AZ-305 Question 168
Single answerYour organization is building a new microservices-based e-commerce platform on Azure. The business anticipates unpredictable spikes in user traffic, especially during seasonal sales. You need to ensure that each microservice can scale independently, maintain minimal latency for critical transactions like checkout, and decouple long-running processes such as updating inventory or sending notifications. Which architectural approach best meets these requirements?
- A
Deploy all components in a single Azure App Service instance with an Azure SQL Database for business logic and inventory operations
- B
Use a containerized microservices approach in Azure Kubernetes Service (AKS) with an event-driven messaging solution such as Azure Service Bus or Event Grid
- C
Run everything on a single Azure Virtual Machine configured with autoscaling, and rely on synchronous REST calls to coordinate services
- D
Implement a monolithic application on Azure App Service with a background worker role for processing inventory updates
Show answer and explanation
Correct answer: B
Explanation
In designing an application architecture for large-scale e-commerce, adopting a microservices pattern with independent scaling and event-driven interactions is key to handling unpredictable traffic spikes and ensuring minimal latency for critical transactions. Azure Kubernetes Service (AKS) provides robust orchestration for containerized workloads, while using Azure Service Bus or Event Grid for messaging ensures asynchronous communication and loose coupling among services. For more details, see the Microservices architecture guidance in the Azure Architecture Center.
- A. Incorrect.
Option 1 is incorrect because hosting all services in a single Azure App Service instance creates a monolithic deployment pattern, limiting independent scalability. While App Service can handle moderate workloads, decoupling is minimal here, and asynchronous processes would still be tightly coupled to the main application.
- B. Correct.
Option 2 is correct because using AKS for containerized microservices allows each service to scale independently. Adding an event-driven messaging layer (e.g., Azure Service Bus or Event Grid) enables asynchronous communication between services like checkout and inventory updates, reducing latency and improving performance under high load.
- C. Incorrect.
Option 3 is incorrect because running everything on a single Virtual Machine, even with autoscaling, centralizes the workload and makes horizontal scaling more cumbersome. Synchronous REST calls between tightly coupled services also do not align with a truly decoupled microservices architecture.
- D. Incorrect.
Option 4 is incorrect because a monolithic application with a background worker role still does not offer the same level of independent scalability and decoupling as a microservices architecture. Even though background tasks are offloaded, the design remains largely monolithic.