Switching the JVM JDK from Sun JDK to Oracle JRockit JDK and viceversa

A JDK JVM is selected during the domain creation. Sometimes it is required to change the JDK from Sun to Oracle JRockit or Oracle JRockit to Sun Hotspot. In this blog I will go through the steps for switching from Sun to Oracle JRockit. Similar steps are required while switching from Oracle JRockit to Sun JDK.

Step#1 - Download latest version of Oracle JRockit from Oracle site. ( I have downloaded p17852847_2831_Linux-x86-64.zip from oracle.support.com)

Step#2 - Copy this zip on your server and unzip it to the desired location.

Step#3 - If you have downloaded .bin file then follow below steps:

• Give executable rights to .bin file (chmod a+x  <jrockit_bin_file>)
• Execute the bin file (./<jrockit_bin_file>)

Step#4 - Bring down complete domain ( Admin + Managed Servers). If you are using nodemanager to start servers, then bring down nodemanagers too on their respective machines.

Step#5 - Modify commEnv.sh file @$WLS_HOME/common/bin

Search for line similar to below in commEnv.sh (Actual value of JAVA_HOME will be different in your environment)

JAVA_HOME="/apps/oracle/jdk/jdk1.6.0_45"

now replace the Sun JAVA_HOME with Oracle JRockit JAVA_HOME

JAVA_HOME="/apps/oracle/jdk/jrockit-jdk1.6.0_71"
Replace JAVA_VENDOR=Sun by JAVA_VENDOR=Oracle

Step#6 - Modify setDomainEnv.sh file @$DOMAIN_HOME/bin

Search for line similar to below in setDomainEnv.sh

BEA_JAVA_HOME=""
SUN_JAVA_HOME="/apps/oracle/jdk/jdk1.6.0_45"

now replace the Sun JAVA_HOME with Oracle JRockit JAVA_HOME

BEA_JAVA_HOME="/apps/oracle/jdk/jrockit-jdk1.6.0_71"

SUN_JAVA_HOME=""

**Modify your JVM parameters for Admin/Managed Server.

Step#7 - Modify config.xml file @$DOMAIN_HOME/config

Search for all occurrence of line similar to below in config.xml

<java-home>/apps/oracle/jdk/jdk1.6.0_45</java-home>

now replace the Sun JAVA_HOME with Oracle JRockit JAVA_HOME

<java-home>/apps/oracle/jdk/jrockit-jdk1.6.0_71</java-home>

**Modify your JVM parameters for Managed Servers in this file as well if you are using node manager to restart them.

Step#8 - Modify nodemanager.properties file @$WLS_HOME/common/nodemanager

Update javaHome & JavaHome with the currect JDK as below

javaHome=/apps/oracle/jdk/jrockit-jdk1.6.0_71

JavaHome=/apps/oracle/jdk/jrockit-jdk1.6.0_71/jre

Step#9 - Delete tmp & cache folder for admin and managed servers.

Step#10 - Start NodeManager, Admin Server and Managed Servers.