Amazon AWS Certified DevOps Engineer - Professional DOP-C02 Practice Test 1
Question 1
An AWS platform team investigates this condition: A production stack enters UPDATE_ROLLBACK_FAILED after a deleted external resource cannot be restored. Which DevOps principle BEST explains the core problem?
- Failure investigation should use CloudFormation stack events and supported recovery operations.
- Request throttling may occur at API Gateway before integration invocation.
- Capacity failures require examining availability zones, allocation strategy and quotas.
- Automated recovery must distinguish replaceable task failure from persistent systemic causes.
Explanation
Correct Answer
A:Failure investigation should use CloudFormation stack events and supported recovery operations. Relevant first evidence: Inspect failed logical resources, status reasons, external dependencies and stack events. The resulting controlled response is: Correct the blocking dependency and continue rollback using supported CloudFormation recovery.
Incorrect Answers
B:Request throttling may occur at API Gateway before integration invocation. This instead addresses a different case: A mobile API intermittently returns HTTP 429 during marketing peaks, but its Lambda error metric stays nearly zero. For the stated situation (A production stack enters UPDATE_ROLLBACK_FAILED after a deleted external resource cannot be restored.), the better principle is: Failure investigation should use CloudFormation stack events and supported recovery operations. The deciding distinction is: Failure investigation should use CloudFormation stack events and supported recovery operations.
C:Capacity failures require examining availability zones, allocation strategy and quotas. This instead addresses a different case: An Auto Scaling group repeatedly fails to launch enough instances in one AZ despite other AZs having capacity. For the stated situation (A production stack enters UPDATE_ROLLBACK_FAILED after a deleted external resource cannot be restored.), the better principle is: Failure investigation should use CloudFormation stack events and supported recovery operations. The deciding distinction is: Failure investigation should use CloudFormation stack events and supported recovery operations.
D:Automated recovery must distinguish replaceable task failure from persistent systemic causes. This instead addresses a different case: An ECS application task fails health checks every few minutes, and the team restarts the same failing task manually without identifying a dependency outage. For the stated situation (A production stack enters UPDATE_ROLLBACK_FAILED after a deleted external resource cannot be restored.), the better principle is: Failure investigation should use CloudFormation stack events and supported recovery operations. The deciding distinction is: Failure investigation should use CloudFormation stack events and supported recovery operations.
Question 2
After implementing a proposed fix, the team reviews: A service needs stateful application access, but network engineers rely on one stateless NACL inbound allow rule and response traffic is blocked. Which result would BEST confirm that the risk is addressed?
- Permitted connection and return traffic succeed while prohibited access is denied.
- A password-only privileged session cannot perform the protected action.
- A load test blocks abusive patterns while approved customers remain serviceable.
- A test delete before retention expiry is denied and authorized readers retain access.
Explanation
Correct Answer
A:Permitted connection and return traffic succeed while prohibited access is denied. The approved action is: Correct subnet stateless rules or use appropriate security group rules for application access. The risk principle is: NACLs are stateless and require explicit return-path allowances; security groups are stateful.
Incorrect Answers
B:A password-only privileged session cannot perform the protected action. This instead addresses a different case: Human operators access high-risk account settings without multifactor authentication, even though a company policy mandates it. For the stated situation (A service needs stateful application access, but network engineers rely on one stateless NACL inbound allow rule and response traffic is blocked.), the better verification is: Permitted connection and return traffic succeed while prohibited access is denied. The deciding distinction is: NACLs are stateless and require explicit return-path allowances; security groups are stateful.
C:A load test blocks abusive patterns while approved customers remain serviceable. This instead addresses a different case: A public application faces high-volume abusive HTTP requests that pass the ALB security group and overwhelm login processing. For the stated situation (A service needs stateful application access, but network engineers rely on one stateless NACL inbound allow rule and response traffic is blocked.), the better verification is: Permitted connection and return traffic succeed while prohibited access is denied. The deciding distinction is: NACLs are stateless and require explicit return-path allowances; security groups are stateful.
D:A test delete before retention expiry is denied and authorized readers retain access. This instead addresses a different case: An organization must retain regulatory audit evidence for seven years, but administrators can remove every copy using ordinary DeleteObject. For the stated situation (A service needs stateful application access, but network engineers rely on one stateless NACL inbound allow rule and response traffic is blocked.), the better verification is: Permitted connection and return traffic succeed while prohibited access is denied. The deciding distinction is: NACLs are stateless and require explicit return-path allowances; security groups are stateful.
Question 3
Before changing production, engineers find: The platform team needs to analyze months of historical organization CloudTrail records across accounts to detect policy changes. Which investigation should the engineer perform FIRST?
