proxy_cache_valid for zero seconds

[shmapty]

Greetings,

I am trying to configure nginx proxy_cache so that it stores a cached copy
of a HTTP response, but serves from cache *only* under the conditions
defined by proxy_cache_use_stale.

I have tried something like this without success:

    proxy_cache_valid           200 204 301 302 0s;
    proxy_cache_use_stale       error timeout updating invalid_header
http_500 http_502 http_504;

"0s" appears to avoid caching completely.  "1s" stores a cached copy, but
presumably serves from cache for one second.  I am trying to serve from
cache only when the upstream errs.

Thank you

Posted at Nginx Forum: http://forum.nginx.org/read.php?2,232815,232815#msg-232815