CF911: Are you finding performance problems with CFDOCUMENT? Aware of the important LOCALURL attr.?
Note: This blog post is from 2011. Some content may be outdated--though not necessarily. Same with links and subsequent comments from myself or others. Corrections are welcome, in the comments. And I may revise the content as necessary.This is something that I find nearly no one has talked about, as a problem and solution. Did you know that by default, a single request doing a CFDOCUMENT may cause CF to execute several additional requests, each doing a CFHTTP to grab any images on the page? even if the images could be found locally on the server? This can be quite tragic.
The good news is that the problem can be solved using the simple LOCALURL attribute. The bad news is that you have to do it at all, and that if you don't do it, it can have such unfortunate and unexpected impact. (And just as bad, again, is that hardly anyone has talked about it.) This entry will elaborate on the issue (and a couple of other possible CFDocument performance issues, as a bonus.)
I've been meaning to write about the importance of this problem and solution (the LocalURL attribute) for a long time (it came out in CF8). Often when I'm helping people with CF troubleshooting problems, whether on mailing lists or in my consulting services, I've been able to show that long-running requests (or an unexpectedly excessive number of requests) were sometimes due to this very problem.
Basics of the LocalURL attribute