AWS Certified DevOps Engineer - Professional DOP-C02 Practice Test 60
Question 590
An AWS DevOps engineer must address this situation: A production event source generates duplicate notifications and the response workflow creates repeated incident tickets and conflicting actions. Which implementation choice BEST meets the main operational requirement?
- Create EventBridge rules for relevant AWS Health events and route them to an owned incident channel.
- Apply idempotency keys and deduplication in the event-processing workflow using stable event identity.
- Configure cross-account EventBridge bus routing and resource policies for authorized senders and targets.
- Introduce durable SQS buffering and appropriate dead-letter handling with idempotent consumers where suitable.
Explanation
Correct Answer
B:This response directly addresses the stated requirement: Apply idempotency keys and deduplication in the event-processing workflow using stable event identity. The relevant technical mechanism is that distributed event delivery may be at least once, so consumers must tolerate duplicate messages safely. Without this design, duplicate events can launch repeated remediation and confuse responders with parallel incident records. An operational acceptance check should confirm that injecting the same incident event twice yields one accountable incident and no repeated destructive action.
Incorrect Answers
A:This design is appropriate for another AWS operational requirement: A company relies on employees to check AWS Health dashboards to find planned service disruptions affecting production. In that situation the corresponding response would be to create EventBridge rules for relevant AWS Health events and route them to an owned incident channel. It does not directly mitigate the current failure mode, where duplicate events can launch repeated remediation and confuse responders with parallel incident records. The current requirement instead calls for apply idempotency keys and deduplication in the event-processing workflow using stable event identity.
C:This design is appropriate for another AWS operational requirement: Security events from dozens of workload accounts must reach a central security event bus with controlled source permissions. In that situation the corresponding response would be to configure cross-account EventBridge bus routing and resource policies for authorized senders and targets. It does not directly mitigate the current failure mode, where duplicate events can launch repeated remediation and confuse responders with parallel incident records. The current requirement instead calls for apply idempotency keys and deduplication in the event-processing workflow using stable event identity.
D:This design is appropriate for another AWS operational requirement: An EventBridge-triggered Lambda sometimes fails to process payment events and the publisher assumes delivery succeeded. In that situation the corresponding response would be to introduce durable SQS buffering and appropriate dead-letter handling with idempotent consumers where suitable. It does not directly mitigate the current failure mode, where duplicate events can launch repeated remediation and confuse responders with parallel incident records. The current requirement instead calls for apply idempotency keys and deduplication in the event-processing workflow using stable event identity.
Question 591
The team has omitted the measure to assess a supported Multi-AZ replica group with automatic failover and ensure client reconnection behavior. It operates in this setting: An Amazon ElastiCache Redis-based application uses a single primary node for a critical cache whose outage triggers expensive database failures. Which resulting risk is MOST direct?
- A disaster could exceed the expected recovery point or leave applications pointing at a former writer.
- Load balancing or failover can force users to log in again or lose in-progress work.
- One cache failure may cascade into database overload and customer-visible errors.
- Users may continue reaching a failed Region because DNS routing still advertises its endpoint.
Explanation
Correct Answer
C:The omitted control leaves this direct failure exposure: One cache failure may cascade into database overload and customer-visible errors. This follows from the specific situation: An Amazon ElastiCache Redis-based application uses a single primary node for a critical cache whose outage triggers expensive database failures. The proposed safeguard would be to assess a supported Multi-AZ replica group with automatic failover and ensure client reconnection behavior. The governing engineering reason is that caching layers can become availability dependencies if a single cache node failure overwhelms the backing service. A test would check that a controlled cache primary failover restores client operations without saturating the origin database.
Incorrect Answers
A:This failure could arise in a related but different scenario: An Aurora application runs in two Regions but failover documentation assumes asynchronous replica lag is always zero. There the appropriate mitigation is to design Aurora Global Database recovery with monitored replication lag and explicit cross-Region promotion and reconnection steps. The current environment is specifically an Amazon ElastiCache Redis-based application uses a single primary node for a critical cache whose outage triggers expensive database failures. Its omitted safeguard creates the more direct consequence: One cache failure may cascade into database overload and customer-visible errors.
