If a Service Consumer Program Needs to Get Data from a Service

question 54

Multiple Choice

If a service consumer program needs to get data from a service that is not available, it can poll the service by periodically issuing a request message. This type of interaction can be inefficient because it can lead to unnecessary message transmissions. Which of the following statements describes a solution to this problem?

• A) By applying the Messaging Metadata pattern, the service consumer can write a request identifier in the message header. Service agents then intercept the request messages and do not forward those that contain a previously detected identifier. This practice eliminates the delivery of the duplicate messages to the service.
• B) The Event-Driven Messaging pattern can be applied to establish a messaging framework in which service consumers are automatically notified of relevant runtime service events.
• C) By applying the Atomic Service Transaction pattern, a service can be designed to invoke an alternative exception handling process when it is unavailable to receive a given message.
• D) None of these statements describe solutions that directly solve this problem.

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Definitions:

Implicit Costs

The opportunity costs that arise from using assets, resources, or funds in a certain way rather than in the next best alternative.

Wheat Farm

A specialized agricultural operation focused on the cultivation and production of wheat.

Free-rider Problem

A situation where individuals or entities receive the benefit of a good or service without contributing to its cost, commonly associated with public goods.

Market Failure

A situation where the allocation of goods and services is not efficient, often leading to a net social welfare loss.