AWS Certified DevOps Engineer – Professional (DOP-C02) — Question 388
A company is migrating its web application to AWS. The application uses WebSocket connections for real-time updates and requires sticky sessions.
A DevOps engineer must implement a highly available architecture for the application. The application must be accessible to users worldwide with the least possible latency.
Which solution will meet these requirements with the LEAST operational overhead?
Answer options
- A. Deploy an Application Load Balancer (ALB). Deploy another ALB in a different AWS Region. Enable cross-zone load balancing and sticky sessions on the ALBs. Integrate the ALBs with Amazon Route 53 latency-based routing.
- B. Deploy a Network Load Balancer (NLB). Deploy another NLB in a different AWS Region. Enable cross-zone load balancing and sticky sessions on the NLBs. Integrate the NLBs with Amazon Route 53 geolocation routing.
- C. Deploy a Network Load Balancer (NLB) with cross-zone load balancing enabled. Configure the NLB with IP-based targets in multiple Availability Zones. Use Amazon CloudFront for global content delivery. Implement sticky sessions by using source IP address preservation on the NLB.
- D. Deploy an Application Load Balancer (ALB) for HTTP traffic. Deploy a Network Load Balancer (NLB) in each of the company’s AWS Regions for WebSocket connections. Enable sticky sessions on the ALB. Configure the ALB to forward requests to the NLB.
Correct answer: A
Explanation
Application Load Balancers (ALBs) natively support both WebSocket connections and cookie-based sticky sessions, making them the most operationally efficient choice for this scenario. Deploying ALBs in multiple AWS Regions and routing traffic via Amazon Route 53 latency-based routing ensures that global users are directed to the closest deployment with minimal latency. Network Load Balancers (NLBs) do not natively support cookie-based sticky sessions, meaning options involving NLBs would require more complex configurations and higher operational overhead.