AWS RDS for PostgreSQL cannot be connected after several hours

Question

I created several instances of RDS with PostgreSQL and get the same problems:

• I can connect to all of them right after creating the instances.
• After several hours (I stop working on it, turn off my laptop), I cannot connect to any of them again.
• I use DBeaver for the connections, the error show is "Connection attempt timed out."

I attached the information of the . Hope someone can help me with this problem. Thank you in advance.

Answer 1

Finally, I found the answer for my problem. For the error of "connection timeout", one of the reasons can be from the security settings. Although I set it as public when creating the RDS instance, the instance is attached with a private VPC security group which is not exposed public. We can attach the RDS instance with a public security group inside the VPC (I don't think it is a good setting, just for the beginner in AWS like me) as below:

• from Services, select EC2, select Security Groups in the left panel.
• click "Create Security Group" button.
• in the dialog, enter the name for the Group, e.g "postgres-public-access"
• in the dialog, click "Add Rule" button.
• In the "Type" column, select "PostgreSQL" or other types of RDS instances (or you can input the port of your RDS instance, usually it is 5432 for Postgres).
• In the "Source" column, enter "0.0.0.0/0".
• Click "Save" button.
• from Services, select RDS, select the RDS instance, click "Modify" button.
• In "Network & Security", "Security group", select the VPC Security Group you just created, in my case, it is "postgres-public-access".
• Click "Continue" button. Now you can go ahead and connect with your database everywhere.