Microsoft Microsoft Certifications DP-420 Questions & Answers

• Question 1:

  You have a container in an Azure Cosmos DB for NoSQL account. You need to create an alert based on a custom Log Analytics query. Which signal type should you use?

  A. Log

  B. Metrics

  C. Activity Log

  D. Resource Health

  Correct Answer: A

  Explanation:

  You can receive an alert based on the metrics, activity log events, or Log Analytics logs on your Azure Cosmos DB account:

  *-> Log Analytics logs– This alert triggers when the value of a specified property in the results of a Log Analytics query crosses a threshold you assign. For example, you can write a Log Analytics query to monitor if the storage for a logical

  partition key is reaching the 20 GB logical partition key storage limit in Azure Cosmos DB.

  Incorrect:

  Metrics - The alert triggers when the value of a specified metric crosses a threshold you assign. For example, when the total request units consumed exceed 1000 RU/s. This alert is triggered both when the condition is first met and then

  afterwards when that condition is no longer being met.

  Activity log events – This alert triggers when a certain event occurs. For example, when the keys of your Azure Cosmos DB account are accessed or refreshed.

  Reference:

  https://learn.microsoft.com/en-us/azure/cosmos-db/create-alerts

• Question 2:

  You develop an application that uses Azure Cosmos DB Core (SQL) API.

  You create an Azure pipeline to build and deploy the application.

  You need to change the pipeline to run integration tests that you wrote for the application. The solution must execute entirely in the pipeline.

  What should you add to the pipeline?

  A. a deployment group named Cosmos DB testing

  B. an Azure Cosmos DB Emulator task

  C. a NuGet service connection that uses an Azure Cosmos DB API key

  D. a secret variable that has a connection string to an Azure Cosmos DB database

  Correct Answer: B

  Explanation:

  Set up a CI/CD pipeline with the Azure Cosmos DB Emulator build task in Azure DevOps

  The Azure Cosmos DB Emulator provides a local environment that emulates the Azure Cosmos DB service for development purposes. The emulator allows you to develop and test your application locally, without creating an Azure

  subscription or incurring any costs.

  Reference:

  https://learn.microsoft.com/en-us/azure/cosmos-db/tutorial-setup-ci-cd

• Question 3:

  Your company develops an application named App1 that uses the Azure Cosmos DB SDK and the Eventual consistency level.

  App1 queries an Azure Cosmos DB for NoSQL account named account1.

  You need to identify which consistency level to assign to App1 to meet the following requirements:

  Maximize the throughput of the queries generated by App1 without increasing the number of request units currently used by the queries.

  Provide the highest consistency guarantees.

  Which consistency level should you identify?

  A. Strong

  B. Bounded Staleness

  C. Session

  D. Consistent Prefix

  Correct Answer: D

  Reference: https://learn.microsoft.com/en-us/azure/cosmos-db/consistency-levels

• Question 4:

  You have an Azure Cosmos DB database that contains a container named container1. The container1 container is configured with a maximum of 20,000 RU/s and currently contains 240 GB of data.

  You need to estimate the costs of container1 based on the current usage.

  How many RU/s will be charged?

  A. 240

  B. 4,000

  C. 20,000

  D. 24,000

  Correct Answer: B

  Incorrect:

  Not A: Request Units in Azure Cosmos DB

  The minimum RU/s is here MAX(400, 240 * 1 RU/s per GB, 20,000 RU/s / 100) = MAX(400, 240, 200)=400 RU/s.

  Note: Minimum throughput on container

  To estimate the minimum throughput required of a container with manual throughput, find the maximum of:

  400 RU/s

  Current storage in GB * 1 RU/s

  Highest RU/s ever provisioned on the container / 100

  For example, you have a container provisioned with 400 RU/s and 0-GB storage. You increase the throughput to 50,000 RU/s and import 20 GB of data. The minimum RU/s is now MAX(400, 20 * 1 RU/s per GB, 50,000 RU/s / 100) = 500 RU/

  s. Over time, the storage grows to 2000 GB. The minimum RU/s is now MAX(400, 2000 * 1 RU/s per GB, 50,000 / 100) = 2000 RU/s.

  Reference: https://learn.microsoft.com/en-us/azure/cosmos-db/concepts-limits

• Question 5:

  You have an Azure Cosmos DB for NoSQL account named account1.

  You need to create a container named Container1 in account1 by using the Azure Cosmos DB .NET SDK. The solution must ensure that the items in Container1 never expire.

  What should you set?

  A. TimeToLivePropertyPath to null

  B. TimeToLivePropertyPath to 0

  C. DefaultTimeToLive to null

  D. DefaultTimeToLive to –1

  Correct Answer: D

  Explanation:

  Time to live for containers and items

  The time to live value is set in seconds, and it is interpreted as a delta from the time that an item was last modified. You can set time to live on a container or an item within the container:

  Time to Live on a container (set using DefaultTimeToLive):

  If missing (or set to null), items are not expired automatically.

  If present and the value is set to "-1", it is equal to infinity, and items don't expire by default.

  If present and the value is set to some non-zero number "n" – items will expire "n" seconds after their last modified time.

