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.

• ✗

  Enable session state in the function app.

  Why it's wrong here

  Enabling session state in a function app is irrelevant for processing Event Hubs events. Session state is a concept primarily used in web applications (like ASP.NET) to maintain user-specific data across multiple HTTP requests. Azure Functions processing Event Hubs events operates in a stateless, event-driven model, where individual events or batches are processed independently without the need for a persistent "session" context across different event invocations.

• ✗

  Use a Service Bus queue trigger with a singleton lock.

  Why it's wrong here

  Using a Service Bus queue trigger with a singleton lock is not the correct solution for ordered stream processing. While a singleton lock might attempt to restrict concurrent processing, Azure Service Bus queues do not inherently guarantee message order across partitions or even within a single queue when multiple consumers are involved. Event Hubs is specifically designed for high-throughput stream ingestion and provides strong ordering guarantees within each partition, which is a fundamental requirement for many stream processing scenarios.

• ✗

  Disable checkpointing to ensure no duplicates.

  Why it's wrong here

  Disabling checkpointing would be detrimental to ensuring reliable, non-duplicate processing. Checkpointing is the mechanism by which the Event Hubs trigger records the last successfully processed event's offset for each partition. If checkpointing is disabled, upon a function restart or scale-out, the function would lose its processing state and likely reprocess events from an earlier point in the stream, leading to increased duplicate processing rather than preventing it.

• ✓

  Use the Event Hubs trigger for Azure Functions with default configuration.

  Why this is correct

  The Azure Functions Event Hubs trigger, with its default configuration, is the ideal choice for processing Event Hubs events reliably and in order. It automatically handles partition management, ensuring that events within a single Event Hub partition are processed sequentially. Furthermore, it leverages built-in checkpointing to an Azure Storage account, which tracks the progress of event processing for each partition, enabling "at-least-once" delivery and facilitating "exactly-once" processing when combined with idempotent function logic.

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