AZ-204 Develop Azure compute solutions Practice Question

Answer analysis

Option-by-option breakdown

For each option: why learners choose it and why it is or isn't the right answer here.

• ✓

  Fan-out/fan-in

  Why this is correct

  The Fan-out/fan-in pattern in Durable Functions is specifically designed to execute multiple activity functions concurrently and then wait for all of them to complete before proceeding. This is achieved by initiating several parallel tasks and then using `Task.WhenAll` (or similar language construct) within the orchestrator function to aggregate their results. For a checkout API needing to call five distinct services, this pattern efficiently distributes the workload and ensures all necessary responses are collected before the workflow continues.

• ✗

  Human interaction

  Why it's wrong here

  The Human Interaction pattern is employed when an orchestration needs to pause its execution and await an external event, typically triggered by a human action or an external system. This pattern involves sending a notification and then waiting for an external event to resume the orchestration, often via an external API call to the orchestrator's event endpoint. It is unsuitable for automated, internal API calls within a workflow, as it introduces a deliberate, potentially long-running, manual pause.

• ✗

  Function chaining

  Why it's wrong here

  Function chaining executes a sequence of activity functions in a specific, predefined order, where the output of one activity function often serves as the input for the subsequent one. This pattern is ideal for workflows where tasks have strict dependencies and must complete sequentially. However, for independent API calls that do not rely on prior results, chaining them sequentially would be inefficient and unnecessarily prolong the overall workflow execution time.

• ✗

  Monitor pattern

  Why it's wrong here

  The Monitor pattern is utilized for creating long-running processes that periodically check the status of an external system or resource until a specific condition is met. It typically involves a loop that calls an activity function to check state, then waits for a specified duration, and repeats until a termination condition is satisfied. This pattern is not appropriate for simply executing a fixed set of distinct API calls as part of a single workflow step, as its primary purpose is continuous polling rather than one-time execution and aggregation.