B:This failure could arise in a related but different scenario: An EC2 web service has a redundant fleet and database but stores every authenticated session on local disk. There the appropriate mitigation is to move shared session state to a suitable resilient store or adopt stateless session handling across application targets. The current environment is specifically an Amazon ElastiCache Redis-based application uses a single primary node for a critical cache whose outage triggers expensive database failures. Its omitted safeguard creates the more direct consequence: One cache failure may cascade into database overload and customer-visible errors.
D:This failure could arise in a related but different scenario: A SaaS front door resolves to one Region despite a fully deployed standby application in another Region. There the appropriate mitigation is to configure health-aware Route 53 routing or an approved global entry-point failover solution with tested dependencies. The current environment is specifically an Amazon ElastiCache Redis-based application uses a single primary node for a critical cache whose outage triggers expensive database failures. Its omitted safeguard creates the more direct consequence: One cache failure may cascade into database overload and customer-visible errors.
Question 592
A team proposes this change: Use a CloudFormation stack policy and appropriate IAM permissions to restrict unintended updates to protected resources. The environment is: Developers can deploy a reviewed CloudFormation application template but must not change protected shared networking resources. Which AWS engineering principle most directly supports the proposal?
- Governed self-service exposes approved infrastructure while limiting which actions developers can perform directly.
- Infrastructure drift requires detection and correction without silently overriding approved emergency changes.
- Resource lifecycle policy must distinguish disposable infrastructure from data that must survive stack teardown.
- Stack update protection can limit changes to critical resources in addition to identity permissions.
Explanation
Correct Answer
D:The central principle is that stack update protection can limit changes to critical resources in addition to identity permissions. It supports the decision to use a CloudFormation stack policy and appropriate IAM permissions to restrict unintended updates to protected resources. because the workload problem is: Developers can deploy a reviewed CloudFormation application template but must not change protected shared networking resources. The consequence of ignoring the principle is: A routine application deployment might unexpectedly modify a shared network or foundational resource. The design can be tested by confirming that a simulated update of a protected resource fails while an authorized application update succeeds.
Incorrect Answers
A:This principle concerns the different situation in which an internal platform team wants developers to provision approved infrastructure without giving them IAM administrator rights. It explains the alternative control to publish reviewed CloudFormation products through AWS Service Catalog with suitable portfolios and launch constraints. For the present workload, developers can deploy a reviewed CloudFormation application template but must not change protected shared networking resources. the design rationale is instead that stack update protection can limit changes to critical resources in addition to identity permissions.
B:This principle concerns the different situation in which operators have edited security groups in the console for a stack-managed service and deploy the original CloudFormation template again. It explains the alternative control to run CloudFormation drift detection and reconcile the desired state through the authorized template and change workflow. For the present workload, developers can deploy a reviewed CloudFormation application template but must not change protected shared networking resources. the design rationale is instead that stack update protection can limit changes to critical resources in addition to identity permissions.
C:This principle concerns the different situation in which cloudFormation destroys persistent storage when a test stack is deleted, even though the storage contains audit evidence required for retention. It explains the alternative control to set appropriate CloudFormation DeletionPolicy or retention controls for protected stateful resources. For the present workload, developers can deploy a reviewed CloudFormation application template but must not change protected shared networking resources. the design rationale is instead that stack update protection can limit changes to critical resources in addition to identity permissions.
Question 593
A team proposes this change: Run CloudFormation drift detection and reconcile the desired state through the authorized template and change workflow. The environment is: Operators have edited security groups in the console for a stack-managed service and deploy the original CloudFormation template again. Which AWS engineering principle most directly supports the proposal?
- Infrastructure drift requires detection and correction without silently overriding approved emergency changes.
- CloudFormation's resource-state transitions and event history identify the failing dependency of a stack operation.
- Infrastructure parameters separate reusable desired-state logic from environment-dependent configuration and secrets.
