A sys admin has created a shopping cart application and hosted it on EC2. The EC2 instances are
running behind ELB. The admin wants to ensure that the end user request will always go to the
EC2 instance where the user session has been created. How can the admin configure this?

A.
Enable ELB cross zone load balancing

B.
Enable ELB cookie setup

C.
Enable ELB sticky session

D.
Enable ELB connection draining

Explanation:
Generally AWS ELB routes each request to a zone with the minimum load. The Elastic Load
Balancer provides a feature called sticky session which binds the user’s session with a specific
EC2 instance. If the sticky session is enabled the first request from the user will be redirected to
any of the EC2 instances. But, henceforth, all requests from the same user will be redirected to the
same EC2 instance. This ensures that all requests coming from the user during the session will be
sent to the same application instance.