S90-09A · Question #38
You are an architect with a project team building services for Service Inventory A . You are told that no SLAs for Service B and Service C are available. You cannot determine how available these…
The correct answer is C. The Asynchronous Queuing pattern is applied so that a central messaging queue is positioned. Asynchronous Queuing is correct because the central requirement - Service Consumer A must send messages 24/7 without disruption - is best solved by placing a persistent message queue between the consumer and Service A. The queue accepts and stores messages independently of…
Question
You are an architect with a project team building services for Service Inventory A . You are told that no SLAs for Service B and Service C are available. You cannot determine how available these services will be, but it has been confirmed that both of these services support atomic transactions and the issuance of positive and negative acknowledgements. However, you also find out that the services in Service Inventory B use different data models than the services in Service Inventory A. Furthermore, recent testing results have shown that the performance of Service D is steady and reliable. However, Service D uses a different transport protocol than the services in Service Inventory A. The response time of Service A is not a primary concern, but Service Consumer A does need to be able to issue request messages to Service A 24 hours a day without disruption. What steps can be taken to fulfill these requirements?
Options
- AThe Event-Driven Messaging pattern is applied so that a subscriber-publisher relationship is
- BThe Reliable Messaging pattern is applied so that a system of acknowledgements is established
- CThe Asynchronous Queuing pattern is applied so that a central messaging queue is positioned
- DNone of the above.
How the community answered
(51 responses)- A10% (5)
- B20% (10)
- C65% (33)
- D6% (3)
Explanation
Asynchronous Queuing is correct because the central requirement - Service Consumer A must send messages 24/7 without disruption - is best solved by placing a persistent message queue between the consumer and Service A. The queue accepts and stores messages independently of whether Service A is currently available, decoupling the consumer's uptime from the service's uptime. Since response time is explicitly not a concern, the inherent latency of async processing is acceptable here.
Option A (Event-Driven Messaging) is wrong because a publisher-subscriber model is designed for broadcasting events to multiple subscribers, not for guaranteeing that a single consumer can reliably submit requests around the clock regardless of service availability.
Option B (Reliable Messaging) is a tempting distractor - Services B and C do support atomic transactions and acknowledgements, which aligns with that pattern. However, Reliable Messaging focuses on ensuring delivery over unreliable networks, not on shielding a consumer from service downtime. It doesn't provide the store-and-forward buffer needed for true 24/7 availability.
Memory tip: When you see "consumer must send 24/7 without disruption" paired with "response time is not a concern," that's the Asynchronous Queuing signal. Think: "queue = unplug the consumer from the service's schedule." Reliable Messaging = network reliability; Async Queuing = service availability.
Topics
Community Discussion
No community discussion yet for this question.