You must install a Management Agent on a host that has a connection to the External Database. Diagnostics & Management will use the Management Agent for operations such as collecting data and metrics from the External Database. Here's information on the required Management Agent versions for External Databases:

• A Management Agent 201215.1850 or later is required for single instance databases and a Management Agent 210403.1349 or later is required for RAC databases.
• A Management Agent 210403.1349 or later is required to use AWR Explorer.
• A Management Agent 240508.1440 or later is required to monitor primary and standby databases.

Note that Diagnostics & Management can be used to monitor and manage External Databases on IBM AIX, however, there are additional Management Agent-related prerequisite tasks that must be performed.

For information on the additional Management Agent-related prerequisite tasks that must be performed to monitor and manage External Databases on IBM AIX, see OCI Database Management Service: Support for Database Management on AIX (Doc ID 3015022.1) in My Oracle Support.

If you encounter issues when installing the Management Agent, see Errors Encountered When Enabling Database Management for External Databases for the likely cause and solution.

You can register an External Database in the External Database service or by clicking Register external databases on the Managed databases page for External Databases in Database Management.

For information on how to access the Managed databases page for External Databases in Database Management, see Enable Diagnostics & Management for External Databases.

Use the Oracle Cloud Infrastructure Vault service to save the database user password in a secret with an encryption key. The Vault service is a managed service that enables you to centrally manage the encryption keys that protect your data and the secret credentials that you use to securely access resources. Note that if you change the database user password, then you must also update the secret with the new password by creating a new version of the secret and updating the contents.

Configure Gradual Password Rollover

For Oracle Databases 19c and later, it's recommended that you define a gradual password rollover time, which allows you to connect to the database using both the old and new passwords during the gradual rollover time period. Since both the old and new passwords are valid for some time, downtime is minimized. Using a gradual password rollover, you can avoid any disruptions in the use of Diagnostics & Management features for your databases.

For information on the SQL script to create a monitoring user with the privileges required to monitor the External Database, see Creating the Oracle Database Monitoring Credentials for Database Management (Doc ID 2857604.1) in My Oracle Support.

For information on the SQL script to create a user with the privileges required to perform advanced diagnostics and administrative tasks, see Creating the Oracle Database Management Advanced Diagnostics User and Administration User (Doc ID 2978493.1) in My Oracle Support.

For information on the Vault service, its concepts, and how to create vaults, keys, and secrets, see Vault.

For information on the Gradual Password Rollover feature, see Managing Gradual Database Password Rollover for Applications in Oracle Database Security Guide.

You can add a connection to an External Database in the External Database service or on the Managed databases page for External Databases in Database Management by:

• Clicking Connect in the Status column.
• Clicking + New connector when enabling Diagnostics & Management for the database.

For information on how to add a connection on the Managed databases page for External Databases in Database Management, see Enable Diagnostics & Management for External Databases.

For information on how to add a connector, see Add a Connection.