AZ-204 Develop for Azure storage Practice Test 5 — 15 Questions

Question 1

A serverless app must react whenever audit documents are inserted or updated in Cosmos DB. Which trigger should the Azure Function use? The design must avoid adding custom operational scripts.

Accepted Answer

Cosmos DB trigger. The Azure Cosmos DB trigger is the correct choice because it natively listens to the Cosmos DB change feed, which captures inserts and updates to documents. This allows the Azure Function to react automatically without any custom scripts or polling logic, aligning with the serverless and operational simplicity requirements.

Answer

Queue trigger

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Timer trigger

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HTTP trigger

Question 2

An application stores sensor readings in Azure Table Storage. Each sensor produces thousands of readings per hour. Queries always filter by sensor ID and time range. A developer needs to choose the partition key and row key. Which design best balances query performance and write throughput?

Accepted Answer

Partition key: sensor ID; row key: ISO timestamp of the reading. Option A is correct because it uses sensor ID as the partition key, which ensures all readings for a given sensor are stored in the same partition, enabling efficient range queries by row key (timestamp). This design avoids hot partitions by distributing writes across different sensors, while the row key allows fast point lookups and range scans within a time window, balancing query performance and write throughput.

Answer

Partition key: a single constant ('all-sensors'); row key: sensor ID + timestamp

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Partition key: timestamp (rounded to the hour); row key: sensor ID

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Partition key: random GUID per reading; row key: timestamp

Question 3

A background worker retrieves a message from Azure Queue Storage and begins processing. The processing logic takes longer than the configured visibility timeout. Before the worker finishes, the timeout expires. What happens to the message?

Accepted Answer

The message becomes visible again in the queue and another worker can dequeue it. When the visibility timeout expires, the message becomes visible again in the queue because Azure Queue Storage uses a lease-based mechanism. The worker that dequeued the message loses its exclusive visibility lease, allowing another worker to dequeue and process the same message. This ensures at-least-once delivery semantics, preventing message loss if a worker fails or takes too long.

Answer

The message is permanently deleted because the worker already dequeued it

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The message moves to a dead-letter queue after the visibility timeout expires

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Processing continues uninterrupted; the visibility timeout applies only to the initial retrieval window

Question 4

Audit logs are written daily as block blobs to an Azure Storage account. Logs older than 90 days must move to Cool tier automatically; logs older than 365 days must be deleted. The developer wants to implement this with no custom code and no recurring jobs. What is the correct solution?

Accepted Answer

Create a lifecycle management policy with two rules: tier to Cool after 90 days and delete after 365 days. Azure Blob Storage lifecycle management policies allow you to automate tier transitions and deletions based on blob age, without any custom code or recurring jobs. By defining a rule to tier blobs to Cool after 90 days and another rule to delete blobs after 365 days, the developer meets all requirements with a fully managed, no-code solution.

Answer

Write an Azure Function with a Timer trigger that lists all blobs, checks last-modified dates, and tiers or deletes them via the SDK

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Enable Blob versioning and set a version retention policy of 365 days

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Configure a Logic App with a Recurrence trigger to enumerate and process blobs weekly

Question 5

A Windows desktop application uses standard .NET file system calls such as File.ReadAllText and Directory.GetFiles. The team wants to move the file storage to Azure. The application code must not be rewritten. Which Azure storage service supports this requirement?

Accepted Answer

Azure Files with an SMB share mounted as a drive letter on the Windows machine. Azure Files with an SMB share mounted as a drive letter on the Windows machine allows the existing .NET application to use standard file system calls like File.ReadAllText and Directory.GetFiles without any code changes. This is because the mounted SMB share presents itself as a local drive, and the .NET runtime interacts with it through the standard Windows file system API, which internally uses the SMB protocol (CIFS) to communicate with Azure Files. No SDK or API rewrite is required.

Answer

Azure Blob Storage with the Azure Storage SDK replacing all file system calls

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Azure Queue Storage for staging files between producer and consumer processes

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Azure Table Storage with the file content stored as base64-encoded entity properties

Question 6

An e-commerce platform writes orders to a Cosmos DB container. A downstream inventory service must process every new or updated order exactly once, even if the inventory service restarts mid-batch. The solution must scale horizontally when order volume increases. What is the recommended design?

Accepted Answer

Use the change feed processor library with a dedicated lease container; each worker instance claims partition leases and commits checkpoints after processing each batch. The change feed processor library with a dedicated lease container is the recommended design because it provides exactly-once processing semantics through checkpointing, automatic partition lease management for horizontal scaling, and resilience to worker restarts by resuming from the last committed checkpoint. This pattern is purpose-built for Cosmos DB change feed consumption in distributed systems.

