SAA-C03 Question 227
Single answerA company is running a web application on Amazon EC2 instances behind an Application Load Balancer (ALB). The application stores session data on the instance's local storage. The company wants to ensure that users do not lose their session data if an EC2 instance fails or is replaced. What is the BEST solution to address this requirement?
- A
Store session data in Amazon ElastiCache for Redis.
- B
Enable sticky sessions (session affinity) on the Application Load Balancer.
- C
Use Amazon S3 to store session data.
- D
Store session data in an Amazon RDS database.
Show answer and explanation
Correct answer: A
Explanation
The best solution is to store session data in Amazon ElastiCache for Redis. This service provides low-latency, in-memory data storage, making it ideal for session management. It ensures that session data is not tied to a specific EC2 instance, addressing the issue of session loss if an instance fails or is replaced. While other options, such as sticky sessions or Amazon RDS, may partially address the requirement, they do not provide the same level of scalability, performance, and fault tolerance as ElastiCache.
- A. Correct.
Storing session data in Amazon ElastiCache for Redis is a highly scalable and low-latency solution for session management. It ensures session data is preserved even if an EC2 instance fails or is replaced.
- B. Incorrect.
Enabling sticky sessions on the ALB ensures that users are always routed to the same EC2 instance. However, this does not solve the problem of session loss if the instance fails or is replaced.
- C. Incorrect.
Amazon S3 is used for object storage and is not suitable for storing session data, as it does not provide low-latency access required for session management.
- D. Incorrect.
Although Amazon RDS can be used to store session data, it is not the best option compared to ElastiCache, as RDS introduces higher latency and additional costs.