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