JON fails to load or install custom agent plug-in when its rhq-plugin.xml file is missing or located in the wrong place

Solution Verified - Updated -


  • something wrong with the plug-in
  • Custom plug-in fails to load
  • Server log contains the following warning:

    WARN  [org.rhq.enterprise.server.core.plugin.AgentPluginScanner] Failed to scan agent plugin [/opt/jboss/jboss-on/jon-server/jbossas/server/default/deploy/rhq.ear/rhq-downloads/rhq-plugins/my-jmx-plugin.jar] found on filesystem. Skipping. Cause: org.rhq.core.clientapi.agent.PluginContainerException: Could not successfully parse the plugin descriptor [META-INF/rhq-plugin.xml] found in plugin jar at [file:/opt/jboss/jboss-on/jon-server/jbossas/server/default/deploy/rhq.ear/rhq-downloads/rhq-plugins/my-jmx-plugin.jar].
  • Server fails to install custom plug-in with the following warning in the log:

    WARN  [org.rhq.enterprise.server.core.plugin.PluginDeploymentScanner] Does not look like [/opt/jboss/jboss-on/jon-server/plugins/my-jmx-plugin.jar.fixme] is a plugin jar -(Cause: java.lang.NullPointerException:no xml descriptor found in jar). It will be ignored. Please fix that file or remove it.


  • Red Hat JBoss Operations Network (ON) 3.1.2
  • Agent plug-in has been placed in the server's:
    • <RHQ_SERVER_HOME>/plugins directory
    • OR <RHQ_SERVER_HOME>/jbossas/server/default/deploy/rhq.ear/rhq-downloads/rhq-plugins directory
  • META-INF/rhq-deploy.xml is missing from the plug-in JAR's root directory

Subscriber exclusive content

A Red Hat subscription provides unlimited access to our knowledgebase, tools, and much more.

Current Customers and Partners

Log in for full access

Log In