Why can’t I connect to my RDS instance?

Not being able to connect to your RDS instance can stem from several common issues. Here are some things to check:

1. Network and Security Group Settings

• Security Groups: Make sure the security group attached to your RDS instance allows inbound traffic on the database port (e.g., 3306 for MySQL, 5432 for PostgreSQL) from your IP or VPC.

• VPC/Subnet: Check that your RDS instance is in a subnet with proper routing, and if it's a private subnet, ensure you have access (VPN, bastion host, etc.).

• Public Accessibility: If you’re connecting from outside AWS, ensure your RDS instance is set to be publicly accessible, or use a VPN or bastion host.

2. Endpoint and Port

• Verify you’re using the correct RDS endpoint (DNS name) and port.

• Sometimes copy-pasting or typos cause issues.

3. Database Credentials

• Double-check your username and password.

• Ensure the user has permission to connect.

4. Database Engine Status

• Check that your RDS instance is available and not in a maintenance or rebooting state.

5. Network ACLs

• Confirm that your subnet’s Network ACLs allow inbound and outbound traffic on the port.

6. Client-side Issues

• Try connecting with a different client or from another network to rule out local firewall or network problems.

7. SSL or Encryption Settings

• If your RDS instance requires SSL connections, ensure your client is configured to use SSL.