Amazon DOP-C01 Online Practice Questions and Exam Preparation

Amazon DOP-C01 Online Questions & Answers

• Question 551:

  Your team wants to begin practicing continuous delivery using CloudFormation, to enable automated builds and deploys of whole, versioned stacks or stack layers. You have a 3-tier, mission-critical system. Which of the following is NOT a best practice for using CloudFormation in a continuous delivery environment?

  A. Use the AWS CloudFormation ValidateTemplate call before publishing changes to AWS.
  B. Model your stack in one template, so you can leverage CloudFormation's state management and dependency resolution to propagate all changes.
  C. Use CloudFormation to create brand new infrastructure for all stateless resources on each push, and run integration tests on that set of infrastructure.
  D. Parametrize the template and use Mappings to ensure your template works in multiple Regions.
  B. Model your stack in one template, so you can leverage CloudFormation's state management and dependency resolution to propagate all changes.

  ---

  Putting all resources in one stack is a bad idea, since different tiers have different life cycles and frequencies of change. For additional guidance about organizing your stacks, you can use two common frameworks: a multi-layered architecture and service-oriented architecture (SOA).

  Reference: http://docs.aws.amazon.com/AWSCloudFormation/latest/UserGuide/ bestpractices.html#organizingstacks

• Question 552:

  A development team manually builds an artifact locally and then places it in an Amazon S3 bucket. The application has a local cache that must be cleared when a deployment occurs. The team executes a command to do this, downloads the artifact from Amazon S3, and unzips the artifact to complete the deployment.

  A DevOps team wants to migrate to a CI/CD process and build in checks to stop and roll back the deployment when a failure occurs. This requires the team to track the progression of the deployment.

  Which combination of actions will accomplish this? (Choose three.)

  A. Allow developers to check the code into a code repository. Using Amazon CloudWatch Events, on every pull into master, trigger an AWS Lambda function to build the artifact and store it in Amazon S3.
  B. Create a custom script to clear the cache. Specify the script in the BeforeInstall lifecycle hook in the AppSpec file.
  C. Create user data for each Amazon EC2 instance that contains the clear cache script. Once deployed, test the application. If it is not successful, deploy it again.
  D. Set up AWS CodePipeline to deploy the application. Allow developers to check the code into a code repository as a source for the pipeline.
  E. Use AWS CodeBuild to build the artifact and place it in Amazon S3. Use AWS CodeDeploy to deploy the artifact to Amazon EC2 instances.
  F. Use AWS Systems Manager to fetch the artifact from Amazon S3 and deploy it to all the instances.
  C. Create user data for each Amazon EC2 instance that contains the clear cache script. Once deployed, test the application. If it is not successful, deploy it again.
  E. Use AWS CodeBuild to build the artifact and place it in Amazon S3. Use AWS CodeDeploy to deploy the artifact to Amazon EC2 instances.
  F. Use AWS Systems Manager to fetch the artifact from Amazon S3 and deploy it to all the instances.

• Question 553:

  Your company currently runs a large multi-tier web application. One component is an API service that all other components of your application rely on to perform read/write operations. This service must have high availability and zero

  downtime during deployments.

  Which technique should you use to provide cost-effective, zero-downtime deployments for this component?

  A. Use an AWS CloudFormation template to re-deploy your application behind a load balancer, and launch a new AWS CloudFormation stack during each deployment. Update your load balancer to send traffic to the new stack, and then deploy your software. Leave your old stacks running, and tag their resources with the version for rollback.
  B. Re-deploy your application on Elastic Beanstalk. During deployment, create a new version of your application, and create a new environment running that version in Elastic BeanStalk. Finally, take advantage of the Elastic Beanstalk Swap CNAME operation to switch to the new environment.
  C. Re-deploy your application behind a load balancer that uses Auto Scaling groups. Create a new identical Auto Scaling group and associate it to your Amazon Route53 zone. Configure Amazon Route53 to auto- weight traffic over to the new Auto Scaling group when all instances are marked as healthy.
  D. Re-deploy your application behind a load balancer using an AWS OpsWorks stack and use AWS OpsWorks stack versioning, during deployment create a new version of your application, tell AWS OpsWorks to launch the new version behind your load balancer, and when the new version is launched, terminate the old AWS OpsWorks stack.
  B. Re-deploy your application on Elastic Beanstalk. During deployment, create a new version of your application, and create a new environment running that version in Elastic BeanStalk. Finally, take advantage of the Elastic Beanstalk Swap CNAME operation to switch to the new environment.

• Question 554:

  You have a high-traffic application running behind a load balancer with clients that are very sensitive to latency. How should you determine which back-end Amazon Elastic Compute Cloud application instances are causing increased latency so that they can be replaced?

  A. By using the Elastic Load Balancing Latency CloudWatch metric.
  B. By using the HTTP X-Forwarded-For header for requests from the load balancer.
  C. By running a distributed load test to the load balancer.
  D. By using the load balancer access logs.
  D. By using the load balancer access logs.

