Services in linux are always executed as the root user. The MettleCI Workbench installer configures the service to execute the script located in /opt/dm/mci/dm-mettleci-workbench to provide the service. When this script runs it will switch user to the mciworkb user and execute the start-mettleci.sh script which is responsible for setting required environment variables and starting the Workbench server.
The chain of technologies works like this:
Linux O/S → dm-mettleci-workbench → start-mettleci.sh → Java v1.8 → workbench.jar
In an environment running multiple versions of Java, the mciworkb user's path and environment variables must be configured so that when the mciworkb user executes java -version it shows the expected OpenJDK v1.8 JVM.
Note: The start-mettleci.sh and dm-mettleci-workbench scripts should not be manually modified as they may be replaced during MettleCI software updates.