Topic: reverse proxy / IE7 / Page Not Found

[mrichards]

I have a strange problem that seems only to affect IE7 when a static doc is served via reverse proxy.

I'm using Apache 2.2.4 on Windows 2003. When an IE7 client connects and requests a document for the first time the target server (the one that requests are proxied to) logs show status 200, the server that the client connected to shows a status of 200 and the error log shows mod_proxy going through the various steps, never indicating a problem. However the result at the client is 'Page not Found'. On the second attempt for the same file, and every attempt afterward, the document is served just fine.

I also notice that this seems to affect Microsoft Word, Excel and PDF files only - images and .zip files never really seem to have any trouble.

Anybody run into this before? Any tips? Please let me know if you need a config excerpt.

Thanks,

-marc

[James Blond]

Is that problem only with IE 7? What about IE6 or FF 2?
What kind of server is the connected server? IIS?
Do you use "Save as" oder just clicking?

With IIS I had some trouble cause is send a vary header. Turning off helped.

[mrichards]

The backend server is Apache running on IBM iSeries.

It really seems to be related only to IE7 and when you click 'Open' instead of 'save'. FF seems to work because it always saves the document before trying to open, but IE will open an Office document or PDF directly in the browser window. I have no idea why IE6 works.

I was kind of assuming that it had something to do with the response headers because both http servers return a 200 status, but I'm pretty much stumped as to why it would work on the second hit.

I'll try turning off the vary and see what happens though.

-marc

[mrichards]

Interestingly, when I explicitly unset the vary header and comment out the append vary header, IE6 begins to have the same problem. FF continues to work fine.

I guess vary doesn't do it though, which makes sense because vary is intended to set cache criteria, correct? What is odd is that I turned caching off during my test, yet it still had an effect. Any other ideas?

Thanks,

-marc

[mrichards]

More on this - I now discovered that the stream of the 'page not found' documents is being prematurely truncated for some reason. In one example I received only 13032 bytes out of 83968.

Has anybody seen this?

Thanks,

-marc

[James Blond]

You may try

[mrichards]

Thanks James, but I actually found the problem and it didn't have anything to do with Apache. Turns out my load balancer was set to drop idle connections after only 1.6 seconds.

The problem wasn't actually related to static documents at all, it was related to documents that prompt you with the window giving the choice between 'Open', 'Save', 'Cancel'. Most Office documents do this and, on my computer, PDF files do to.

So, if it takes you longer then 1.6 seconds to click the 'Open' button, you get only the partial content that was streamed before IE had the chance to give you the pop up. If you're quick, you get the whole thing.

That explains why IE7 was only affected at first - it runs so much slower and takes so long to render the pop up that it's virtually impossible to click the Open button 1.6 seconds from the time that the content stops streaming.

No idea how that setting got in my balancer, but glad I found it. Thanks for trying to help...

-marc