php - Errors connecting to MySQL database from alternate domain -

i have 2 domains on 2 separate servers, foo.com , bar.com.

i have website , mysql database setup on foo want migrate bar, bar doesn't have mysql.

as solution, i'm moving files across leaving database on foo, , connecting remotely.

i'm connecting so:

connect.php

$hostname = 'database.foo.com'; $username = 'username'; $password = 'password'; $dbname   = 'database';  try {     $dbh = new pdo("mysql:host=$hostname;dbname=$dbname", $username, $password); }  catch(pdoexception $e){     echo($e->getmessage()); } 

this works fine on foo.com when migrate file bar.com error:

sqlstate[hy000] [2003] can't connect mysql server on 'database.foo.com' (110)

i can have 2 sites, foo.com , bar.com open in 2 windows, , 1 work while other doesn't - despite fact both connecting (or trying connect) same database.

why happening , how can rectified?

the database server not configured listen on network port accessible other server.

there several reasons why might be.

it typical listen on local sockets , not use tcp/ip @ since more efficient , secure.

the port might firewalled off other machine.

the server might accessible on local network , foo.com might different network no route bar.com database.foo.com.