AZ-204 Practice Test 48 — 15 Questions

Question 1

You need to store a large (terabytes) append-only dataset for compliance purposes. The data must be immutable to prevent tampering after writes. You also want to minimize storage cost and achieve high write throughput. Which Azure Storage solution should you use?

Accepted Answer

Azure Blob Storage with Append Blobs and an immutable blob policy. Azure Blob Storage with Append Blobs and an immutable blob policy is correct because Append Blobs are optimized for append-only operations (e.g., logging, audit trails) and support high write throughput. Immutable blob policies (WORM – Write Once, Read Many) enforce data immutability at the blob level, preventing modification or deletion during the retention period, which meets compliance requirements. This combination minimizes storage cost by using the cool or archive tier for Append Blobs, while still achieving the required write performance.

Answer

Azure Data Lake Storage Gen2 with Append Blobs and immutability

Answer

Azure Files with immutable shares

Answer

Azure NetApp Files with immutability

Question 2

You are developing an IoT solution that stores device metadata (device ID, location, firmware version, last seen timestamp) in Azure Table Storage. Each device has a unique DeviceId and a Timestamp. You need to design the PartitionKey and RowKey to optimize query performance for the following query: Retrieve all firmware versions for devices in a specific city that were last seen within the last 24 hours. The query must be efficient (partition scan minimized). Which key design is most appropriate?

Accepted Answer

PartitionKey = City, RowKey = Inverted timestamp (e.g., DateTime.MaxValue.Ticks - Timestamp.Ticks). Option B is correct because it uses City as the PartitionKey, ensuring all devices in the same city are in a single partition, and an inverted timestamp as the RowKey, which allows efficient range queries for the last 24 hours. Azure Table Storage sorts entities by RowKey within a partition, so querying for RowKey values greater than the inverted timestamp for 24 hours ago retrieves only the relevant rows without scanning the entire partition.

Answer

PartitionKey = City, RowKey = DeviceId_Timestamp (e.g., "device123_2023-10-01T12:00:00")

Answer

PartitionKey = DeviceId, RowKey = Timestamp

Answer

PartitionKey = City, RowKey = DeviceId

Question 3

A storage account for thumbnail metadata must allow an application to read only blobs under one container for two hours. The application should not receive the account key. What should be issued? The design must avoid adding custom operational scripts.

Accepted Answer

A service SAS scoped to the container with read permission and expiry. A service SAS (Shared Access Signature) scoped to a specific container with read permission and an expiry time of two hours meets the requirement: it grants time-limited read access to blobs under that container without exposing the account key. The SAS token is issued to the application, which can then use it to authenticate requests directly to Azure Blob Storage, avoiding the need for custom scripts.

Answer

A public access level on the container

Answer

A management group assignment

Answer

The storage account access key

Question 4

You are processing messages from an Azure Storage queue in a worker role. To handle messages that repeatedly fail, you want to move them to a separate 'poison' queue after 5 delivery attempts. Which property of the received message should you check to determine the number of attempts?

Accepted Answer

DequeueCount. The DequeueCount property tracks how many times a message has been dequeued from the queue. Each time a worker role retrieves the message but fails to process it (and does not delete it), the message becomes visible again after the visibility timeout expires, incrementing DequeueCount. By checking this property, you can implement a retry policy that moves the message to a poison queue after a threshold (e.g., 5 attempts).

Answer

MessageId

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ExpirationTime

Answer

PopReceipt

Question 5

You are developing an application that stores user-uploaded profile pictures in Azure Blob Storage. Users frequently access these pictures for the first 7 days after upload, then rarely. To minimize costs, you need to automatically delete pictures that are older than 30 days. Which Azure Storage feature should you use to achieve this?

Accepted Answer

Lifecycle management policy. Azure Blob Storage lifecycle management policies allow you to automatically tier or expire blobs based on age. By defining a rule that deletes blobs after 30 days from creation, you can remove old profile pictures without manual intervention, directly minimizing storage costs.

Answer

Blob snapshots

Answer

Change feed

Answer

Soft delete

Question 6

You need to store billions of small telemetry data entries (each ~100 bytes) from IoT devices. The data is written once and rarely updated. You need to run analytical queries on the last 30 days of data daily. The queries scan large ranges of data by timestamp and require sub-second response times. You need the lowest storage cost while meeting query latency requirements. Which Azure Storage solution should you use?

Accepted Answer

Azure Blob Storage with cool access tier and Azure Data Lake Storage Gen2.. Option D is correct because Azure Blob Storage with the cool access tier provides the lowest storage cost for data that is written once and rarely accessed, while Azure Data Lake Storage Gen2 enables hierarchical namespace and POSIX-like access, allowing efficient analytical queries on large timestamp-ranged data with sub-second response times via partitioning and parallel processing.

Answer

Azure Blob Storage with hot access tier and Data Lake Storage Gen2.

Answer

Azure Table Storage with a timestamp partition key.

Answer

Azure Cosmos DB with SQL API and automatic indexing.

Question 7

You need to upload large files (up to 100 GB) to Azure Blob Storage from a web application. The upload must be resilient to network failures and support pausing/resuming. Which approach should you use?

