Large files download problem from Apache2/Tomcat5 webserver.


I have the mysterious problem that (larger) files (>3mb) which i provide in the cms on my linux (lamp) webserver (running apach2/tomcat5) can't be downloaded successfully.
The files are downloaded only partially using ie or firefox and "save target as" option. After some tries the download then is successful.
I found nothing in the server logs. I did an analysis with tcpdump an wireshark but got no interesting results.
The problem is replicable on different clients with different internet connections so it must be the server.
Any suggestions?

Thanks in advance,
Michael S.

Please excuse me if my english is not so good at all but i'm from germany.
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Is the download really handled by apache httpserver or by tomcat/php?
Which CMS is used?

(ginge aber auch in Deutsch ;-)
centronikerAuthor Commented:
The downloads are handled by apache2 only. The cms is a proprietary development of my customer but based on openCMS. The files provided for download are stored in a separate folder and delivered trough the apache2.

(Deutsch wäre schön aber ich möchte ja unsere nicht-deutschsprachigen Experten nicht ausschließen ;)

If you encounter problems running Apache 2 under, such as corrupted or incomplete file downloads, unexplained error messages, or a conflict with a software firewall, please place the following three directives in your httpd.conf configuration file to see if they eliminate the problems:

    EnableSendfile Off
    EnableMMAP Off

The general problem is that many people install various add-ons to windows (such as software firewalls, virus checkers, etc) that break some of the advanced functionality that Apache uses to speed the sending of files. The above directives turn off the advanced functionality and make Apache fall back to more basic (but slower) techniques. This resolves most, but not all of the potential problems. If you continue to experience problems, be certain that there is no spyware installed on the box, which exhibits exactly the same sorts of flaws (often more obviously).

Another possible could be some kind of load balancing and/or traffic shaping configurations.


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As nonocosm is suggesting, this could also be a problem with the network configuration - are you using Bond-networking? if so, which bond-configuration are you using?

centronikerAuthor Commented:
the server is a standalone lamp server only connected over a cisco switch to the network/internet. so i don't think that there is a network problem. I recently added the two (where is the third ? ;) apache parameters (which nanocosm posted) to my global apache configuration an I couldn't reproduce the issue since i added them. maybe this is the solution but first my customer and me will test this extensive.
It was a quote. I removed the third directive because it applies on Windows Hosts only.
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