Amazon DVA-C02 Online Practice Questions and Exam Preparation

Amazon DVA-C02 Online Questions & Answers

• Question 221:

  A company has a serverless application on AWS that uses a fleet of AWS Lambda functions that have aliases. The company regularly publishes new Lambda function by using an in-house deployment solution. The company wants to improve the release process and to use traffic shifting. A newly published function version should initially make available only to a fixed percentage of production users.

  Which solution will meet these requirements?

  A. Configure routing on the alias of the new function by using a weighted alias.
  B. Configure a canary deployment type for Lambda.
  C. Configure routing on the new versions by using environment variables.
  D. Configure a linear deployment type for Lambda.
  A. Configure routing on the alias of the new function by using a weighted alias.

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  Explanation

• Question 222:

  A company uses Amazon API Gateway to expose a set of APIs to customers. The APIs have caching enabled in API Gateway. Customers need a way to invalidate the cache for each API when they test the API.

  What should a developer do to give customers the ability to invalidate the API cache?

  A. Ask the customers to use AWS credentials to call the InvalidateCache API operation.
  B. Attach an InvalidateCache policy to the IAM execution role that the customers use to invoke the API. Ask the customers to send a request that contains the Cache-Control:max-age=0 HTTP header when they make an API call.
  C. Ask the customers to use the AWS SDK API Gateway class to invoke the InvalidateCache API operation.
  D. Attach an InvalidateCache policy to the IAM execution role that the customers use to invoke the API. Ask the customers to add the INVALIDATE_CACHE query string parameter when they make an API call.
  B. Attach an InvalidateCache policy to the IAM execution role that the customers use to invoke the API. Ask the customers to send a request that contains the Cache-Control:max-age=0 HTTP header when they make an API call.

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  Explanation

• Question 223:

  A company uses AWS X-Ray to monitor a serverless application. The components of the application have different request rates. The user interactions and transactions are important to trace, but they are low in volume. The background

  processes such as application health checks, polling, and connection maintenance generate high volumes of read-only requests.

  Currently, the default X-Ray sampling rules are universal for all requests. Only the first request per second and some additional requests are recorded. This setup is not helping the company review the requests based on service or request

  type.

  A developer must configure rules to trace requests based on service or request properties. The developer must trace the user interactions and transactions without wasting effort recording minor background tasks.

  Which solution will meet these requirements?

  A. Disable sampling for high-volume read-only requests. Sample at a lower rate for all requests that handle user interactions or transactions.
  B. Disable sampling and trace all requests for requests that handle user interactions or transactions. Sample high-volume read-only requests at a higher rate.
  C. Disable sampling and trace all requests for requests that handle user interactions or transactions. Sample high-volume read-only requests at a lower rate.
  D. Disable sampling for high-volume read-only requests. Sample at a higher rate for all requests that handle user interactions or transactions.
  B. Disable sampling and trace all requests for requests that handle user interactions or transactions. Sample high-volume read-only requests at a higher rate.

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  Explanation

• Question 224:

  A developer uses AWS CloudFormation to deploy an Amazon API Gateway API and an AWS Step Functions state machine The state machine must reference the API Gateway API after the CloudFormation template is deployed The developer needs a solution that uses the state machine to reference the API Gateway endpoint.

  Which solution will meet these requirements MOST cost-effectively?

  A. Configure the CloudFormation template to reference the API endpoint in the DefinitionSubstitutions property for the AWS StepFunctions StateMachme resource.
  B. Configure the CloudFormation template to store the API endpoint in an environment variable for the AWS::StepFunctions::StateMachine resourc Configure the state machine to reference the environment variable
  C. Configure the CloudFormation template to store the API endpoint in a standard AWS: SecretsManager Secret resource Configure the state machine to reference the resource
  D. Configure the CloudFormation template to store the API endpoint in a standard AWS::AppConfig;:ConfigurationProfile resource Configure the state machine to reference the resource.
  A. Configure the CloudFormation template to reference the API endpoint in the DefinitionSubstitutions property for the AWS StepFunctions StateMachme resource.

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  Explanation

  The most cost-effective solution is to use the DefinitionSubstitutions property of the AWS::StepFunctions::StateMachine resource to inject the API endpoint as a variable in the state machine definition. This way, the developer can use the intrinsic function Fn::GetAtt to get the API endpoint from the AWS::ApiGateway::RestApi resource, and pass it to the state machine without creating any additional resources or environment variables. The other solutions involve creating and managing extra resources, such as Secrets Manager secrets or AppConfig configuration profiles, which incur additional costs and complexity. References AWS::StepFunctions::StateMachine - AWS CloudFormation Call API Gateway with Step Functions AWS Step Functions amazon-web-services aws-api-gateway terraform aws-step-functions

• Question 225:

  An online food company provides an Amazon API Gateway HTTP API to receive orders for partners. The API is integrated with an AWS Lambda function. The Lambda function stores the orders in an Amazon DynamoDB table.

  The company expects to onboard additional partners. Some of the partners require additional Lambda functions to receive orders. The company has created an Amazon S3 bucket. The company needs to store all orders and updates in the S3 bucket for future analysis.

