Provide a quick reference when configuring the DataStax AMI for JConsole access. Datastax is working on updating their documentation for this, but in the mean time, here you go:
1) Change the cassandra-env.sh to provide a jmx hostname like the following:
JVM_OPTS="$JVM_OPTS -Djava.rmi.server.hostname=<ec2 public name> like ec2-xx-xxx-xxx-xxxx.us-west-1.compute.amazonaws.com"
2) Open up your Security Group to allow access to port 7199 (default Cassandra JMX port) as well as 1024 - 65535 for the machine that you are connecting from.
3) Start JConsole using the following service:jmx:rmi://ec2-xx-xxx-xxx-xxxx.us-west-1.compute.amazonaws.com:7199/jndi/rmi://ec2-xx-xxx-xxx-xxxx.us-west-1.compute.amazonaws.com:7199/jmxrmi
Note: use an insecure connection if ssl is disabled (what i did)
That should do it.