title: What is the username and password for Cloud SQL instance?
body: <p>lets say that may app has: </p>
  
  <p>GAE app id: <code>foo123</code><br>
  GAE app name: <code>foo</code><br>
  GAE cloud SQL instance id:  <code>foo123:myInstance</code></p>
  
  <p>I have set the root password to "foobar" in the access control of the Cloud SQL instance.</p>
  
  <pre><code>    try{
  
     $pdo = new pdo("mysql:unix_socket=/cloudsql/foo:foo123:myInstance;charset=utf8", "root", "");
  
  }catch(PDOException $ex){
      die(json_encode(
          array('outcome' =&gt; false, 'message' =&gt; 'Unable to connect')
          )
      );
  }
  </code></pre>
  
  <p>But it can not connect. I'm testing from localhost:8080. 
  The Cloud SQL instance location is USA and my location is Europe.</p>
  
  <p>How can I see what is causing this? </p>
  
  <p>Thanks.
  I have also tried root@"" with no success.</p>
  
  <p>I'm doing exactly as the docs in here: <a href="https://developers.google.com/appengine/docs/php/cloud-sql/" rel="nofollow noreferrer">https://developers.google.com/appengine/docs/php/cloud-sql/</a></p>