Revalidate While Stale

Applies To:

HTTP LargeThis platform has been optimized to cache and deliver static content (e.g., HTML, CSS, JavaScript, ISO, multimedia, and software downloads, etc.) over HTTP or HTTPS.

HTTP SmallLegacy. If you are currently serving traffic over this platform, then you may continue to do so. However, we recommend that you serve your traffic over our more robust HTTP Large platform.

ADNThe Application Delivery Network platform has been optimized to deliver dynamic content (e.g., login credentials, account information, etc.) over HTTP or HTTPS. Typically, user-specific and database-driven content are served over this platform.

Rules EngineAllows the customization of how requests are handled by our CDN service. It may be used to override the default response provided by an origin server, CDN settings, and the default edge server behavior. - Advanced

This feature only affects how often our system communicates with your origin server. Do not confuse this feature with the Stale While Revalidate feature that allows the delivery of stale content.

This capability requires Rules Engine - Advanced Rules which must be purchased separately. Contact your CDN account manager to activate it.

Category: Specialty

Purpose: Determines whether our service will attempt revalidationCache revalidation is the process through which an edge server checks the origin server for a newer version of a cached asset. Revalidation is triggered when the TTL for the requested content has expired. with your origin server when communication has been temporarily disabled due to repeated origin server availability issues.

Key information:

Background Information: The system temporarily disables an origin server configuration after repeated TCP connection failures. This is known as stale mode. Once stale mode expires, the system will allow a single revalidation request to the origin server. The origin server's response determines how the system will handle future requests.
- Success: If the system is able to establish a TCP connection with the origin server, then it will enable the origin server configuration for all future requests.
- Failure: The system will extend stale mode for a longer time period. This process is repeated until a TCP connection can be established with the origin server.

This feature determines whether the system will attempt to connect to your origin server while it is in stale mode.

Enabled	Result
Yes	The system will attempt to connect to your origin server while it is in stale mode according to the time interval defined within the Revalidate While Stale Timer feature.
No	The system will not attempt to connect to your origin server while it is in stale mode.

This capability requires both the Revalidate While Stale and Revalidate While Stale Timer features.
This feature does not affect requests that have been assigned a Cache-Control: must-revalidate directive. This directive requires a successful validation on the origin server in order to serve stale content.

Default Behavior: Disabled.