Not able to connect AWS RDS (MYSQL) From EC2

Question

Hi I am trying to host PHP code in AWS EC2(Windows) server on IIS. I am able to host the php webpages but the issue is the the webpages are not able to communicate to AWS RDS. PHP Code for Database:

<?php
$con=mysqli_connect("mysqldatabase.xxxxxxxxxx.ap-south-1.rds.amazonaws.com", "admin", "xxxxxxx", "detsdb", "3306");
if(mysqli_connect_errno()){
echo "Connection Fail".mysqli_connect_error();
}

  ?>

I am using default VPC rule and in both RDS and EC2 Security Group(Both Inbound and Outbound) I have opened all traffic as well as Opened SG id with port 3306 with each other.

**Error on Webpage: Connection FailServer sent charset unknown to the client. Please, report to the developers **

When I am trying the same code from my personal computer, I am able to communicate with RDS. I am using Wamp server to communicate and host it locally.

written a simple code to test the functionality that's also working:

<?php
$con = mysqli_connect("mysqldatabase.xxxxxx.ap-south-1.rds.amazonaws.com", "admin", "xxxxx", "detsdb", "3306");
if($con){
echo "Connection Success";
}
else
{
    echo "Error";
}

?>

Please help me on this.

Edit: Screenshot attcahed for both Ec2 and RDS SG

Answer 1

On the windows server make a.txt file, then rename the extension to.UDL open the file and use it as a quick way to test the connection.

Next follow this fix: PDO::__construct(): Server sent charset (255) unknown to the client. Please, report to the developers

If this fails create a second RDS DB in a private subnet and test John's advice about DNS resolving to private IP using the UDL file.

Answer 2

Go to the server and try to connect RDS directly and check whether you can able to access or not.

Answer 3

Basically Its a parameter group issue: so what i did was: Created a new Parameter group and then edited them. Searched all character-set parameters. These are blank by default. edit them individually and select utf8 from drop down list. character_set_results, character_set_server and SAVE. Now you can able to connect