The method addConnection() adds an ADOdb connection, created by the instantiation of the ADOdbLoadBalancerConnection() class to the load balancer connection pool. Until the connection is added to the pool it cannot be used by the load balancer.

$db = new ADOdbLoadBalancer();
 
$driver = 'mysqli';
$database = 'employees';
$user     = 'adodb';
$password = 'adodb';
$host     = '192.168.0.200';
$db0 = new ADOdbLoadBalancerConnection( $driver,
                                        'write', 
                                        10, 
                                        false, 
                                        $host, 
                                        $user, 
                                        $password, 
                                        $database );
/*
* Add the connection to the pool
*/
$db->addConnection( $db0 );