  Reference:

  https://learn.microsoft.com/en-us/azure/cosmos-db/nosql/time-to-live

• Question 6:

  You have an Azure Cosmos DB database.

  You plan to create a new container named container1 that will store product data and product category data and will primarily support read requests.

  You need to configure a partition key for container1. The solution must meet the following requirements:

  Minimize the size of the partition.

  Minimize maintenance effort.

  Which two characteristics should you prioritize? Each correct answer presents part of the solution.

  NOTE: Each correct selection is worth one point.

  A. unique

  B. high cardinality

  C. low cardinality

  D. static

  Correct Answer: BD

  Explanation:

  B: For all containers, your partition key should:

  *

  Have a high cardinality. In other words, the property should have a wide range of possible values.

  *

  Etc.

  D: Be a property that has a value, which doesn't change. If a property is your partition key, you can't update that property's value.

  Reference: https://learn.microsoft.com/en-us/azure/cosmos-db/partitioning-overview

• Question 7:

  You have an Azure Cosmos DB for NoSQL account configured for global distribution across four regions.

  At connection time, the SQL SDK needs to identify the optimal endpoint for reading and writing.

  Which two factors can influence the SDK? Each correct answer presents a complete solution.

  NOTE: Each correct selection is worth one point.

  A. the consistency level in RequestOptions

  B. regional latency

  C. the default consistency level

  D. the PreferredLocations configuration

  E. a region being available

  Correct Answer: DE

  Explanation:

  Connecting to a preferred region using the API for NoSQL

  The SDKs accept an optional parameter PreferredLocations that is an ordered list of Azure regions.

  The SDK will automatically send all writes to the current write region. All reads will be sent to the first available region in the preferred locations list. If the request fails, the client will fail down the list to the next region.

  The SDK will only attempt to read from the regions specified in preferred locations. So, for example, if the Azure Cosmos DB account is available in four regions, but the client only specifies two read(non-write) regions within the

  PreferredLocations, then no reads will be served out of the read region that is not specified in PreferredLocations. If the read regions specified in the PreferredLocations list are not available, reads will be served out of write region.

  Reference: https://learn.microsoft.com/en-us/azure/cosmos-db/nosql/tutorial-global-distribution

• Question 8:

  You have an Azure Cosmos DB Core (SQL) API account named account1 that uses autoscale throughput.

  You need to run an Azure function when the normalized request units per second for a container in account1 exceeds a specific value.

  Solution: You configure Azure Event Grid to send events to the function by using an Event Grid trigger in the function.

  Does this meet the goal?

  A. Yes

  B. No

  Correct Answer: B

  Explanation:

  Instead configure an Azure Monitor alert to trigger the function.

  You can set up alerts from the Azure Cosmos DB pane or the Azure Monitor service in the Azure portal.

  Reference:

  https://docs.microsoft.com/en-us/azure/cosmos-db/create-alerts

• Question 9:

  You are developing an application that will use an Azure Cosmos DB Core (SQL) API account as a data source. You need to create a report that displays the top five most ordered fruits as shown in the following table.

  

  A collection that contains aggregated data already exists. The following is a sample document:

  {

  "name": "apple",

  "type": ["fruit", "exotic"],

  "orders": 10000

  }

  Which two queries can you use to retrieve data for the report? Each correct answer presents a complete solution. NOTE: Each correct selection is worth one point.

  

  A. Option A

  B. Option B

  C. Option C

  D. Option D

  Correct Answer: BD

  ARRAY_CONTAINS returns a Boolean indicating whether the array contains the specified value. You can check for a partial or full match of an object by using a boolean expression within the command. Incorrect Answers:

  A: Default sorting ordering is Ascending. Must use Descending order.

  C: Order on Orders not on Type.

  Reference: https://docs.microsoft.com/en-us/azure/cosmos-db/sql/sql-query-array-contains

• Question 10:

  You are designing an Azure Cosmos DB Core (SQL) API solution to store data from IoT devices. Writes from the devices will be occur every second. The following is a sample of the data.

  

  You need to select a partition key that meets the following requirements for writes:

  1.

  Minimizes the partition skew

  2.

  Avoids capacity limits

  3.

  Avoids hot partitions What should you do?

  A. Use timestampas the partition key.

  B. Create a new synthetic key that contains deviceIdand sensor1Value.

  C. Create a new synthetic key that contains deviceIdand deviceManufacturer.

  D. Create a new synthetic key that contains deviceIdand a random number.

  Correct Answer: D

  Use a partition key with a random suffix. Distribute the workload more evenly is to append a random number at the end of the partition key value. When you distribute items in this way, you can perform parallel write operations across partitions.

  Incorrect Answers:

  A: You will also not like to partition the data on “DateTime”, because this will create a hot partition. Imagine you have partitioned the data on time, then for a given minute, all the calls will hit one partition. If you need to retrieve the data for a customer, then it will be a fan-out query because data may be distributed on all the partitions.

  B: Senser1Value has only two values.

  C: All the devices could have the same manufacturer.

  Reference: https://docs.microsoft.com/en-us/azure/cosmos-db/sql/synthetic-partition-keys