Interesting Problem with apache

Hello All,

I am facing an interesting problem with apache.

A particular file (xxx.php) gets a lot of requests in a day. Its quite
frequently happening that together there are a lot of requests for this
particular file ( more than 120 ). Enabling the server - status shows
that almost each of these requests are in 'W' state. In the httpd.conf
file i found that the MaxClients is 150 and TimeOut is 300.

I also monitored the MySQL queries during this heavy load on server.
There were NO queries of xxx.php pending. But almost all queries were
taking thrice the time that they normally take to execute.

On running TOP i found that IOWAIT is almost 100% and CPU IDLE is 0%.
What could be wrong. Is Apache causing the trouble? or is it the
Script? Or is MySQL the actual culprit?


Thanks in advance

Ratheesh K J