The Caching behavior

This behavior lets you specify basic caching behaviors for our Edge servers. You can define how responses should be cached, for how long, and whether the response can be served stale if the origin server cannot be reached to re-validate the response.

You can select from the following options:

  • No Store (default): Content is served directly from the specified origin, and any versions in the cache are cleared.
  • Cache: Content is cached, based on additional settings that are revealed:
    • Force Revalidation of Stale Objects: Once content remains in cache for a predetermined amount of time (either what's been defined specifically for the origin, or what's been set in the Max-age field), it is considered "stale." Select how you want requests for cached content to be handled once that content is stale:
      • Serve stale if unable to validate: The request tries to re-validate with the origin to get the content, but if it can't the "stale" content is served.
      • Always revalidate with origin: The request only serves content that has been re-validated from the origin. (The request is retried until revalidation occurs, or it times out.)
    • Max-age: Set the amount of time that content will be cached if the origin does not specify one.
  • Bypass cache: Content is served from the specified origin, but cached versions of the content are not removed. This may be useful for certain subcustomers. For example, if using central authorization, bypass the cache for the client request. If end users are authenticated, they are redirected to the cached content. (Otherwise, a login module could be returned.)
  • Honor Origin...: You can choose to honor the caching settings defined in origin response headers: Honor Origin Cache Control, Honor Origin Expires), or both. When you use origin response headers, you also set a Default Max-age to use if the relevant origin header is not found or is invalid. You van also optionally enable support for caching settings that may be set in "Private" and "Must-Revalidate" response headers, by setting the applicable switches to Yes.