Connect to RDS from EC2 instance -- both inside VPC

Question

I have a VPC with two private subnets (two were required to get an RDS instance set up). I have a security group for this VPC, let's call it vpc-sg. vpc-sg allows TCP access on port 22 from my home machine, and allows all outbound traffic. That's it.

I have a public-facing EC2 server launched inside the VPC, that I've attached a public Elastic IP to. I'm using the EIP to ssh into this EC2 server. I set the security group to vpc-sg. I installed PostgreSQL 9.2 on the EC2 instance.

I have an RDS instance within the same VPC. It's using vpc-sg for a security group too. I was forced to pick PostgreSQL version 9.3 when creating the instance. I try accessing the RDS PostgreSQL database from my EC2 instance:

[ec2-user@ip-10-0-0-20 ~]$ psql the_db_name -U the_db_username -h my-db-instance.random-string.us-east-1.rds.amazonaws.com -p 5432 -W
Password for user the_db_username:
psql: could not connect to server: Connection timed out
        Is the server running on host "my-db-instance.random-string.us-east-1.rds.amazonaws.com" (10.0.0.147) and accepting
        TCP/IP connections on port 5432?

What should I be doing?

EDIT -- I am getting the No Inbound Permissions error on RDB, but don't know how to fix it.

Solution

Just create a new securitygroup with 5432 as inbound TCP connection and replace current security group on your RDS instance with the newly created one.

Comments

[Drew Khoury]

Have you opened port 5432 on the RDS service?

[wrongusername]

@DrewKhoury Probably not. How do I do that?

[Chida]

Just create a new securitygroup with 5432 as inbound TCP connection and replace current security group on your RDS instance with the newly created one.

[Dhruba Adhikari]

Is the solution still valid in 2014 ?

[dubvfan87]

Nope, doing through this through security groups are "Classic" EC2 now.