB for these files. I didn't have these consistent download problems with these same large files before. Direct links for these download fine. This morning I had trouble downloading a 224 pg 3MB file. It just stopped.

Does anyone know how the number of pages would adversely affect the download process? Also, this doesn't explain why my download by streaming is no longer working either (unless it has something to do with page headers RE: Dr. Byte's comment above).

Here's what my webhost says after they tested the files through the customer account area:

"This is what happened to me when I tried to download your files. When I clicked on the link, a new page opened up and my adobe pdf plugin in my browser tried to open the 800+ page in my browser. It choked about half-way through due to the amount of resources my own computer was using to try to open the file within the browser. When I went back to the download page and right-clicked on the download image and selected the save as file function, I was able to download the file with no problem.

As for server load, the server that you are on is a 2 cpu service which means the server load that you see should be divided by the number of cpus which in this case is 2. So if the server is running at a load of 3 then divide that number between the 2 cpus and the load per cpu is really around 1.5 which is not a problem. You typically would not see any adverse effects such as slow loading of a page unless the load was around 4-5. Even then the server would still be fully functional.

I monitored the server load while I was trying the open the pdf file within my browser and the load actually went down while I was trying to open the file in my browser. The server load was a little higher when I used the "save as file" function but I was able to download the file no problem that way.
With this testing, I am convinced the issue lies with the Adobe plugin and perhaps with the way you are creating your pdf files. Since I am able to open the pdf file in Adobe with no problem once I downloaded it, I think the issues lies with the Adobe plugin in the browser."

I'll research this Adobe plugin as they suggest here. My concern still though is that these same links(& files) in the customer account area used to work just fine (well, occasional hiccups here and there but nothing like what I experience now). Plus, direct links work.

Even today, the same file (for me) would sometimes download w/o any errors and then the next time it would not.

How does that happen? Seems like it either should work or not work - not both.

Also, is it possible for direct links to work and then not for the redirect to work due to an Adobe plug-in issue? This is where I get lost in the technical processes of what's going on here.

Thanks.