The reason is "Connection refused".
I asked ChatGPT.
Quote:The error you're encountering indicates that CodeIgniter is unable to connect to the database using the "remote" database group configuration specified in your .env file. The error message "Connection refused" suggests that there might be an issue with the database server, credentials, or networking.
Here are some steps you can take to troubleshoot and resolve the issue:
1. **Check Database Credentials**:
Ensure that the database credentials (e.g., hostname, username, password, database name) specified in the .env file for the "remote" database group are correct.
2. **Verify Database Server**:
Confirm that the database server specified in the .env file is accessible and running. Ensure that the server is accepting connections from the machine running your CodeIgniter application.
3. **Check Database Host and Port**:
Double-check the database hostname and port specified in the .env file. Ensure that the port is correct and that the database server is listening on that port.
4. **Check Database Permissions**:
Verify that the database user associated with the credentials in the .env file has the necessary permissions to perform SELECT queries on the specified database.
5. **Verify Database Connection**:
Test the database connection manually using the credentials from the .env file. You can use a MySQL client or a tool like `mysqli` in PHP to establish a connection and execute a simple SELECT query to ensure connectivity.
6. **Check Firewall and Network Settings**:
Ensure that there are no firewall rules or network restrictions preventing the CodeIgniter application from connecting to the database server.
7. **Review CodeIgniter Configuration**:
Double-check the database configuration in CodeIgniter (e.g., app/Config/Database.php) to ensure it matches the settings in your .env file.
8. **Check Database Service Status**:
Verify that the database service is running and accessible on the specified host and port. Check the database server logs for any related errors.
By carefully reviewing and verifying the database credentials, server settings, and CodeIgniter configurations, you should be able to identify and resolve the issue causing the "Connection refused" error.
