Microsoft Azure Architect Design (AZ-301) Practice Exam

To ensure a web application remains available even if one Azure data center is down, which Azure deployment should be recommended?

1. Traffic Manager profile and a web app in two regions

2. Load balancer and a virtual machine scale set

3. Load balancer across availability zones

4. Traffic Manager profile and a virtual machine scale set

The correct answer is: Traffic Manager profile and a web app in two regions

In scenarios where a web application must maintain high availability despite the potential failure of one Azure data center, the use of a Traffic Manager profile alongside a web app deployed in multiple regions is highly effective. This approach ensures that if one data center experiences an outage, Traffic Manager can route incoming traffic to a functioning instance in another region, thus maintaining availability and performance for users. A Traffic Manager profile enables geographic routing, which optimizes response time by directing users to the closest, healthy instance of the application. Since the web app is hosted in two different Azure regions, this setup inherently provides redundancy. As a result, if one region goes down, users can seamlessly connect to the alternative region, ensuring service continuity. While alternatives such as a load balancer and virtual machine scale sets across availability zones might provide resilience at a level where servers are concerned, they typically operate within a single region. This does not safeguard against a regional outage effectively since all instances could potentially become unavailable. Therefore, relying solely on load balancing mechanisms within a single region wouldn’t offer the same level of reliability against a complete data center failure, unlike the region-based Traffic Manager solution.