upstream module - using both fastcgi and http proxy - possible ?

[Imran]

  Hello, 

I am currently trying to setup a nginx setup like the following : 

upstream backend {

server unix:/tmp/php.socket weight=10; 
server 10.0.0.200:8080 weight=2;

}

The first one is a FASTCGI + the second is a backend PHP proxy that I want to
use so that if the main one is overloading the server, the backend can apply
help reduce the load. 

Is there any way this can be done ? I'm specifically also asking how I can
configure the FASTCGI / mod_Proxy parts. 

Is my only option to run two NGINX- one for front end ( redirecting to a local
nginx and a backend server as http proxy)  , and the other doing fastcgi work ?