Re: Information in the log file to calculate approximate response time

Ari Luotonen ([email protected])
Mon, 10 Jul 1995 21:57:39 -0700 (PDT)


> Ari Luotonen wrote on 23 Jun 1995 that Netscape servers store the
> transfer time for each request. How is this calculated, that is, at
> what points in the code are the timestamps recorded?

The Netscape Proxy starts the timer just after the point when the
request is fully received and translated, but just before the DNS
server is contacted to resolve the remote IP address (or if it's
already found in the proxy's IP cache, just before contacting the
origin server). The timer is stopped when the remote server shuts
down the connection.

So in effect, it's measuring the network response time, which, in the
case of the proxy, is the one of real interest. It's measured in
seconds, which would be too big a unit for regular HTTP servers, but
accurate enough for proxies (because proxies are bound by the network
and remote server speed, not the speed of the server itself, so their
typical response time is between 1 and 3 seconds, in average,
depending on the internet connection).

Cheers,

--
Ari Luotonen				[email protected]
Netscape Communications Corp.		http://home.netscape.com/people/ari/
501 East Middlefield Road
Mountain View, CA 94043, USA		Netscape Server Development Team