带CDN的PHP缓存头

Question

I am trying the php header() function to set caching headers to my page. I have a CDN that caches the http requests. What I am trying to achieve here is that the CDN should cache my page for 2 days, and the browser should check for new version to the CDN every 5 minutes.

Cache-Control: max-age=300, s-maxage=172800, public

Does this avoe cache header work?

Answer 1

Does this avoe cache header work?

Why don't you know from your traffic?

Manual :

s-maxage
   If a response includes an s-maxage directive, then for a shared
   cache (but not for a private cache), the maximum age specified by
   this directive overrides the maximum age specified by either the
   max-age directive or the Expires header.

Yes, it should work - but makes no sense to use a shorter expiry time on the client than on an intermediate proxy (unless the client is likely to move between different CDN zones and the content is CDN zone specific).

Answer 2

The expires header is the one you are looking for, it tells all caches how long the associated representation is fresh for. After that time, caches will always check back with the origin server to see if a document is changed.

Also, if your pages are not password protected, use must-revalidate .

You would have a method at the CDN to set your TTL to 2 days