Question 1

Your application consists of 10% writes and 90% reads. You currently service all requests through a Route53 Alias Record directed towards an AWS ELB, which sits in front of an EC2 Auto Scaling Group. Your system is getting very expensive when there are large traffic spikes during certain news events, during which many more people request to read similar data all at the same time. What is the simplest and cheapest way to reduce costs and scale with spikes like this?
A) Create an S3 bucket and asynchronously replicate common requests responses into S3 objects. When a request comes in for a precomputed response, redirect to AWS S3.
B) Create another ELB and Auto Scaling Group layer mounted on top of the other system, adding a tier to the system. Serve most read requests out of the top layer.
C) Create a CloudFront Distribution and direct Route53 to the Distribution. Use the ELB as an Origin and specify Cache Behaviours to proxy cache requests which can be served late.
D) Create a Memcached cluster in AWS ElastiCache. Create cache logic to serve requests which can be served late from the in-memory cache for increased performance.

Accepted Answer

Using CloudFront as a caching layer in front of your ELB allows you to cache and serve the majority of read requests directly from edge locations, reducing the load on your backend and lowering costs during traffic spikes.

Question 2

A DevOps engineer is creating a CI/CD pipeline for an Amazon ECS service. The ECS container instances run behind an Application Load Balancer as the web tier of a three-tier application. An acceptance criterion for a successful deployment is the verification that the web tier can communicate with the database and middleware tiers of the application upon deployment. How can this be accomplished in an automated fashion?
A) Create a health check endpoint in the web application that tests connectivity to the data and middleware tiers. Use this endpoint as the health check URL for the load balancer.
B) Create an approval step for the quality assurance team to validate connectivity. Reject changes in the pipeline if there is an issue with connecting to the dependent tiers.
C) Use an Amazon RDS active connection count and an Amazon CloudWatch ELB metric to alarm on a significant change to the number of open connections.
D) Use Amazon Route 53 health checks to detect issues with the web service and roll back the CI/CD pipeline if there is an error.

Accepted Answer

Creating a health check endpoint in the web application that tests connectivity to the data and middleware tiers allows for automated verification of communication between tiers. This can be integrated into the load balancer's health check to ensure the web tier is functioning correctly post-deployment.

Question 3

Your company needs to automate 3 layers of a large cloud deployment. You want to be able to track this deployment's evolution as it changes over time, and carefully control any alterations. What is a good way to automate a stack to meet these requirements?
A) Use OpsWorks Stacks with three layers to model the layering in your stack.
B) Use CloudFormation Nested Stack Templates, with three child stacks to represent the three logical layers of your cloud.
C) Use AWS Config to declare a configuration set that AWS should roll out to your cloud.
D) Use Elastic Beanstalk Linked Applications, passing the important DNS entires between layers using the metadata interface.

Accepted Answer

CloudFormation Nested Stack Templates allow you to manage and track changes over time, and control alterations by using version-controlled templates for each layer.

Question 4

Which EBS volume type is best for high performance NoSQL cluster deployments?
A) io1
B) gp1
C) standard
D) gp2

Accepted Answer

The io1 volume type is designed for high performance and is suitable for applications like NoSQL databases that require high IOPS and low latency.

Question 5

You need to scale an RDS deployment. You are operating at 10% writes and 90% reads, based on your logging. How best can you scale this in a simple way?
A) Create a second master RDS instance and peer the RDS groups.
B) Cache all the database responses on the read side with CloudFront.
C) Create read replicas for RDS since the load is mostly reads.
D) Create a Multi-AZ RDS installs and route read traffic to standby.

Accepted Answer

Creating read replicas for RDS is an effective way to scale read-heavy workloads, as it allows you to distribute read traffic across multiple instances.

