JWP and JCP won't start from smgr; exit code '0'; no other errors

Products

• CA Automic Workload Automation - Automation Engine

Issue/Introduction

JWP and JCP will not start from the service manager (smgr / servicemanager) on unix/linux  
When attempt to start the process, the smgr shows the process staying as red or stopped
smgr log shows:
20210628/151506.466 - U00022004 Starting process 'UC4 JWP' ...
20210628/151506.466 - U00022005 ... with command line  '/usr/wrongjavadir/java -d64 -Xmx2G -jar ucsrvjp.jar -I/opt/dem/smgr/bin/../../AutomationEngine/bin/ucsrv.ini -svc0x18edc60ort'.
20210628/151506.466 - U00022006 ... and start directory  '/opt/dem/smgr/bin/../../AutomationEngine/bin'.
20210628/151506.466 - ERROR: errno '2' returned: No such file or directory
20210628/151506.466 - U00022007 Process 'UC4 JWP' (ID '174752') successfully started.
20210628/151506.466 - U00022012 Process 'UC4 JWP' (ID '174752') ended.
20210628/151506.466 - U00022022 Process 'UC4 JWP' ended, exit code='0'.

No log is generated for JWP, JCP or any other Java components (like RA FTP, SAP agent, db service, sql agent, etc...)

Environment

Release : 12.3

Component : AUTOMATION ENGINE

Cause

This is caused by the incorrect java bin directory being pointed to.  

Troubleshooting steps:

1. Open the service manager dialog
2. Right-click on the process that is not starting and choose "Properties"
3. copy the "Command" entry
4. Paste this into the linux command line, put nohup before the string and & after
   1. For example, the command above: /usr/wrongjavadir/java -d64 -Xmx2G -jar ucsrvjp.jar -I/opt/dem/smgr/bin/../../AutomationEngine/bin/ucsrv.ini -svc0x18edc60ort
   2. would be: nohup /usr/wrongjavadir/java -d64 -Xmx2G -jar ucsrvjp.jar -I/opt/dem/smgr/bin/../../AutomationEngine/bin/ucsrv.ini -svc%port% &
5. Hit enter to submit the command and note the output

Running a which java and making sure that it matches the path to java above also helps confirm where java should be pointed to

Resolution

If the correct java returns from running the command: which java

1. Open the service manager dialog
2. Right-click the java component that is not starting and choose "Properties"
3. In the "Command" field, remove the path before the java program so that the command just starts with java -d64 -Xmx2G ...

Alternatively,
     3. In the "Command" field, use the correct full path to java, for example, if this is "/opt/java/jdk/bin/", update the Start Command to: /opt/java/jdk/bin/java -d64 -Xmx2G ...