AWS

AWS Interview Questions and Answer Part – 18

January 15, 2020 comments off

Choose the correct types of access policy statements:

  • API gateways and access policies
  • Testimonies and affidavits
  • Action-statements and resource-statements (Ans)
  • Access policies and statements

How many servers should be configured to support lambda functions?

  • None (Ans)
  • 2 times the number of compute cycles
  • 1 per cpu
  • It depends on load

Which is not a client SDK option?

  • Javascript
  • IOS
  • Android
  • OSX (Ans)

Users connect to a web application (for which you are responsible) that is running on AWS. The web application runs on a fleet of EC2 instances in an autoscaling
 group. Traffic to the web application is load balanced by Amazon Route 53. The web application stores orders in an Amazon RDS database instance. You need to roll
out a new version of the application. No database schema changes are required. What is the best way to roll out the application with minimal downtime?

  • Create a second environment identical to the production environment. Install the new version of the application on the new infrastructure. Slowly move users over to the new environment by using Amazon Route 53 weighted routing. (Ans)
  • Deploy the new version of your application using GitHub and AWS CodePipeline.
  • Create a CodeDeploy application for the new version of your application. Install the CodeDeploy agent on each EC2 instance. Create a new Deployment
    Group in CodeDeploy and push out the application to one server at a time.
  • Use AWS CloudFormation to update the stack for your application and deploy the CodeDeploy agent. Roll out the new version of your application to each EC2
    instance.

You need to use multiple cookbooks from different repositories in your OpsWorks stack. What do you need to do to allow this?

  • Enable custom cookbooks and berkshelf on the stack. Add a berksfile to your custom cookbook repository. (Ans)
  • Enable custom cookbooks on your OpsWorks stack.
  • Enable autohealing on your OpsWorks stack.
  • Enable bershelf on your OpsWorks stack.

You’ve noticed that one of your application server instances is no longer communicating with the OpsWorks service, yet OpsWorks has not attempted to auto heal the instance. What could be the issue?

  • The instance is a load-based instance.
  • The instance belongs to a layer that has auto-healing disabled. (Ans)
  • The instance is a 24×7 instance.
  • The instance is a time-based instance.

You need to roll back an AWS OpsWorks application deployment. Which AWS CLI command should you use?

  • aws opsworks deploy-app
  • aws opsworks rollback-deployment
  • aws opsworks create-deployment (Ans)
  • aws ec2 rollback-deployment

The developers on your team report an issue when deploying application revisions to an Elastic Beanstalk environment. Based on the existing settings for the environment, the application goes offline for several minutes when they deploy a new version of the application since it requires a restart to the webserver service. What should you do to correct the problem?

  • Redeploy the application on AWS OpsWorks.
  • Reconfigure the Elastic Beanstalk environment to use rolling application updates. (Ans)
  • Use AWS CloudFormation for new application deployments.
  • Reconfigure the Elastic Beanstalk environment to use rolling configuration updates.

You’re creating a new CloudFormation template that will be used in your continuous delivery pipeline to deploy your infrastructure. Where should you save the template?

  • Save the template in an S3 bucket.
  • Save the template on an EBS volume and create a snapshot of the volume.
  • Save the template on your development machine.
  • Commit the template to your version control repository. (Ans)

You’ve created a CloudFormation template to deploy the infrastructure that supports a web application. One of the developers mentions that the application deployed through the template doesn’t seem to work immediately after the stack is launched. She says if she waits about 10 minutes then the application starts working. What should you do to resolve this?

  • Create WaitConditions in your CloudFormation template for the EC2 instances running the application. (Ans)
  • Use Elastic Beanstalk to deploy the application instead.
  • Create a fully-configured AMI for the application servers.
  • Add a notice to the template description that says the application will take 10 minutes to initialize.

You need to automate the deployment of new application versions for your Elastic Beankstalk environment. What command should you use with the EB CLI?

  • EB Create
  • EB Deploy (Ans)
  • EB Start
  • EB Update

You’re building a CloudFormation template that will automate the deployment of an application. Your template needs to provide input parameters to customize the deployment. How can you include the values provided as input via parameters into your bootstrapping scripts?

  • Use the Join intrinsic function to reference the template parameters in your bootstrapping script.
  • Write a bootstrapping script that queries the CloudFormation service to parse the template parameter values for the associated stack.
  • Use the GetAtt intrinsic function to reference the template parameters in your bootstrapping script.
  • Use the Ref intrinsic function to reference the template parameters in your bootstrapping script. (Ans)

You use the blue-green deployment pattern for rolling out new versions of your application. You notice that even though you’ve configured weighted routing, users are not being routed to your green environment. What is the most likely cause of the problem?

  • The Elastic Load Balancer is not configured to use the green environment.
  • End-users must reboot their device to reset their connection to the application.
  • The time-to-live TTL for the application DNS record is too high. (Ans)
  • You need to enable split-brain DNS in Route53.

You need to provision an S3 bucket used to store static assets as part of your web application. You plan to run the application using Elastic Beanstalk.
How can you configure your Elastic Beanstalk application source bundle so the S3 bucket is created during deployment?

  • Use a Dockerfile to create a container to host the application and run a command from within the container to create the S3 bucket.
  • Create a UserData script that will run when the first instance is deployed.
  • Configure your application to create the bucket the first time that it’s launched.
  • Create an .ebextentions folder in the root of your application source bundle and create a configuration file to provision the custom resource. (Ans)

Which OpsWorks lifecycle event runs when an instance enters or leaves the online state?

  • Configure (Ans)
  • Deploy
  • Undeploy
  • Setup

You need to add a stage to your CI server that verifies your CloudFormation templates are correctly formatted. Which AWS CLI command should you use to automate this process?

  • aws cloudformation validate-stack
  • aws cloudformation validate-template (Ans)
  • aws cloudformation validate-cft
  • aws ec2 validate-template

You are responsible for automating the deployment of three different applications on AWS. Each application is architected to run in a custom Amazon VPC that spans multiple availability zones. You need to create CloudFormation templates for each application using the least amount of effort. What should you do?

  • Create a single template for the VPC infrastructure. Use nested templates so that each application can reuse the same VPC template to eliminate code duplication (Ans)
  • Use Visual Studio and the AWS .NET SDK for authoring your templates
  • Use the AWS Toolkit for Eclipse to author your templates
  • Use the AWS CloudFormation Designer to visually create the templates

You support a web application that runs on a fleet of EC2 instances in an autoscaling group. The development team is complaining that it takes a long time to scale out when the application load increases due to the amount of work that needs to be done by bootstrapping scripts. What changes can you make to ensure that
new instances in the autoscaling group launch as fast as possible?

  • Create a fully-configured AMI for your EC2 instances. (Ans)
  • Increase the minimum size of the autoscaling group so it includes more instances.
  • Change the autoscaling group MaxScaleOutSpeed setting to True.
  • Use PIOPS EBS volumes for the OS root disk.

You need to automate the creation of an AMI using the AWS CLI. Which EC2 command should you use?

  • copy-image
  • run-instances
  • create-image (Ans)
  • create-snapshot

You need to define your infrastructure as code so your DevOps team can reliably release new versions of your application. Which of the following is the best approach?

  • Use declarative templates to define your infrastructure and commit the templates to version control. (Ans)
  • Write a script using the AWS CLI that creates all of the required infrastructure and add the script to your version control repository.
  • Use Chef to create custom a custom cookbook to define your infrastructure and add the cookbook to your version control repository.
  • Write a program using the AWS SDK for Java that creates all of the required infrastructure and add the source code for the program to your
    version control repository.
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