Following this tutorial, I set up an Aurora PostgreSQL database. I then tried to access the database from my computer using pgAdmin. However, pgAdmin gives the error: "Unable to connect to server: timeout expired"
I have tried the following things:
It looks like you have deployed the Aurora DB cluster into two subnets of a VPC and the problem is that one subnet is public, while the other is private. I suspect the DB will be accessible publicly as long as the public DNS resolves to the DB instance in the public subnet, but will be unreachable when it resolves to the instance in the private subnet (though I have not verified this).
To correct this and make the cluster publicly accessible, deploy the DB into public subnets only.