Fictional Corp expects to deploy more than one web server to handle increasing traffic. For load balancing a shopping site, which feature should they look for?

• A. Sticky sessions
• B. Basic health checks
• C. Round-robin by IP
• D. DDoS protection

Answer: (A)

For a multi-server web deployment, keeping a user’s session data consistent across requests is crucial to a smooth shopping experience. Sticky sessions provide session affinity, directing all subsequent requests from the same user to the same backend server for the duration of the session. This means in-memory data like the shopping cart and login state stay on one server, avoiding losses or repeated logins as the user browses. Basic health checks ensure servers are healthy but don’t guarantee session continuity. Round-robin by IP distributes requests evenly and can move a user between servers, potentially breaking in-memory session data. DDoS protection guards against malicious traffic, but it doesn’t manage per-user session state. So, for maintaining an active shopping session across multiple servers, sticky sessions is the best fit. If you use an external session store or token-based sessions, sticky sessions becomes less critical, but given the scenario, it’s the right feature to look for.