  How can the developer ensure that all orders and updates are stored to Amazon S3 with the LEAST development effort?

  A. Create a new Lambda function and a new API Gateway API endpoint. Configure the new Lambda function to write to the S3 bucket. Modify the original Lambda function to post updates to the new API endpoint.
  B. Use Amazon Kinesis Data Streams to create a new data stream. Modify the Lambda function to publish orders to the data stream. Configure the data stream to write to the S3 bucket.
  C. Enable DynamoDB Streams on the DynamoDB table. Create a new Lambda function. Associate the stream's Amazon Resource Name (ARN) with the Lambda function. Configure the Lambda function to write to the S3 bucket as records appear in the table's stream.
  D. Modify the Lambda function to publish to a new Amazon Simple Notification Service (Amazon SNS) topic as the Lambda function receives orders. Subscribe a new Lambda function to the topic. Configure the new Lambda function to write to the S3 bucket as updates come through the topic.
  C. Enable DynamoDB Streams on the DynamoDB table. Create a new Lambda function. Associate the stream's Amazon Resource Name (ARN) with the Lambda function. Configure the Lambda function to write to the S3 bucket as records appear in the table's stream.

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  Explanation

• Question 226:

  A developer has created a Java application that makes HTTP requests directly to AWS services. Application logging shows 5xx HTTP response codes that occ irregular intervals. The errors are affecting users.

  How should the developer update the application to improve the application's resiliency?

  A. Revise the request content in the application code.
  B. Use the AWS SDK for Java to interact with AWS APIs.
  C. Scale out the application so that more instances of the application are running.
  D. Add additional logging to the application code.
  B. Use the AWS SDK for Java to interact with AWS APIs.

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  Explanation

• Question 227:

  A company is building a serverless application that uses AWS Lambda functions. The company needs to create a set of test events to test Lambda functions in a development environment. The test events will be created once and then will be used by all the developers in an IAM developer group. The test events must be editable by any of the IAM users in the IAM developer group.

  Which solution will meet these requirements?

  A. Create and store the test events in Amazon S3 as JSON objects. Allow S3 bucket access to all IAM users.
  B. Create the test events. Configure the event sharing settings to make the test events shareable.
  C. Create and store the test events in Amazon DynamoDB. Allow access to DynamoDB by using IAM roles.
  D. Create the test events. Configure the event sharing settings to make the test events private.
  B. Create the test events. Configure the event sharing settings to make the test events shareable.

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  Explanation

  Under the "Test" tab there's an option. (Shareable)

  This event is available to IAM users within the same account who have permissions to access and use shareable events.

  You can check this by yourself on the Lambda

  Also, here's a documentation

  https://docs.aws.amazon.com/lambda/latest/dg/testing-functions.html#creating-shareable-events

• Question 228:

  A developer deployed an application to an Amazon EC2 instance. The application needs to know the public IPv4 address of the instance. How can the application find this information?

  A. Query the instance metadata from http://169.254.169.254/latest/meta-data/.
  B. Query the instance user data from http://169.254.169.254/latest/user-data/.
  C. Query the Amazon Machine Image (AMI) information from http://169.254.169.254/latest/meta-data/ami/.
  D. Check the hosts file of the operating system.
  A. Query the instance metadata from http://169.254.169.254/latest/meta-data/.

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  Explanation

• Question 229:

  A developer at a company needs to create a small application that makes the same API call once each day at a designated time. The company does not have infrastructure in the AWS Cloud yet, but the company wants to implement this functionality on AWS.

  Which solution meets these requirements in the MOST operationally efficient manner?

  A. Use a Kubernetes cron job that runs on Amazon Elastic Kubernetes Service (Amazon EKS).
  B. Use an Amazon Linux crontab scheduled job that runs on Amazon EC2.
  C. Use an AWS Lambda function that is invoked by an Amazon EventBridge scheduled event.
  D. Use an AWS Batch job that is submitted to an AWS Batch job queue.
  C. Use an AWS Lambda function that is invoked by an Amazon EventBridge scheduled event.

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  Explanation

• Question 230:

  A company uses AWS CloudFormation templates to manage infrastructure for a public-facing application in its development, pre-production, and production environments. The company needs to scale for increasing customer demand. A

  developer must upgrade the Amazon RDS DB instance type to a larger instance.

  The developer deploys an update to the CloudFormation stack with the instance size change in the pre-production environment. The developer notices that the stack is in an UPDATE_ROLLBACK_FAILED slate in CloudFormation.

  Which option is the cause of this issue?

  A. The new instance type specified in the CloudFormation template is invalid
  B. The database was deleted or modified manually outside of the CloudFormation stack
  C. There is a syntax error in the CloudFormation template
  D. The developer has insufficient IAM permissions to provision an instance of the specified type
  B. The database was deleted or modified manually outside of the CloudFormation stack

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  Explanation

  When CloudFormation encounters an issue during the stack update process, it attempts to roll back to the previous state. If resources have been modified or deleted outside of CloudFormation, the rollback process can fail, resulting in the UPDATE_ROLLBACK_FAILED state.