DOP-C02 Practice Test 2 — 30 Questions

Question 1

A company wants to design a highly available web application using AWS services. The application must be resilient to the failure of an entire AWS Region. Which THREE components should the architecture include? (Choose THREE.)

Accepted Answer

Amazon Route 53 with a failover routing policy.. Amazon Route 53 with a failover routing policy is correct because it enables DNS-based health checking and automatic traffic routing to a secondary region when the primary region becomes unavailable. This is essential for cross-region disaster recovery, as Route 53 can monitor endpoint health and update DNS records to direct users to the healthy region, ensuring application availability despite a full region failure.

Answer

An Application Load Balancer (ALB) deployed in one Region.

Answer

Amazon EC2 instances in a single Region.

Question 2

A DevOps engineer needs to grant cross-account access to an S3 bucket in Account A for a user in Account B. Which combination of policies is required?

Accepted Answer

An S3 bucket policy in Account A and an IAM policy in Account B.. An S3 bucket policy in Account A granting access to Account B's user, and an IAM user policy in Account B allowing access to the bucket. Option C is correct.

Answer

An IAM role in Account A and an IAM policy in Account B.

Answer

Only an IAM policy in Account B.

Answer

Only an S3 bucket policy in Account A.

Question 3

A DevOps team is troubleshooting a slow application. They enabled AWS X-Ray tracing and see that one of the downstream services has a high average response time. However, the traces show that the service itself is fast; the delay is in the network call from the upstream service. Which X-Ray feature should the team use to identify the root cause?

Accepted Answer

Examine the trace map to see the connection between services.. The trace map in AWS X-Ray provides a visual representation of the service graph, showing the connections and latency between services. Since the delay is in the network call from the upstream service to the downstream service, the trace map can highlight the specific edge where the high latency occurs, allowing the team to pinpoint whether the issue is due to network congestion, DNS resolution, or a slow HTTP connection. This is the most direct way to identify the root cause of the inter-service communication delay.

Answer

Add annotations to the traces for better filtering.

Answer

View the raw segments of the upstream service.

Answer

Adjust the sampling rules to capture more traces.

Question 4

A company is building a multi-tier web application on AWS. The application must be resilient to the failure of an entire Availability Zone. The architecture includes an Application Load Balancer (ALB), EC2 instances in an Auto Scaling group, and an Amazon RDS for MySQL database. Which TWO actions should be taken to achieve this resilience? (Choose two.)

Accepted Answer

Configure the Auto Scaling group to launch EC2 instances in at least two Availability Zones.. Option D is correct because configuring the Auto Scaling group to launch EC2 instances in at least two Availability Zones ensures that if one AZ fails, the remaining AZ(s) can continue serving traffic. This is a fundamental pattern for building AZ-resilient compute tiers. Option E is correct because deploying Amazon RDS for MySQL in a Multi-AZ configuration automatically provisions and maintains a synchronous standby replica in a different AZ, providing automatic failover if the primary DB instance fails, thus ensuring database resilience.

Answer

Configure an RDS read replica in a different Availability Zone.

Answer

Use a Single-AZ RDS for MySQL database to keep costs low.

Answer

Place all EC2 instances in the same Availability Zone to reduce cross-AZ data transfer costs.

Question 5

A company runs a critical application on AWS using Amazon EC2 instances in an Auto Scaling group, an Application Load Balancer (ALB), and an Amazon RDS for PostgreSQL Multi-AZ DB cluster. The application must maintain an RTO of 5 minutes and an RPO of 1 second for database transactions. The current setup meets these requirements, but the DevOps team wants to improve the resilience of the application tier to withstand a regional failure. Which THREE actions should be taken? (Choose three.)

Accepted Answer

Replace the RDS Multi-AZ cluster with Amazon Aurora Global Database to replicate data across regions.. Amazon Aurora Global Database is the correct choice because it provides cross-region replication with a typical RPO of 1 second and RTO of 1 minute, meeting the stated requirements. Unlike standard RDS Multi-AZ, which is limited to a single region, Aurora Global Database replicates data asynchronously across multiple regions with minimal lag, ensuring the database tier can survive a regional failure while maintaining the required RPO of 1 second.

Answer

Use Amazon EFS Replication to replicate application data across regions with a recovery point objective (RPO) of 1 second.

Answer

Extend the existing Auto Scaling group to launch instances in two regions by specifying a second region in the launch template.

Question 6

A company uses AWS Organizations with multiple accounts. The security team wants to ensure that all IAM roles in member accounts have a maximum session duration of 1 hour. They need a way to detect any roles that violate this policy. What should they do?