- Inspect centralized CloudTrail object layout, partitioning and access permissions.
- Inspect X-Ray service map, trace segments, status errors and downstream call durations.
- Review AWS Config resource timeline and recorded CloudTrail changes for the period.
- Review alarm dependencies, parent symptoms and notification routing.
Explanation
Correct Answer
A:Inspect centralized CloudTrail object layout, partitioning and access permissions. The governing principle is: Long-term audit queries can use protected S3 log data with suitable analytics tables. The next controlled engineering decision is: Use an appropriate Athena-backed query or CloudTrail Lake pattern to search retained audit events.
Incorrect Answers
B:Inspect X-Ray service map, trace segments, status errors and downstream call durations. This instead addresses a different case: An application has slow checkout requests only when external credit checks are called, but aggregate ALB metrics cannot locate the dependency. For the stated situation (The platform team needs to analyze months of historical organization CloudTrail records across accounts to detect policy changes.), the better investigation is: Inspect centralized CloudTrail object layout, partitioning and access permissions. The deciding distinction is: Long-term audit queries can use protected S3 log data with suitable analytics tables.
C:Review AWS Config resource timeline and recorded CloudTrail changes for the period. This instead addresses a different case: A tagged production S3 bucket is currently private, but auditors need to know whether it was public during a past incident window. For the stated situation (The platform team needs to analyze months of historical organization CloudTrail records across accounts to detect policy changes.), the better investigation is: Inspect centralized CloudTrail object layout, partitioning and access permissions. The deciding distinction is: Long-term audit queries can use protected S3 log data with suitable analytics tables.
D:Review alarm dependencies, parent symptoms and notification routing. This instead addresses a different case: Five related alarms page the same team simultaneously for a single database outage, overwhelming responders. For the stated situation (The platform team needs to analyze months of historical organization CloudTrail records across accounts to detect policy changes.), the better investigation is: Inspect centralized CloudTrail object layout, partitioning and access permissions. The deciding distinction is: Long-term audit queries can use protected S3 log data with suitable analytics tables.
Question 4
An AWS platform team investigates this condition: An authenticated read-heavy API repeatedly queries a database for identical catalog metadata, exhausting database read capacity. Which DevOps principle BEST explains the core problem?
- Caching or read replicas can reduce repeated reads when consistency requirements permit.
- Scaling should reflect actual workload demand and processing time, not unrelated utilization alone.
- Stream throughput depends on partition distribution as well as shard capacity.
- Pilot-light recovery must pre-plan network, service quota and scale-up capacity.
Explanation
Correct Answer
A:Caching or read replicas can reduce repeated reads when consistency requirements permit. Relevant first evidence: Inspect hit ratios, query rate, freshness needs and per-user access controls. The resulting controlled response is: Introduce an appropriate cache or replicated read path with clear invalidation rules.
Incorrect Answers
B:Scaling should reflect actual workload demand and processing time, not unrelated utilization alone. This instead addresses a different case: A worker fleet uses CPU utilization to scale even though pending SQS message backlog increases rapidly while CPU remains low. For the stated situation (An authenticated read-heavy API repeatedly queries a database for identical catalog metadata, exhausting database read capacity.), the better principle is: Caching or read replicas can reduce repeated reads when consistency requirements permit. The deciding distinction is: Caching or read replicas can reduce repeated reads when consistency requirements permit.
C:Stream throughput depends on partition distribution as well as shard capacity. This instead addresses a different case: A streaming workload begins dropping or delaying records because all events use the same partition key and one Kinesis shard is hot. For the stated situation (An authenticated read-heavy API repeatedly queries a database for identical catalog metadata, exhausting database read capacity.), the better principle is: Caching or read replicas can reduce repeated reads when consistency requirements permit. The deciding distinction is: Caching or read replicas can reduce repeated reads when consistency requirements permit.
D:Pilot-light recovery must pre-plan network, service quota and scale-up capacity. This instead addresses a different case: A pilot-light disaster recovery setup replicates data but recovery scripts try to restore full production capacity into an undersized subnet with insufficient IPs. For the stated situation (An authenticated read-heavy API repeatedly queries a database for identical catalog metadata, exhausting database read capacity.), the better principle is: Caching or read replicas can reduce repeated reads when consistency requirements permit. The deciding distinction is: Caching or read replicas can reduce repeated reads when consistency requirements permit.
Question 5
The DevOps team must resolve this scenario: A critical single EC2 instance occasionally fails hardware health checks, but operators discover the outage only when customers complain. Which engineering change is MOST appropriate?
