I was privy to a situation the other day where ColdFusion appeared to be the cause of an overall web site performance problem what it turned out to be was a problem with an internal firewall between ColdFusion and a database server.  In many of our recent engagements we have clients with virtual environments, mainly VM Ware with some Xen environments.  We are particularly sensitive to critical shared resources such as network interfaces and hard-drives which are inherently bottlenecks and can become more-so when shared.  

The moral of this blog post is that it is really important to consider everything involved in the request response cycle right from the browser to and from all servers and back-end devices.  We have found the best way to troubleshoot such things is a combination of enhanced logging, the use of a good server monitor, FusionReactor or SeeFusion and controlled load-testing on a subnet by subnet basis.

A Merry Christmas to all.