AWS Certified DevOps Engineer - Professional DOP-C02 Practice Test 25
Question 240
An AWS DevOps engineer must address this situation: An ALB-backed application has healthy EC2 hosts but clients experience increased 5xx responses and unacceptable response time. Which implementation choice BEST meets the main operational requirement?
- Use CloudWatch anomaly detection or workload-normalized thresholds with suitable evaluation periods.
- Use suitable dimensional custom metrics or CloudWatch Contributor Insights rules for high-cardinality traffic patterns.
- Enable the appropriate CloudTrail data-event selectors for the relevant S3 object activity.
- Monitor Application Load Balancer error and target-response-time metrics alongside business-level availability indicators.
Explanation
Correct Answer
D:This response directly addresses the stated requirement: Monitor Application Load Balancer error and target-response-time metrics alongside business-level availability indicators. The relevant technical mechanism is that infrastructure health does not prove end-to-end application response quality under customer traffic. Without this design, operators can miss an application-layer outage because host CPU and status checks remain nominal. An operational acceptance check should confirm that synthetic requests and ALB metrics detect a simulated backend regression before the business SLO is breached.
Incorrect Answers
A:This design is appropriate for another AWS operational requirement: A nightly batch varies naturally with business volume and a hardcoded CloudWatch threshold creates constant false alerts. In that situation the corresponding response would be to use CloudWatch anomaly detection or workload-normalized thresholds with suitable evaluation periods. It does not directly mitigate the current failure mode, where operators can miss an application-layer outage because host CPU and status checks remain nominal. The current requirement instead calls for monitor Application Load Balancer error and target-response-time metrics alongside business-level availability indicators.
B:This design is appropriate for another AWS operational requirement: An application uses Amazon SQS and one noisy producer dominates message backlog, but aggregate queue metrics do not identify top contributors. In that situation the corresponding response would be to use suitable dimensional custom metrics or CloudWatch Contributor Insights rules for high-cardinality traffic patterns. It does not directly mitigate the current failure mode, where operators can miss an application-layer outage because host CPU and status checks remain nominal. The current requirement instead calls for monitor Application Load Balancer error and target-response-time metrics alongside business-level availability indicators.
C:This design is appropriate for another AWS operational requirement: An audit requires the identities that downloaded one confidential S3 object, but only management operations appear in CloudTrail evidence. In that situation the corresponding response would be to enable the appropriate CloudTrail data-event selectors for the relevant S3 object activity. It does not directly mitigate the current failure mode, where operators can miss an application-layer outage because host CPU and status checks remain nominal. The current requirement instead calls for monitor Application Load Balancer error and target-response-time metrics alongside business-level availability indicators.
Question 241
An AWS DevOps engineer must address this situation: An application requires recovery within minutes, but the proposed disaster-recovery Region keeps no preprovisioned running services. Which implementation choice BEST meets the main operational requirement?
- Consider a warm-standby or suitable active pattern with enough live capacity to meet the validated recovery window.
- Schedule representative AWS Backup restore testing or equivalent rehearsals and validate application integrity after restore.
- Automate documented recovery orchestration with dependency checks, bounded retries and explicit business approval where needed.
- Use suitably protected backup vaults and supported Vault Lock controls with separate backup administration.
Explanation
Correct Answer
A:This response directly addresses the stated requirement: Consider a warm-standby or suitable active pattern with enough live capacity to meet the validated recovery window. The relevant technical mechanism is that recovery time depends on the resources already running and the time needed to activate full service. Without this design, cold provisioning can take longer than the allowed interruption even when data is replicated. An operational acceptance check should confirm that a warm-standby failover rehearsal reaches the minimum required throughput within the approved RTO.
Incorrect Answers
B:This design is appropriate for another AWS operational requirement: Backup jobs complete successfully for a critical workload but no one knows whether the backups can be restored. In that situation the corresponding response would be to schedule representative AWS Backup restore testing or equivalent rehearsals and validate application integrity after restore. It does not directly mitigate the current failure mode, where cold provisioning can take longer than the allowed interruption even when data is replicated. The current requirement instead calls for consider a warm-standby or suitable active pattern with enough live capacity to meet the validated recovery window.
C:This design is appropriate for another AWS operational requirement: A regional outage recovery procedure updates DNS and databases in an undocumented order and requires a single expert to execute. In that situation the corresponding response would be to automate documented recovery orchestration with dependency checks, bounded retries and explicit business approval where needed. It does not directly mitigate the current failure mode, where cold provisioning can take longer than the allowed interruption even when data is replicated. The current requirement instead calls for consider a warm-standby or suitable active pattern with enough live capacity to meet the validated recovery window.