- Route relevant AWS Health events through EventBridge to the approved operations channel.
- Configure suitable scheduled or predictive scaling alongside reactive controls.
- Configure a CloudWatch alarm with supported EC2 recovery action where appropriate.
- Query historical configuration snapshots and correlate with authorization records.
Explanation
Correct Answer
C:Configure a CloudWatch alarm with supported EC2 recovery action where appropriate. Its validation is: A simulated supported infrastructure impairment triggers the documented recovery workflow. The principle is: Supported EC2 recovery alarms can automate appropriate recovery responses to infrastructure issues.
Incorrect Answers
A:Route relevant AWS Health events through EventBridge to the approved operations channel. This instead addresses a different case: A regional AWS Health event indicates maintenance of a service used by five accounts, but no on-call team receives it. For the stated situation (A critical single EC2 instance occasionally fails hardware health checks, but operators discover the outage only when customers complain.), the better engineering action is: Configure a CloudWatch alarm with supported EC2 recovery action where appropriate. The deciding distinction is: Supported EC2 recovery alarms can automate appropriate recovery responses to infrastructure issues.
B:Configure suitable scheduled or predictive scaling alongside reactive controls. This instead addresses a different case: A predictable daily traffic peak starts before the reactive Auto Scaling policy can launch sufficient EC2 instances. For the stated situation (A critical single EC2 instance occasionally fails hardware health checks, but operators discover the outage only when customers complain.), the better engineering action is: Configure a CloudWatch alarm with supported EC2 recovery action where appropriate. The deciding distinction is: Supported EC2 recovery alarms can automate appropriate recovery responses to infrastructure issues.
D:Query historical configuration snapshots and correlate with authorization records. This instead addresses a different case: A tagged production S3 bucket is currently private, but auditors need to know whether it was public during a past incident window. For the stated situation (A critical single EC2 instance occasionally fails hardware health checks, but operators discover the outage only when customers complain.), the better engineering action is: Configure a CloudWatch alarm with supported EC2 recovery action where appropriate. The deciding distinction is: Supported EC2 recovery alarms can automate appropriate recovery responses to infrastructure issues.
Question 6
Before changing production, engineers find: An AWS Health event affects a critical enterprise database in an otherwise quiet account, but the team monitors only application CloudWatch alarms. Which investigation should the engineer perform FIRST?
- Inspect redrive policy, maxReceiveCount, retention and consumer failures.
- Inspect AWS Health event scope, affected entities and incident routing coverage.
- Inspect event identifiers, destination conditional writes and retry behavior.
- Inspect ACM certificate status, DNS validation, import provenance and attached listeners.
Explanation
Correct Answer
B:Inspect AWS Health event scope, affected entities and incident routing coverage. The governing principle is: Provider health notifications complement application and resource telemetry. The next controlled engineering decision is: Subscribe to relevant health events through centralized EventBridge and incident workflows.
Incorrect Answers
A:Inspect redrive policy, maxReceiveCount, retention and consumer failures. This instead addresses a different case: A broken message repeatedly fails an event-driven worker and blocks useful progress while on-call has no way to inspect it. For the stated situation (An AWS Health event affects a critical enterprise database in an otherwise quiet account, but the team monitors only application CloudWatch alarms.), the better investigation is: Inspect AWS Health event scope, affected entities and incident routing coverage. The deciding distinction is: Provider health notifications complement application and resource telemetry.
C:Inspect event identifiers, destination conditional writes and retry behavior. This instead addresses a different case: An S3 upload event triggers a Lambda that copies customer records, and retries create duplicate records in a destination store. For the stated situation (An AWS Health event affects a critical enterprise database in an otherwise quiet account, but the team monitors only application CloudWatch alarms.), the better investigation is: Inspect AWS Health event scope, affected entities and incident routing coverage. The deciding distinction is: Provider health notifications complement application and resource telemetry.
D:Inspect ACM certificate status, DNS validation, import provenance and attached listeners. This instead addresses a different case: An ACM-managed certificate is nearing expiration, but an application relies on manually imported certificates whose renewal notifications are ignored. For the stated situation (An AWS Health event affects a critical enterprise database in an otherwise quiet account, but the team monitors only application CloudWatch alarms.), the better investigation is: Inspect AWS Health event scope, affected entities and incident routing coverage. The deciding distinction is: Provider health notifications complement application and resource telemetry.
Question 7
After implementing a proposed fix, the team reviews: Chargeback reports omit resources because each team uses different tag keys and case variants. Which result would BEST confirm that the risk is addressed?
- Actual installed package inventory reconciles to approved software baseline.