- CloudFormation syntax validation cannot establish the operational impact of an update or replacement action.
Explanation
Correct Answer
A:The central principle is that infrastructure drift requires detection and correction without silently overriding approved emergency changes. It supports the decision to run CloudFormation drift detection and reconcile the desired state through the authorized template and change workflow. because the workload problem is: Operators have edited security groups in the console for a stack-managed service and deploy the original CloudFormation template again. The consequence of ignoring the principle is: An uncontrolled template update can undo required access changes or preserve undocumented network exposure. The design can be tested by confirming that a drift report identifies the modified security group and an approved template revision restores the intended policy.
Incorrect Answers
B:This principle concerns the different situation in which a CloudFormation stack fails halfway through creation, leaving developers unsure which resources were created or rolled back. It explains the alternative control to use stack events and controlled failure investigation before retrying or changing rollback settings. For the present workload, operators have edited security groups in the console for a stack-managed service and deploy the original CloudFormation template again. the design rationale is instead that infrastructure drift requires detection and correction without silently overriding approved emergency changes.
C:This principle concerns the different situation in which a team manually enters account-specific database endpoints into each deployment, creating inconsistent application configuration. It explains the alternative control to reference approved Systems Manager Parameter Store values or secure CloudFormation parameters instead of copying environment settings. For the present workload, operators have edited security groups in the console for a stack-managed service and deploy the original CloudFormation template again. the design rationale is instead that infrastructure drift requires detection and correction without silently overriding approved emergency changes.
D:This principle concerns the different situation in which a CloudFormation stack update will replace a production database and the infrastructure team assumes a green template validation means no disruption. It explains the alternative control to create and review a CloudFormation change set for resource replacements, then require approval for destructive changes. For the present workload, operators have edited security groups in the console for a stack-managed service and deploy the original CloudFormation template again. the design rationale is instead that infrastructure drift requires detection and correction without silently overriding approved emergency changes.
Question 594
An AWS DevOps engineer must address this situation: A Lambda event-processing function times out during downstream database calls, triggering retries and a growing SQS backlog. Which implementation choice BEST meets the main operational requirement?
- Correlate AWS Health, CloudWatch service metrics and deployment history to distinguish platform events from workload defects.
- Correlate Lambda duration, timeout, invocation errors, dependency latency and queue age before modifying concurrency.
- Inspect Kubernetes pod descriptions, readiness failures, container logs and cluster scheduling events.
- Review CloudFormation stack events and the resource status reason before choosing a targeted recovery approach.
Explanation
Correct Answer
B:This response directly addresses the stated requirement: Correlate Lambda duration, timeout, invocation errors, dependency latency and queue age before modifying concurrency. The relevant technical mechanism is that troubleshooting asynchronous failures requires measuring both execution and the downstream service bottleneck. Without this design, raising Lambda concurrency blindly may overload the same database and worsen backlog growth. An operational acceptance check should confirm that a controlled test shows the bottleneck and revised timeout or downstream handling reduces retries and message age.
Incorrect Answers
A:This design is appropriate for another AWS operational requirement: An application failure starts during an AWS service disruption, but the team treats every instance restart as the root cause. In that situation the corresponding response would be to correlate AWS Health, CloudWatch service metrics and deployment history to distinguish platform events from workload defects. It does not directly mitigate the current failure mode, where raising Lambda concurrency blindly may overload the same database and worsen backlog growth. The current requirement instead calls for correlate Lambda duration, timeout, invocation errors, dependency latency and queue age before modifying concurrency.
C:This design is appropriate for another AWS operational requirement: An EKS Deployment reports three desired replicas but users see no ready pods after a configuration change. In that situation the corresponding response would be to inspect Kubernetes pod descriptions, readiness failures, container logs and cluster scheduling events. It does not directly mitigate the current failure mode, where raising Lambda concurrency blindly may overload the same database and worsen backlog growth. The current requirement instead calls for correlate Lambda duration, timeout, invocation errors, dependency latency and queue age before modifying concurrency.
