AZ-204 Develop Azure compute solutions Practice Test 17 — 15 Questions

Question 1

You are designing a serverless application using Azure Functions that processes high-volume events from Azure Event Hubs. The events are then written to Azure Cosmos DB. The function must guarantee at-least-once delivery and be resilient to failures. The Cosmos DB account uses the SQL API and is configured with a single write region. You need to design the function to handle transient failures when writing to Cosmos DB without losing events. What should you do?

Accepted Answer

Use the Cosmos DB output binding with built-in retry policy and configure the trigger to checkpoint only after successful writes.. Option D is correct because using the Cosmos DB output binding with its built-in retry policy automatically handles transient failures by retrying writes. By configuring the Event Hubs trigger to checkpoint only after a successful write, you ensure that events are not acknowledged until they are durably stored in Cosmos DB, guaranteeing at-least-once delivery and resilience to failures.

Answer

Increase the Event Hubs trigger's batch size to reduce the number of writes.

Answer

Implement a poison message queue to store failed events and reprocess them later.

Answer

In the function code, manually write to Cosmos DB and then manually checkpoint the Event Hubs partition.

Question 2

Your company runs a web application on Azure App Service that uses a custom domain. The application must be accessible only via HTTPS. You have already uploaded an SSL certificate for the custom domain. However, users can still access the site via HTTP. You need to enforce HTTPS redirection. What should you do?

Accepted Answer

Enable the 'HTTPS Only' setting in the App Service's TLS/SSL settings blade.. The 'HTTPS Only' setting in the App Service's TLS/SSL settings blade enforces that all incoming requests are redirected from HTTP to HTTPS at the platform level, before any application code runs. Since you have already uploaded an SSL certificate, enabling this setting ensures that users cannot access the site via HTTP, meeting the requirement without modifying application code.

Answer

Set the 'Minimum TLS Version' to 1.2.

Answer

Add a rewrite rule in the web.config file to redirect HTTP to HTTPS.

Answer

Configure the App Service to require client certificates.

Question 3

You are deploying a containerized application on Azure Container Instances (ACI) that needs to run as a background job every hour. The job processes data from an Azure SQL Database and sends a report via email. You need to minimize costs while ensuring the job runs reliably on schedule. The job takes about 10 minutes to complete. What should you do?

Accepted Answer

Create an Azure Logic App with a recurrence trigger that starts the container group using the 'Start Container Group' action, and stop it after completion.. Option B is correct because it uses Azure Logic Apps with a recurrence trigger to start the container group only when needed, and stops it after the job completes. This minimizes costs by avoiding continuous running charges for the container, while the Logic App itself incurs minimal execution cost. The job's 10-minute duration fits well within the 1-hour recurrence window, ensuring reliable scheduling without idle compute time.

Answer

Use Azure Batch with a job schedule to run the container as a task.

Answer

Deploy the container on a single Azure virtual machine and schedule it using Windows Task Scheduler.

Answer

Use an Azure Function with a timer trigger that uses the Azure Container Instances SDK to start the container group.

Question 4

Your company uses Azure App Service to host a web application that requires periodic database maintenance. The maintenance tasks are time-consuming and must run outside of peak hours. You need to schedule these tasks to run automatically at 2:00 AM every Sunday. The tasks should be implemented as an Azure Function that runs in the same App Service plan to reduce costs. What should you do?

Accepted Answer

Add a WebJob to the App Service that uses a scheduled trigger to run the maintenance code.. Option C is correct because WebJobs in Azure App Service allow you to run background tasks on a schedule using a settings.job file with a CRON expression. Since the WebJob runs in the same App Service plan as the web application, it shares the same resources and incurs no additional cost, meeting the requirement to reduce costs. The scheduled trigger at 2:00 AM every Sunday can be configured with the CRON expression '0 0 2 * * 0'.

Answer

Deploy the maintenance code as an Azure Function in the Consumption plan and configure a timer trigger.

Answer

Create a separate Azure Function App in the same App Service plan and configure a timer trigger.

Answer

Use Azure Logic Apps with a recurrence trigger to call the web application's maintenance endpoint.

Question 5

You are developing a solution that processes messages from an Azure Storage Queue. Each message triggers a long-running operation that may take up to 30 minutes. You need to ensure that if the processing fails, the message is not lost and can be retried later. The current implementation uses a console application that polls the queue and deletes messages after processing. What should you change?

Accepted Answer

After processing fails, update the message's visibility timeout to a later time so it becomes visible again for retry.. The correct approach is to update the message's visibility timeout to a later time when processing fails. This makes the message reappear in the queue after the specified timeout, allowing another consumer to retry processing. Azure Storage Queue messages have a default visibility timeout of 30 seconds, but you can extend it to up to 7 days. This ensures the message is not lost and can be retried without being deleted or moved prematurely.

Answer

Move the message to a poison queue after the first failure.

Answer

Increase the polling interval to reduce the chance of missing messages.

