nginx [engine x] is a HTTP and reverse proxy server, as well as a mail…
Rate Limiting with nginx
This article explains how to use the nginx HttpLimitReqModule to limit the number of requests for a given session. This is useful, for example, if your site is hammered by a bot doing multiple requests per second and thus increasing your server load. With the ngx_http_limit_req_module, you can define a rate limit, and if a visitor exceeds this rate, he will get a 503 error.