Question 6

A company used AWS CloudFormation to deploy a three-tier web application that stores data in an Amazon RDS MySQL Multi-AZ DB instance. A DevOps Engineer must upgrade the RDS instance to the latest major version of MySQL while incurring minimal downtime. How should the Engineer upgrade the instance while minimizing downtime?
A) Update the EngineVersion property of the AWS::RDS::DBInstance resource type in the CloudFormation template to the latest desired version. Launch a second stack and make the new RDS instance a read replica. Update the EngineVersion property of the AWS::RDS::DBInstance resource type in the CloudFormation template to the latest desired version. Launch a second stack and make the new RDS instance a read replica.
B) Update the DBEngineVersion property of the AWS:: RDS::DBInstance resource type in the CloudFormation template to the latest desired version. Perform an Update Stack operation. Create a new RDS Read Replicas resource with the same properties as the instance to be upgraded. Perform a second Update Stack operation. DBEngineVersion AWS:: RDS::DBInstance resource type in the CloudFormation template to the latest desired version. Perform an Update Stack operation. Create a new RDS Read Replicas resource with the same properties as the instance to be upgraded. Perform a second operation.
C) Update the DBEngineVersion property of the AWS::RDS::DBInstance resource type in the CloudFormation template to the latest desired version. Create a new RDS Read Replicas resource with the same properties as the instance to be upgraded. Perform an Update Stack operation. resource type in the CloudFormation template to the latest desired version. Create a new RDS Read Replicas resource with the same properties as the instance to be upgraded. Perform an
D) Update the EngineVersion property of the AWS::RDS::DBInstance resource type in the CloudFormation template to the latest version, and perform an Update Stack operation. resource type in the CloudFormation template to the latest version, and perform an

Accepted Answer

The correct answer is A because it describes the process of creating a read replica, which can be used to minimize downtime during an RDS instance upgrade.

Question 7

You have deployed an application to AWS which makes use of Autoscaling to launch new instances. You now want to change the instance type for the new instances. Which of the following is one of the action items to achieve this deployment?
A) Use Elastic Beanstalk to deploy the new application with the new instance type
B) Use Cloudformation to deploy the new application with the new instance type
C) Create a new launch configuration with the new instance type
D) Create new EC2 instances with the new instance type and attach it to the Autoscaling Group

Accepted Answer

To change the instance type for new instances in an Auto Scaling group, you need to create a new launch configuration with the desired instance type and update the Auto Scaling group to use this new launch configuration.

Question 8

You need to perform ad-hoc analysis on log data, including searching quickly for specific error codes and reference numbers. Which should you evaluate first?
A) AWS Elasticsearch Service
B) AWS RedShift
C) AWS EMR
D) AWS DynamoDB

Accepted Answer

AWS Elasticsearch Service is designed for searching and analyzing log data quickly, making it suitable for ad-hoc analysis of log data to find specific error codes and reference numbers.

Question 9

What is a circular dependency in AWS CloudFormation?
A) When a Template references an earlier version of itself.
B) When Nested Stacks depend on each other.
C) When Resources form a DependOn loop.
D) When a Template references a region, which references the original Template.

Accepted Answer

A circular dependency in AWS CloudFormation occurs when resources are dependent on each other in a way that creates a loop, such as when resources form a DependOn loop.

Question 10

You are building a Docker image with the following Dockerfile. How many layers will the resulting image have? FROM scratch CMD /app/hello.sh
A) 2
B) 4
C) 1
D) 3

Accepted Answer

The answer of You are building a Docker image with...

Question 11

An application's users are encountering bugs immediately after Amazon API Gateway deployments. The development team deploys once or twice a day and uses a blue/green deployment strategy with custom health checks and automated rollbacks. The team wants to limit the number of users affected by deployment bugs and receive notifications when rollbacks are needed. Which combination of steps should a DevOps engineer use to meet these requests? (Choose two.)
A) Implement a blue/green strategy using path mappings.
B) Implement a canary deployment strategy.
C) Implement a rolling deployment strategy using multiple stages.
D) Use Amazon CloudWatch alarms to notify the development team.
E) Use Amazon CloudWatch Events to notify the development team.

