Check the log files:

Check the database log files for any error messages or warnings, to help outline the cause of the issue.

Troubleshoot networking issues:

If the issue appears to be related to a connection that is not reaching the database, check the networking issues to ensure all ports are open and accessible from the application’s server.

Validate user credentials:

Ensure the username and password being used by the application is valid and has access to the database.

Check for firewall settings:

Ensure there are no firewall restrictions blocking access to the database.

Increase timeout and connection limits:

Increase the timeout and maximum number of allowed connections if applicable, as this can often resolve connection issues.

Investigate hardware problems:

If hardware appears to be the possible cause of the issue, check the storage and network resources associated with the database and make sure they are running properly.

Restart the database:

Restart the database or its associated services to ensure any temporary issues are resolved.

Upgrade software components:

If the issue appears to be related to software components such as drivers or libraries, upgrade to ensure compatibility with the database.