Enable clustering.

Fastly reads this header from requests. It is proprietary to Fastly.

In most cases, Fastly will relay requests from the first server that handles the request to a second server that acts as the primary storage location for the resource being requested. This process is called clustering. If a service configuration executes a restart during request or response processing, the clustering mechanism is automatically disabled. This header exists to re-enable it if desired.

vcl_recv { ... }
Fastly VCL
set req.http.Fastly-Force-Shield = "1";

WARNING: Despite the name, this header has nothing to do with shielding.

User contributed notes


Do you see an error in this page? Do have an interesting use case, example or edge case people should know about? Share your knowledge and help people who are reading this page! (Comments are moderated; for support, please contact