Multiple restarts of a JON agent's plug-in container can cause OutOfMemoryError: PermGen space when JBoss EAP 6 management plug-in is installed

Issue

• Agents become unresponsive and run out of PermGen space when recycled
• Restart operation for agent exhausts its PermGen space and becomes unresponsive

• Agent log contains the following error:

  org.rhq.core.clientapi.agent.PluginContainerException: Could not build component for Resource [Resource[id=10009, uuid=6c6dd970-753b-45bd-9fc0-fdda829248db, type={JBossAS}JBossAS Server, key=/opt/jboss/jboss-on/jon-server/jbossas/server/default, name=loleary:2099 RHQ Server, parent=myagent.example.com, version=AS 4.2.3.GA]]
      at org.rhq.core.pc.inventory.InventoryManager.prepareResourceForActivation(InventoryManager.java:1644)
      at org.rhq.core.pc.inventory.InventoryManager.activateAndUpgradeResourceRecursively(InventoryManager.java:3075)
      ...
  Caused by: java.lang.OutOfMemoryError: PermGen space
      at java.lang.ClassLoader.defineClass1(Native Method)
      at java.lang.ClassLoader.defineClass(ClassLoader.java:634)
      at java.security.SecureClassLoader.defineClass(SecureClassLoader.java:142)
      at java.net.URLClassLoader.defineClass(URLClassLoader.java:277)
      at java.net.URLClassLoader.access$000(URLClassLoader.java:73)
      at java.net.URLClassLoader$1.run(URLClassLoader.java:212)
      at java.security.AccessController.doPrivileged(Native Method)
      at java.net.URLClassLoader.findClass(URLClassLoader.java:205)
      at java.lang.ClassLoader.loadClass(ClassLoader.java:321)
      at org.rhq.core.pc.plugin.PluginClassLoader.loadClass(PluginClassLoader.java:63)
      at java.lang.ClassLoader.loadClass(ClassLoader.java:266)
      at java.lang.Class.forName0(Native Method)
      at java.lang.Class.forName(Class.java:264)
      at org.rhq.core.pc.plugin.PluginComponentFactory.instantiateClass(PluginComponentFactory.java:259)
      at org.rhq.core.pc.plugin.PluginComponentFactory.buildResourceComponent(PluginComponentFactory.java:164)
      at org.rhq.core.pc.inventory.InventoryManager.prepareResourceForActivation(InventoryManager.java:1642)
      ... 10 more
  
  WARN  [RHQ Agent Restart Thread] (rhq.core.pc.inventory.InventoryManager)- Cannot give activated resource its discovery component. Cause: org.rhq.core.clientapi.agent.PluginContainerException: Cannot get discovery component proxy for [org.rhq.modules.plugins.jbossas7.SubsystemDiscovery@b5f3fb0]
  ERROR [InventoryManager.discovery-1] (rhq.core.pc.inventory.AutoDiscoveryExecutor)- Error in auto discovery
  java.lang.OutOfMemoryError: PermGen space
      at java.lang.ClassLoader.defineClass1(Native Method)
      at java.lang.ClassLoader.defineClassCond(ClassLoader.java:631)
      at java.lang.ClassLoader.defineClass(ClassLoader.java:615)
  ERROR [InventoryManager.discovery-1] (rhq.core.pc.inventory.RuntimeDiscoveryExecutor)- Error in runtime discovery
  java.lang.OutOfMemoryError: PermGen space