As Linode is a virtual hosting service, the performance of our web servers is important to all of us. I tried using '%D' in Apache's log format string to report page serve times, but quickly discovered that they reflected client connection speed more than how my Linode was doing.
So, I wrote a module allowing you to log the time between the request being read and the first byte of the response being served. Unlike the total serve time, this tells you how long Apache actually spent loading the file off the disk or executing your script: it's
independent of client connection speed. It makes a great performance benchmark for your server!
For more details, visit:
http://matthewlloyd.net/software/mod_log_firstbyte/
-- Matthew