- New stacks carry normalized cost allocation tags and untagged exceptions are detectable.
- A removed employee loses intended account access without searching for duplicate IAM users.
- A role session can write only target resources and expires without key rotation overhead.
Explanation
Correct Answer
B:New stacks carry normalized cost allocation tags and untagged exceptions are detectable. The approved action is: Adopt a documented tag taxonomy with organization tag policies and deployment checks. The risk principle is: Organization-scale resource classification benefits from governed consistent tag policies and enforcement.
Incorrect Answers
A:Actual installed package inventory reconciles to approved software baseline. This instead addresses a different case: Operations estimates patch compliance from EC2 tags but has no verified installed software inventory. For the stated situation (Chargeback reports omit resources because each team uses different tag keys and case variants.), the better verification is: New stacks carry normalized cost allocation tags and untagged exceptions are detectable. The deciding distinction is: Organization-scale resource classification benefits from governed consistent tag policies and enforcement.
C:A removed employee loses intended account access without searching for duplicate IAM users. This instead addresses a different case: An enterprise manually creates duplicate IAM users in dozens of accounts for employees, creating slow offboarding. For the stated situation (Chargeback reports omit resources because each team uses different tag keys and case variants.), the better verification is: New stacks carry normalized cost allocation tags and untagged exceptions are detectable. The deciding distinction is: Organization-scale resource classification benefits from governed consistent tag policies and enforcement.
D:A role session can write only target resources and expires without key rotation overhead. This instead addresses a different case: A central deployment role uses a shared user access key to write objects to member-account buckets. For the stated situation (Chargeback reports omit resources because each team uses different tag keys and case variants.), the better verification is: New stacks carry normalized cost allocation tags and untagged exceptions are detectable. The deciding distinction is: Organization-scale resource classification benefits from governed consistent tag policies and enforcement.
Question 8
Before changing production, engineers find: Five related alarms page the same team simultaneously for a single database outage, overwhelming responders. Which investigation should the engineer perform FIRST?
- Review CodeDeploy deployment group alarms, target health and service error signals.
- Review alarm dependencies, parent symptoms and notification routing.
- Inspect historical CPU seasonality, anomaly band and alert validation cases.
- Inspect ApproximateAgeOfOldestMessage, visibility, DLQ configuration and consumer errors.
Explanation
Correct Answer
B:Review alarm dependencies, parent symptoms and notification routing. The governing principle is: Composite alarms can group related signals into meaningful incident notifications. The next controlled engineering decision is: Use CloudWatch composite alarm logic with deliberate suppression or grouping.
Incorrect Answers
A:Review CodeDeploy deployment group alarms, target health and service error signals. This instead addresses a different case: A new ECS task definition produces errors after traffic shift, but the deployment continues to completion because alarms are not associated with the release. For the stated situation (Five related alarms page the same team simultaneously for a single database outage, overwhelming responders.), the better investigation is: Review alarm dependencies, parent symptoms and notification routing. The deciding distinction is: Composite alarms can group related signals into meaningful incident notifications.
C:Inspect historical CPU seasonality, anomaly band and alert validation cases. This instead addresses a different case: A seasonal shopping workload triggers fixed CPU threshold alerts every evening although nightly traffic is normal and expected. For the stated situation (Five related alarms page the same team simultaneously for a single database outage, overwhelming responders.), the better investigation is: Review alarm dependencies, parent symptoms and notification routing. The deciding distinction is: Composite alarms can group related signals into meaningful incident notifications.
D:Inspect ApproximateAgeOfOldestMessage, visibility, DLQ configuration and consumer errors. This instead addresses a different case: A queue's depth remains modest but its oldest message waits 40 minutes because one poison message repeatedly fails processing. For the stated situation (Five related alarms page the same team simultaneously for a single database outage, overwhelming responders.), the better investigation is: Review alarm dependencies, parent symptoms and notification routing. The deciding distinction is: Composite alarms can group related signals into meaningful incident notifications.
Question 9
A DevOps team is reviewing: An enterprise manually creates duplicate IAM users in dozens of accounts for employees, creating slow offboarding. Which TWO complementary actions should it take? Select TWO answers.
- Use IAM Identity Center groups and governed permission sets for cross-account staff access.
- Inspect Control Tower landing zone, Account Factory templates and detective guardrails.
- Review tag policies, required dimensions, untagged inventory and deployment templates.
- Use scoped paths or separate accounts with least-privilege parameter read access.
- Inspect IAM Identity Center assignments, identity source, permission sets and deprovisioning.
