Question 1

You want to build a new search tool feature for your monitoring system that will allow your information security team to quickly audit all API calls in your AWS accounts. What combination of AWS services can you use to develop and automate the backend processes supporting this tool? (Choose three.)

Accepted Answer

The answer of You want to build a new search...

Question 2

Which of these is not a Pseudo Parameter in AWS CloudFormation?

Accepted Answer

AWS::StackArn is not a pseudo parameter in AWS CloudFormation. The pseudo parameters include AWS::StackName, AWS::AccountId, and AWS::NotificationARNs, but not AWS::StackArn.

Question 3

A user has attached an EBS volume to a running Linux instance as a "/dev/sdf" device. The user is unable to see the attached device when he runs the command "df -h". What is the possible reason for this?

Accepted Answer

The "df -h" command shows mounted filesystems. If the volume is not mounted, it won't appear in the output of this command.

Question 4

How long are the messages kept on an SQS queue by default?

Accepted Answer

By default, messages in an Amazon SQS queue are retained for 4 days if they are not deleted after being read.

Question 5

When thinking of DynamoDB, what are true of Global Secondary Key properties?

Accepted Answer

Global Secondary Indexes (GSI) in DynamoDB allow both the partition key and the sort key to be different from those of the base table.

Question 6

You need to grant a vendor access to your AWS account. They need to be able to read protected messages in a private S3 bucket at their leisure. They also use AWS. What is the best way to accomplish this?

Accepted Answer

Creating a cross-account IAM Role with permission to access the bucket allows the vendor to assume the role from their AWS account, providing secure and controlled access to the S3 bucket.

Question 7

You are designing a system which needs, at minumum, 8 m4.large instances operating to service traffic. When designing a system for high availability in the us-east-1 region, which has 6 Availability Zones, you company needs to be able to handle death of a full availability zone. How should you distribute the servers, to save as much cost as possible, assuming all of the EC2 nodes are properly linked to an ELB? Your VPC account can utilize us-east-1's AZ's a through f, inclusive.

Accepted Answer

Distributing 2 servers in each of AZ's a through e ensures that if one AZ fails, there are still 8 servers running across the remaining AZs, meeting the minimum requirement while minimizing costs.

Question 8

You are creating a new API for video game scores. Reads are 100 times more common than writes, and the top 1% of scores are read 100 times more frequently than the rest of the scores. What's the best design for this system, using DynamoDB?

Accepted Answer

The answer of You are creating a new API for...

Question 9

A user has created a new EBS volume from an existing snapshot. The user mounts the volume on the instance to which it is attached. Which of the below mentioned options is a required step before the user can mount the volume?

Accepted Answer

The answer of A user has created a new EBS...

Question 10

There are a number of ways to purchase compute capacity on AWS. Which orders the price per compute or memory unit from LOW to HIGH (cheapest to most expensive), on average?

Accepted Answer

Reserved Instances are the cheapest option, followed by Spot Instances, and then On-Demand Instances.

Question 11

Your DevOps team is responsible for a multi-tier, Windows-based web application consisting of web servers, Amazon RDS database instances, and a load balancer behind Amazon Route53. You have been asked by your manager to build a cost-effective rolling deployment solution for this web application. What method should you use?

Accepted Answer

AWS CloudFormation rolling deployment policies allow you to update your stack in a rolling manner, which means that you can update a portion of your stack at a time, while the rest of the stack remains operational. This is a cost-effective way to deploy updates to your web application, as it minimizes the amount of downtime that your application experiences.

Question 12

You have written a server-side Node.Js application and a web application with an HTML/JavaScript front end that uses the Angular.js framework. The server-side application connects to an Amazon Redshift cluster, issues queries, and then returns the results to the front end for display. Your user base is very large and distributed, but it is important to keep the cost of running this application low. Which deployment strategy is both technically valid and the most cost-effective?

Accepted Answer

Using Amazon S3 and CloudFront for the static front end is cost-effective and scalable. AWS Elastic Beanstalk simplifies deployment and management of the Node.js application, and using Amazon Redshift for the database is appropriate for handling large datasets.

Question 13

You would like to run automated, continuous application level integration tests on all members of an Auto Scaling group. Which two options should you use? (Choose two.)

