Java

For quick analysis of the options and health of a Java VM I used the jconsole tool (part of JDK) in the past. But that changed.

Ubuntu announced to discontinue packaging of Sun/Oracle’s Java for Ubuntu, because Oracle changed the licensing.

Please be careful with upgrades on these packages, since it may drop your Java installation on the system, not only the browser plug-in.

SNMP is not really simple, but quite useful, if you want to run standard monitoring tools like Nagios, Zero RRD or Cacti.

Even though Java offers JMX over RMI for runtime information like thread and memory consumption, you can also activate SNMP to read at least a subset.