This info is probably somewhere else, but I want to put it here for others and myself because I seem to always forget when I'm setting up a ColdFusion Multi-server cluster on Linux (RedHat or CentOS 5.x):

Remember that you're trying to connect your Web Server (Apache) to the cluster, and not an individual instance of CF. So, you must do things in the correct order:

  1. When installing ColdFusion, of course choose the Multi-server installation.
  2. Then, do not connect to the Web Server during installation
  3. From the cfusion instance (port 8300), create new CF instances that you want to put in your cluster
  4. Next, create the cluster and put those instances into that cluster
  5. Go to your command line and make sure the httpd-devel is installed on the server: yum install httpd-devel
  6. Stop Apache: service httpd stop
  7. Make the connection from Apache to that new cluster: /opt/jrun4/bin/wsconfig -cluster cluster_name_here -coldfusion -ws Apache -dir /etc/httpd/conf -v
  8. Verify it's all running with: /opt/jrun4/bin/wsconfig -list -host localhost -v
  9. To watch requests hit different instances:
    1. stop all instances: /opt/jrun4/bin/jrun -stop
    2. start each instance in the cluster in separate terminal (or putty) windows: /opt/jrun4/bin/jrun -nohup -start -childVM instance1
    3. when each one starts up, you should see a bunch of startup text about the ClusterManager starting up
    4. hit the web server from a browser. If sticky sessions are turned off for your cluster, you should see the requests hit each server after each browser refresh.

Hope it helps :)