Description:
------------
On a number of examples on the mysqlnd_ms documentation, this code is shown:

<?php
/* Load balanced following "myapp" section rules from the plugins config file */
$mysqli = new mysqli("myapp", "username", "password", "database");
if (mysqli_connect_errno())
  /* Of course, your error handling is nicer... */
  die(sprintf("[%d] %s\n", mysqli_connect_errno(), mysqli_connect_error()));

However, there is a problem here - because mysqlnd_ms connections are lazy and will not actually be connected until a statement is executed, the call to mysqli_connect_errno() will return 0.

There is no way to check the connection has succeeded unless you executed a statement and check for errno or validate only that $mysqli is actually instantiated as a mysqli object.

Test script:
---------------
Make sure the credentials below will not actually work on your MySQL instance, if so, die() will not be triggered.

<?php
/* Load balanced following "myapp" section rules from the plugins config file */
$mysqli = new mysqli("myapp", "username", "password", "database");
if (mysqli_connect_errno())
  /* Of course, your error handling is nicer... */
  die(sprintf("[%d] %s\n", mysqli_connect_errno(), mysqli_connect_error()));
?>