Created attachment 24468 [details]
a patch to include duration in apache notes

This is a simple change to save the time spent in processing the request:
1. Time it took mod_proxy_ajp to get the request from client and send it to
tomcat.
2. Time it took tomcat to generate a response.
3. Time it took client to accept the response.
4. Total time it took to process the request (sum of 1, 2, 3).

This is helpful for debugging. If a client is on low bandwidth connection, it
may hang a apache thread, who is waiting on the client to accept all the
response. It may also be desirable to my changes in #ifdefined so it can be
compiled out if the user chooses not to use this feature. 

The time is in microseconds and can be printed out later by mod_log_config,
using this format:

LogFormat "%{ajp_send_request_duration}n %{ajp_response_create_duration}n 
%{ajp_send_response_duration}n %{ajp_lifetime}n"

The diff was created from httpd svn tree as of 11/3. To apply this patch do
these 2 steps:
1. cd trunk/modules/proxy/
2. patch < mod_proxy_ajp_duration_as_notes.patch