D:This design is appropriate for another AWS operational requirement: A CloudFormation update rolls back because one resource cannot be created, but operators delete the entire stack in frustration. In that situation the corresponding response would be to review CloudFormation stack events and the resource status reason before choosing a targeted recovery approach. It does not directly mitigate the current failure mode, where raising Lambda concurrency blindly may overload the same database and worsen backlog growth. The current requirement instead calls for correlate Lambda duration, timeout, invocation errors, dependency latency and queue age before modifying concurrency.
Question 595
The team has omitted the measure to configure readiness probes and controlled rolling-update availability settings before routing requests to new pods. It operates in this setting: An EKS Deployment replaces pods that are not ready, causing intermittent 503 responses at the ingress. Which resulting risk is MOST direct?
- A flawed new task definition can remove healthy serving capacity before error rates are measured.
- A shared application defect may take down both production Regions simultaneously.
- The load balancer can route user traffic to a pod whose dependencies have not initialized.
- An unhealthy release can be judged successful while its customer-facing endpoint remains unavailable.
Explanation
Correct Answer
C:The omitted control leaves this direct failure exposure: The load balancer can route user traffic to a pod whose dependencies have not initialized. This follows from the specific situation: An EKS Deployment replaces pods that are not ready, causing intermittent 503 responses at the ingress. The proposed safeguard would be to configure readiness probes and controlled rolling-update availability settings before routing requests to new pods. The governing engineering reason is that kubernetes rollouts require readiness-aware traffic eligibility, not just a container that has started. A test would check that an intentionally slow-to-initialize pod receives no service traffic until its readiness probe succeeds.
Incorrect Answers
A:This failure could arise in a related but different scenario: An Amazon ECS service must deploy a new task definition while preserving the existing healthy service during validation. There the appropriate mitigation is to use a supported ECS blue/green deployment strategy with CodeDeploy, target groups and application health validation. The current environment is specifically an EKS Deployment replaces pods that are not ready, causing intermittent 503 responses at the ingress. Its omitted safeguard creates the more direct consequence: The load balancer can route user traffic to a pod whose dependencies have not initialized.
B:This failure could arise in a related but different scenario: An application is deployed in two AWS Regions and the team switches global traffic to both new versions before validating either Region. There the appropriate mitigation is to stage regional releases with explicit health gates and controlled Route 53 or front-door traffic transitions. The current environment is specifically an EKS Deployment replaces pods that are not ready, causing intermittent 503 responses at the ingress. Its omitted safeguard creates the more direct consequence: The load balancer can route user traffic to a pod whose dependencies have not initialized.
D:This failure could arise in a related but different scenario: A CodeDeploy release frequently fails because the application-start lifecycle hook is successful before the service is actually usable. There the appropriate mitigation is to implement lifecycle hook health validation and fail the deployment when required readiness checks do not pass. The current environment is specifically an EKS Deployment replaces pods that are not ready, causing intermittent 503 responses at the ingress. Its omitted safeguard creates the more direct consequence: The load balancer can route user traffic to a pod whose dependencies have not initialized.
Question 596
The team has omitted the measure to configure accurate target-group health checks and appropriate deregistration behavior for the application's readiness path. It operates in this setting: A public API runs across multiple AZs but its application load balancer sends traffic to unhealthy targets after a deployment. Which resulting risk is MOST direct?
- A single-Region table can make all regional users dependent on a distant failed endpoint.
- One cache failure may cascade into database overload and customer-visible errors.
- Load balancing or failover can force users to log in again or lose in-progress work.
- New requests can be routed to nonfunctional targets while healthy capacity exists elsewhere.
Explanation
Correct Answer
D:The omitted control leaves this direct failure exposure: New requests can be routed to nonfunctional targets while healthy capacity exists elsewhere. This follows from the specific situation: A public API runs across multiple AZs but its application load balancer sends traffic to unhealthy targets after a deployment. The proposed safeguard would be to configure accurate target-group health checks and appropriate deregistration behavior for the application's readiness path. The governing engineering reason is that load-balancer availability depends on correct health signals and safe connection draining, not instance count alone. A test would check that a failure test removes the unhealthy target from routing and preserves active business requests during draining.
