Hello, > On 09 Jul 2015, at 04:43, Alt <[email protected]> wrote: > > Hello, > > From the documentation, I don't understand how the fastcgi_cache_revalidate > (or scgi_cache_revalidate or proxy_cache_revalidate or > uwsgi_cache_revalidate) works. > Please, can someone explain what nginx does when cache is enabled and the > revalidate directive is set to "on"?
Normally, when a cache entry is expired in nginx cache, nginx fetches a replacement from upstream. If cache revalidation is enabled, nginx asks the upstream if the current (expired) entry is still valid using “If-Modified-Since” and “If-None-Match” HTTP headers. The upstream can reply with "304 Not Modified" to confirm the validity. In this case the entry remains in cache until it expires again. -- Roman Arutyunyan _______________________________________________ nginx mailing list [email protected] http://mailman.nginx.org/mailman/listinfo/nginx
