# S-maxage not being honored with proxy\_cache **URL:** \ **Category:** NGINX\ **Created:** [April 23, 2013, 5:06pm UTC](https://www.ruby-forum.com/t/s-maxage-not-being-honored-with-proxy-cache/228469 "2013-04-23T17:06:24Z")\ **Posts on this page:** 3\ **Page:** 1
**Author:** ![Ryan\_P.ish](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/r/cab0a1/32.png) [@Ryan\_P.ish](https://www.ruby-forum.com/u/Ryan_P.ish)\ **Post date:** [April 23, 2013, 5:06pm UTC](https://www.ruby-forum.com/t/s-maxage-not-being-honored-with-proxy-cache/228469/1 "2013-04-23T17:06:24Z")
I have a slow backend application that I’m using nginx to provide the authentication and caching for. It’s been working great however there is one nagging issue that I cannot seem to resolve, when the backend app sets a s-maxage and a maxage Cache-Control, nginx only seems to honor the maxage and expires the cache with its value. An example response from the backend is like this… Cache-Control: max-age=60, s-maxage=3600, public, must-revalidate My idea here is I only want the client to cache this data for a short amount of time before checking in with me it see if it’s still valid. The data usually wont be changing that often so I want nginx to cache it for an hour, but in the event it does I use the excellent nginx-cache-purge script in my backend app to invalidate the cache and the next time a client checks in (after 60 seconds) they will get the new data. However in all my testing and usage I will only get a cache HIT for 60 seconds after the first request to a resource, after 60 seconds it will be EXPIRED then it will go to the backend again. Am I missing something in the Cache-Control that is causing this behavior? – Ryan P.ish ---
**Author:** ![Ryan\_P.ish](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/r/cab0a1/32.png) [@Ryan\_P.ish](https://www.ruby-forum.com/u/Ryan_P.ish)\ **Post date:** [April 24, 2013, 1:42pm UTC](https://www.ruby-forum.com/t/s-maxage-not-being-honored-with-proxy-cache/228469/2 "2013-04-24T13:42:32Z")
Hello! On Tue, Apr 23, 2013 at 11:05:58AM -0400, Ryan P.ish wrote: > amount of time before checking in with me it see if it’s still valid. The > data usually wont be changing that often so I want nginx to cache it for an > hour, but in the event it does I use the excellent nginx-cache-purge script > in my backend app to invalidate the cache and the next time a client checks > in (after 60 seconds) they will get the new data. Note: you will not be able to purge shared chaches outside of your control, so this might not work as you expect. > However in all my testing and usage I will only get a cache HIT for 60 > seconds after the first request to a resource, after 60 seconds it will be > EXPIRED then it will go to the backend again. Am I missing something in > the Cache-Control that is causing this behavior? As of now nginx doesn’t handle s-maxage. Trivial solution is to use X-Accel-Expires to specifi expiration time for your nginx cache. This should also better match a use case you’ve described (as it will only ask your nginx cache to cache longer, not all shared caches in the world). – Maxim D. > **[nginx: donation](http://nginx.org/en/donation.html)** ---
**Author:** ![Ryan\_P.ish](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/r/cab0a1/32.png) [@Ryan\_P.ish](https://www.ruby-forum.com/u/Ryan_P.ish)\ **Post date:** [April 24, 2013, 3:52pm UTC](https://www.ruby-forum.com/t/s-maxage-not-being-honored-with-proxy-cache/228469/3 "2013-04-24T15:52:13Z")
On Wed, Apr 24, 2013 at 7:41 AM, Maxim D. [removed\_email\_address@domain.invalid](mailto:removed_email_address@domain.invalid) wrote: > > in my backend app to invalidate the cache and the next time a client > > the Cache-Control that is causing this behavior? > > As of now nginx doesn’t handle s-maxage. > > Trivial solution is to use X-Accel-Expires to specifi expiration > time for your nginx cache. This should also better match a use > case you’ve described (as it will only ask your nginx cache to > cache longer, not all shared caches in the world). That worked perfectly, thank you! – – Ryan P.ish Chief Technologist, Member CoreLogic LLC M: (408)966-4673 > **[CoreLogic LLC | Solutions For The Extended Enterprise](http://www.corelogicllc.com)** solutions for the extended enterprise