The time interval since the request started up to the point before the
vcl_deliver function ran. When used in a string context, an RTIME variable like
this one will be formatted as a number in seconds with 3 decimal digits of
vcl_deliver this interval will be very close to
the difference between
time.to_first_byte will be the time that it took to send the response body.
Try it out
time.to_first_byte is used in the following solution recipes, which show real world use cases. Click RUN to provision a Fastly service, execute the code on Fastly, and see how the function behaves.
Fastly offers a myriad of different variables that you can log. See and test a large collection here.
User contributed notes
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