Answer

Delete the message only if processing succeeds; otherwise, leave it in the queue.

Question 6

You are developing a serverless application using Azure Functions. The application processes orders from a queue and writes results to Azure Cosmos DB. You need to ensure that the function scales out automatically to handle sudden spikes in order volume. Which two actions should you take? (Choose two.)

Accepted Answer

Configure the function app to use the Premium plan with Always Ready instances enabled.. Option A is correct because the Premium plan supports Always Ready instances, which pre-warm a specified number of instances to eliminate cold start latency and ensure the function can handle sudden spikes in order volume without delay. This is critical for serverless applications that require consistent performance under load.

Answer

Use the Consumption plan with a max instance count of 200.

Answer

Implement a retry policy in the queue trigger to handle throttling.

Answer

Set the function's WEBSITE_MAX_DYNAMIC_APPLICATION_SCALE_OUT app setting to 500.

Question 7

Your company is migrating a legacy on-premises .NET Framework 4.7.2 web application to Azure. The application uses session state stored in-memory and reads/writes to a local SQL Server database. The migration must minimize code changes, support auto-scaling, and handle session state across multiple instances. You plan to use Azure App Service with Windows OS. You need to recommend a solution for session state storage and database connectivity. Which option should you choose?

Accepted Answer

Use Azure Cache for Redis as the session state provider via the RedisSessionStateProvider NuGet package, and configure the database connection string in Azure App Service App Settings.. Option A is correct because Azure Cache for Redis provides a distributed, in-memory session state provider that supports session state sharing across multiple App Service instances without requiring code changes to the application logic. The RedisSessionStateProvider NuGet package is a drop-in replacement for the default in-memory provider, and configuring the database connection string in App Settings allows you to change the target without modifying web.config, minimizing migration effort.

Answer

Store session state in Azure Table Storage using a custom session state provider, and use a connection string for Azure SQL Database.

Answer

Configure session state using Azure SQL Database with a session state database, and update the connection string in web.config.

Answer

Use App Service's built-in session state with ARR affinity and connect to Azure SQL Database using Managed Identity.

Question 8

You are developing a containerized application that will be deployed to Azure Container Instances (ACI). The application consists of a web front-end and a background worker that processes messages from an Azure Storage Queue. You need to ensure that the worker container runs continuously and processes messages as they arrive. The solution must minimize cost and management overhead. What should you do?

Accepted Answer

Deploy the worker as a container group in ACI with the restart policy set to Always.. Option D is correct because ACI with a restart policy of Always ensures the worker container restarts immediately after it finishes processing a message, allowing it to continuously poll the Azure Storage Queue for new messages. This minimizes cost by using a serverless container model without provisioning VMs or managing orchestration, and it reduces management overhead compared to alternatives like Azure Container Apps or VMs.

Answer

Use Azure Container Apps with a scale rule that triggers on queue length.

Answer

Run the worker inside an Azure virtual machine with a container runtime.

Answer

Deploy the worker as a container in ACI with the restart policy set to OnFailure.

Question 9

Your company is developing a real-time dashboard that displays live metrics from IoT devices. The backend processes device data using Azure Functions with an Event Hubs trigger. The processed data is stored in Azure Cosmos DB. You need to ensure that the system can handle a sudden increase in device data without losing messages or overloading Cosmos DB. The solution must minimize latency and cost. What should you do?

Accepted Answer

Implement a buffer using Azure Blob storage: the Event Hubs triggered function writes raw data to blobs, and a separate timer-triggered function batches and writes to Cosmos DB at a controlled rate.. Option A is correct because it decouples the ingestion rate from the write rate to Cosmos DB. By buffering raw data in Azure Blob storage and using a timer-triggered function to batch-write at a controlled rate, the system can absorb sudden spikes in device data without overwhelming Cosmos DB or losing messages. This approach minimizes latency by keeping the Event Hubs trigger processing fast (writing to blob) and reduces cost by avoiding the need to over-provision RU/s on Cosmos DB.

Answer

Configure the Event Hubs trigger to use a checkpointing strategy with a larger batch size to reduce the number of function invocations.

Answer

Use Azure Stream Analytics to process the Event Hubs data and write directly to Cosmos DB.

Answer

Increase the provisioned throughput (RU/s) on the Cosmos DB container to handle peak loads.

Question 10

You are developing a web app that processes images uploaded by users. The processing can take up to 30 seconds per image. You need to ensure that the web app remains responsive and can handle spikes in traffic. Which Azure service should you use to offload the image processing?

Accepted Answer

Azure Queue Storage. Option A is correct because Azure Queue Storage decouples the web frontend from the processing backend, allowing the web app to remain responsive and scale independently. Option B is wrong because Event Grid is for event notifications, not long-running queue-based work. Option C is wrong because Azure Cosmos DB is a database. Option D is wrong because SignalR Service is for real-time messaging.