Explanation
Correct Answers
A:Use IAM Identity Center groups and governed permission sets for cross-account staff access. This is a required controlled engineering action for the stated situation: An enterprise manually creates duplicate IAM users in dozens of accounts for employees, creating slow offboarding. The complementary correct action is: Inspect IAM Identity Center assignments, identity source, permission sets and deprovisioning. Both follow the principle: Workforce access should be federated and provisioned centrally with time-limited account sessions.
E:Inspect IAM Identity Center assignments, identity source, permission sets and deprovisioning. This is a required diagnostic evidence step for the stated situation: An enterprise manually creates duplicate IAM users in dozens of accounts for employees, creating slow offboarding. The complementary correct action is: Use IAM Identity Center groups and governed permission sets for cross-account staff access. Both follow the principle: Workforce access should be federated and provisioned centrally with time-limited account sessions.
Incorrect Answers
B:Inspect Control Tower landing zone, Account Factory templates and detective guardrails. This is suitable for another situation: A company provisions AWS accounts manually and regularly forgets baseline logging and governance settings. In this case, engineers instead need the paired investigation (Inspect IAM Identity Center assignments, identity source, permission sets and deprovisioning.) and design change (Use IAM Identity Center groups and governed permission sets for cross-account staff access.). These two steps address: An enterprise manually creates duplicate IAM users in dozens of accounts for employees, creating slow offboarding.
C:Review tag policies, required dimensions, untagged inventory and deployment templates. This is suitable for another situation: Chargeback reports omit resources because each team uses different tag keys and case variants. In this case, engineers instead need the paired investigation (Inspect IAM Identity Center assignments, identity source, permission sets and deprovisioning.) and design change (Use IAM Identity Center groups and governed permission sets for cross-account staff access.). These two steps address: An enterprise manually creates duplicate IAM users in dozens of accounts for employees, creating slow offboarding.
D:Use scoped paths or separate accounts with least-privilege parameter read access. This is suitable for another situation: Multiple environments share unqualified /db/password parameter names and a production application accidentally reads a staging secret. In this case, engineers instead need the paired investigation (Inspect IAM Identity Center assignments, identity source, permission sets and deprovisioning.) and design change (Use IAM Identity Center groups and governed permission sets for cross-account staff access.). These two steps address: An enterprise manually creates duplicate IAM users in dozens of accounts for employees, creating slow offboarding.
Question 10
An engineering review identifies: An enterprise stores thousands of S3 objects across accounts and needs to discover unclassified personal records at scale. Which shortcut is MOST unsafe for this exact condition?
- Treat bucket names alone as proof that all contained records are non-sensitive.
- Put the long-lived access key in user data and assume it is hidden.
- Disable KMS encryption on the entire bucket to make objects accessible.
- Assume normal S3 versioning blocks permanent deletion of every historical version.
Explanation
Correct Answer
A:Treat bucket names alone as proof that all contained records are non-sensitive. The case is: An enterprise stores thousands of S3 objects across accounts and needs to discover unclassified personal records at scale. A safer engineering response is: Enable suitable Macie discovery with centralized review of detected sensitive data. The deciding principle is: Sensitive-data discovery should be automated and authorized across relevant storage scopes.
Incorrect Answers
B:Put the long-lived access key in user data and assume it is hidden. This instead addresses a different case: An EC2 application stores a permanent IAM access key in a local configuration file to upload reports to S3. For the stated situation (An enterprise stores thousands of S3 objects across accounts and needs to discover unclassified personal records at scale.), the better unsafe assumption to reject is: Treat bucket names alone as proof that all contained records are non-sensitive. The deciding distinction is: Sensitive-data discovery should be automated and authorized across relevant storage scopes.
C:Disable KMS encryption on the entire bucket to make objects accessible. This instead addresses a different case: An application has s3:GetObject permission but cannot read encrypted objects after a KMS key policy update. For the stated situation (An enterprise stores thousands of S3 objects across accounts and needs to discover unclassified personal records at scale.), the better unsafe assumption to reject is: Treat bucket names alone as proof that all contained records are non-sensitive. The deciding distinction is: Sensitive-data discovery should be automated and authorized across relevant storage scopes.
D:Assume normal S3 versioning blocks permanent deletion of every historical version. This instead addresses a different case: An organization must retain regulatory audit evidence for seven years, but administrators can remove every copy using ordinary DeleteObject. For the stated situation (An enterprise stores thousands of S3 objects across accounts and needs to discover unclassified personal records at scale.), the better unsafe assumption to reject is: Treat bucket names alone as proof that all contained records are non-sensitive. The deciding distinction is: Sensitive-data discovery should be automated and authorized across relevant storage scopes.