Nginx – Limiting per-request download AND upload speed on Apache or Nginx

I will also try to explains the settings for tuning:-

• Maximum number of POST request parameters - This refers to the maximum number of attributes/parameters sent over a particular request. Used particularly, while posting data on a form.
• Maximum size of post data - This is the maximum data which can be posted on a server. This is the sum of all the data in a particular form during a POST request.
• Request Throttle Threshold - ColdFusion can throttle (forcefully slow down) incoming requests if needed. However, really small requests (those with a small payload) can be allowed through regardless of the throttle state. To allow small requests to be processed, specify the maximum allowed size (the default is a maximum of 4 MB).
• Request Throttle Memory - To throttle requests, specify the maximum amount of memory allocated for the throttle. If not enough total memory is available, ColdFusion queues requests until enough memory is free (the default is 200 MB). It wou;ld not reserve the memory for Req1, as its lower than Threshold.

Consider that there are three simultaneous requests Req1 (3 MB), Req2 (6 MB) and Req3 (9 MB). With the default settings, Request Throttle Threshold set to 4MB, ColdFusion will reserve (6+9=15MB) in the Throttle Memory. Likewise, it would keep on adding the Request Throttle Memory for all simultaneous requests and the limit is what we have set for Request Throttle Memory (default is 200 MB)

Hope this helps.

I think the solution lies in a nested location. So "location /api/files "should be inside your php location block. Your fastcgi config should be inherited to the "files" location.

http://nginx.org/en/docs/http/ngx_http_core_module.html#location

location ~* \.php$ {
     try_files $uri =404;
     fastcgi_pass backend; 
     # [...]

     location /api/files { 
          client_max_body_size 10m;
     }
}

If you have location /api/files outside your php location nginx would find 'api/files' and remember it. But before using it, it would check whether there is a location with a matching regular expression, which would be the php location for php file requests. It would then use the php location and discard 'location api/files'.