S90-09A · Question #10
Service A is a task service that sends Service B a message (2) requesting that Service B return data back to Service A in a response message (3). Depending on the response received. Service A may be…
The correct answer is B. The Data Model Transformation pattern can be applied by establishing an intermediate processing. Option B is correct because it addresses both problems present in the scenario: the incompatible data models between Service Inventory A and B (solved via the Data Model Transformation pattern using an intermediate processing component to translate between schemas), and Service…
Question
Service A is a task service that sends Service B a message (2) requesting that Service B return data back to Service A in a response message (3). Depending on the response received. Service A may be required to send a message to Service C (4) for which it requires no response. Before it contacts Service B, Service A must first retrieve a list of code values from its own database (1) and then place this data into its own memory. If it turns out that it must send a message to Service C, then Service A must combine the data it receives from Service B with the data from the code value list in order to create the message it sends to Service C. If Service A is not required to invoke Service C, it can complete its task by discarding the code values. Service A and Service C reside in Service Inventory A. Service B resides in Service Inventory B. You are told that the services in Service Inventory A were designed with service contracts based on different design standards than the services in Service Inventory B. As a result, Service A and Service B use different data models to represent the data they need to exchange. Therefore, Service A and Service B cannot currently communicate. Furthermore, Service C is an agnostic service that is heavily accessed by many concurrent service consumers. Service C frequently reaches its usage thresholds during which it is not available and messages sent to it are not received. How can this service composition architecture be changed to avoid these problems?
Exhibit
Options
- AThe Data Model Transformation pattern can be applied by establishing an intermediate processing
- BThe Data Model Transformation pattern can be applied by establishing an intermediate processing
- CThe Data Model Transformation pattern can be applied by establishing an intermediate processing
- DNone of the above.
How the community answered
(38 responses)- A8% (3)
- B66% (25)
- C8% (3)
- D18% (7)
Explanation
Option B is correct because it addresses both problems present in the scenario: the incompatible data models between Service Inventory A and B (solved via the Data Model Transformation pattern using an intermediate processing component to translate between schemas), and Service C's availability threshold issue (solved via the Reliable Messaging pattern, which queues the one-way fire-and-forget message to Service C so it is delivered when Service C becomes available again).
Option A is wrong because, while it applies Data Model Transformation, it likely addresses only the Service A/B incompatibility and fails to account for Service C's unreliability-leaving the dropped-message problem unsolved.
Option C is wrong because it either combines the correct patterns incorrectly or introduces an unnecessary/wrong secondary pattern that doesn't properly handle the asynchronous, no-response-required nature of the Service A → Service C message (step 4).
Option D is eliminated because valid SOA patterns absolutely exist to solve both problems without a complete redesign.
Memory tip: When a scenario has two distinct problems (schema mismatch + service unavailability), the correct answer must apply two complementary patterns. Match "different data models" → Data Model Transformation, and "frequently unreachable / fire-and-forget message" → Reliable Messaging. If only one pattern is applied, the answer is incomplete.
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