Answer

Poll the Cosmos DB container every 30 seconds using a _ts timestamp filter to find recently modified documents

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Subscribe to Azure Event Grid Cosmos DB events and process them in an Azure Function

Answer

Enable Cosmos DB analytical store and run batch queries from an Azure Synapse Spark pool every hour

Question 7

Arrange the steps to implement Azure AD authentication in an ASP.NET Core web app in the correct order.

Question 8

Arrange the steps to secure an Azure API Management API using OAuth 2.0 with Azure AD in the correct order.

Question 9

Match each Azure Storage access tier to its description.

Question 10

Match each Azure messaging pattern to its description.

Question 11

You are building a solution that uploads large files (up to 100 GB) to Azure Blob Storage. Users frequently experience timeout errors when uploading files over slow network connections. Which approach should you use to maximize reliability?

Accepted Answer

Use the Azure Storage SDK to upload the file as a block blob with multiple parallel blocks and implement retry logic with exponential backoff.. Option B is correct because uploading a large file as a block blob with multiple parallel blocks maximizes throughput and reliability over slow networks. The Azure Storage SDK automatically splits the file into blocks (up to 100 MB each), uploads them concurrently, and implements retry logic with exponential backoff to handle transient failures. This approach is specifically designed for large file uploads and mitigates timeout errors by keeping individual block transfers small and resumable.

Answer

Upload the file as a page blob in 512-byte chunks.

Answer

Increase the client-side timeout value to 10 minutes.

Answer

Use AzCopy with the /Z parameter to enable checkpointing.

Question 12

You are developing an application that stores sensitive user data in Azure Table Storage. You need to ensure that data is encrypted at rest and that only authorized users can access it. What should you implement?

Accepted Answer

Enable Azure Storage Service Encryption (SSE) and use Microsoft Entra ID for authentication.. Option B is correct because Azure Storage Service Encryption (SSE) is enabled by default for all storage accounts, encrypting data at rest. Additionally, using Microsoft Entra ID (formerly Azure AD) for authentication provides fine-grained access control via RBAC. Option A is wrong because client-side encryption is possible but not required; SSE already provides at-rest encryption. Option C is wrong because shared access signatures (SAS) provide delegated access but do not enforce RBAC. Option D is wrong because Azure Information Protection is a data classification solution, not for encryption.

Answer

Apply Azure Information Protection labels to the storage account.

Answer

Implement client-side encryption using the Azure Storage SDK and manage keys via Azure Key Vault.

Answer

Use shared access signatures (SAS) with a stored access policy to limit access to the data.

Question 13

Your application stores user profile images in Azure Blob Storage. You need to serve these images to users with low latency from a domain name that you own. What should you use?

Accepted Answer

Create an Azure CDN endpoint with a custom domain and point it to the blob container.. Option B is correct because Azure CDN provides global edge caching, which reduces latency for serving static images from Blob Storage. By configuring a custom domain on the CDN endpoint, you can serve content under your own domain name while benefiting from CDN acceleration. This combination addresses both the low-latency requirement and the custom domain ownership.

Answer

Enable static website hosting and configure a custom domain directly on the storage account.

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Configure a custom domain in Azure DNS and point it to the storage account endpoint.

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Use Azure Front Door with a custom domain.

Question 14

You are designing a solution that requires atomic operations on a counter stored in Azure Blob Storage. The counter must be updated by multiple instances without conflicts. Which approach should you use?

Accepted Answer

Store the counter in Azure Cosmos DB and use stored procedures to increment atomically.. Option A is correct because Azure Cosmos DB stored procedures execute within the database engine's transactional scope, providing ACID-compliant atomic operations. This ensures that concurrent increments from multiple instances are serialized without conflicts, which is not natively supported by Azure Blob Storage's eventual consistency model.

Answer

Use Azure Queue Storage to queue increment messages.

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Store the counter in Azure Table Storage and use optimistic concurrency with ETags.

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Use Append Blob to append each increment as a new block and sum them later.

Question 15

You are using Azure File Sync to sync on-premises file shares to Azure. You need to ensure that files are cached locally on the on-premises server for fast access, but only the most frequently accessed files should be cached. What should you configure?

Accepted Answer

Enable cloud tiering on the server endpoint and set a volume free space policy.. Cloud tiering on an Azure File Sync server endpoint allows you to keep only frequently accessed files cached locally while infrequently accessed files are tiered to Azure. By setting a volume free space policy, you control how much local disk space is reserved for frequently accessed files, ensuring that only the most accessed files remain cached. This directly meets the requirement of caching only the most frequently accessed files locally.

Answer

Configure a caching rule using Azure File Sync's built-in cache size limit.

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Configure a sync group with a custom server endpoint that filters files by last access time.

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Use the Invoke-AzStorageSyncFileRecall cmdlet to recall files on demand.