nginx reverse proxy all requests to two upstream servers?

I need to adjust a nginx reverse proxy which used to front a single server to send all requests it receives to two different upstream servers.

I was thinking I could do it with the configuration below, but I wasn't sure if that would work and if I'd have to use re-write rules instead?

upstream  original_upstream  {
   server   <ip address>
}
upstream  new_upstream  {
  server   <ip address>
}

server {
  location / {
    proxy_pass  http://original_upstream;
  }
  location / {
    proxy_pass http://new_upstream;
  }
}

Any suggestions?

Solution 1:

define your upstream servers like

upstream yourname { server <ip serverA>; server <ip serverB>; }

(use weight or backup in your upstream conf if needed)

and use this upstream within your location

location / { proxy_pass http://yourname; }