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A company is developing a new serverless application that uses Azure Functions. They need to ensure that when a new JSON file is uploaded to an Azure Blob Storage container, a specific Azure Function is triggered to process its content. This trigger should be highly reliable and efficient, minimizing latency. Which Azure Function trigger should they configure?

  1. ABlob trigger
  2. BTimer trigger
  3. CQueue trigger
  4. DHTTP trigger
Show answer & explanation

Correct answer: A. Blob trigger

The Azure Blob trigger is specifically designed to run an Azure Function when a new or updated blob is detected in a specified container. This provides the most efficient and direct way to react to blob uploads.

Why the other options are wrong

  • B. A Timer trigger runs the function on a schedule, not in response to a blob upload event.
  • C. A Queue trigger responds to messages added to an Azure Storage Queue, not directly to blob uploads.
  • D. An HTTP trigger requires an external HTTP request to invoke the function, not suitable for automatic blob upload detection.

Azure Function Blob Trigger

An Azure Function Blob trigger automatically executes a function when a new or updated blob is detected in a specified Azure Blob Storage container.

  • Reacts directly to blob events (creation, update).
  • Automatically binds to the blob content for easy access.
  • Efficient for processing file uploads or changes.

Memory trick: Triggers are what 'poke' your function to run.

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