OverOps Agent: JBoss logmanager Error

OverOps Experts
1

After adding the OverOps agent JBoss fails to start with

Failed to load the specific log manager class org.jboss.logmanager.LogManager

or a similar Error message.

Environments

Java 11 and newer JBoss/Wildfly Agent : any version

Resolution

Ensure that (the sequence is important):

  • -javaagent:$JBOSS_HOME/jboss-modules.jar is configured
  • com.sparktale.bugtale is added to -Djboss.modules.system.pgks argument (see example below)

-Djboss.modules.system.pkgs=org.jboss.byteman,com.sparktale.bugtale

  • OverOps is configured after the above
    Starting with JBoss EAP 7.4; you can use MODULE_OPTS to attach the OverOps agent which will ensure the correct sequence.
  • Remove -Xbootclasspath/a flag if still used

Route Cause

Starting with jdk11, having JBoss logmanager on the boot classpath causes various problems, where the main one could be seen in: [MODULES-393] Make jboss-modules a Java agent and allow other agents to be set as module arguments - Red Hat Issue Tracker.

As seen in the link above Redhat changed how they work and now instead of supplying the logmanager, through -Xbootclasspath/a flag they supply their own java agent which loads the modules for himself and other agents as well.
These need to be configured correctly to work side by side with other agents.