Check manual page of j4p_performance.mem

Memory usage of Java application server via JMX and j4p.war - DEPRECATED

Distribution: official part of Check_MK
License: GPL
Supported Agents: Linux

Do not use this plugin. It will be removed soon. Use jolokia_metrics instead.

This checks uses the JSON HTTP service of j4p (from jmx4perl) to monitor the current memory usage of a Java application server like Tomcat or JBoss. You can define levels against the total memory usage of the Java machine (heap + non heap).

In order for the check to work, you need to load the j4p.war into your application server. Furthermore you need the agent plugin j4p_performance in your Check_MK agent's plugins directory. If you do not use the default port 8080 for j4p - lets say 9090 - then you have to create a configuration file j4p.conf in the agents configuration directory (usually /etc/check_mk/j4p.conf) with the single line port = 9090.

Note: No jmx4perl is needed - neither on the target host nor on the monitoring server. No Perl is needed, either. The agent connects to the application server always via localhost.


The instance name as configured in j4p.conf with the variable instance. If you do not specify an instance then the port number converted to a string is used.

Please note that the current implementation of the agent plugin supports only one instance per host.


One check is created for each JMX instance sent by the agent. The agent currently supports only one instance, but that might be changed in future.