The number of transmitted packets in the current connection that
contained data being retransmitted measured between when this request
started and now. For HTTP/1, this is the number of retransmissions
associated with this HTTP request. For multiplexed versions of HTTP
(e.g., HTTP/2) the number cannot be accurately ascribed to any
particular HTTP request. This metric primarily covers the response
message data and therefore is most meaningful after that has been sent
vcl_log). Bytes the HTTP stack has sent by
the time this metric is read may not have been sent successfully to
the client yet due to other system buffers and therefore more
retransmissions are still possible after VCL is no longer executing.
Try it out
client.socket.tcpi_delta_retrans 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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