nginx.conf

# Request Limiter checking multiple values with small footprint 
        
        # if referer is not set 
        map $http_referer $limit_referer {
        default     "";
        ""          "1";
        "-"         "1";
        }

        # if custom parameter is not set. i.e. you always expect urls like "/tracker?campaignid=1234"
        map $arg_campaignid $limit_campaignid {
        default     "";
        ""          "1";
        "-"         "1";
        }


        map "$limit_referer$limit_campaignid" $custom_limit {

        default     "";
        "11"         1;
        }

        limit_req_zone $custom_limit zone=custom:1m rate=1r/s;