Amazon DVA-C01 Online Practice Questions and Exam Preparation

Amazon DVA-C01 Online Questions & Answers

• Question 341:

  A development team is using AWS Elastic Beanstalk to deploy a two-tier application that consists of a load-balanced web tier and an Amazon RDS database tier in production. The team would like to separate the RDS instance from the Elastic Beanstalk.

  How can this be accomplished?

  A. Use the Elastic Beanstalk CLI to disassociate the database.

  B. Use the AWS CLI to disassociate the database.

  C. Change the deployment policy to disassociate the database.

  D. Recreate a new Elastic Beanstalk environment without Amazon RDS.

  Correct Answer: D

  https://aws.amazon.com/premiumsupport/knowledge-center/decouple-rds-from-beanstalk/

• Question 342:

  A Developer is designing a fault-tolerant environment where client sessions will be saved. How can the Developer ensure that no sessions are lost if an Amazon EC2 instance fails?

  A. Use sticky sessions with an Elastic Load Balancer target group.

  B. Use Amazon SQS to save session data.

  C. Use Amazon DynamoDB to perform scalable session hadling.

  D. Use Elastic Load Balancer connection draining to stop sending requests to failing instances.

  Correct Answer: C

• Question 343:

  A Developer needs temporary access to resources in a second account. What is the MOST secure way to achieve this?

  A. Use the Amazon Cognito user pools to get short-lived credentials for the second account.

  B. Create a dedicated IAM access key for the second account, and send it by mail.

  C. Create a cross-account access role, and use sts:AssumeRole API to get short-lived credentials.

  D. Establish trust, and add an SSH key for the second account to the IAM user.

  Correct Answer: C

  Reference: https://docs.aws.amazon.com/IAM/latest/UserGuide/tutorial_cross-account-with-roles.html

• Question 344:

  A Developer is building a three-tier web application that should be able to handle a minimum of 5000 requests per minute. Requirements state that the web tier should be completely stateless while the application maintains session state for the users.

  How can session data be externalized, keeping latency at the LOWEST possible value?

  A. Create an Amazon RDS instance, then implement session handling at the application level to leverage a database inside the RDS database instance for session data storage

  B. Implement a shared file system solution across the underlying Amazon EC2 instances, then implement session handling at the application level to leverage the shared file system for session data storage

  C. Create an Amazon ElastiCache Memcached cluster, then implement session handling at the application level to leverage the cluster for session data storage

  D. Create an Amazon DynamoDB table, then implement session handling at the application level to leverage the table for session data storage

  Correct Answer: C

  https://aws.amazon.com/caching/session-management/

• Question 345:

  A Developer is creating a template that uses AWS CloudFormation to deploy an application. This application is serverless and uses Amazon API Gateway, Amazon DynamoDB, and AWS Lambda. Which tool should the Developer use to define simplified syntax for expressing serverless resources?

  A. CloudFormation serverless intrinsic functions

  B. AWS serverless express

  C. An AWS serverless application model

  D. A CloudFormation serverless plugin

  Correct Answer: A

• Question 346:

  If an application is storing hourly log files from thousands of instances from a high traffic web site, which naming scheme would give optimal performance on S3?

  A. Sequential

  B. instanceID_log-HH-DD-MM-YYYY

  C. instanceID_log-YYYY-MM-DD-HH

  D. HH-DD-MM-YYYY-log_instanceID

  E. YYYY-MM-DD-HH-log_instanceID

  Correct Answer: B

  Reference: https://acloud.guru/forums/aws-certified-developer-associate/discussion/-KU2dEtJb-LI5lSbH_S4/if- an-application-is-storing-hourly-log-files-from-thousands-of-instances-from-a

• Question 347:

  During non-peak hours, a Developer wants to minimize the execution time of a full Amazon DynamoDB table scan without affecting normal workloads. The workloads average half of the strongly consistent read capacity units during non-peak

  hours.

  How would the Developer optimize this scan?

  A. Use parallel scans while limiting the rate

  B. Use sequential scans

  C. Increase read capacity units during the scan operation

  D. Change consistency to eventually consistent during the scan operation

  Correct Answer: A

  https://aws.amazon.com/blogs/developer/rate-limited-scans-in-amazon-dynamodb/

• Question 348:

  A Developer uses AWS CodeDeploy to automate application deployment that connects to an external MySQL database. The Developer wants to securely access the encrypted secrets, such as API keys and database passwords. Which of the following solutions would involve the LEAST administrative effort?

  A. Save the secrets in Amazon S3 with AWS KMS server-side encryption, and use a signed URL to access them by using the IAM role from Amazon EC2 instances.

  B. Use the instance metadata to store the secrets and to programmatically access the secrets from EC2 instances.

  C. Use the Amazon DynamoDB client-side encryption library to save the secrets in DynamoDB and to programmatically access the secrets from EC2 instances.

  D. Use AWS SSM Parameter Store to store the secrets and to programmatically access them by using the IAM role from EC2 instances.

  Correct Answer: D

  https://docs.aws.amazon.com/systems-manager/latest/userguide/systems-manager-parameter-store.html

• Question 349:

  A large e-commerce site is being designed to deliver static objects from Amazon S3. The Amazon S3 bucket wills server more than 300 GET requests per second. What should be done to optimize performance? (Select TWO.)

  A. Integrate Amazon CloudFront with Amazon S3.

  B. Enable Amazon S3 cross-region replication.

  C. Delete expired Amazon S3 server log files.

  D. Configure Amazon S3 lifecycle rules.

  E. Randomize Amazon S3 key name prefixes.

  Correct Answer: AE

  CloudWatch definitely. Random key prefixes is still a valid method of improving performance by using parallel reads. It doesn't mention prefix hashing. For instance prefixes 1/,2/,3/,4,5/ could provide 5 x parallel streams for S3 as opposed to all objects being in a single folder/prefix e.g. dev/ https://docs.aws.amazon.com/AmazonS3/latest/dev/optimizing-performance.html "There are no limits to the number of prefixes in a bucket. You can increase your read or write performance by parallelizing reads. For example, if you create 10 prefixes in an Amazon S3 bucket to parallelize reads, you could scale your read performance to 55,000 read requests per second." The assumption that prefixes don't matter is incorrect, as described by "Amazon S3 performance guidelines recommended randomizing prefix naming with **hashed characters** to optimize performance for frequent data retrievals. You no longer have to randomize prefix naming for performance, and can use sequential date-based naming for your prefixes"

• Question 350:

  After launching an instance that you intend to serve as a NAT (Network Address Translation) device in a public subnet you modify your route tables to have the NAT device be the target of internet bound traffic of your private subnet. When you try and make an outbound connection to the Internet from an instance in the private subnet, you are not successful.

  Which of the following steps could resolve the issue?

  A. Attaching a second Elastic Network interface (ENI) to the NAT instance, and placing it in the private subnet

  B. Attaching a second Elastic Network Interface (ENI) to the instance in the private subnet, and placing it in the public subnet

  C. Disabling the Source/Destination Check attribute on the NAT instance

  D. Attaching an Elastic IP address to the instance in the private subnet

  Correct Answer: C

  https://docs.aws.amazon.com/vpc/latest/userguide/VPC_NAT_Instance.html#NATInstance