Accepted Answer

The answer of You would like to run automated, continuous...

Question 14

You currently run your infrastructure on Amazon EC2 instances behind an Auto Scaling group. All logs for you application are currently written to ephemeral storage. Recently your company experienced a major bug in code that made it through testing and was ultimately deployed to your fleet. This bug triggered your Auto Scaling group to scale up and back down before you could successfully retrieve the logs off your server to better assist you in troubleshooting the bug. Which technique should you use to make sure you are able to review your logs after your instances have shut down?

Accepted Answer

Installing the CloudWatch Logs Agent and configuring it to stream logs to CloudWatch Logs ensures that logs are continuously sent to a persistent storage service, allowing you to access them even after instances are terminated.

Question 15

Your application Amazon Elastic Compute Cloud (EC2) instances bootstrap by using a master configuration file that is kept in a version-enabled Amazon Simple Storage Service (S3) bucket. Which one of the following methods should you use to securely install the current configuration version onto the instances in a cost-effective way?

Accepted Answer

Associating an IAM EC2 role to the instances allows them to securely access the S3 bucket. By default, accessing an object in a version-enabled S3 bucket retrieves the current version, making it cost-effective and straightforward.

Question 16

Your application has an Auto Scaling group of m3.large instances running an application that receives messages born an Amazon SQS queue. After a while, the number of instances reaches the maximum set for the group and the number of messages on the queue continues to increase. You have discovered that a third- party library used by the application has a bug that causes a memory leak. What cost-effective steps can you take to continue message processing while the library developer fixes the bug?

Accepted Answer

The answer of Your application has an Auto Scaling group...

Question 17

You manage a web advertising platform on a single AWS account. This platform produces realtime ad-click data that you store as objects in an Amazon S3 bucket called "dick-data." Your advertising partners want to use Amazon Elastic MapReduce in their own AWS accounts to do analytics on the ad-click data. They have asked for immediate access to the ad-dick data so that they can run analytics. Which two choices are required to facilitate secure access to this data? (Choose two.)

Accepted Answer

To securely allow access to the S3 bucket from another AWS account, you need to create a cross-account IAM role with a trust policy (A) and configure the S3 bucket policy to allow read-only access (C).

Question 18

You are responsible for a large-scale video transcoding system that operates with an Auto Scaling group of video transcoding workers. The Auto Scaling group is configured with a minimum of 750 Amazon EC2 instances and a maximum of 1000 Amazon EC2 instances. You are using Amazon SQS to pass a message containing the URI for a video stored in Amazon S3 to the transcoding workers. An Amazon CloudWatch alarm has notified you that the queue depth is becoming very large. How can you resolve the alarm without the risk of increasing the time to transcode videos? (Choose two.)

Accepted Answer

The answer of You are responsible for a large-scale video...

Question 19

You are responsible for a popular file sharing application that uses Elastic Load Balancing to distribute traffic to an Amazon EC2 application tier deployed in an Auto Scaling group that runs across multiple Availability Zones. You currently record the number of user file transfers to a log file on the application server, and then write data points from the logs to an Amazon RDS MySQL instance. You are not happy with how your application scales, and want to implement a new scaling policy based on the average number of user file transfers in a 10-minute period instead of average CPU utilization in the last five minutes. What steps should you take to ensure that your application tier scales based on this new policy? (Choose two.)

Accepted Answer

To scale based on the average number of user file transfers, you need to publish a custom metric to CloudWatch from the file transfer logs (C). Additionally, you need to ensure that the logs are streamed to CloudWatch by configuring a CloudWatch Logs Agent on the EC2 instances (D).

Question 20

You have been asked to de-risk deployments at your company. Specifically, the CEO is concerned about outages that occur because of accidental inconsistencies between Staging and Production, which sometimes cause unexpected behaviors in Production even when Staging tests pass. You already use Docker to get high consistency between Staging and Production for the application environment on your EC2 instances. How do you further de-risk the rest of the execution environment, since in AWS, there are many service components you may use beyond EC2 virtual machines?

Accepted Answer

Using CloudFormation to model your entire cloud system ensures that both Staging and Production environments are created from the same infrastructure as code, reducing the risk of inconsistencies.

Exam 12: AWS DevOps Engineer - Professional (DOP-C01)