Get Selected backend info

Server NGINX
1

Hello,

I couldn’t find much information other than this thread
http://mailman.nginx.org/pipermail/nginx/2008-February/003550.html
which
is a dead-end.

I would like to add the selected backend/upstream to an “X-Backend”
header
before dispatching the request to the backend.

In Varnish I can do this via:
set req.http.X-Backend = req.backend

In HAProxy I can do this via:
http-send-name-header X-Backend

However, I am stumped with Nginx. I imagine I could work around it by
redirecting to the same server or some other trickery (not sure if
that’s a
reasonable approach–what would the config look like in any case here?).

Any other tips or suggestion are welcome.

Thanks,
Aleem

2

Hello!

On Wed, Sep 03, 2014 at 12:50:27AM +0500, Aleem B wrote:

Hello,

I couldn’t find much information other than this thread
http://mailman.nginx.org/pipermail/nginx/2008-February/003550.html which
is a dead-end.

I would like to add the selected backend/upstream to an “X-Backend” header
before dispatching the request to the backend.

You can’t. The request is created before the backend server
will be selected (and the same request may be sent to more than
one backend server due to proxy_next_upstream).

–
Maxim D.
http://nginx.org/