When you use the Upgrade Assistant to upgrade the infrastructure schema database during service instance upgrade, you might receive an error message and the upgrade fails. The problem is intermittent, so you might not receive this error message.
Failed to establish a connection to data source <data_source_name> because of the error: UPGAST-00214: Unable to connect to database as the schema user <db_user>
If you receive this message, complete the following steps:
- Verify that the host name and port you specified in the Upgrade Assistant are correct.
- Ensure that the database is up and running.
- Ensure that the database is configured for network access.
- Retry the operation.