Fastly-Cookie-Overflow
Set when a cookie header is stripped because it is too large.
Fastly writes this header into requests. It is proprietary to Fastly.
When an inbound Cookie
header attached to a request exceeds the maximum allowed length, it will be removed and req.http.Cookie
will be empty. The header Fastly-Cookie-Overflow
will be set to "1"
to allow this to be distinguished from a request that had no Cookie
header in the first place.
The Fastly-Cookie-Overflow
header is automatically removed from requests when they arrive on a Fastly server, before being set if the Cookie
header is too long. Therefore, in services that are configured to use clustering, the header is present only in vcl_recv
and vcl_deliver
, and will not be present in requests made to backends.