Install SeeFusion and take a look at what threads are running while the machine is “hung”.
If no page requests are running, pull a full thread dump of the JVM as it could be a scheduled task or non-HTTP thread.
What is CPU usage like while CF doesn’t is responding?
Are there any running spids in the database from CF?
If SeeFusion is also hung (i.e., nothing is responding on the JVM) my first thought would be system GC is running. How big is your heap space? Enable verbose GC logging and see how long major collections are taking.
Those are just a couple stabs in the dark.
I don’t think it is GC related, but I will check it out.
The reason I say that is because Jrun is around 800mb, and I know it can go higher than that as I have seen it as high as 1.5gb.
But GC problems usually also show up in the logs as well, this shows nothing. And the fact that it hangs for over 20mins at a time is saying its not GC as well.
But I could be wrong here.
Ok FusionReactor is reporting nothing here, both the Jrun and Cfusion instances are 400mb roughly.
Ok if it helps I am able to duplicate this problem 100%.
First do an import on a blog so there is a lot of entries in ContenBox (not sure this is required so can try it without this) then run the cbadmin, and browse the front end at the same time.
Goto the cbadmin when it is ready then edit a post, and hit the back button on the browser. Bingo ColdFusion 9.01 has entered into an endless loop.
Fusion Reactor shows a usage on 19% of memory, and nothing more out of the ordinary to report.