AZ-305 Question 172
Single answerYou oversee an e-commerce platform that processes thousands of orders daily from multiple retail and web channels. Each incoming order must be guaranteed to be processed exactly once by the downstream microservices, and certain status updates also need to be published simultaneously to multiple subscribers (e.g., for notifications and analytics). Messages are less than 256 KB. Which Azure messaging service should you recommend to meet these requirements?
- A
Use Azure Storage Queues for order processing and notifications
- B
Use Azure Service Bus with queues and topics
- C
Use Azure Event Hubs for real-time data ingestion
- D
Use Azure Event Grid for push-based event routing
Show answer and explanation
Correct answer: B
Explanation
Azure Service Bus is often recommended when an application requires exactly-once message delivery, transactional support, and a publish-subscribe model via topics. Storage Queues, Event Hubs, and Event Grid each address different needs (simple queueing, streaming ingestion, and reactive event routing, respectively). For detailed guidance, consult Microsoft Docs on 'Azure Service Bus concepts and features' alongside best practices in designing microservices using queues and topics.
- A. Incorrect.
Option 1: Azure Storage Queues are a simple queue-based solution but they do not provide advanced publish-subscribe features like topics and subscriptions, nor do they inherently guarantee exactly-once delivery. This falls short of the scenario’s requirements.
- B. Correct.
Option 2: Azure Service Bus supports guaranteed once-only delivery, ordering, and durable messaging. It also provides topic-based publish-subscribe capabilities, allowing multiple subscribers to receive the same message. This aligns well with the scenario’s needs.
- C. Incorrect.
Option 3: Azure Event Hubs is designed primarily for high-throughput data streaming scenarios, such as telemetry or streaming data ingestion. It does not offer queue semantics or advanced publish-subscribe patterns needed for order processing with exactly-once delivery.
- D. Incorrect.
Option 4: Azure Event Grid provides push-based event routing and is well-suited for reactive event-driven architectures but does not offer queue semantics or guaranteed exactly-once message processing for order data.