Implementing OpenJDK with XCOM for Linux and Windows

Products

• XCOM - SUPPORT
• XCOM Data Transport - Linux PC
• XCOM Data Transport
• XCOM Data Transport - Windows

Issue/Introduction

Currently using XCOM Data Transport r11.6 16083 SP01 64bit on RHEL 6.5. Would like to know if XCOM uses Java internally and if it is possible to use OpenJDK?

Environment

Release : 11.6

Component : XCOM Data Transport for Linux PC

Resolution

1. Currently the install of XCOM for Linux also installs its own JRE (Oracle Java HotSpot(TM) 64-Bit Server VM) under XCOM_HOME:
   
   
2. XCOM does not use Java in its core functionality for the transfer of data between systems and only uses Java for the following:

a. XCOM GUI (StandaloneUI.sh)
    Most XCOM functionality can be achieved from the command line. However, in the case of trusted configurations or to test history or trusted database setup, XCOM GUI is the only option. 
b. SMTP Email notifications
c. Base XCOM - XCOM Gateway connections if XCOM Gateway id is being used.
d. To trigger the Splunk client, in the case of XCOM - Splunk feed 
e. XCOM Base Uninstaller uses Java. 

3. Even if not using any of the above, switching to OpenJDK now is possible and is supported. IMPORTANT: Use only  Java 8 (1.8.xxx)  which have been tested with XCOM. Avoid higher major versions (Java 11 or later) that may pose problems as we haven't tested our GUI with the latest Java versions

Two changes are required:

a. Update XCOM_JVM in the $XCOM_HOME/config/xcom.glb file to the OpenJDK libjvm.so shared library file:  XCOM Data Transport for UNIX/Linux 11.6.1 > Reference > XCOM Parameters > List of Parameters > XCOM_JVM
A restart of xcomd will be required as always when there is any change to the xcom.glb file.
b. Create a new environment variable XCOM_JAVA_HOME pointing to the OpenJDK jre directory so that StandaloneUI.sh will be able to pick up OpenJDK to launch the XCOM GUI. 
c. XCOM Engineering advises that the Uninstaller looks for Java at the same location as the Installer and removing the supplied $XCOM_HOME/JRE directory can therefore cause problems with Uninstalling the product. So, it is suggested to just "archive" $XCOM_HOME/JRE in case a clean up of the install directory is required for whatever reason.

Additional Information

NOTES: The above advice is also valid for Windows where, as of 11.6 SP03, environment variable XCOM_JAVA_HOME already exists.

In future releases, XCOM will support OpenJDK and will stop redistributing Oracle Java with product installations.