Amazon DVA-C02 Online Practice Questions and Exam Preparation

Amazon DVA-C02 Online Questions & Answers

• Question 391:

  A developer uses Amazon S3 Event Notifications to invoke AWS Lambda functions. The Lambda functions process images after the images are uploaded to S3 buckets. The developer has set up a development S3 bucket, a production S3

  bucket, a development Lambda function, and a production Lambda function in the same AWS account.

  The developer notices that uploads to the development S3 bucket wrongly invoke the production Lambda function. The developer must prevent development data from affecting the production Lambda function.

  What should the developer do to meet these requirements?

  A. Update the execution role for the production Lambda function. Add a policy that allows the execution role to read from only the production S3 bucket.
  B. Update the S3 bucket policy for the production S3 bucket to invoke the production Lambda function. Update the S3 bucket policy for the development S3 bucket to invoke the development Lambda function.
  C. Separate the development environment and the production environment into their own AWS accounts. Update the execution role for each Lambda function. Add a policy that allows the execution role to read from only the S3 bucket that is in the same account.
  D. Separate the development environment and the production environment into their own AWS accounts. Add a resource policy to the Lambda functions to allow only S3 bucket events in the same account to invoke the functions.
  B. Update the S3 bucket policy for the production S3 bucket to invoke the production Lambda function. Update the S3 bucket policy for the development S3 bucket to invoke the development Lambda function.

  ---

  Explanation

• Question 392:

  A company created an application to consume and process data. The application uses Amazon SQS and AWS Lambda functions. The application is currently working as expected, but it occasionally receives several messages that it cannot process properly. The company needs to clear these messages to prevent the queue from becoming blocked. A developer must implement a solution that makes queue processing always operational. The solution must give the company the ability to defer the messages with errors and save these messages for further analysis.

  What is the MOST operationally efficient solution that meets these requirements?

  A. Configure Amazon CloudWatch Logs to save the error messages to a separate log stream.
  B. Create a new SQS queue. Set the new queue as a dead-letter queue for the application queue. Configure the Maximum Receives setting.
  C. Change the SQS queue to a FIFO queue. Configure the message retention period to 0 seconds.
  D. Configure an Amazon CloudWatch alarm for Lambda function errors. Publish messages to an Amazon SNS topic to notify administrator users.
  B. Create a new SQS queue. Set the new queue as a dead-letter queue for the application queue. Configure the Maximum Receives setting.

  ---

  Explanation

  Using a dead-letter queue (DLQ) with Amazon SQS is the most operationally efficient solution for handling unprocessable messages.

  Amazon SQS Dead-Letter Queue:

  A DLQ is used to capture messages that fail processing after a specified number of attempts.

  Allows the application to continue processing other messages without being blocked.

  Messages in the DLQ can be analyzed later for debugging and resolution.

  Why DLQ is the Best Option:

  Operational Efficiency: Automatically defers messages with errors, ensuring the queue is not blocked.

  Analysis Ready: Messages in the DLQ can be inspected to identify recurring issues.

  Scalable: Works seamlessly with Lambda and SQS at scale.

  Why Not Other Options:

  Option A: Logs the messages but does not resolve the queue blockage issue.

  Option C: FIFO queues and 0-second retention do not provide error handling or analysis capabilities.

  Option D: Alerts administrators but does not handle or store the unprocessable messages.

  Steps to Implement:

  Create a new SQS queue to serve as the DLQ.

  Attach the DLQ to the primary queue and configure the Maximum Receives setting.

  References:

  Using Amazon SQS Dead-Letter Queues

  Best Practices for Using Amazon SQS with AWS Lambda

• Question 393:

  A developer created an AWS Lambda function that performs a series of operations that involve multiple AWS services. The function's duration time is higher than normal. To determine the cause of the issue, the developer must investigate traffic between the services without changing the function code.

  Which solution will meet these requirements?

