Question 1

You are using AWS Elastic Beanstalk to deploy your application and must make data stored on an Amazon Elastic Block Store (EBS) volume snapshot available to the Amazon Elastic Compute Cloud (EC2) instances. How can you modify your Elastic Beanstalk environment so that the data is added to the Amazon EC2 instances every time you deploy your application?

Accepted Answer

You can use the .ebextensions configuration files to specify additional resources and settings for your Elastic Beanstalk environment. By adding a "BlockDeviceMappings" option, you can specify the snapshot to use for the block device in the Auto Scaling launch configuration, ensuring that the EBS volume is attached to the EC2 instances every time they are launched.

Question 2

Your company operates a website for promoters to sell tickets for entertainment events. You are using a load balancer in front of an Auto Scaling group of web servers. Promotion of popular events can cause surges of website visitors. During scaling-out at these times, newly launched instances are unable to complete configuration quickly enough, leading to user disappointment. What options should you choose to improve scaling yet minimize costs? (Choose two.)

Accepted Answer

The answer of Your company operates a website for promoters...

Question 3

Currently, your deployment process consists of setting your load balancer to point to a maintenance page, turning off ea web application servers, deploying your code, turning the web application servers back on, and removing the maintenance page. Working with your development team, you've agreed that performing rolling deployments of your software would provide a better user experience and a more agile deployment process. Which techniques could you use to provide a cost-effective rolling deployment process? (Choose two.)

Accepted Answer

The answer of Currently, your deployment process consists of setting...

Question 4

Your application requires a fault-tolerant, low-latency and repeatable method to load configurations files via Auto Scaling when Amazon Elastic Compute Cloud (EC2) instances launch. Which approach should you use to satisfy these requirements?

Accepted Answer

Using an Amazon EC2 UserData script to copy configurations from an Amazon S3 bucket is fault-tolerant, low-latency, and repeatable. S3 is highly available and reliable, making it suitable for storing configuration files that need to be accessed by EC2 instances during launch.

Question 5

You recently encountered a major bug in your Windows-based web application during a deployment cycle. During this failed deployment, it took the team four hours to roll back to a previously working state, which left customers with a poor user experience. During the post-mortem, your team discussed the need to provide a quicker way to roll back failed deployments. You currently run your web application on Amazon EC2 using Windows 2012R2 and use Elastic Load Balancing for your load balancing needs. Which technique should you use to solve this problem?

Accepted Answer

The answer of You recently encountered a major bug in...

Question 6

Your team is responsible for an AWS Elastic Beanstalk application. The business requires that you move to a continuous deployment model, thus releasing updates to the application multiple times per day with zero downtime. What should you do to enable this and still be able to roll back to the previous version almost immediately in an emergency?

Accepted Answer

Swapping environment CNAMEs allows for zero downtime deployment and quick rollback by switching back to the previous environment if needed.

Question 7

You run a large number of applications on Amazon EC2 instances. Each application has associated metadata, such as cost center, support contact, and application ID. Many applications usually co-exist on each Amazon EC2 instance, so the amount of metadata per instance can range from 10 to 200 items. The customer wants to be able to quickly access this metadata using an API without logging into the instances. Which of the following options will satisfy their requirements? (Choose two.)

Accepted Answer

Using compound tags allows for efficient metadata management and retrieval via the ec2-describe-tags API. Storing metadata in DynamoDB provides scalable and quick access through the DynamoDB API.

Question 8

Your company operates an application consisting of an AWS CloudFormation stack that contains a load balancer, an Auto Scaling group of web servers, and an Amazon RDS instance. To save time and costs, you update the current test stack when testing minor changes, and create a new stack for major changes. As part of the testing procedure of your application, each version needs to be registered once and only once with a Configuration Management Database (CMDB). What cost-effective solution should you choose to perform this registration?

Accepted Answer

Using an AWS::CloudFormation::CustomResource allows you to trigger custom logic during stack operations, such as notifying a CMDB, and can be configured to react to stack creation and updates.

Question 9

You set up a scalable continuous integration platform on AWS. The platform consists of a master node that can delegate project build jobs to multiple slave nodes, all running on Amazon EC2. The build output will be stored in Amazon S3. You always have five slave nodes deployed. Each slave node can handle 10 build jobs simultaneously. Your master node publishes a custom Amazon CloudWatch metric with the name "RunningBuildiobs" that Slows you to programmatically track how many build jobs are running across your platform. Which two configuration options will allow you to flexibly scale your platform to support more than 50 simultaneous build jobs while minimizing costs? (Choose two.)

Accepted Answer

A) This option allows the platform to scale out by adding more slave nodes when the number of running build jobs is high, ensuring that the system can handle more than 50 jobs.  E) This option allows the platform to scale in by terminating instances when the number of running build jobs is low, minimizing costs by reducing unnecessary resources.

Question 10

Your Company wants to perform A/B testing on a new website feature for 20 percent of its users. The website uses CloudFront for whole site delivery, with some content cached for up to 24 hours. How do you enable this testing for the required proportion of users while minimizing performance impact?

Accepted Answer

By using cookies, you can control the feature toggle at the application level without affecting the caching behavior of CloudFront, thus minimizing performance impact.

