How to resolve database connection failure in Nacos?

There could be several reasons for the failure of Nacos to connect to the database.

1. The database connection information configuration is incorrect: Please check if the database connection information in the Nacos configuration file is correct, including the database address, username, password, etc.
2. The database service is not running: Please make sure the database service has been started and is running properly.
3. Database firewall restrictions: Sometimes, the database firewall may block external programs from connecting to the database, requiring appropriate firewall rules to be configured on the database server.
4. Insufficient database permissions: Please verify that the database user has sufficient permissions to connect to the database.

Solution:

1. Check the database connection information in the Nacos configuration file, including the address, port, username, and password.
2. Ensure that the database service has been started and is running properly.
3. Check the database firewall settings to ensure that the nacos server is allowed to connect to the database.
4. Confirm that the database user has sufficient permissions to connect to the database.
5. Try restarting the Nacos service and database service to see if it resolves the issue. If the problem persists, consider reaching out to the database administrator or the official Nacos support team for assistance.