DOP-C02 Timed Practice Test 5 — 10 Questions

Question 1

A DevOps engineer is designing a deployment pipeline for a serverless application using AWS SAM. The pipeline must include the following stages: source, build, deploy to a development environment, run integration tests, and promote to production after manual approval. Which AWS services and features should be used to implement this pipeline? (Choose two.)

Accepted Answer

AWS CodePipeline to orchestrate the pipeline stages.. AWS CodePipeline is the correct service for orchestrating the pipeline stages because it provides native support for defining source, build, deploy, test, and manual approval stages in a sequential workflow. It integrates directly with AWS SAM and can trigger builds and deployments based on source code changes, making it the ideal orchestrator for this multi-stage pipeline.

Answer

AWS CodeDeploy for deploying the SAM application.

Answer

AWS CodeCommit to build the SAM application.

Question 2

A company runs a web application on Amazon EC2 instances behind an Application Load Balancer. The DevOps team has enabled detailed CloudWatch metrics for the ALB and is using CloudWatch Logs for the EC2 instances. Recently, users report intermittent 503 errors. The team notices that the ALB's 'RequestCount' metric shows a sudden drop during error periods, while the 'ActiveConnectionCount' remains steady. Which TWO steps should the team take to diagnose the issue? (Choose two.)

Accepted Answer

Enable and analyze the ALB access logs to see the HTTP response codes and target processing time.. Option A is correct because ALB access logs contain detailed per-request data, including HTTP response codes (e.g., 503) and target processing time. Analyzing these logs will reveal whether the 503 errors are coming from the ALB itself (e.g., due to request queue overflow) or from the targets, and whether the sudden drop in RequestCount is due to clients aborting or the ALB throttling requests.

Answer

Check the Amazon Route 53 health checks for the ALB DNS name.

Answer

Review the EC2 instances' CloudWatch metrics for CPU utilization and network traffic.

Answer

Inspect AWS CloudTrail logs for the ALB to see if there are any configuration changes.

Question 3

A company uses Amazon RDS for MySQL with Multi-AZ deployment. The database instance fails and AWS automatically fails over to the standby. After the failover, the application cannot connect to the database. The engineer checks the RDS console and sees that the instance status is Available. What is the MOST likely cause of the connectivity issue?

Accepted Answer

The application is using the database's DNS endpoint for the old primary, which is no longer the writer.. After an RDS Multi-AZ failover, the DNS endpoint for the DB instance remains the same but its underlying IP address changes to point to the new primary (formerly the standby). If the application caches the IP address of the old primary or uses a direct connection to the old writer endpoint, it will attempt to connect to a node that is no longer the writer. The correct practice is to always connect using the RDS instance endpoint (CNAME), which automatically resolves to the current writer, and to avoid caching the resolved IP address. Since the instance status is 'Available', the new primary is ready, so the issue is a stale connection target.

Answer

The security group for the RDS instance has changed during failover.

Answer

The DNS record for the RDS endpoint has not propagated to the application's DNS resolver.

Answer

The database instance is still in the process of failover and is not yet accepting connections.

Question 4

An application log excerpt shows repeated HTTP 500 errors for the /api/orders endpoint, with occasional successful health checks. The application runs on EC2 instances behind an ALB. What is the MOST likely cause of this pattern?

Accepted Answer

The backend service that the /api/orders endpoint depends on is unavailable or failing.. The pattern of repeated HTTP 500 errors for /api/orders with occasional successful health checks strongly indicates that the backend service dependency (e.g., a database, cache, or another microservice) is intermittently failing or unavailable. HTTP 500 errors are server-side errors, meaning the application code is running but cannot complete the request due to a downstream failure. Successful health checks confirm the EC2 instances themselves are healthy and in-service, ruling out instance-level or ALB misconfiguration issues.

Answer

The EC2 instances are running out of memory and the application is crashing.

Answer

The ALB is misconfigured and routing requests to the wrong target group.

Answer

The EC2 instances are not passing health checks and are being deregistered from the target group.

Question 5

A DevOps engineer is troubleshooting an Auto Scaling group (ASG) that is not launching instances as expected. The ASG is configured with a launch template that uses an Amazon Linux 2 AMI. The engineer checks the EC2 Auto Scaling console and sees that the group's desired capacity is set to 2, but only 1 instance is running. The last scaling activity shows 'Failed to launch instance. Error: Your quota allows for 0 more running instance(s).' What is the most likely cause?

Accepted Answer

The account has reached the EC2 instance limit for the selected instance type in the region.. The error message 'Your quota allows for 0 more running instance(s)' directly indicates that the AWS account has reached its EC2 instance limit for the specific instance type in the region. Auto Scaling groups cannot launch instances beyond the service quota, regardless of the desired capacity. This is a common issue when the default limit (e.g., 5 or 20 instances per instance family) has been exhausted.

Answer

The launch template has insufficient IAM permissions to create instances.

Answer

The VPC subnet does not have enough available IP addresses.

Answer

There is an instance that is not passing health checks, preventing new instances.

Question 6

Match each AWS compute or container service with its description.

Question 7

Match each AWS service health or performance concept to its meaning.

Question 8

Match each AWS CloudFormation concept to its description.

Question 9

Match each AWS Config rule to its purpose.

Question 10

A DevOps engineer receives the error shown in the exhibit when attempting to update an existing CloudFormation stack that deploys a VPC with subnets. The stack was created successfully earlier using the same template. What is the most likely cause of this error?

Accepted Answer

The IAM role used for the stack update lacks the 'ec2:DescribeSubnets' permission.. When updating a CloudFormation stack that deploys a VPC with subnets, the update operation must be able to read the current state of the subnet resources to determine if changes are needed. The IAM role used for the stack update must have the 'ec2:DescribeSubnets' permission to query the existing subnet configuration. Without this permission, CloudFormation cannot verify the subnet's current properties, leading to the error shown in the exhibit.

Answer

The subnet ID in the template is already used by another stack in the same account.

Answer

The subnet specified in the template does not exist in the selected AWS region.

Answer

The CloudFormation template has a syntax error in the subnet definition.