nginx: Is it possible to capture response headers in access log when using nginx as a reverse proxy?

Question

We are using nginx as a reverse proxy to control and log access to a Clojure (Java) web service application.

We are able to generate an access_log and captu

Answer 1

$http_x_uuid is header sent by client. Response header send by upstream is $upstream_http_x_uuid

http://wiki.nginx.org/HttpUpstreamModule#.24upstream_http_.24HEADER