I have the same web application written in PHP running on 2 different machines. On one of the machines, connections are often abort while uploading big files via HTTP; while on the other machine, the application runs perfectly. Both machines run on CentOS, but it was not installed and configured by me. The webserver software is XAMPP for Linux, which was installed and configured by me, so I am sure that they share exactly the same configurations.
So what are the possible reasons for the problem?