  A. Enable AWS X-Ray active tracing in the Lambda function Review the logs in X-Ray
  B. Configure AWS CloudTrail View the trail logs that are associated with the Lambda function.
  C. Review the AWS Config logs in Amazon Cloud Watch.
  D. Review the Amazon CloudWatch logs that are associated with the Lambda function.
  A. Enable AWS X-Ray active tracing in the Lambda function Review the logs in X-Ray

  ---

  Explanation

  AWS X-Ray is a service that helps you analyze and debug your applications. You can use X- Ray to trace requests made to your Lambda function and other AWS services, and identify performance bottlenecks and errors. Enabling active tracing in your Lambda function allows X-Ray to collect data from the function invocation and the downstream services that it calls. You can then review the logs and service maps in X-Ray to diagnose the issue. References Monitoring and troubleshooting Lambda functions - AWS Lambda Using AWS Lambda with AWS X-Ray Troubleshoot Lambda function cold start issues | AWS re:Post

• Question 394:

  An ecommerce application is running behind an Application Load Balancer. A developer observes some unexpected load on the application during non-peak hours. The developer wants to analyze patterns for the client IP addresses that use the application.

  Which HTTP header should the developer use for this analysis?

  A. The X-Forwarded-Proto header
  B. The X-Forwarded-Host header
  C. The X-Forwarded-For header
  D. The X-Forwarded-Port header
  C. The X-Forwarded-For header

  ---

  Explanation

• Question 395:

  A developer is building a microservice that uses AWS Lambda to process messages from an Amazon Simple Queue Service (Amazon SQS) standard queue. The Lambda function calls external APIs to enrich the SQS message data before loading the data into an Amazon Redshift data warehouse. The SQS queue must handle a maximum of 1,000 messages per second.

  During initial testing, the Lambda function repeatedly inserted duplicate data into the Amazon Redshift table. The duplicate data led to a problem with data analysis. All duplicate messages were submitted to the queue within 1 minute of each other.

  How should the developer resolve this issue?

  A. Create an SQS FIFO queue. Enable message deduplication on the SQS FIFO queue.
  B. Reduce the maximum Lambda concurrency that the SQS queue can invoke.
  C. Use Lambda's temporary storage to keep track of processed message identifiers
  D. Configure a message group ID for every sent message. Enable message deduplication on the SQS standard queue.
  A. Create an SQS FIFO queue. Enable message deduplication on the SQS FIFO queue.

  ---

  Explanation

• Question 396:

  A company is migrating its PostgreSQL database into the AWS Cloud. The company wants to use a database that will secure and regularly rotate database credentials. The company wants a solution that does not require additional programming overhead.

  Which solution will meet these requirements?

  A. Use Amazon Aurora PostgreSQL for the database. Store the database credentials in AWS Systems Manager Parameter Store. Turn on rotation.
  B. Use Amazon Aurora PostgreSQL for the database. Store the database credentials in AWS Secrets Manager. Turn on rotation.
  C. Use Amazon DynamoDB for the database. Store the database credentials in AWS Systems Manager Parameter Store. Turn on rotation.
  D. Use Amazon DynamoDB for the database. Store the database credentials in AWS Secrets Manager. Turn on rotation.
  B. Use Amazon Aurora PostgreSQL for the database. Store the database credentials in AWS Secrets Manager. Turn on rotation.

  ---

  Explanation

• Question 397:

  A company runs its website on AWS. The company posts daily polls on its website and publishes the poll results next day. The website stores user responses in an Amazon DynamoDB table. After the poll results are published, the company does not need to keep the user responses.

  A developer needs to implement a solution that will automatically remove old user responses from the DynamoDB table. The developer adds a new expiration_date attribute to the DynamoDB table. The developer plans to use the

  expiration_date attribute for the automation.

  Which solution will meet these requirements with the LEAST development effort?

