difference between request _time vs upstream_response_time

[kamalakarv]

As per my understanding upstream_response_time is subset of
request_time.

# request_time : This shows how long Nginx dealt with the request
# upstream_response_time: Gives us the time it took our upstream server
(in this case Apache/mod_wsgi) to respond

request_time = time nginx got the request to the time it sends the
reponse to client(browser).

 request_time  = variable component + upstream_response_time 

Can anybody explain me what exactly the "variable component" is ?


Regards
Kamalakar

Posted at Nginx Forum: http://forum.nginx.org/read.php?2,216948,216948#msg-216948