I am very keen to use mod_security for my Apache throttling requirement. 

I need to limit the number of request to the following URL.


The limit is 2 request per second from any user or any IP. So this limit is globally and not specific to any IP or user. If any request go beyond the limit, they will need to reject immediately with a HTTP error code.

I just found couple of sample rules, but they all are  based on IP or user collection.