Question 11

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?

Accepted Answer

Elastic Beanstalk's Swap CNAME operation allows for zero-downtime deployments by switching traffic to a new environment running the updated application version, ensuring high availability and cost-effectiveness.

Question 12

You have a fleet of Elastic Compute Cloud (EC2) instances in an Auto Scaling group. All of these instances are running Microsoft Windows Server 2012 backed by Amazon Elastic Block Store (EBS). These instances were launched through AWS CloudFormation. You have determined that your instances are underutilized, and in order to save some money, have decided to modify the instance type of the fleet. In which of the following ways can you achieve the desired result during a scheduled maintenance window? (Choose two.)

Accepted Answer

A: Create a new Auto Scaling launch configuration specifying the new instance type, associate it to the existing Auto Scaling group, and terminate the running instances.D: Change the instance type in the AWS CloudFormation template that was used to create the Amazon EC2 instances, and then update the stack.

Question 13

You have been asked to use your departments existing continuous Integration (CI) tool to test a three-tier web architecture defined In an AWS CloudFormation template. The tool already supports AWS APIs and can launch new AWS CloudFormation stacks after polling version control. The CI tool reports on the success of the AWS CloudFormation stack creation by using the Describe Stacks API to look for the CREATE COMPLETE status. The architecture tiers defined in the template consist of: - One load balancer - Five Amazon EC2 instances running the web application - One multi-AZ Amazon ROS instance How would you implement this? (Choose two.)

Accepted Answer

The answer of You have been asked to use your...

Question 14

You manage a three-tier web application consisting of an autoscaled web proxy tier, an autoscaled application tier, and an Amazon RDS database tier. You use a load balancer to distribute requests from end users to the web proxy tier and another, internal load balancer to distribute requests between the web tier and the application tier. After deploying a small database schema update, you notice that all of your web and application instances have been terminated. What may have caused this?

Accepted Answer

The HTTP health check likely failed because the page it checks relies on the database, which was affected by the schema update, causing the instances to be terminated.

Question 15

You run a SIP-based telephony application that uses Amazon EC2 for its web tier and uses MySQL on Amazon RDS as its database. The application stores only the authentication profile data for its existing users in the database and therefore is read-intensive. Your monitoring system shows that your web instances and the database have high CPU utilization. Which of the following steps should you take in order to ensure the continual availability of your application? (Choose two.)

Accepted Answer

Auto Scaling can automatically scale the application tier based on CPU utilization, ensuring availability. Read replicas can handle read-intensive workloads, reducing database CPU utilization.

Question 16

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?

Accepted Answer

The answer of You have a high-traffic application running behind...

Question 17

You are building a large, multi-tenant SaaS (software-as-a-service) application with a component that fetches data to process from a customer-specific Amazon S3 bucket in their account. How should you ensure that your application follows security best practices and limits risk when fetching data from customer-owned Amazon S3 buckets?

Accepted Answer

Using a cross-account IAM role with a policy that grants read-only access is a secure way to allow access without sharing credentials, as it leverages AWS's built-in security features and avoids storing sensitive access keys.

Question 18

Your application is currently running on Amazon EC2 instances behind a load balancer. Your management has decided to use a Blue/Green deployment strategy. How should you implement this for each deployment?

Accepted Answer

In a Blue/Green deployment, you create a new environment (green) with the new version of your application, test it, and then switch traffic from the old environment (blue) to the new one. Creating a new load balancer and switching DNS after testing aligns with this strategy.

Question 19

You have an application consisting of a stateless web server tier running on Amazon EC2 instances behind load balancer, and are using Amazon RDS with read replicas. Which of the following methods should you use to implement a self-healing and cost-effective architecture? (Choose two.)

Accepted Answer

The answer of You have an application consisting of a...

Question 20

Your organization has decided to implement a third-party configuration management tool that uses a master server from which nodes pull configuration. You have built a custom base Amazon Machine Image that already has the third-party configuration management agent installed. You want to use the same base AMI in Development, Test and Production environments, each of which has its own master server. How should you configure your Amazon EC2 instances to register with the correct master server on launch?

Accepted Answer

Using Amazon CloudFormation with an input parameter for the master server hostname/address allows you to dynamically configure the EC2 instances to register with the correct master server based on the environment. This approach is efficient and leverages AWS infrastructure as code capabilities.

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

Your application requires a fault-tolerant, low-latency and repeatable method to load configurations files via Auto Scaling when Amazon Elastic Compute Cloud (EC2) instances launch. Which approach should you use to satisfy these requirements?

Your Company wants to perform A/B testing on a new website feature for 20 percent of its users. The website uses CloudFront for whole site delivery, with some content cached for up to 24 hours. How do you enable this testing for the required proportion of users while minimizing performance impact?

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?

Your application is currently running on Amazon EC2 instances behind a load balancer. Your management has decided to use a Blue/Green deployment strategy. How should you implement this for each deployment?

You have an application consisting of a stateless web server tier running on Amazon EC2 instances behind load balancer, and are using Amazon RDS with read replicas. Which of the following methods should you use to implement a self-healing and cost-effective architecture? (Choose two.)