If you are using the Google Pagespeed module and notice constant MISSes for HTML pages, check the Cache-Control settings in the module's .htaccess file.
By default, Google Pagespeed serves all HTML with
Cache-Control: no-cache, max-age=0. This setting conflicts with Fastly's default configuration. If your origin sends the headers
Cache-Control: private or
Cache-Control: max-age=0, Fastly will pass requests straight to the origin.
To change the Google Pagespeed directive and leave the original HTML caching headers, update your origin's .htaccess file with:
More details about the Pagespeed Module can be found within Google Developers directory. For additional information about controlling how long Fastly caches your resources, start with our documentation on cache freshness.