Q100 — AWS DVA-C02 Ch.2

Question 100 of 100 | ← Chapter 2

An application runs behind multiple EC2 instances managed by an Elastic Load Balancing (ELB) load balancer. To reliably track session data across multiple requests, where should the session data be stored?

• A. Write the data to Amazon ElastiCache. ✓
• B. Write the data to Amazon Elastic Block Store.
• C. Write the data to Amazon EC2 instance store.
• D. Write the data to the root file system.

Correct Answer: A. Write the data to Amazon ElastiCache.

Explanation

Amazon ElastiCache is a managed in-memory caching service ideal for reliable, high-performance session data storage shared across multiple EC2 instances. Options B, C, and D involve storage types less suitable for scalable, shared, and persistent session state—EBS volumes are instance-attached and not inherently shared; instance store is ephemeral; and the root file system is local to each instance and not synchronized.