Verify your database connection settings, including host, port, username, password, and ensure the database service is running.

If your Node.js application is unable to connect to the database, there are several key areas to check to resolve the issue promptly. Start by verifying your database connection settings, ensuring that the host, port, username, and password are all correct. A common oversight is misconfigured environment variables; double-check that these are set properly, especially if you are using a configuration management tool or environment files. Ensure that the database service is running; for local databases, you can check the service status on your machine, while for remote databases, you may need to consult your hosting provider’s dashboard or API. If your application connects over the network, check for firewall settings that might be blocking the connection; ensure that the database server allows connections from your application’s IP address. If you’re using a cloud database, consult the provider’s documentation for any additional settings required for remote access. Review your database client configuration in the application to make sure that it correctly handles connection timeouts and retries; consider implementing logic to handle connection errors gracefully to inform users of the issue. Lastly, use logging to capture connection attempts and any errors returned by the database client, which can provide valuable insight into the problem. By carefully examining these aspects, you can effectively troubleshoot and resolve database connection issues in your Node.js application.