AZ-204 Technology & Digital Applications 3 — Questions and Answers
Question 1: You need to deploy an Azure Web App and ensure zero-downtime deployments. Which App Service feature should you use?
- Deployment Center with GitHub Actions
- Deployment slots with slot swap (Correct answer)
- WebDeploy with the –deleteExistingFiles flag
- Azure DevOps rolling deployment pipeline
Correct answer: Deployment slots with slot swap
Deployment slots let you deploy to a staging slot, warm it up, then perform an atomic swap to production — eliminating downtime during the transition.
Question 2: An application reads messages from an Azure Service Bus queue. Sometimes the same message is processed twice. Which Service Bus feature should you enable to prevent duplicate processing?
- Dead-letter queue
- Message lock renewal
- Duplicate detection (Correct answer)
- Message deferral
Correct answer: Duplicate detection
Service Bus duplicate detection uses a MessageId-based history window to discard messages that were already received within a configurable time period.
Question 3: You need to secure communication between your Azure App Service and an Azure SQL Database so that neither traverses the public internet. What should you configure?
- Enable SSL on the SQL Database connection string
- Deploy the App Service into a VNet and use a Private Endpoint for the SQL Database (Correct answer)
- Use the SQL Database firewall to allow only the App Service outbound IP addresses
- Enable Transparent Data Encryption on the SQL Database
Correct answer: Deploy the App Service into a VNet and use a Private Endpoint for the SQL Database
VNet integration for App Service combined with a Private Endpoint for SQL Database routes all traffic over Azure's private network backbone, never touching the public internet.
Question 4: A Cosmos DB container uses 'userId' as its partition key. A query needs to retrieve all orders across ALL users. What is a concern with this design?
- The query will fail because cross-partition queries are not supported
- The query will execute as a cross-partition fan-out, consuming more RUs and increasing latency (Correct answer)
- Cosmos DB will automatically repartition the data to optimize the query
- The query will only return results from the partition that receives the most traffic
Correct answer: The query will execute as a cross-partition fan-out, consuming more RUs and increasing latency
Cross-partition queries fan out to every partition, multiplying RU consumption and increasing latency — this is expected behavior but must be accounted for in capacity planning.
Question 5: You are implementing retry logic for calls to Azure Blob Storage in a .NET application. Which library provides built-in retry policies including exponential backoff?
- Polly
- Azure.Storage.Blobs SDK (built-in retry pipeline) (Correct answer)
- Microsoft.Extensions.Http
- System.Net.Http.HttpClient with manual retries
Correct answer: Azure.Storage.Blobs SDK (built-in retry pipeline)
The Azure.Storage.Blobs SDK v12+ includes a configurable retry pipeline with exponential backoff and jitter built in, requiring no external library.
Question 6: Your Azure Logic App workflow must send an HTTP request to an external API and wait up to 48 hours for an asynchronous callback. Which pattern should you implement?
- Polling action loop with a 1-minute delay between polls
- Webhook action that pauses the workflow until the callback URL is called (Correct answer)
- HTTP action with a 48-hour timeout parameter
- Use an Azure Function to proxy and hold the connection open
Correct answer: Webhook action that pauses the workflow until the callback URL is called
Logic Apps' Webhook action subscribes to a callback URL and pauses execution, resuming only when the external service calls back — supporting waits of days without polling.
Question 7: You need to implement a feature flag system for an Azure App Service application to gradually roll out new features. Which Azure service is designed for this purpose?
- Azure App Configuration with feature management (Correct answer)
- Azure Key Vault with versioned secrets
- Azure Monitor with custom metrics
- Azure API Management with product policies
Correct answer: Azure App Configuration with feature management
Azure App Configuration's feature management library provides built-in feature flag storage, targeting filters for percentage rollouts, and SDK integration for .NET and other platforms.
AZ-204 Technology & Digital Applications 3
You need to deploy an Azure Web App and ensure zero-downtime deployments.
Which App Service feature should you use?