I've recently setup and configured a server farm running Windows Server 2012 and ColdFusion 10 Enterprise. I have a cluster created using named instances (not cfusion, though I find it curious that CF10 will allow you to cluster the cfusion instances now - but that presents problems - a different discussion later) anyhow.
I began with Sticky Sessions enabled on the Cluster and it worked as expected, I then wanted to turn off Sticky Sessions so that the applications would enjoy a seemless failover. Unchecking the box on the Cluster manager, restarting IIS and CF, had no effect. Sticky was still, well, sticky. An examination of the cluster.xml revealed that the <stickysession> node was set to "false" but workers.properties still had sticky set to true, so I edited workers.properties, saved, restarted and voila the cluster was no longer sticky.
Now here's where things get weird. I get a call from a member of my team, a user is losing their session and getting logged out. A test was conducted, we dumped the session to the browser and began refreshing the page with a delay between refreshes (F5 key down, F5 key up) and the session id stayed the same, as expected. So I held down F5 for a few seconds, bombarding the server with page requests, and suddenly the sessionid began cycling all sorts of randomness! Going back to a delayed pulse of refreshes, session stayed replicated, holding refresh again within seconds we get a constantly changing sessionid.
The reason the user was losing their session was because the application is a heavily ajax based system, there are many ajax calls happening whenever the user manipulates objects on screen (it's a CMS) so naturally these occur very fast (akin to holding refresh key down)
ColdFusion 10 Update 10 10,0,10,284825
Tomcat 7.0.23.0
Java Version 1.7.0_15
OS Version 6.2
Thanks for any ideas/help. Apologies for the short story. 