Fundamental
Prepare and test your skills
Fundamental
Prepare and test your skills
How Blob Storage Triggers Invoke Azure Functions
Free sample question, answered and explained below. The AZ-900 Microsoft Azure Fundamentals Exam practice bank has 688 more like it. Try 10 free: instant score, no account.
An organization is deploying an event-driven serverless solution in Azure to process invoices. The development team needs the application code to execute automatically whenever a new document is uploaded to Azure Blob Storage, without provisioning or maintaining persistent virtual servers.
Which Azure Functions feature should the team configure to initiate code execution in response to this cloud event?
Explanations
A function trigger
A function trigger
What a Function Trigger Is
An Azure Functions trigger is an architectural construct that defines how a serverless function is invoked. Triggers monitor specific cloud event sources—such as HTTP webhooks, scheduled timers, message queues, or storage events—and pass relevant payload data to the function code upon execution.
How It Meets the Requirement
In a serverless environment, applications do not run continuously waiting for input. Instead, the Blob Storage trigger (or an Event Grid event subscription on the container) listens for newly uploaded files. As soon as a document arrives, the platform allocates compute resources dynamically, runs the function, and releases those resources immediately afterward.
Key Advantages and Capabilities
- Event-Driven Invocation: Automatically initiates code execution immediately when predefined events occur in Azure services.
- Zero Idle Costs: Works seamlessly with serverless Consumption plans, ensuring costs are only incurred while the code is actively executing.
- Built-In Data Binding: Easily pairs with input and output bindings to streamline data reading and writing without boilerplate SDK code.
- Broad Ecosystem Support: Integrates out-of-the-box with Azure services like Azure Blob Storage, Azure Event Hubs, Azure Service Bus, and Azure Cosmos DB.
Why This Is Optimal
A function trigger is the native, purpose-built mechanism in Azure serverless computing for running on-demand code without dedicated server infrastructure.
An Azure Resource Manager lock
An Azure Resource Manager lock
What a Resource Lock Is
An Azure Resource Manager (ARM) lock is a governance and security feature applied to Azure subscriptions, resource groups, or individual resources to prevent accidental deletion or unwanted configuration changes.
Why It Doesn't Meet the Requirement
Resource locks operate purely at the management plane for governance purposes (CanNotDelete or ReadOnly). They have no operational role in application logic, code invocation, or reacting to data changes within storage containers.
Key Characteristics and Limitations
- Accidental Deletion Safeguard: Blocks delete operations from administrators and automated scripts.
- Configuration Protection: Prevents unauthorized modifications when set to Read-Only mode.
- Zero Compute Control: Does not execute application code, evaluate data events, or manage runtime execution.
This Answer Would Be Correct If
The organization needed to protect the Azure Storage account or Function App from being accidentally deleted by administrative users.
A virtual machine scale set rule
A virtual machine scale set rule
What a Virtual Machine Scale Set Is
An Azure Virtual Machine Scale Set (VMSS) is an Infrastructure as a Service (IaaS) resource management offering that allows administrators to deploy, configure, and automatically scale a pool of identical, load-balanced virtual machines.
Why It Doesn't Meet the Requirement
Using a Virtual Machine Scale Set represents traditional IaaS cloud computing rather than serverless computing. A VMSS requires managing underlying operating systems, runtime dependencies, patches, and base infrastructure capacity, which directly conflicts with the serverless requirement of running code on-demand without managing servers.
Key Characteristics and Limitations
- Infrastructure Management: Requires ongoing maintenance of virtual machine OS images, security patches, and VM sizes.
- Continuous Compute Billing: Costs accrue as long as virtual machine instances are running, regardless of whether they are actively handling requests.
- Metric-Based Scaling: Typically scales based on CPU utilization, memory usage, or queue depth rather than individual event triggers.
This Answer Would Be Correct If
The requirement asked to horizontally scale dedicated IaaS virtual machines based on average CPU utilization or memory metrics.
A deployment slot
A deployment slot
What a Deployment Slot Is
A deployment slot is an application lifecycle management feature available in hosting environments like Azure App Service and certain Azure Functions plans. Deployment slots allow teams to run different versions of an application (such as staging and production) under distinct hostnames.
Why It Doesn't Meet the Requirement
Deployment slots do not listen for external cloud events or invoke code execution when files are uploaded. Their role is strictly related to release management, continuous delivery (CI/CD), and validating new application versions prior to swapping them into production.
Key Characteristics and Limitations
- Release Management: Facilitates blue-green deployments and zero-downtime application updates.
- Traffic Swapping: Allows seamless endpoint traffic redirection without restarting the underlying infrastructure.
- No Event Handling: Does not process incoming messages or invoke event-driven workflows.
This Answer Would Be Correct If
The organization needed to deploy and test a new version of their serverless function code in a staging environment before swapping it into production without downtime.
Try 10 interactive questions like this one, free
Answer them yourself and get your score the moment you finish. No account needed.
Full access includes
- 688 practice questions across all 3 exam domains
- Every answer explained: why it is right, and why the others are not
- Scout, an AI tutor that answers your follow-up questions
- Readiness tracking by domain, so you know when to book the exam
Related questions
Keep the momentum going with these hand-picked practice scenarios
FundamentalAZ-900 Microsoft Azure Fundamentals Exam
Serverless Scaling to Zero and Per-Second Billing
Describe serverless
FundamentalAZ-900 Microsoft Azure Fundamentals Exam
Azure Functions and Azure SignalR Service
Describe serverless
FundamentalAZ-900 Microsoft Azure Fundamentals Exam
Azure Functions Event-Driven Serverless Compute
Describe serverless
FundamentalAZ-900 Microsoft Azure Fundamentals Exam
Serverless Consumption Plan
Describe serverless
FundamentalAZ-900 Microsoft Azure Fundamentals Exam
Serverless Computing
Describe serverless
ExpertAZ-500 Microsoft Azure Security Technologies Exam
Application Permissions vs Delegated Permissions
Configure app registration permission scopes
Last updated Validated