beresp.stale_if_error
RTIME, can be read and set
, but not unset
.
Available infetch
The maximum stale age that is acceptable for a particular object.
However, for each request, req.max_stale_if_error
limits the maximum stale
age. For example, if beresp.stale_if_error
for an object is set to one hour,
but req.max_stale_if_error
is set to ten minutes, ten minutes is the maximum
stale age for that particular request. If beresp.stale_if_error
for an object
is set to ten minutes, but req.max_stale_if_error
is set to one hour, ten
minutes is the maximum stale age for that particular request.
By default, the value of beresp.stale_if_error
will be parsed from the
stale-if-error
value in the Surrogate-Control
or Cache-Control
headers
received from the backend.
Try it out
beresp.stale_if_error
is used in the following code examples. Examples apply VCL to real-world use cases and can be deployed as they are, or adapted for your own service. See the full list of code examples for more inspiration.
Click RUN on a sample below to provision a Fastly service, execute the code on Fastly, and see how the function behaves.
Serve stale content from cache while origins are offline
Deal with all potential scenarios for using stale content to satisfy requests when origin is unhealthy or misbehaving.