[Zope] When is access.log written?

[Eddie Butcher]

Can someone please clarify for me..

At what exact stage during accepting and responding to an HTTP request 
does ZOPE write to it's access.log?

When the request is initially received and before it is processed?

When ZOPE has finished creating the response and serves the completed 
page out?

I'm trying to determine if apparently poor server performance is caused 
by a slow web proxy on our network.

-- 
Eddie Butcher
Road Tech Computer Systems Ltd.
http://www.roadrunner.uk.com
01923 338033