Accepted Answer

Use block blob with multiple blocks and parallel upload.. Option B is correct because block blobs support uploading large files (up to ~4.75 TB) by splitting the file into multiple blocks, uploading them in parallel for speed, and committing the block list atomically. This approach provides resilience to network failures (individual blocks can be retried) and supports pausing/resuming by tracking which blocks have been uploaded.

Answer

Upload the blob as a single PUT operation.

Answer

Use append blob.

Answer

Use AzCopy from the server.

Question 8

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

Answer

Timer trigger

Answer

HTTP trigger

Question 9

You need to store millions of small JSON documents (each ~1 KB) that are frequently updated by multiple concurrent users. You require low-latency access to individual documents. Which Azure Storage solution should you use?

Accepted Answer

Azure Table Storage. Azure Table Storage is a NoSQL key-value store optimized for storing large volumes of structured, non-relational data with low-latency access by partition key and row key. It supports millions of small JSON documents (~1 KB) and handles frequent concurrent updates via optimistic concurrency control using ETags, making it ideal for this scenario.

Answer

Azure Blob Storage with Block blobs

Answer

Azure Files with SMB protocol

Answer

Azure Cosmos DB for NoSQL

Question 10

A serverless app must react whenever audit documents are inserted or updated in Cosmos DB. Which trigger should the Azure Function use?

Accepted Answer

Cosmos DB trigger. The Azure Cosmos DB trigger listens to the change feed of a Cosmos DB container, which captures inserts and updates to documents. This makes it the ideal choice for reacting to audit document changes in a serverless app, as it automatically invokes the function when new or modified documents appear in the feed.

Answer

Queue trigger

Answer

Timer trigger

Answer

HTTP trigger

Question 11

A storage account for thumbnail metadata must allow an application to read only blobs under one container for two hours. The application should not receive the account key. What should be issued?

Accepted Answer

A service SAS scoped to the container with read permission and expiry. A service SAS scoped to a container with read permission and an expiry of two hours is the correct approach because it provides delegated, time-limited access to specific blobs under that container without exposing the storage account key. The SAS token is generated using the account key but the application only receives the token, not the key itself, ensuring the key remains secure. This meets the requirement for read-only access to a single container for a limited duration.

Answer

A public access level on the container

Answer

A management group assignment

Answer

The storage account access key

Question 12

You are building a compliance solution that stores terabytes of data in Azure Blob Storage. Data is appended frequently and never modified. Regulatory requirements mandate that no data can be overwritten or deleted for 7 years. Which storage configuration should you enable?

Accepted Answer

Enable immutability policy (time-based retention). A is correct because a time-based retention policy under Azure Blob Storage immutability policy ensures that blobs cannot be overwritten or deleted for a specified duration (here, 7 years). This meets the regulatory requirement of write-once-read-many (WORM) compliance, and the policy is enforced at the storage container level, preventing any modifications or deletions even by the storage account owner.

Answer

Enable blob soft delete

Answer

Enable blob versioning

Answer

Enable change feed

Question 13

You are building a data pipeline that writes billions of small log records (each ~200 bytes) to Azure Blob Storage. The logs are always written in chronological order and are read sequentially in order. You must minimize storage cost and achieve maximum write throughput. Which blob type should you use?

Accepted Answer

Append blobs in the Hot tier. Append blobs are optimized for append operations, making them ideal for writing billions of small log records in chronological order. They support high-throughput sequential writes without the overhead of managing block IDs, and the Hot tier provides low-latency access for immediate reading, minimizing storage cost while maximizing write throughput.

Answer

Block blobs in the Cool tier

Answer

Page blobs in the Premium tier

Answer

Block blobs in the Archive tier

Question 14

You are designing a backup solution for a virtual machine. Monthly backups are large VHD files (up to 1 TB) that must be retained for 7 years. After creation, backups are accessed only rarely (once or twice per year). You need to minimize storage cost. Which storage tier should you use for the VHD files?

Accepted Answer

Archive tier. The Archive tier is the correct choice because it offers the lowest storage cost for data that is rarely accessed (once or twice per year) and has a long retention period (7 years). Azure Archive storage is optimized for data that can tolerate a retrieval latency of several hours, which is acceptable given the infrequent access pattern of these monthly backup VHD files.

Answer

Hot tier

Answer

Cool tier

Answer

Premium tier

Question 15

You are designing a solution to ingest billions of small IoT sensor messages (each ~500 bytes). Messages arrive at high velocity and must be retained for 90 days. You need to query the data efficiently by device ID and timestamp. You want to minimize storage cost and write latency. Which Azure Storage solution should you use?

Accepted Answer

Azure Table Storage. Azure Table Storage is ideal for this scenario because it provides a cost-effective, schema-less NoSQL store that supports high-volume ingestion of billions of small messages with low write latency. Its partition key (device ID) and row key (timestamp) design enables efficient point queries by device and time range, while the 90-day retention aligns with Table Storage's lifecycle management capabilities.

Answer

Azure Blob Storage with JSON logs

Answer

Azure Queue Storage

Answer

Azure File Storage