With the new sticky session feature, it is possible to instruct the load balancer to route repeated requests to the same EC2 instance whenever possible.

In this case, the instances can cache user data locally for better performance. A series of requests from the user will be routed to the same EC2 instance if possible. If the instance has been terminated or has failed a recent health check, the load balancer will route the request to another instance.

via aws.typepad.com

Die noch recht einfach gestrickte Loadbalancing-Funktion der Amazon Web Services bietet jetzt auch "sticky sessions", wodurch Anfragen des gleichen Benutzers auch immer auf die gleiche Instanz (sofern verfügbar) geleitet werden.