Incorrect Answers
A:This failure could arise in a related but different scenario: A globally distributed application needs users in two Regions to continue writing to DynamoDB when one Region becomes unavailable. There the appropriate mitigation is to evaluate DynamoDB global tables with correct conflict handling and application failover design. The current environment is specifically a public API runs across multiple AZs but its application load balancer sends traffic to unhealthy targets after a deployment. Its omitted safeguard creates the more direct consequence: New requests can be routed to nonfunctional targets while healthy capacity exists elsewhere.
B:This failure could arise in a related but different scenario: An Amazon ElastiCache Redis-based application uses a single primary node for a critical cache whose outage triggers expensive database failures. There the appropriate mitigation is to assess a supported Multi-AZ replica group with automatic failover and ensure client reconnection behavior. The current environment is specifically a public API runs across multiple AZs but its application load balancer sends traffic to unhealthy targets after a deployment. Its omitted safeguard creates the more direct consequence: New requests can be routed to nonfunctional targets while healthy capacity exists elsewhere.
C:This failure could arise in a related but different scenario: An EC2 web service has a redundant fleet and database but stores every authenticated session on local disk. There the appropriate mitigation is to move shared session state to a suitable resilient store or adopt stateless session handling across application targets. The current environment is specifically a public API runs across multiple AZs but its application load balancer sends traffic to unhealthy targets after a deployment. Its omitted safeguard creates the more direct consequence: New requests can be routed to nonfunctional targets while healthy capacity exists elsewhere.
Question 597
An AWS DevOps engineer must address this situation: The team publishes an AWS CodeBuild artifact to S3 and then edits the binary in a separate account before production deployment. Which implementation choice BEST meets the main operational requirement?
- Promote the identical immutable build artifact across environments and preserve checksum and source-revision traceability.
- Configure appropriately regionalized CodePipeline artifact stores and KMS permissions for cross-Region actions.
- Separate pipeline stage execution roles and grant narrowly scoped build and deployment permissions.
- Version and provision the pipeline and its supporting roles through reviewed infrastructure-as-code templates.
Explanation
Correct Answer
A:This response directly addresses the stated requirement: Promote the identical immutable build artifact across environments and preserve checksum and source-revision traceability. The relevant technical mechanism is that build once and promote the same verified artifact reduces environmental variability and supports provenance auditing. Without this design, an unreviewed mutation between staging and production can invalidate testing and make rollback uncertain. An operational acceptance check should confirm that the hashes and source revision of the deployed production bundle match the integration-tested release artifact.
Incorrect Answers
B:This design is appropriate for another AWS operational requirement: A central delivery account must publish application artifacts into two AWS Regions, but the team assumes one artifact bucket automatically covers every Region. In that situation the corresponding response would be to configure appropriately regionalized CodePipeline artifact stores and KMS permissions for cross-Region actions. It does not directly mitigate the current failure mode, where an unreviewed mutation between staging and production can invalidate testing and make rollback uncertain. The current requirement instead calls for promote the identical immutable build artifact across environments and preserve checksum and source-revision traceability.
C:This design is appropriate for another AWS operational requirement: A deployment pipeline runs as one broad role that can delete organization logs and create IAM users although it only updates an ECS service. In that situation the corresponding response would be to separate pipeline stage execution roles and grant narrowly scoped build and deployment permissions. It does not directly mitigate the current failure mode, where an unreviewed mutation between staging and production can invalidate testing and make rollback uncertain. The current requirement instead calls for promote the identical immutable build artifact across environments and preserve checksum and source-revision traceability.
