Cannot connect to mysql server

Hello I am trying to connect to mysql server from php using PDO.

But I get this error :

An error occured : SQLSTATE[HY000] [2002] Can't connect to local MySQL server through socket '/var/lib/mysql/mysql.sock' (2)

Note that this is not a database I host. I was simply given the username and password to construct the database, create the users etc.

function ConnectToDb()
{
    try{
        $dns = 'mysql:host=1.1.1.1;dbname=dummyDbName';
        $username = 'dummyUser';
        $password = 'dummyPassword';
        $LINK = new PDO($dns, $username, $password);
        $LINK->setAttribute(PDO::ATTR_EMULATE_PREPARES, false);
        $LINK->setAttribute(PDO::ATTR_ERRMODE, PDO::ERRMODE_EXCEPTION);
        if (!$LINK){
            die('Could not connect : ' .mysql_error());
        }
        else{
            return $LINK;
        }
    } catch (PDOException $ex){
        echo "An error occured : " .$ex->getMessage();
    }
}

I know that this works on localhost. I'm using it no problem, but as soon as I try to connect to the production database it fails. Anyone has an hint?