Friday, 2 November 2012

ColdFusion: Problem with session replication with CF10 clustering

This is a quick one, just an appendix to yesterday's article about ColdFusion 10 instance clustering. You might recall I was having problems getting sessions working, and that lead on to a discussion about how to get session replication working on a CF10 cluster.

Well I think I have spotted a problem.

Here's the cluster-edit screen on ColdFusion 9 (9.0.2):

And here's the equivalent screen on ColdFusion 10 (10.0... oh, I dunno... I've got updater 2 installed):

What's missing on CF10? Well: the option to enable session replication. So that's probably why neither Dave Ferguson nor I could find it. So that sux.


In the comments we discuss "the bug", but I never thought to link to it anywhere. It's this one: "No setting in cluster admin to enable session replication (3361502)".

With neither sticky sessions nor session replication enabled, I saw the same problem as I did on the CF10 cluster: I was not expecting each node to share the same session (obviously), but I did expect them to maintain their own sessions, which they did not. Every hit to a given node restarted the session. I consider this a bug, unless someone can explain why it's not.

However when I configured the cluster for session replication on the ColdFusion 9 cluster, the sessions did indeed replicate correctly: I had the same session on both nodes. So that's cool for CF9... it doesn't help me on CF10 though.

I'm gonna have a sniff around the place in Tomcat's XML files to see if I can find some mention of replication, and fiddle with the settings and see what happens. I call this my "scientific approach" ;-)

I'll update this article if I find anything useful.