Accepted Answer

The answer of An application's users are encountering bugs immediately...

Question 12

What are the default memory limit policies for a Docker container?
A) Limited memory, limited kernel memory
B) Unlimited memory, limited kernel memory
C) Limited memory, unlimited kernel memory
D) Unlimited memory, unlimited kernel memory

Accepted Answer

By default, Docker containers have unlimited memory and unlimited kernel memory unless explicitly set otherwise.

Question 13

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.
A) PUT
B) HTTPS
C) POST
D) GET

Accepted Answer

The answer of To access the AWS Security Token Service...

Question 14

You need to create an audit log of all changes to customer banking data. You use DynamoDB to store this customer banking data. It is important not to lose any information due to server failures. What is an elegant way to accomplish this?
A) Use a DynamoDB StreamSpecification and stream all changes to AWS Lambda. Log the changes to AWS CloudWatch Logs, removing sensitive information before logging.
B) Before writing to DynamoDB, do a pre-write acknoledgment to disk on the application server, removing sensitive information before logging. Periodically rotate these log files into S3.
C) Use a DynamoDB StreamSpecification and periodically flush to an EC2 instance store, removing sensitive information before putting the objects. Periodically flush these batches to S3.
D) Before writing to DynamoDB, do a pre-write acknoledgment to disk on the application server, removing sensitive information before logging. Periodically pipe these files into CloudWatch Logs.

Accepted Answer

Using DynamoDB Streams with AWS Lambda allows for real-time processing of changes and logging to AWS CloudWatch Logs ensures durability and availability of the audit logs, while also allowing for sensitive information to be removed before logging.

Question 15

What is the default maximum number of Roles per AWS account?
A) 500
B) 250
C) 100
D) There is no limit.

Accepted Answer

The answer of What is the default maximum number of...

Question 16

A company is deploying a new application that uses Amazon EC2 instances. The company needs a solution to query application logs and AWS account API activity. Which solution will meet these requirements?
A) Use the Amazon CloudWatch agent to send logs from the EC2 instances to Amazon CloudWatch Logs. Configure AWS CloudTrail to deliver the API logs to Amazon S3. Use CloudWatch to query both sets of logs.
B) Use the Amazon CloudWatch agent to send logs from the EC2 instances to Amazon CloudWatch Logs. Configure AWS CloudTrail to deliver the API logs to CloudWatch Logs. Use CloudWatch Logs Insights to query both sets of logs.
C) Use the Amazon CloudWatch agent to send logs from the EC2 instances to Amazon Kinesis. Configure AWS CloudTrail to deliver the API logs to Kinesis. Use Kinesis to load the data into Amazon Redshift. Use Amazon Redshift to query both sets of logs.
D) Use the Amazon CloudWatch agent to send logs from the EC2 instances to Amazon S3. Use AWS CloudTrail to deliver the API logs to Amazon S3 Amazon S3. Use Amazon Athena to query both sets of logs in Amazon S3.

Accepted Answer

The answer of A company is deploying a new application...

Question 17

A company's application is running on Amazon EC2 instances in an Auto Scaling group. A DevOps engineer needs to ensure there are at least four application servers running at all times. Whenever an update has to be made to the application, the engineer creates a new AMI with the updated configuration and updates the AWS CloudFormation template with the new AMI ID. After the stack finishes, the engineer manually terminates the old instances one by one, verifying that the new instance is operational before proceeding. The engineer needs to automate this process. Which action will allow for the LEAST number of manual steps moving forward?
A) Update the CloudFormation template to include the UpdatePolicy attribute with the AutoScalingRollingUpdate policy.
B) Update the CloudFormation template to include the UpdatePolicy attribute with the AutoScalingReplacingUpdate policy.
C) Use an Auto Scaling lifecycle hook to verify that the previous instance is operational before allowing the DevOps engineer's selected instance to terminate.
D) Use an Auto Scaling lifecycle hook to confirm there are at least four running instances before allowing the DevOps engineer's selected instance to terminate.

