1) Use OpenJDK 1.6 - e.g. IcedTea 1.7.4 from RHEL 6
2) Run JON 2.4.0 (I was running it with EAP 5.1 but that most probably does not
3) Go to some page with a chart, e.g., DLQ Queue page
4) Check the rhq-server-log4j.log, should contain the following NCDFEx:
... see Bugzilla.