How to change the Garbage collection options on JBoss EAP on OpenShift

Solution Verified - Updated -

Environment

  • Red Hat JBoss Enterprise Application Platform (EAP)
    • 6.x
    • 7.x
  • OpenJDK 8
  • Red hat OpenShift Container Platform (OCP)

Issue

We need to find a way to change the default Garbage Collector settings in the JVM used by JBoss EAP on OpenShift

Resolution

  • For EAP 6.4 version 1.6 and later , follow this solution article.
  • For JBoss EAP 6.4 till version 1.5 follow below steps:
    Use the JAVA_OPTS_APPEND environment variable to add new options to the JVM. See the following example, how to set the JVM non standard option -XX:+UseG1GC in the Deployment Config of a running EAP image:
$ oc get dc
NAME      REVISION   DESIRED   CURRENT   TRIGGERED BY
demoeap   3          1         1         config,image(demoeap:latest)

$ oc set env dc/demoeap JAVA_OPTS_APPEND=-XX:+UseG1GC

Now you can check from the Pod logs that the option -XX:+UseG1GC has been included in the JBoss EAP JVM:

$ oc logs demoeap-3-7k00d  

Running jboss-eap-7/eap70-openshift image, version 1.4-30
=========================================================================

  JBoss Bootstrap Environment

  JBOSS_HOME: /opt/eap

  JAVA: /usr/lib/jvm/java-1.8.0/bin/java

  JAVA_OPTS:  -server -verbose:gc -Xloggc:"/opt/eap/standalone/log/gc.log" -XX:+PrintGCDetails -XX:+PrintGCDateStamps -XX:+UseGCLogFileRotation -XX:NumberOfGCLogFiles=5 -XX:GCL
ogFileSize=3M -XX:-TraceClassUnloading -Xms1303m -Xmx1303m -XX:MetaspaceSize=96M -XX:MaxMetaspaceSize=256m -Djava.net.preferIPv4Stack=true -Djboss.modules.system.pkgs=org.jboss
.logmanager,jdk.nashorn.api -Djava.awt.headless=true -Xbootclasspath/p:/opt/eap/jboss-modules.jar:/opt/eap/modules/system/layers/base/org/jboss/logmanager/main/jboss-logmanager
-2.0.3.Final-redhat-1.jar:/opt/eap/modules/system/layers/base/org/jboss/logmanager/ext/main/jboss-logmanager-ext-1.0.0.Alpha2-redhat-1.jar -Djava.util.logging.manager=org.jboss
.logmanager.LogManager -javaagent:/opt/eap/jolokia.jar=port=8778,protocol=https,caCert=/var/run/secrets/kubernetes.io/serviceaccount/ca.crt,clientPrincipal=cn=system:master-pro
xy,useSslClientAuthentication=true,extraClientCheck=true,host=0.0.0.0,discoveryEnabled=false -Djava.security.egd=file:/dev/./urandom -XX:+UseG1GC

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