  A. Create an AWS Lambda function to delete old user responses based on the expiration_date attribute. Create an Amazon EventBridge schedule to run the Lambda function daily.
  B. Create an AWS Fargate task in Amazon Elastic Container Service (Amazon ECS) to delete old user responses based on the expiration_date attribute. Create an Amazon EventBridge schedule to run the Fargate task daily.
  C. Create an AWS Glue job to delete old user responses based on the expiration_date attribute. Create an AWS Glue trigger schedule to run the job daily.
  D. Enable TTL on the DynamoDB table and specify the expiration_date attribute. Expire old user responses by using DynamoDB TTL.
  A. Create an AWS Lambda function to delete old user responses based on the expiration_date attribute. Create an Amazon EventBridge schedule to run the Lambda function daily.

  ---

  Explanation

• Question 398:

  A company has hundreds of AWS Lambda functions that the company's QA team needs to test by using the Lambda function URLs. A developer needs to configure the authentication of the Lambda functions to allow access so that the QA IAM group can invoke the Lambda functions by using the public URLs.

  Which solution will meet these requirements?

  A. Create a CLI script that loops on the Lambda functions to add a Lambda function URL with the AWS_IAM auth type. Run another script to create an IAM identity-based policy that allows the lambda:InvokeFunctionUrl action to all the Lambda function Amazon Resource Names (ARNs). Attach the policy to the QA IAM group.
  B. Create a CLI script that loops on the Lambda functions to add a Lambda function URL with the NONE auth type. Run another script to create an IAM resource-based policy that allows the lambda:InvokeFunctionUrl action to all the Lambda function Amazon Resource Names (ARNs). Attach the policy to the QA IAM group.
  C. Create a CLI script that loops on the Lambda functions to add a Lambda function URL with the AWS_IAM auth type. Run another script to loop on the Lambda functions to create an IAM identity-based policy that allows the lambda:InvokeFunctionUrl action from the QA IAM group's Amazon Resource Name (ARN).
  D. Create a CLI script that loops on the Lambda functions to add a Lambda function URL with the NONE auth type. Run another script to loop on the Lambda functions to create an IAM resource-based policy that allows the lambda:InvokeFunctionUrl action from the QA IAM group's Amazon Resource Name (ARN).
  A. Create a CLI script that loops on the Lambda functions to add a Lambda function URL with the AWS_IAM auth type. Run another script to create an IAM identity-based policy that allows the lambda:InvokeFunctionUrl action to all the Lambda function Amazon Resource Names (ARNs). Attach the policy to the QA IAM group.

  ---

  Explanation

  https://docs.aws.amazon.com/lambda/latest/dg/urls-auth.html

• Question 399:

  A company has a website that displays a daily newsletter. When a user visits the website, an AWS Lambda function processes the browser's request and queries the company's on-premises database to obtain the current newsletter. The

  newsletters are stored in English. The Lambda function uses the Amazon Translate TranslateText API operation to translate the newsletters, and the translation is displayed to the user.

  Due to an increase in popularity, the website's response time has slowed. The database is overloaded. The company cannot change the database and needs a solution that improves the response time of the Lambda function.

  Which solution meets these requirements?

  A. Change to asynchronous Lambda function invocation.
  B. Cache the translated newsletters in the Lambda/tmp directory.
  C. Enable TranslateText API caching.
  D. Change the Lambda function to use parallel processing.
  B. Cache the translated newsletters in the Lambda/tmp directory.

  ---

  Explanation

• Question 400:

  A developer wants to insert a record into an Amazon DynamoDB table as soon as a new file is added to an Amazon S3 bucket. Which set of steps would be necessary to achieve this?

  A. Create an event with Amazon EventBridge that will monitor the S3 bucket and then insert the records into DynamoDB.
  B. Configure an S3 event to invoke an AWS Lambda function that inserts records into DynamoDB.
  C. Create an AWS Lambda function that will poll the S3 bucket and then insert the records into DynamoDB.
  D. Create a cron job that will run at a scheduled time and insert the records into DynamoDB.
  B. Configure an S3 event to invoke an AWS Lambda function that inserts records into DynamoDB.

  ---

  Explanation