Configure CakePHP 2.* session and session cache in database

When I switched to the AWS Load balancer (multiple server), Session should be maintained unique. When I used to login my site the session lost and it redirected to the home page. So I have tried to store the session in DB using following code.

Configure::write('Session', array(
    'defaults' => 'database',
    'handler' => array(
        'model' => 'cake_sessions'

But it used to store the session data when admin used to logout. I have tried to configure cake session handler interface its fails.

How to haddle the session and cache in database.