nginx load balancing with network redirect - redirect

Question

I'm looking for a solution to dispatch requests with nginx to optimize network connection bandwith of main server (then it should dispatch download requests to some other servers).
Here is an extract of nginx sample to perform load balacing:
upstream mystream {
server ip1:port1;
server ip2:port2;
}
server {
listen myport;
location / {
proxy_pass http://mystream;
}
}
The problem in this sample is that main server looks acting as a proxy of background servers and then not redirecting client. (it is providing file itself and then not saving bandwith).
Is there a way to configure nginx to dispatch download requests to background servers without acting as a proxy. (keep URL might be nice, but I'm open to rewrite it if needed).
Thanks

Answer 1

I finally found that split_clients is the best solution for my case as goal was to redirect clients to various download sites without any specific rule.
Note that this is changing URL so client will see the server URL (not important in my case).
With this solution, client asking server:myport/abcd will be redirected to serverx:portx/abcd based on MurmurHash2, see http://nginx.org/en/docs/http/ngx_http_split_clients_module.html
split_clients "${remote_addr}" $destination {
40% server1:port1;
30% server2:port2
20% server3:port3;
10% server4:port4
}
server {
listen myport;
location / {
return 302 http://$destination$request_uri;
}
}
Update
If you want to manage unique URL and background servers directly replying to client without any URL dispatch, you can configure load balancing using Linux Virtual Servers in Direct Routing mode.
To configure it, you can manage a Director VM & several "real servers" to which requests are dispatched transparently. See http://www.linuxvirtualserver.org/VS-DRouting.html

Answer 2

That's just how reverse proxying works:
A reverse proxy is a type of proxy server that retrieves resources on behalf of a client from one or more servers. These resources are then returned to the client as if they originated from the Web server itself.
One possible solution is to configure your upstream servers to serve traffic to the public and then redirect your clients there.