Error 2003 (HY000) when i try to connect amazon rds server from ec2 server

If it works from your laptop, apparently you have authorized the IP at which your laptop appears on the Internet to connect to RDS. Browse whatismyip.com to see that public IP. If you browse to whatismyip from your dedicated server, you can verify that server's public IP, and make sure it is authorized in AWS. If it's just one IP, enter it as x.x.x.x/32.

If you use tcp port 3306 for MySQL, from a shell/cmd prompt on the dedicated server, enter

telnet db.address.us-east-1.rds.amazonaws.com 3306

If the connection times out instead of opening a new window, and you confirm that your dedicated server's public IP is authorized, then something in your server or hosting provider's network is probably blocking your connection. Support should be able to help find and fix it.

You're going down the wrong path with this. The root cause is that you can't connect to the SQL server from the node you're using the PHP script on.

Check your firewalls to make sure you can contact it on the right port (the default is 3306, but you may have chosen something else), that you have the right IP (it happens), and that it is listening on the interface you're trying to use to connect to it.

If you are using selinux, you will need to do something along the lines of setsebool -P httpd_can_network_connect=1. However, I don't often see people run selinux and phpmyadmin at the same time, so I'm going to guess you aren't. If it does happen that you are, though, this policy needs to be set on the server running httpd (apache) because that is the software to which it will apply (by enabling it to connect to network hosts).