Oracle Server: Common Issues and Fixes

In a Fresh Start machine using DaDesktop (DD), the vast majority of applications operate without issues. However, a handful of programs may behave unexpectedly after cloning, requiring a few additional adjustments to restore normal functionality.

System Details

• Oracle Database 19c (other versions likely show similar behavior)

• Deployed with a Windows 10 template

Fresh Start Fix Notes

1. Note: This guide offers a generic solution for the application within Fresh Start. Your exact configuration might require variations in the steps.

2. In a nutshell: During the fix, we replace the Fresh Start machine's original hostname with 127.0.0.1 (localhost), because cloning assigns a different machine name. Also, any extra database Listeners that create confusion should be removed, as illustrated below.
   
   

Resolution Steps

1. The image below illustrates a network connection failure in the Oracle SQL Developer application.

2. Open the Oracle Net Manager application.

The xe service details are displayed, showing the original hostname (alexei-uuae.vm in this example).

3. The connection test fails after entering userid=system and the password.

4. In Oracle Net Manager under Listening Locations for the Listener, the host details display the original hostname 'alexei-uue.vm' which needs updating.
Host details showing the original hostname 'alexei-uue.vm'; this must be changed.

5. LISTENER1 shows no configured databases. Inspect any Listeners without database services and remove them.Check for any Listeners that may not have database services configured for them. If so, delete that Listener.

6. Therefore, delete LISTENER1 and confirm. Note: This was our specific case; your scenario might differ, but the same approach applies.

7. For the DEFAULT SERVER LISTENER, check each one: here, there is no listening location configured.

8. Hence, remove the DEFAULT SERVER LISTENER.

9. With only the LISTENER remaining, the current hostname (which will differ after cloning) must be updated.

10. Replace the hostname (in our example, 'alexi.uuae.vm') with 127.0.0.1, keeping the port unchanged.

Next, configure the existing database

11. Set the SID to XE and the Global Database Name to xe.local

12. Save the network configuration and exit the application.

13. Open a command prompt and restart the listener service by running 'lsnrctl status', then 'lsnrctl stop', followed by 'lsnrctl start'.

Type ‘lsnrctl status’, Type 'lsnrctl stop'

Type 'lsnrctl start'

Open Oracle Net Manager once more.

14. Remove alexei-vm from the Service Naming → xe section.

15. Set the host to 127.0.0.1

16. Save the network connection.

17. Perform a connection test: click the small button shown in the image below to initiate it.

18. Update the login credentials: set the username to 'system' and enter the appropriate password.

Save the network connection if prompted.

19. Return to the main Oracle SQL Developer application and run the connection test once more.

20. Assuming the test succeeds, navigate to Connections on the left, expand Oracle Connections, and verify that the database tables appear correctly.

21. Proceed with any remaining FreshStart machine configuration and then clone the machines for trainers and participants.

The Oracle Database server should now function properly on all machines.

If you continue to face difficulties, reach out to DaDesktop Support through the chat app; we're here to assist.