• Question 555:

  You are responsible for your company's large multi-tiered Windows-based web application running on Amazon EC2 instances situated behind a load balancer.

  While reviewing metrics, you have started noticing an upwards trend for slow customer page load time. Your manager has asked you to come up with a solution to ensure that customer load time is not affected by too many requests per

  second.

  Which technique would you use to solve this issue?

  A. Re-deploy your infrastructure using an AWS CloudFormation template. Configure Elastic Load Balancing health checks to initiate a new AWS CloudFormation stack when health checks return failed.
  B. Re-deploy your infrastructure using an AWS CloudFormation template. Spin up a second AWS CloudFormation stack. Configure Elastic Load Balancing SpillOver functionality to spill over any slow connections to the second AWS CloudFormation stack.
  C. Re-deploy your infrastructure using AWS CloudFormation, Elastic Beanstalk, and Auto Scaling. Set up your Auto Scaling group policies to scale based on the number of requests per second as well as the current customer load time.
  D. Re-deploy your application using an Auto Scaling template. Configure the Auto Scaling template to spin up a new Elastic Beanstalk application when the customer load time surpasses your threshold.
  C. Re-deploy your infrastructure using AWS CloudFormation, Elastic Beanstalk, and Auto Scaling. Set up your Auto Scaling group policies to scale based on the number of requests per second as well as the current customer load time.

• Question 556:

  Your serverless architecture using AWS API Gateway, AWS Lambda, and AWS DynamoDB experienced a large increase in traffic to a sustained 400 requests per second, and dramatically increased in failure rates. Your requests, during

  normal operation, last 500 milliseconds on average. Your DynamoDB table did not exceed 50% of provisioned throughput, and Table primary keys are designed correctly.

  What is the most likely issue?

  A. Your API Gateway deployment is throttling your requests.
  B. Your AWS API Gateway Deployment is bottlenecking on request (de)serialization.
  C. You did not request a limit increase on concurrent Lambda function executions.
  D. You used Consistent Read requests on DynamoDB and are experiencing semaphore lock.
  C. You did not request a limit increase on concurrent Lambda function executions.

  ---

  AWS API Gateway by default throttles at 500 requests per second steady-state, and 1000 requests per second at spike. Lambda, by default, throttles at 100 concurrent requests for safety. At 500 milliseconds (half of a second) per request, you can expect to support 200 requests per second at 100 concurrency. This is less than the 400 requests per second your system now requires. Make a limit increase request via the AWS Support Console. AWS Lambda: Concurrent requests safety throttle per account -> 100.

  Reference: http://docs.aws.amazon.com/general/latest/gr/aws_service_limits.html#limits_lambda

• Question 557:

  If designing a single playbook to run across multiple Linux distributions that have distribution specific commands, what would be the best method to allow a successful run?

  A. Enable fact gathering and use the `when' conditional to match the distribution to the task.
  B. This is not possible, a separate playbook for each target Linux distribution is required.
  C. Use `ignore_errors: true' in the tasks.
  D. Use the `shell' module to write your own checks for each command that is ran.
  A. Enable fact gathering and use the `when' conditional to match the distribution to the task.

  ---

  Ansible provides a method to only run a task when a condition is met using the `when' declarative. With gather facts enabled, the play has access to the distribution name of the Linux system, thus, tasks can be tailored to a specific distribution and ran only when the condition is met, e.g.: ` - when: ansible_os_family == "Debian"'.

  Reference: http://docs.ansible.com/ansible/playbooks_conditionals.html

• Question 558:

  A company uses AWS KMS with CMKs and manual key rotation to meet regulatory compliance requirements. The security team wants to be notified when any keys have not been rotated after 90 days. Which solution will accomplish this?

  A. Configure AWS KMS to publish to an Amazon SNS topic when keys are more than 90 days old.
  B. Configure an Amazon CloudWatch Events event to launch an AWS Lambda function to call the AWS Trusted Advisor API and publish to an Amazon SNS topic.
  C. Develop an AWS Config custom rule that publishes to an Amazon SNS topic when keys are more than 90 days old.
  D. Configure AWS Security Hub to publish to an Amazon SNS topic when keys are more than 90 days old.
  C. Develop an AWS Config custom rule that publishes to an Amazon SNS topic when keys are more than 90 days old.

• Question 559:

  You need to migrate 10 million records in one hour into DynamoDB. All records are 1.5KB in size. The data is evenly distributed across the partition key. How many write capacity units should you provision during this batch load?

  A. 6667
  B. 4166
  C. 5556
  D. 2778
  C. 5556

  ---

  You need 2 units to make a 1.5KB write, since you round up. You need 20 million total units to perform this load. You have 3600 seconds to do so. Divide and round up for 5556.

  Reference: http://docs.aws.amazon.com/amazondynamodb/latest/developerguide/ HowItWorks.ProvisionedT hroughput.html