Resolving Oracle Server Issues

The majority of applications run without any problems on a Fresh Start machine set up via DaDesktop (DD). However, a handful of apps may behave unexpectedly after cloning and require a few additional configuration tweaks to get them working properly.

System Details

• Oracle Database 19c, (other versions will probably exhibit the same behaviour)

• Installed using Windows 10 template

 

Notes for Fixing Fresh Start Issues

1. This is a general guide for resolving application issues within Fresh Start. Depending on your specific configuration, you might need to adjust certain steps.

2. To quickly sum up the fix: The Fresh Start machine’s original hostname becomes irrelevant after cloning, since the cloned machine will have a different name. So we switch to using 127.0.0.1 (localhost) instead. Also, any extra database Listeners that were added can muddy the configuration, so it’s a good idea to remove them—as we’ll detail below.
   
    

Fix Procedure

1. The image below illustrates a database connection failure encountered in Oracle SQL Developer.

2. Open Oracle Net Manager.

You’ll see the XE service details along with the original host name—here, that’s alexei-uuae.vm.

3. The connection test fails when you enter userid=system and the password.

4. In Oracle Net Manager, go to Listening Locations > Listener.
Note the host details that currently display the original hostname—in our case, alexei-uue.vm. We’re going to update this.

5. When no databases appear under LISTENER1, verify whether any Listeners lack configured database services. If they do, you can safely delete that Listener.

6. Accordingly, delete LISTENER1 and confirm the removal. Keep in mind this is just an example from our setup; your situation might differ.

7. For DEFAULT SERVER LISTENER, check each Listener individually. In this instance, there’s no listening location available.

8. So go ahead and delete DEFAULT SERVER LISTENER.

9. Now only LISTENER remains. We can see the existing VM hostname that needs updating because it will differ after cloning.

10. Replace the hostname (which in our example was alexi.uuae.vm) with 127.0.0.1, keeping the same port number.

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 close the application.

13. Open a command prompt to restart the listener service. Run these commands:

‘lsnrctl status’, ‘lsnrctl stop’, ‘lsnrctl start’

Reopen Oracle Net Manager.

14. Under Service Naming > xe, remove the alexei-vm entry.

15. Change the host to 127.0.0.1. 

16. Save the network connection.

17. Run the Connection Test by clicking the small button shown in the screenshot.

18. Change the login credentials: enter ‘system’ for the username and the appropriate password.

Save the network connection again if prompted.

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

20. If the connection succeeds, navigate to the Connections pane on the left and expand Oracle Connections to verify that the database tables appear as expected.

21. Complete any remaining FreshStart machine configuration, then clone the machine to the Trainer and Participant instances.

The Oracle Database server should now work correctly on both the Trainer’s and Participants’ machines.

If you still encounter issues, don’t hesitate to contact DaDesktop Support through the chat app right here in Hong Kong—we’re always happy to help.