Hello dear community!
I have faced with a trouble which I trying to solve for a long time.

I have service of video streaming. And I have web and video roles for servers.
Video servers upload video using SWFUpload and then stream it.
Issue became during uploading of video.
In random time users receive "I/O error", and I have record in database about this failure.
Also I am unable to repeat this error because don't know reasons.

Below are details of system:
CentOS 5 x86_64
Arch : x86_64
Version: 2.2.3
Release: 11.el5_2.centos.4

Arch : i386
Version: 5.8.8
Release: 15.el5_2.1

Below is answer I've receive on the same question from SWFUpload forum:
There are a few common causes for IO errors. Unfortunately the Flash Player doesn't give any details.

The only way I can think of to log the details is to handle the uploadError event and send the "message" parameter to the server as an ajax request.

Whatever is shown in the message parameter is all the information that Flash gives us.

Most often IO errors are seen:
1. The POST (file size + other post paramters) exceeds the max allowed by the server.
2. The server script execution time exceeds the timeout limit
3. mod_security rejects the upload (because the Flash Player uses a valid but suspicious format for the upload)
4. An error in the page terminates the connection without a response
5. Some other timeout.
6. Anti-virus software.
I don't have #3 mod_security and #6 Anti-virus software on servers.

Is there any way to set timeouts for perl like for php in php.ini?

For Apache there are these settings for timeout:
Timeout 3000
KeepAliveTimeout 1500

Seems it would be enough. Is there any other timeout settings I could set for perl scripts?

Also, I'm using prefork MPM. If I change it for worker MPM could it help someway?

Help please to find the reason of errors.
I'll write any additional details which need to do progress.