The correct choice is the Blob trigger with the Consumption plan. The Blob trigger is purpose-built to fire a function automatically whenever a new blob is created or updated in Azure Blob Storage, which directly satisfies the requirement for serverless image processing to run on each new upload. The Consumption plan complements this by providing automatic, demand-driven scaling that handles high upload volumes without manual intervention, making it the ideal serverless hosting model for event-driven workloads. On the AZ-204 exam, this pairing tests your understanding of Azure Functions triggers and hosting options, often appearing in scenario-based questions where you must distinguish between Blob, HTTP, or Queue triggers and between Consumption, Premium, or Dedicated plans. A common trap is selecting the Premium plan for scaling, but the Consumption plan is sufficient and cost-effective for simple blob-triggered processing. Memory tip: think "Blob fires, Consumption scales" — the trigger reacts to the storage event, and the plan handles the burst.
AZ-204 Develop Azure compute solutions Practice Question
This AZ-204 practice question tests your understanding of develop azure compute solutions. Match the stated requirement to the specific cloud service, access model, or configuration option — many options are valid in isolation but not for this scenario. After answering, compare your reasoning against the explanation and wrong-answer breakdown below. Once you have made your selection, read the full explanation to reinforce the concept and understand why each distractor is designed to mislead on exam day.
You are building a serverless image-processing solution using Azure Functions. The function must automatically run whenever a new image is uploaded to a blob container and must scale out to handle high upload volumes. Which trigger and hosting plan should you use?
Why wrong: A timer trigger runs on a fixed schedule, not in response to blob uploads. It does not activate on new blobs.
B
Blob trigger with Consumption plan
The blob trigger runs when a new blob is created, and the Consumption plan automatically scales out to handle high volumes.
C
HTTP trigger with Premium plan
Why wrong: An HTTP trigger requires an incoming HTTP request; it does not fire automatically on blob uploads. The Premium plan is not needed for scaling.
D
Queue trigger with App Service plan
Why wrong: A queue trigger processes messages from an Azure Storage Queue, not blob events. The App Service plan would be unnecessary for the stated requirement and requires manual scaling or always-on.
Answer the question above first, then reveal the full breakdown to understand why each option is right or wrong.
Correct answer & explanation
✓
Blob trigger with Consumption plan
The Blob trigger is designed to automatically execute a function when a blob is created or updated in Azure Blob Storage, making it the correct choice for an image-processing solution that must run on new uploads. The Consumption plan provides automatic scaling to handle high upload volumes by allocating resources on demand, which aligns with the serverless, event-driven requirement.
Key principle: Answer the scenario, not the keyword: identify the specific constraint before choosing the most familiar-sounding option.
Answer analysis
Option-by-option breakdown
For each option: why learners choose it and why it is or isn't the right answer here.
✗
Timer trigger with Consumption plan
Why it's wrong here
A timer trigger runs on a fixed schedule, not in response to blob uploads. It does not activate on new blobs.
✓
Blob trigger with Consumption plan
Why this is correct
The blob trigger runs when a new blob is created, and the Consumption plan automatically scales out to handle high volumes.
Related concept
Read the scenario before looking for a memorised answer.
✗
HTTP trigger with Premium plan
Why it's wrong here
An HTTP trigger requires an incoming HTTP request; it does not fire automatically on blob uploads. The Premium plan is not needed for scaling.
✗
Queue trigger with App Service plan
Why it's wrong here
A queue trigger processes messages from an Azure Storage Queue, not blob events. The App Service plan would be unnecessary for the stated requirement and requires manual scaling or always-on.
Common exam traps
Common exam trap: answer the scenario, not the keyword
The trap here is that candidates may confuse the Blob trigger with other triggers (like Timer or Queue) that can indirectly process blobs, but only the Blob trigger directly and automatically responds to blob creation events without additional infrastructure.
Detailed technical explanation
How to think about this question
Under the hood, the Blob trigger uses Azure Storage event subscriptions (via Event Grid) to detect new blobs, which ensures near-real-time invocation even at high throughput. The Consumption plan scales out to hundreds of instances based on the number of new blobs, with each instance processing blobs from different partitions to avoid contention. A subtle behavior is that the Blob trigger can have up to a 10-minute delay in high-scale scenarios due to internal polling when Event Grid is not used, but the default integration with Event Grid minimizes this latency.
KKey Concepts to Remember
Read the scenario before looking for a memorised answer.
Find the constraint that changes the correct option.
Eliminate answers that are true in general but not in this case.
TExam Day Tips
→Watch for words such as best, first, most likely and least administrative effort.
→Review why wrong options are wrong, not only why the correct option is correct.
Key takeaway
Answer the scenario, not the keyword: identify the specific constraint before choosing the most familiar-sounding option.
Real-world example
How this comes up in practice
A media company stores terabytes of video archives that are accessed once a year for audit purposes. Moving these objects to a cold storage tier (Azure Archive, S3 Glacier, or Google Nearline) costs a fraction of hot storage. Questions like this test whether you understand storage tiers, access frequency tradeoffs, and retrieval latency requirements.
Related glossary terms
Concepts from this question explained
These glossary pages explain the core terms tested in this AZ-204 question in full detail.
Develop Azure compute solutions — This question tests Develop Azure compute solutions — Read the scenario before looking for a memorised answer..
What is the correct answer to this question?
The correct answer is: Blob trigger with Consumption plan — The Blob trigger is designed to automatically execute a function when a blob is created or updated in Azure Blob Storage, making it the correct choice for an image-processing solution that must run on new uploads. The Consumption plan provides automatic scaling to handle high upload volumes by allocating resources on demand, which aligns with the serverless, event-driven requirement.
What should I do if I get this AZ-204 question wrong?
Identify which exam domain this question belongs to, review the core concept, then practise similar questions from the same domain.
What is the key concept behind this question?
Read the scenario before looking for a memorised answer.
About these practice questions
Courseiva creates original exam-style practice questions with explanations and wrong-answer analysis. It does not publish real exam questions, exam dumps, or protected exam content. Learn why practice questions differ from exam dumps →
These questions test the same concept from different angles. Work through them to make sure you can recognise it however the exam phrases it.
Variation 1. You are designing a solution to process thousands of images uploaded to Azure Blob Storage. Each image must be resized and metadata extracted. The processing must be serverless and cost-effective. Which Azure service should you use?
medium
A.Azure Container Instances with Blob Storage SDK
B.Azure Logic Apps with Blob Storage connector
C.Azure Event Grid with Webhook to a custom service
✓ D.Azure Functions with Blob Storage trigger
Why D: Azure Functions with a Blob Storage trigger is the correct choice because it provides a serverless, event-driven compute model that automatically scales to process thousands of images as they are uploaded to Blob Storage. The trigger binds directly to a blob container, invoking a function for each new blob, which allows you to resize images and extract metadata without managing infrastructure, making it both cost-effective and efficient for high-throughput workloads.
Share a tip, memory trick, or ask about the reasoning behind this question. Do not post real exam questions, leaked content, braindumps, or copyrighted exam material. Comments are moderated and may be removed without notice.
This AZ-204 practice question is part of Courseiva's free Microsoft certification practice question bank. Courseiva provides original exam-style practice questions with explanations, topic-based practice, mock exams, readiness tracking, and study analytics to help learners prepare for the AZ-204 exam.
Question Discussion
Share a tip, memory trick, or ask about the reasoning behind this question. Do not post real exam questions, leaked content, braindumps, or copyrighted exam material. Comments are moderated and may be removed without notice.
Sign in to join the discussion.