Whether VCL is running in the context of a request that is assembling file segments into a response.
A request for which
vcl_recv enabled segmented caching (by setting
true) will spawn one or more subrequests,
each responsible for a segment of the file. After the sequence of subrequests
has completed (each running
vcl_log will run with
segmented_caching.is_outer_req evaluating to
This is useful for controlling what to log.
segmented_caching.is_outer_req will never be
true at the same time.
They will both be
false when segmented caching is not enabled.