Multiple Identical GET Requests (Apache)

[Birched]

On a largish board, we occasionally get spikes in server load that appear to be caused by users making many simultaneous GET requests (~30-50 in 15 seconds). The problematic requests are identical requests for the same PHP file (e.g. index.php, forumdisplay.php, or showthread.php).

I have chased down users who have done this, and have had various explanations ranging from 'I was having connection problems' to 'I spammed the reload button'. For a while I suspected a browser bug, but after a couple of the latter responses I am less sure....

I was wondering whether anyone else has had this problem, and, if so, what they might have done about it?

In particular, I am curious whether there is a solution where I could prevent simultaneous requests from the same IP address for the same PHP page (but without limiting simultaneous requests for all files, as I have not ruled out the possibility that there are some legitimate duplicate requests for js or image files).

Any comments or suggestions are appreciated!

apache version: Apache/2.2.17 (Unix)

[vbresults]

Try nginx.