D:This design is appropriate for another AWS operational requirement: A microservice team stores a CodePipeline definition only in the console, and rebuilding the production pipeline after an outage is manual. In that situation the corresponding response would be to version and provision the pipeline and its supporting roles through reviewed infrastructure-as-code templates. It does not directly mitigate the current failure mode, where an unreviewed mutation between staging and production can invalidate testing and make rollback uncertain. The current requirement instead calls for promote the identical immutable build artifact across environments and preserve checksum and source-revision traceability.
Question 598
A team proposes this change: Configure accurate target-group health checks and appropriate deregistration behavior for the application's readiness path. The environment is: A public API runs across multiple AZs but its application load balancer sends traffic to unhealthy targets after a deployment. Which AWS engineering principle most directly supports the proposal?
- A multi-instance service must not depend on one instance's volatile local session storage for user continuity.
- Load-balancer availability depends on correct health signals and safe connection draining, not instance count alone.
- Multi-AZ database configurations provide standby or distributed availability mechanisms distinct from read scaling.
- Asynchronous cross-Region database protection requires acknowledging potential data loss and application endpoint changes.
Explanation
Correct Answer
B:The central principle is that load-balancer availability depends on correct health signals and safe connection draining, not instance count alone. It supports the decision to configure accurate target-group health checks and appropriate deregistration behavior for the application's readiness path. because the workload problem is: A public API runs across multiple AZs but its application load balancer sends traffic to unhealthy targets after a deployment. The consequence of ignoring the principle is: New requests can be routed to nonfunctional targets while healthy capacity exists elsewhere. The design can be tested by confirming that a failure test removes the unhealthy target from routing and preserves active business requests during draining.
Incorrect Answers
A:This principle concerns the different situation in which an EC2 web service has a redundant fleet and database but stores every authenticated session on local disk. It explains the alternative control to move shared session state to a suitable resilient store or adopt stateless session handling across application targets. For the present workload, a public API runs across multiple AZs but its application load balancer sends traffic to unhealthy targets after a deployment. the design rationale is instead that load-balancer availability depends on correct health signals and safe connection draining, not instance count alone.
C:This principle concerns the different situation in which a production RDS database is deployed in a Single-AZ configuration although the business requires automated recovery from an AZ outage. It explains the alternative control to use an appropriate Amazon RDS Multi-AZ deployment and test the documented failover behavior. For the present workload, a public API runs across multiple AZs but its application load balancer sends traffic to unhealthy targets after a deployment. the design rationale is instead that load-balancer availability depends on correct health signals and safe connection draining, not instance count alone.
D:This principle concerns the different situation in which an Aurora application runs in two Regions but failover documentation assumes asynchronous replica lag is always zero. It explains the alternative control to design Aurora Global Database recovery with monitored replication lag and explicit cross-Region promotion and reconnection steps. For the present workload, a public API runs across multiple AZs but its application load balancer sends traffic to unhealthy targets after a deployment. the design rationale is instead that load-balancer availability depends on correct health signals and safe connection draining, not instance count alone.
Question 599
A team proposes this change: Use CloudWatch Logs Insights queries with structured fields, narrow time windows and reusable filters. The environment is: A developer searches thousands of CloudWatch log streams manually to find one request correlation identifier. Which AWS engineering principle most directly supports the proposal?
- Behavior-sensitive alarms can reduce false positives for metrics with predictable seasonality or changing baselines.
- Configuration-state evidence and identity-attributed API history complement rather than replace each other.
- Indexed or queryable log analysis reduces diagnostic noise when events span many service instances.
- Synthetic monitoring can validate customer journeys that simple infrastructure checks do not measure.
Explanation
Correct Answer
C:The central principle is that indexed or queryable log analysis reduces diagnostic noise when events span many service instances. It supports the decision to use CloudWatch Logs Insights queries with structured fields, narrow time windows and reusable filters. because the workload problem is: A developer searches thousands of CloudWatch log streams manually to find one request correlation identifier. The consequence of ignoring the principle is: An incident can remain unresolved while engineers read logs that are unrelated to the failing transaction. The design can be tested by confirming that a known trace ID query returns the relevant events and timestamps from the intended log groups.
