We are running CF 9 on Win 2008. We were having issues with our server crashing every few days. We would see ColdFusion become unresponsive, stops processing requests and CPU Spike up and stay busy at above 50%. Normal CPU usage are around 10%. I have another instance of ColdFusion running on that server and that stays up and responsive when the other goes down. So, that eliminated any server/network related issue.
Looking at application and exception log I couldn't find any issue. Running SeeFusion and Fusion Reactor didn't reveal anything either.
Then finally, when looking at the ColdFusion server logs here is what I found:
"java.lang.OutOfMemoryError: PermGen space".
Many of these error at the time of crash! After doing some Google'ing, I found this article which confirmed the issue we were having.
http://www.cfconsultant.com/blog/2010/01/27/jvm-permgen-memory-usage-with-many-cfm-templates/
I changed the -XX:MaxPermSize to 512m. Default JVM setting for MaxPermSize is 192m.
Happy to report that server has been up for 4 days. So, if you are running application that uses any kind of framework that creates lot of class files, make sure you set MaxPermSize appropriately.