What is the state of the art now in apache or modperl related modules that will throttle based on a combination of the following metrics:
* recent bandwidth per IP * recent request count per IP * max number of parallel requests per IP I'm using a tweaked version of the Stonehenge utility and it works ok but a bad robot (and there are SO many now) can fill all request slots before a long enough measurement period has elapsed to start denying it service.. plus the process of denial is not insignificant because the recent request record has to be opened and summed for each new request.. ideally the IP or IP+ua combination should be just bounced out for a defined period of time to cool off. Also this mystical throttle module I'm hoping exists would sit at the front end, along with mod_rewrite, rather than be installed on multiple back end modperl servers.. Something that crawled the apache status tree to deny requests when more than N servers are already engaged in serving the same IP, would be ideal.. Since I offload image serving, I think this would not hurt any legit users. thanks! -Justin
