Proxy_cache_valid for zero seconds

Server NGINX
1

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:

2

Put another way – can I store/cache all content from the proxied
upstream
(up to the limits defined in proxy_cache_path), but serve from the cache
only when the proxied upstream fails (e.g. timeout, error)?

We have content that should be dynamic, and hence every request should
be
transparently proxied. However, I want to protect against the situation
when the upstream is down or having trouble. Serving a stale response
(though normally undesirable), is better than returning an error.

Thank you

Posted at Nginx Forum: