Amazon DVA-C02 Online Practice Questions and Exam Preparation

Amazon DVA-C02 Online Questions & Answers

• Question 451:

  A developer is building a serverless application that is based on AWS Lambda. The developer initializes the AWS software development kit (SDK) outside of the Lambda handler function. What is the PRIMARY benefit of this action?

  A. Improves legibility and stylistic convention
  B. Takes advantage of runtime environment reuse
  C. Provides better error handling
  D. Creates a new SDK instance for each invocation
  B. Takes advantage of runtime environment reuse

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  Explanation

• Question 452:

  What are the MINIMUM properties required in the resources section of the AppSpace file for CodeDeploy to deploy the ECS service successfully?

  A. name, alias, currentversion, and targetversion
  B. TaskDefinition, ContainerName, and PlartformVersion
  C. TaskDefinitionContainerName, ContainerPort
  D. name, Currentversion, NetworkConfiguration, and Platform Version
  A. name, alias, currentversion, and targetversion

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  Explanation

• Question 453:

  A company has an ecommerce application. To track product reviews, the company's development team uses an Amazon DynamoDB table.

  Every record includes the following

  A Review ID a 16-digrt universally unique identifier (UUID) A Product ID and User ID 16 digit UUlDs that reference other tables A Product Rating on a scale of 1-5 An optional comment from the user

  The table partition key is the Review ID. The most performed query against the table is to find the 10 reviews with the highest rating for a given product.

  Which index will provide the FASTEST response for this query"?

  A. A global secondary index (GSl) with Product ID as the partition key and Product Rating as the sort key
  B. A global secondary index (GSl) with Product ID as the partition key and Review ID as the sort key
  C. A local secondary index (LSI) with Product ID as the partition key and Product Rating as the sort key
  D. A local secondary index (LSI) with Review ID as the partition key and Product ID as the sort key
  A. A global secondary index (GSl) with Product ID as the partition key and Product Rating as the sort key

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  Explanation

  This solution allows the fastest response for the query because it enables the query to use a single partition key value (the Product ID) and a range of sort key values (the Product Rating) to find the matching items. A global secondary index

  (GSI) is an index that has a partition key and an optional sort key that are different from those on the base table. A GSI can be created at any time and can be queried or scanned independently of the base table. A local secondary index (LSI)

  is an index that has the same partition key as the base table, but a different sort key. An LSI can only be created when the base table is created and must be queried together with the base table partition key. Using a GSI with Product ID as

  the partition key and Review ID as the sort key will not allow the query to use a range of sort key values to find the highest ratings. Using an LSI with Product ID as the partition key and Product Rating as the sort key will not work because

  Product ID is not the partition key of the base table. Using an LSI with Review ID as the partition key and Product ID as the sort key will not allow the query to use a single partition key value to find the matching items.

  [Global Secondary Indexes], [Querying]

• Question 454:

  A developer manages three AWS accounts. Each account contains an Amazon RDS DB instance in a private subnet. The developer needs to define users in each database in a consistent way. The developer must ensure that the same users are created and updated later in all three accounts.

  Which solution will meet these requirements with the MOST operational efficiency?

  A. Create an AWS CloudFormation template. Declare the users in the template. Attach the users to the database. Deploy the template in each account.
  B. Create an AWS CloudFormation template that contains a custom resource to create the users in the database. Deploy the template in each account.
  C. Write a script that creates the users. Deploy an Amazon EC2 instance in each account to run the script on the databases. Run the script in each account.
  D. Implement an AWS Lambda function that creates the users in the database. Provide the function with the details of all three accounts.
  B. Create an AWS CloudFormation template that contains a custom resource to create the users in the database. Deploy the template in each account.

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  Explanation

• Question 455:

  A developer is updating an Amazon API Gateway REST API to use a mock endpoint. The developer wants to modify the integration request mapping template so that the endpoint responds to mock integration requests with specific HTTP status codes based on different conditions.

  Which of the following templates should the developer use to achieve this?

  A. { if( $input.params(`integration') == "mock" ) "statusCode": 404 else "statusCode": 500 end }
  B. { if( $input.params('scope') == "internal" ) "statusCode": 200 else "statusCode": 500 end }
  C. { if( $input.path("integration") ) "statusCode": 200 else "statusCode":404 end }
  D. { if( $context.integration.status ) "statusCode": 200 else "statusCode": 500 end }
  D. { if( $context.integration.status ) "statusCode": 200 else "statusCode": 500 end }

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  Explanation

  In this scenario, the developer is configuring a mock integration in API Gateway. The integration request mapping template allows the developer to map incoming request data to a format that the API expects. For mock integrations, it is

  common to return specific HTTP status codes based on various conditions.

  Using $context.integration.status:

  The $context.integration.status variable refers to the status of the API Gateway integration, which is useful for generating responses based on specific conditions. Option D correctly uses this variable to determine the HTTP status code,

  returning 200 for a successful mock request and 500 for a failure.

• Question 456:

  A company runs an ecommerce application on AWS. The application stores data in an Amazon Aurora database.

  A developer is adding a caching layer to the application. The caching strategy must ensure that the application always uses the most recent value for each data item.

  Which caching strategy will meet these requirements?

  A. Implement a TTL strategy for every item that is saved in the cache.
  B. Implement a write-through strategy for every item that is created and updated.
  C. Implement a lazy loading strategy for every item that is loaded.
  D. Implement a read-through strategy for every item that is loaded.
  B. Implement a write-through strategy for every item that is created and updated.

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  Explanation

  Write-Through Caching (Option B): With a write-through caching strategy, every time an item is written to the database, it is also written to the cache. This ensures that the cache is always updated with the most recent value immediately after any write operation. Consequently, any read operation can fetch the most recent value directly from the cache, ensuring data consistency between the cache and the database.

• Question 457:

  A developer needs to give a new application the ability to retrieve configuration data.

  The application must be able to retrieve new configuration data values without the need to redeploy the application code. If the application becomes unhealthy because of a bad configuration change, the developer must be able to automatically revert the configuration change to the previous value.

  Which solution meets these requirements?

  A. Use AWS Secrets Manager to manage and store the configuration data. Integrate Secrets Manager with a custom AWS Config rule that has remediation actions to track changes in the application and to roll back any bad configuration changes.
  B. Use AWS Secrets Manager to manage and store the configuration data. Integrate Secrets Manager with a custom AWS Config rule. Attach a custom AWS Systems Manager document to the rule that automatically rolls back any bad configuration changes.
  C. Use AWS AppConfig to manage and store the configuration data. Integrate AWS AppConfig with Amazon CloudWatch to monitor changes to the application. Set up an alarm to automatically roll back any bad configuration changes.
  D. Use AWS AppConfig to manage and store the configuration data. Integrate AWS AppConfig with Amazon CloudWatch to monitor changes to the application. Set up CloudWatch Application Signals to roll back any bad configuration changes.
  D. Use AWS AppConfig to manage and store the configuration data. Integrate AWS AppConfig with Amazon CloudWatch to monitor changes to the application. Set up CloudWatch Application Signals to roll back any bad configuration changes.

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  Explanation

  Comprehensive and Detailed Step-by-Step Explanation:

  Option D: AWS AppConfig with CloudWatch Application Signals

  AWS AppConfig is designed for managing and deploying application configurations dynamically, without redeployment.

  CloudWatch Application Signals provide automatic rollback mechanisms in case of an unhealthy application state due to bad configuration changes. This solution meets the requirements with minimal operational overhead by ensuring both

  dynamic updates and rollback functionality.

  Why Other Options Are Incorrect:

  Option A and B: AWS Secrets Manager is designed for secrets management, not dynamic application configuration. Custom Config rules add unnecessary complexity. Option C: While CloudWatch alarms can monitor application changes,

  using alarms for rollback requires manual setup and lacks the automatic rollback provided by Application Signals.

  References:

  AWS AppConfig Documentation

• Question 458:

  A company is running Amazon EC2 instances in multiple AWS accounts. A developer needs to implement an application that collects all the lifecycle events of the EC2 instances. The application needs to store the lifecycle events in a single Amazon Simple Queue Service (Amazon SQS) queue in the company's main AWS account for further processing.

  Which solution will meet these requirements?

  A. Configure Amazon EC2 to deliver the EC2 instance lifecycle events from all accounts to the Amazon EventBridge event bus of the main account. Add an EventBridge rule to the event bus of the main account that matches all EC2 instance lifecycle events. Add the SQS queue as a target of the rule.
  B. Use the resource policies of the SQS queue in the main account to give each account permissions to write to that SQS queue. Add to the Amazon EventBridge event bus of each account an EventBridge rule that matches all EC2 instance lifecycle events. Add the SQS queue in the main account as a target of the rule.
  C. Write an AWS Lambda function that scans through all EC2 instances in the company accounts to detect EC2 instance lifecycle changes. Configure the Lambda function to write a notification message to the SQS queue in the main account if the function detects an EC2 instance lifecycle change. Add an Amazon EventBridge scheduled rule that invokes the Lambda function every minute.
  D. Configure the permissions on the main account event bus to receive events from all accounts. Create an Amazon EventBridge rule in each account to send all the EC2 instance lifecycle events to the main account event bus. Add an EventBridge rule to themain account event bus that matches all EC2 instance lifecycle events. Set the SQS queue as a target for the rule.
  D. Configure the permissions on the main account event bus to receive events from all accounts. Create an Amazon EventBridge rule in each account to send all the EC2 instance lifecycle events to the main account event bus. Add an EventBridge rule to themain account event bus that matches all EC2 instance lifecycle events. Set the SQS queue as a target for the rule.

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  Explanation

• Question 459:

  A developer is designing an AWS Lambda function that creates temporary files that are less than 10 MB during invocation. The temporary files will be accessed and modified multiple times during invocation. The developer has no need to save or retrieve these files in the future.

  Where should the temporary files be stored?

  A. the /tmp directory
  B. Amazon Elastic File System (Amazon EFS)
  C. Amazon Elastic Block Store (Amazon EBS)
  D. Amazon S3
  A. the /tmp directory

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  Explanation

  A Lambda function has access to local storage in the /tmp directory. Each execution environment provides between 512 MB and 10,240 MB, in 1-MB increments, of disk space in the /tmp directory. https://docs.aws.amazon.com/lambda/latest/dg/foundation-progmodel.html

• Question 460:

  A developer is creating an application that must transfer expired items from Amazon DynamoDB to Amazon S3. The developer sets up the DynamoDB table to automatically delete items after a specific TTL. The application must process the items in DynamoDB and then must store the expired items in Amazon S3. The entire process, including item processing and storage in Amazon S3, will take 5 minutes.

  Which solution will meet these requirements with the LEAST operational overhead?

  A. Configure DynamoDB Accelerator (DAX) to query for expired items based on the TTL. Save the results to Amazon S3.
  B. Configure DynamoDB Streams to invoke an AWS Lambda function. Program the Lambda function to process the items and to store the expired items in Amazon S3.
  C. Deploy a custom application on an Amazon Elastic Container Service (Amazon ECS) cluster on Amazon EC2 instances. Program the custom application to process the items and to store the expired items in Amazon S3.
  D. Create an Amazon EventBridge rule to invoke an AWS Lambda function. Program the Lambda function to process the items and to store the expired items in Amazon S3.
  B. Configure DynamoDB Streams to invoke an AWS Lambda function. Program the Lambda function to process the items and to store the expired items in Amazon S3.

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  Explanation