Incorrect Answers
A:This principle concerns the different situation in which a nightly batch varies naturally with business volume and a hardcoded CloudWatch threshold creates constant false alerts. It explains the alternative control to use CloudWatch anomaly detection or workload-normalized thresholds with suitable evaluation periods. For the present workload, a developer searches thousands of CloudWatch log streams manually to find one request correlation identifier. the design rationale is instead that indexed or queryable log analysis reduces diagnostic noise when events span many service instances.
B:This principle concerns the different situation in which security monitors when an S3 bucket encryption configuration changes but cannot determine who made the API request. It explains the alternative control to use AWS Config configuration history for resource state and CloudTrail for attributable API activity. For the present workload, a developer searches thousands of CloudWatch log streams manually to find one request correlation identifier. the design rationale is instead that indexed or queryable log analysis reduces diagnostic noise when events span many service instances.
D:This principle concerns the different situation in which a public ordering endpoint returns 200 from an internal health check but its user checkout flow fails intermittently. It explains the alternative control to use CloudWatch Synthetics canaries to exercise representative transaction steps and alert on failed end-user workflows. For the present workload, a developer searches thousands of CloudWatch log streams manually to find one request correlation identifier. the design rationale is instead that indexed or queryable log analysis reduces diagnostic noise when events span many service instances.
Question 600
The team has omitted the measure to configure supported EC2 automatic recovery through appropriate CloudWatch status-check alarms or recovery actions. It operates in this setting: An impaired EC2 instance needs recovery when the host fails, but operators currently reboot it manually after a customer complaint. Which resulting risk is MOST direct?
- Retrying a state-changing action can introduce duplicate or conflicting infrastructure configuration.
- A savings routine can stop critical customer infrastructure when selection criteria are too broad.
- Premature instance termination may erase volatile evidence and obstruct root-cause analysis.
- Host failures may extend customer downtime even when automatic recovery is available.
Explanation
Correct Answer
D:The omitted control leaves this direct failure exposure: Host failures may extend customer downtime even when automatic recovery is available. This follows from the specific situation: An impaired EC2 instance needs recovery when the host fails, but operators currently reboot it manually after a customer complaint. The proposed safeguard would be to configure supported EC2 automatic recovery through appropriate CloudWatch status-check alarms or recovery actions. The governing engineering reason is that infrastructure health events can drive bounded automatic recovery of eligible instances without waiting for operator login. A test would check that an eligible simulated recovery path invokes the expected recovery behavior and restores instance health within policy.
Incorrect Answers
A:This failure could arise in a related but different scenario: A CloudWatch alarm triggers a change to a shared routing rule, but a transient Lambda retry executes the route modification twice. There the appropriate mitigation is to design idempotent response steps with controlled retries, current-state checks and compensating recovery actions. The current environment is specifically an impaired EC2 instance needs recovery when the host fails, but operators currently reboot it manually after a customer complaint. Its omitted safeguard creates the more direct consequence: Host failures may extend customer downtime even when automatic recovery is available.
B:This failure could arise in a related but different scenario: Operations schedules an automatic stop of nonproduction instances, but the schedule occasionally targets production because tags are inconsistent. There the appropriate mitigation is to use EventBridge Scheduler with tightly scoped resource selection, validation and explicit production exclusions. The current environment is specifically an impaired EC2 instance needs recovery when the host fails, but operators currently reboot it manually after a customer complaint. Its omitted safeguard creates the more direct consequence: Host failures may extend customer downtime even when automatic recovery is available.
C:This failure could arise in a related but different scenario: A planned security response needs to isolate an EC2 instance for investigation, but an automatic Lambda deletes the instance immediately. There the appropriate mitigation is to use a bounded isolation runbook with incident approval and preservation of evidence before irreversible remediation. The current environment is specifically an impaired EC2 instance needs recovery when the host fails, but operators currently reboot it manually after a customer complaint. Its omitted safeguard creates the more direct consequence: Host failures may extend customer downtime even when automatic recovery is available.