Accepted Answer

Use AWS Config with the managed rule iam-role-max-session-duration to evaluate roles.. AWS Config provides a managed rule called `iam-role-max-session-duration` that specifically evaluates IAM roles to ensure their `MaxSessionDuration` setting does not exceed a specified threshold (default 1 hour). This rule can be deployed across all member accounts in AWS Organizations using a conformance pack or AWS Config aggregator, allowing the security team to continuously detect and report any roles that violate the policy without manual intervention.

Answer

Use IAM Access Analyzer to validate the roles against a policy template.

Answer

Run AWS Trusted Advisor and check the IAM report for roles with long session durations.

Answer

Enable AWS CloudTrail and create a metric filter to detect role creation with session duration greater than 1 hour.

Question 7

A DevOps engineer is troubleshooting a production AWS Lambda function that occasionally times out. The function has a timeout of 30 seconds and uses a synchronous invocation. The engineer wants to capture invocation logs to identify the cause. Which approach will provide the MOST detailed diagnostic information?

Accepted Answer

Enable AWS X-Ray tracing on the Lambda function.. Option D is correct because AWS X-Ray provides end-to-end tracing for Lambda functions, capturing detailed timing information for each invocation, including subsegments for downstream calls, function initialization, and execution phases. This allows the engineer to pinpoint exactly where time is being spent, which is essential for diagnosing intermittent timeouts in synchronous invocations.

Answer

Enable AWS CloudTrail data events for Lambda.

Answer

Create a CloudWatch dashboard with function duration metrics.

Answer

Add more logging statements to the function code and check CloudWatch Logs.

Question 8

A company runs a critical application on Amazon ECS with Fargate. The application experiences intermittent slow responses. The DevOps team enabled Container Insights and CloudWatch ServiceLens. However, traces from the application do not appear in ServiceLens. The application uses the AWS X-Ray SDK for tracing. What is the MOST likely cause?

Accepted Answer

The X-Ray daemon is not running in the task definition.. The X-Ray daemon is required to act as a local intermediary that receives trace segments from the X-Ray SDK and forwards them to the AWS X-Ray API. In Amazon ECS with Fargate, the daemon must be explicitly included as a sidecar container in the task definition. Without it, the SDK cannot send traces, which explains why traces are missing from ServiceLens despite the SDK being integrated.

Answer

The X-Ray SDK cannot send traces to AWS X-Ray from Fargate tasks.

Answer

ServiceLens does not support Amazon ECS with Fargate launch type.

Answer

The application is not sending metrics to CloudWatch Container Insights.

Question 9

A DevOps team has set up centralized logging for multiple AWS accounts using Amazon OpenSearch Service. The team uses CloudWatch cross-account observability to collect logs from various accounts into a monitoring account. Recently, logs from one source account stopped appearing in the monitoring account's OpenSearch dashboard. Other source accounts continue to send logs successfully. Which step should the team take to troubleshoot this issue?

Accepted Answer

Check the source account's CloudWatch Logs subscription filter for the OpenSearch destination.. Option B is correct because the most likely cause of logs from a single source account failing to appear is a misconfigured or broken CloudWatch Logs subscription filter. This filter is responsible for forwarding log events from the source account to the OpenSearch destination in the monitoring account. If the filter is missing, misconfigured, or has been accidentally deleted, logs will not be sent, while other accounts continue to work normally.

Answer

Verify that the monitoring account's CloudWatch cross-account observability is enabled.

Answer

Review the source account's CloudWatch Logs retention policy to confirm logs are not expired.

Answer

Ensure the IAM role in the source account has the correct trust policy for the monitoring account.

Question 10

A company uses AWS CloudFormation to deploy infrastructure. The DevOps team wants to receive notifications when a stack fails to create or update. What is the MOST efficient way to achieve this?

Accepted Answer

Configure an SNS topic in the stack's notification options.. Option A is correct because AWS CloudFormation natively supports specifying Amazon SNS topic ARNs in the stack's notification options. When a stack operation (create, update, or delete) fails, CloudFormation automatically publishes a notification to the configured SNS topic without requiring any custom code, additional resources, or external event processing. This is the most efficient approach as it leverages built-in functionality with zero maintenance overhead.

Answer

Create a custom resource in the stack that publishes to Amazon SNS.

Answer

Create a CloudWatch alarm on the StackStatus metric.

Answer

Use Amazon EventBridge to capture CloudFormation events and publish to SNS.

Question 11

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 12

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 13

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 14

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 15

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 16

Match each AWS compute or container service with its description.

Question 17

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

Question 18

Match each AWS CloudFormation concept to its description.

Question 19

Match each AWS Config rule to its purpose.

Question 20

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.