This behavior generates a response header with information about cache status.

How it works

This behavior can provide information whether the response came from the ​Akamai​ cache, or from the origin server. Status values report with either of these forms of syntax, depending on whether you're deploying traffic using SiteShield or Tiered Distribution which may result in the request going through both a child and parent ​Akamai Technologies, Inc.​ server:

{status} from child
{status} from child, {status} from parent

The status value can be any of the following:

• Hit: The object was retrieved from ​Akamai​'s cache.

• Miss: The object wasn't found in the ​Akamai​ cache.

• RefreshHit: The object was found in ​Akamai​'s cache, but was stale, so an If-Modified-Since request was made to the customer origin, with 304 as the response code, indicating unmodified content.

• HitStale: The object was found in ​Akamai​'s cache and was stale, but a more recent object wasn't available from the customer's origin, so the cache served the stale object to the client.

• NotCacheable: The object is defined as not cacheable in your property, so ​Akamai​ servers always forward requests for it to your origin server.

• Constructed: The Construct response behavior directly specified the response to the client.

• Redirect: The ​Akamai​ edge configuration specified a redirect, typically by executing the Redirect, Redirect Plus, or Edge Redirector Cloudlet behaviors.

• Error: An error occurred, typically when authorization is denied or the request is rejected by the Web Application Firewall (WAF).

Features and options

Examples

If an ​Akamai​ edge server receives a request for a cacheable object, such as a web page, and the object isn't in its cache, it forwards the request to your origin server. The edge server returns the object from your origin with the header set to Miss from child for this request. However, as the requested object is cacheable, the edge server adds it to their cache, so that subsequent requests for the same object to the same edge server will return the object from the edge server's cache with the header set to Hit from child.

Tiered Distribution and SiteShield only: if the ​Akamai​ child server that first received the request doesn't have an object in its cache and forwards the request to a second parent server, where the object is found in cache, the header will return Miss from child, Hit from parent. As the requested object is cacheable, the child edge server adds it to their cache, so that subsequent requests for the same object will return Hit from child.