Accepted Answer

The answer of A company's application is running on Amazon...

Question 18

A company manages an application that stores logs in Amazon CloudWatch Logs. The company wants to archive the logs in Amazon S3. Logs are rarely accessed after 90 days and must be retained for 10 years. Which combination of steps should a DevOps engineer take to meet these requirements? (Choose two.)
A) Configure a CloudWatch Logs subscription filter to use AWS Glue to transfer all logs to an S3 bucket.
B) Configure a CloudWatch Logs subscription filter to use Amazon Kinesis Data Firehose to stream all logs to an S3 bucket.
C) Configure a CloudWatch Logs subscription filter to stream all logs to an S3 bucket.
D) Configure the S3 bucket lifecycle policy to transition logs to S3 Glacier after 90 days and to expire logs after 3.650 days.
E) Configure the S3 bucket lifecycle policy to transition logs to Reduced Redundancy after 90 days and to expire logs after 3.650 days.

Accepted Answer

The answer of A company manages an application that stores...

Question 19

A company maintains a stateless web application that is experiencing inconsistent traffic. The company uses AWS CloudFormation to deploy the application. The application runs on Amazon EC2 On-Demand Instances behind an Application Load Balancer (ALB). The instances run across multiple Availability Zones. The company wants to include the use of Spot Instances while continuing to use a small number of On-Demand Instances to ensure that the application remains highly available. What is the MOST cost-effective solution that meets these requirements?
A) Add a Spot block resource to the AWS CloudFormation template. Use the diversified allocation strategy with step scaling behind the ALB.
B) Add a Spot block resource to the AWS CloudFormation template. Use the lowest-price allocation strategy with target tracking scaling behind the ALB.
C) Add a Spot Fleet resource to the AWS CloudFormation template. Use the capacity-optimized allocation strategy with step scaling behind the ALB.
D) Add a Spot Fleet resource to the AWS CloudFormation template. Use the diversified allocation strategy with scheduled scaling behind the ALB.

Accepted Answer

The capacity-optimized allocation strategy for Spot Fleet helps to maintain availability by choosing instances from the most available Spot capacity pools, which is crucial for maintaining high availability. Step scaling allows for dynamic scaling based on demand.

Question 20

Which of the following Dockerfile commands cannot be overridden at runtime?
A) VOLUME
B) USER
C) ADD
D) CMD

Accepted Answer

The answer of Which of the following Dockerfile commands cannot...

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

Your company needs to automate 3 layers of a large cloud deployment. You want to be able to track this deployment's evolution as it changes over time, and carefully control any alterations. What is a good way to automate a stack to meet these requirements?

Which EBS volume type is best for high performance NoSQL cluster deployments?

You need to scale an RDS deployment. You are operating at 10% writes and 90% reads, based on your logging. How best can you scale this in a simple way?

You have deployed an application to AWS which makes use of Autoscaling to launch new instances. You now want to change the instance type for the new instances. Which of the following is one of the action items to achieve this deployment?

You need to perform ad-hoc analysis on log data, including searching quickly for specific error codes and reference numbers. Which should you evaluate first?

What is a circular dependency in AWS CloudFormation?

You are building a Docker image with the following Dockerfile. How many layers will the resulting image have? FROM scratch CMD /app/hello.sh

What are the default memory limit policies for a Docker container?

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.

You need to create an audit log of all changes to customer banking data. You use DynamoDB to store this customer banking data. It is important not to lose any information due to server failures. What is an elegant way to accomplish this?

What is the default maximum number of Roles per AWS account?

A company is deploying a new application that uses Amazon EC2 instances. The company needs a solution to query application logs and AWS account API activity. Which solution will meet these requirements?

Which of the following Dockerfile commands cannot be overridden at runtime?