Answer

Azure Cosmos DB

Answer

Azure Event Grid

Answer

Azure SignalR Service

Question 11

You are deploying a containerized application to Azure Container Instances. The application must restart automatically if it crashes. You set the restart policy to 'Always'. However, the container keeps restarting continuously even when there is no crash. What is the most likely cause?

Accepted Answer

The application inside the container exits with a non-zero exit code on startup.. Option B is correct because if the application exits with a non-zero exit code, the 'Always' restart policy treats it as a failure and restarts it. This can lead to a continuous restart loop if the application fails immediately on startup. Option A is wrong because CPU/memory limits don't cause restart loops unless the container is repeatedly terminated (OOMKilled), but that would show a crash. Option C is wrong because volumes causing crashes would exit with non-zero, same as B. Option D is wrong because public IP assignment doesn't affect restart behavior.

Answer

The container is configured with an Azure Files volume that is not accessible.

Answer

The container is trying to bind to a port that is already in use on the host.

Answer

The container is exceeding the allocated CPU or memory limits.

Question 12

You are designing a serverless architecture using Azure Functions for a data processing pipeline. The pipeline must process messages from an Azure Service Bus queue. Each message can take up to 5 minutes to process. You need to ensure that if a function fails, the message is not lost and is retried after a delay. What should you configure?

Accepted Answer

Configure the Service Bus queue to dead-letter messages after a specified number of delivery attempts.. Option C is correct because Service Bus queue dead-lettering automatically moves poison messages after exceeding MaxDeliveryCount. Enabling dead-lettering ensures failed messages are preserved for later investigation. Option A is wrong because Durable Functions are for orchestrating long-running workflows, not for simple retry logic. Option B is wrong because Azure Functions host-level retry policy doesn't apply to Service Bus triggers; Service Bus itself handles retries via MaxDeliveryCount. Option D is wrong because using PeekLock mode with automatic completion on success is the default; if the function fails without calling complete, the lock expires and the message becomes visible again, which can cause infinite retries without dead-lettering.

Answer

Use the PeekLock message receive mode and manually complete the message only after successful processing.

Answer

Use Durable Functions with a retry policy.

Answer

Set the Azure Functions retry policy in the host.json file.

Question 13

Your company is migrating a monolithic application to Azure. The application consists of several components that need to be deployed and scaled independently. You need to design a container orchestration solution. Which TWO services should you consider?

Accepted Answer

Azure Container Apps. Option A and D are correct because Azure Kubernetes Service (AKS) and Azure Container Apps are both managed container orchestration services that support independent scaling of components. Option B is wrong because Azure Container Instances is for running individual containers, not orchestration. Option C is wrong because Azure Service Fabric is also an orchestrator but is older and less relevant for new deployments; however, the question asks for two services, and AKS and Container Apps are the primary choices. Option E is wrong because Azure Batch is for batch computing, not general orchestration.

Answer

Azure Container Instances

Answer

Azure Batch

Answer

Azure Service Fabric

Question 14

You are developing an Azure Functions app that processes orders. Each order must be processed exactly once. The function is triggered by an Azure Event Hubs event. You need to ensure that if the function fails during processing, the event is not lost and is retried. Which THREE actions should you take?

Accepted Answer

Configure a dead-letter queue for events that exceed retry attempts.. Options B, D, and E are correct. B: Checkpointing after processing ensures that on restart, the function resumes from the last successful checkpoint, preventing reprocessing of already processed events. D: Enabling dead-lettering on the Event Hubs capture or using a separate queue for failed events ensures messages are not lost. E: Using the default checkpoint store (Azure Storage) ensures checkpoint data is persisted. Option A is wrong because increasing batch size doesn't prevent loss. Option C is wrong because Event Hubs trigger already uses checkpointing; disabling it would cause reprocessing.

Answer

Increase the batch size to process more events per invocation.

Answer

Disable checkpointing to avoid overhead.

Question 15

Refer to the exhibit. You deploy this ARM template to create an Azure App Service. After deployment, the application stops responding after a few minutes. The application is a .NET 6 web API that runs in a Linux container. What is the most likely cause?

Accepted Answer

The 'alwaysOn' setting is enabled but the App Service plan is on a tier that does not support Always On.. Option B is correct. The template sets 'alwaysOn' to true, which keeps the app loaded even when idle. However, the Free and Shared pricing tiers do not support Always On; the feature is only available in Basic, Standard, Premium, and Isolated tiers. If the hosting plan is on a tier that doesn't support Always On, the setting is ignored, but more importantly, the app might be recycled due to idle timeout. The app stops responding, indicating that the app pool recycles. Option A is wrong because 'WEBSITE_RUN_FROM_PACKAGE' is valid. Option C is wrong because 'linuxFxVersion' is correct for .NET 6. Option D is wrong because the template is valid JSON.

Answer

The ARM template is missing the 'dependsOn' element.

Answer

The 'linuxFxVersion' is set incorrectly for .NET 6.

Answer

The 'WEBSITE_RUN_FROM_PACKAGE' app setting is incorrectly set to '1'.