Amazon DOP-C01 Practice Test - Questions Answers, Page 21
List of questions
Question 201
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You are experiencing performance issues writing to a DynamoDB table. Your system tracks high scores for video games on a marketplace. Your most popular game experiences all of the performance issues. What is the most likely problem?
Explanation:
The primary key selection dramatically affects performance consistency when reading or writing to DynamoDB. By selecting a key that is tied to the identity of the game, you forced DynamoDB to create a hotspot in the table partitions, and overrequest against the primary key partition for the popular game. When it stores data, DynamoDB divides a table's items into multiple partitions, and distributes the data primarily based upon the partition key value. The provisioned throughput associated with a table is also divided evenly among the partitions, with no sharing of provisioned throughput across partitions.
Question 202
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You are running a Docker daemon on a Linux host and it becomes unresponsive. Which signal, when sent to a Docker process with the kill command, forces the full stack trace to be logged for debugging purposes?
Explanation:
If the daemon is unresponsive, you can force a full stack trace to be logged by sending a SIGUSR1 signal to the daemon. Linux:
$ sudo kill -SIGUSR1 $(pidof dockerd) Windows Server:
Download docker-signal.
Run the executable with the flag --pid=.
Reference:
https://docs.docker.com/engine/admin/#force-a-stack-trace-to-be-logged
Question 203
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To access the AWS Security Token Service (STS) you can issue calls directly to the AWS STS Query API. This API is a web service interface that accepts ______ requests.
Explanation:
The Query API for IAM and AWS STS lets you call service actions. Query API requests are HTTPS requests that mustcontain an Action parameter to indicate the action to be performed. IAM and AWS STS support GET and POST requests forall actions, that is, the API does not require you to use GET for some actions and POST for others.
Reference: http://docs.aws.amazon.com/IAM/latest/UserGuide/programming.html
Question 204
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A new zero-day vulnerability was found in OpenSSL requiring the immediate patching of a production web fleet running on Amazon Linux. Currently, OS updates are performed manually on a monthly basis and deployed using updates to the production Auto Scaling Group’s launch configuration.
Which method should a DevOps Engineer use to update packages in-place without downtime?
Question 205
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You have a playbook that includes a task to install a package for a service, put a configuration file for that package on the system and restart the service. The playbook is then run twice in a row. What would you expect Ansible to do on the second run?
Explanation:
Ansible follows an idempotence model and will not touch or change the system unless a change is warranted.
Reference: http://docs.ansible.com/ansible/glossary.html
Question 206
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Fill the blanks: __________ helps us track AWS API calls and transitions, _________ helps to understand what resources we have now, and ________ allows auditing credentials and logins.
Explanation:
You can use AWS CloudTrail to get a history of AWS API calls and related events for your account. This includes calls made by using the AWS Management Console, AWS SDKs, command line tools, and higher-level AWS services.
Reference: http://docs.aws.amazon.com/awscloudtrail/latest/userguide/cloudtrail-user-guide.html
Question 207
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A DevOps engineer is tasked with creating a more stable deployment solution for a web application in AWS. Previous deployments have resulted in user-facing bugs, premature user traffic, and inconsistencies between web servers running behind an Application Load Balancer. The current strategy uses AWS CodeCommit to store the code for the application. When developers push to the master branch of the repository, CodeCommit triggers an AWS Lambda deploy function, which invokes an AWS Systems Manager run command to build and deploy the new code to all Amazon EC2 instances. Which combination of actions should be taken to implement a more stable deployment solution? (Choose two.)
Question 208
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For AWS Auto Scaling, what is the first transition state an instance enters after leaving steady state when scaling in due to health check failure or decreased load?
Explanation:
When Auto Scaling responds to a scale in event, it terminates one or more instances. These instances are detached from the Auto Scaling group and enter the Terminating state.
Reference: http://docs.aws.amazon.com/AutoScaling/latest/DeveloperGuide/AutoScalingGroupLifecycle.html
Question 209
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A company is deploying a container-based application using AWS CodeBuild. The Security team mandates that all containers are scanned for vulnerabilities prior to deployment using a password-protected endpoint. All sensitive information must be stored securely.
Which solution should be used to meet these requirements?
Question 210
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What is the scope of an EC2 security group?
Explanation:
A security group is tied to a region and can be assigned only to instances in the same region. You can’t enable an instance.
Question