AZ-204 Develop Azure compute solutions — Timed 10 Questions

Question 1

You are implementing an Azure Durable Functions application that processes orders. The function must call three external APIs (payment gateway, inventory system, and shipping calculator) in parallel, then aggregate the results once all three have completed. Which Durable Functions pattern should you use?

Accepted Answer

Fan-out/Fan-in. The Fan-out/Fan-in pattern is designed exactly for this scenario: it triggers multiple function tasks in parallel (fan-out) and then aggregates their results once all complete (fan-in). In Durable Functions, this is implemented using `CallActivityAsync` in a loop with `Task.WhenAll` to wait for all parallel activities to finish, allowing the orchestrator to collect and process the combined results.

Answer

Function chaining

Answer

Monitor

Answer

Human interaction

Question 2

A company uses Azure Functions with a consumption plan. The function processes messages from a queue. During peak hours, the function takes longer to execute, and some messages are processed twice. What is the most likely cause?

Accepted Answer

The queue message visibility timeout is shorter than the function processing time.. In Azure Functions with a consumption plan, the queue message visibility timeout determines how long a message is invisible to other consumers after being dequeued. If the function's processing time exceeds this visibility timeout, the message becomes visible again and can be picked up by another function instance, leading to duplicate processing. This is the most likely cause of messages being processed twice during peak hours when execution times increase.

Answer

The function timeout is set too low.

Answer

The function uses blob output binding incorrectly.

Answer

The function app is using a premium plan instead of consumption.

Question 3

You are deploying a Node.js application to Azure Web Apps for Containers. The application needs to read configuration settings from Azure App Configuration. What is the recommended method to securely connect the app to the configuration store?

Accepted Answer

Use managed identity.. Option C is correct because using a managed identity allows the Node.js application running in Azure Web Apps for Containers to authenticate to Azure App Configuration without storing any secrets. Managed identities provide an automatically managed service principal in Azure AD, enabling secure, code-free access to the configuration store via Azure AD authentication, which is the recommended approach for production workloads.

Answer

Store connection string in environment variables.

Answer

Use Key Vault references in App Settings.

Answer

Hardcode the connection string.

Question 4

You are implementing an order processing system using Azure Durable Functions. The function must send notifications to multiple channels (email, SMS, push) in parallel and wait for all to complete before sending a confirmation. Which Durable Functions feature should you utilize?

Accepted Answer

Orchestration trigger with fan-out/fan-in pattern. The fan-out/fan-in pattern in Durable Functions allows you to invoke multiple activity functions in parallel (fan-out) and then wait for all of them to complete (fan-in) using `Task.WhenAll`. This is exactly what is needed to send notifications to email, SMS, and push simultaneously and then proceed only after all have finished, making option A correct.

Answer

Entity trigger

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Activity trigger with retry policy

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Timer trigger

Question 5

You are deploying a sensitive configuration to Azure Container Instances. The configuration must be encrypted at rest and not visible in the container logs. What should you use?

Accepted Answer

Azure Key Vault with managed identity and secret volumes. Azure Key Vault with managed identity and secret volumes is the correct choice because it allows you to mount secrets as files into the container without exposing them in environment variables or logs. The secrets are encrypted at rest in Key Vault and are only accessible via a managed identity assigned to the container group, ensuring the configuration remains secure and invisible in container logs.

Answer

Environment variables in the container group

Answer

Azure Files volume mounted into the container

Answer

ConfigMap in a Kubernetes cluster

Question 6

A company deploys a web application to Azure App Service. They want to deploy a new version of the app with zero downtime and the ability to quickly roll back if needed. Which deployment feature should they use?

Accepted Answer

Deployment slots. Deployment slots are separate, live environments within Azure App Service that allow you to stage a new version of your app, perform validation, and then swap it into production with zero downtime. The swap operation ensures all traffic is redirected instantly, and if issues arise, you can immediately swap back to the previous slot for a quick rollback.

Answer

Auto-scaling

Answer

Traffic Manager

Answer

Application Insights

Question 7

A company deploys a stateful application as a container in Azure Container Instances (ACI). They need persistent storage that can be shared across multiple container instances and retain data after container restarts. Which volume mount should they use?

Accepted Answer

Azure Files share. Azure Files shares provide fully managed SMB file shares in the cloud that can be mounted as volumes in Azure Container Instances. This allows multiple container instances to read and write to the same persistent storage concurrently, and data persists independently of container lifecycles, surviving restarts or deletions. The scenario requires shared, persistent storage across instances, which Azure Files uniquely supports among the given options.

Answer

emptyDir

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Host path

Answer

Secret volume

Question 8

A company deploys an Azure Function app that processes orders. The function needs to scale out automatically when the queue length grows and be billed only for execution time. Which hosting plan should you use?

Accepted Answer

Consumption Plan. The Consumption Plan is correct because it automatically scales out the function app based on the length of the Azure Storage queue trigger, and you are billed only for the execution time (per-second billing) and resources consumed. This plan is ideal for event-driven workloads like order processing, where scaling is demand-driven and idle time incurs no cost.

Answer

App Service Plan

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Premium Plan

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Dedicated Plan

Question 9

You deploy a containerized application on Azure Container Instances (ACI). The application writes data that must persist across container restarts and be accessible from multiple instances. Which volume mount should you configure?

Accepted Answer

Azure Files share. Azure Files shares provide a fully managed SMB file share in the cloud that can be mounted as a volume in Azure Container Instances. This allows data written by the container to persist across restarts and be accessed concurrently by multiple container instances, meeting the requirements for durability and shared access.

Answer

emptyDir volume

Answer

Azure Disk

Answer

ConfigMap

Question 10

You deploy a web application to Azure App Service. You need to deploy a new version of the application without downtime and have the ability to test the new version before switching traffic. Which feature should you use?

Accepted Answer

Deployment slots. Deployment slots are live, independently running app versions in Azure App Service that allow you to deploy a new build to a staging slot, validate it with zero impact on production, and then swap it into production with instant traffic redirection. This swap operation is atomic and warm-up aware, ensuring no downtime during the transition.

Answer

Auto-scaling

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Backup

Answer

Custom domains