jg: basically, the first thing to do is telnet localhost 4949 and type list
jbe: shows up there
jg: and what if you do fetch yourpluginname
jbe: fetch jvm_memory
jbe: .
jg: okay, so the plugin is not executing properly via the munin-node process.  does hte munin user have permission to see/execute jmx_?
jbe: aha, i found /var/log/munin/
jg: yes, that too
jbe: i think it's pissed that i'm using relative links to the jmx_ file, instead of absolute
jbe: log is full of Unable to access jarfile ../cassandra/jmxquery.jar, but permissions are fine
jbe: … yup, that fixed it