Unable to connect Oracle database to Hue using SCAN

For high availability purposes, you may want Hue to stay connected to any Oracle database instances running in your cluster. Single Client Access Name (SCAN) serves as a cluster alias for databases in the cluster. Currently, Cloudera Manager does not provide an option to use SCAN to connect to the Oracle database. To use SCAN, you must temporarily install a MySQL database to create a Hue service and then specify Oracle settings in the Hue advanced configuration snippet.

It is possible that other clusters or services may be able to connect to the database using the Oracle SQL Developer. But you may see the following error when you try to add the Hue service using the Cloudera Manager Add Service wizard and specifying SCAN on the Setup Database page: “Able to find the Database server, but not the specified database. Please check if the database name is correct and make sure that the user can access the database.

  1. Sign in to Cloudera Manager as an administrator.
  2. Add the Hue service using a MySQL database.
  3. Check whether the Hue service is added successfully by launching the web UI.
  4. After the Hue service is running, go to Cloudera Manager > Clusters > Hue service > Configuration.
  5. Add the following lines in the Hue Service Advanced Configuration Snippet (Safety Valve) for hue_safety_valve.ini field:
  6. Enter the database password in the Hue Database Password field.
  7. Click Save Changes.
  8. Restart the Hue service.
  9. Check whether you can access your databases from the Hue web UI.
  10. Uninstall the MySQL database if no longer needed.