D:This design is appropriate for another AWS operational requirement: A ransomware threat could delete both production data and backup recovery points using the same compromised administrator role. In that situation the corresponding response would be to use suitably protected backup vaults and supported Vault Lock controls with separate backup administration. It does not directly mitigate the current failure mode, where cold provisioning can take longer than the allowed interruption even when data is replicated. The current requirement instead calls for consider a warm-standby or suitable active pattern with enough live capacity to meet the validated recovery window.
Question 242
An operations team deploys the following safeguard: Reference approved Systems Manager Parameter Store values or secure CloudFormation parameters instead of copying environment settings. Which observed result is the STRONGEST validation that the safeguard works?
- A controlled failure produces stack events that isolate the rejected resource and the approved correction succeeds.
- A multi-account deployment resolves the correct authorized parameter value without embedding it in source.
- A simulated update of a protected resource fails while an authorized application update succeeds.
- Review records link the source revision and synthesized resource diff to the approved production deployment.
Explanation
Correct Answer
B:The best verification result is: A multi-account deployment resolves the correct authorized parameter value without embedding it in source. It specifically demonstrates that the implemented safeguard to reference approved Systems Manager Parameter Store values or secure CloudFormation parameters instead of copying environment settings. is effective. This control matters where a team manually enters account-specific database endpoints into each deployment, creating inconsistent application configuration. Without suitable evidence, the outstanding exposure is that repeated manual entry can target production applications at the wrong data store or expose sensitive values.
Incorrect Answers
A:This measurement validates a different AWS control: Use stack events and controlled failure investigation before retrying or changing rollback settings. It is most relevant where a CloudFormation stack fails halfway through creation, leaving developers unsure which resources were created or rolled back. It would not establish whether the current safeguard is effective; the required acceptance evidence is specifically that a multi-account deployment resolves the correct authorized parameter value without embedding it in source.
C:This measurement validates a different AWS control: Use a CloudFormation stack policy and appropriate IAM permissions to restrict unintended updates to protected resources. It is most relevant where developers can deploy a reviewed CloudFormation application template but must not change protected shared networking resources. It would not establish whether the current safeguard is effective; the required acceptance evidence is specifically that a multi-account deployment resolves the correct authorized parameter value without embedding it in source.
D:This measurement validates a different AWS control: Add CDK synthesis, policy checks, diff review and change approval to the source-controlled deployment workflow. It is most relevant where a project uses AWS CDK source to define infrastructure but does not inspect the synthesized CloudFormation before production deployment. It would not establish whether the current safeguard is effective; the required acceptance evidence is specifically that a multi-account deployment resolves the correct authorized parameter value without embedding it in source.
Question 243
A team proposes this change: Use a restrictive cross-account IAM trust policy with the required external ID or workload identity conditions. The environment is: An external CI provider must deploy into an AWS account, but its role trust policy allows every account belonging to the provider. Which AWS engineering principle most directly supports the proposal?
- Attribute-driven policies can scale least privilege when trusted attributes are consistently enforced.
- Permission boundaries set an upper limit on identity permissions but do not independently grant access.
- Cross-account role trust must identify the intended caller and mitigate confused-deputy risk where applicable.
- Centralized managed secret rotation avoids distributing long-lived passwords in templates and bootstrap logs.
Explanation
Correct Answer
C:The central principle is that cross-account role trust must identify the intended caller and mitigate confused-deputy risk where applicable. It supports the decision to use a restrictive cross-account IAM trust policy with the required external ID or workload identity conditions. because the workload problem is: An external CI provider must deploy into an AWS account, but its role trust policy allows every account belonging to the provider. The consequence of ignoring the principle is: Another tenant of the external provider could assume the deployment role and change production resources. The design can be tested by confirming that a test authorized provider identity assumes the role while an unrelated customer identity is denied.
Incorrect Answers
A:This principle concerns the different situation in which application teams deploy dozens of services needing access to distinct tenant-specific S3 prefixes, and static role policies are manually copied for each tenant. It explains the alternative control to evaluate attribute-based access control with approved session or principal tags and controlled resource tags. For the present workload, an external CI provider must deploy into an AWS account, but its role trust policy allows every account belonging to the provider. the design rationale is instead that cross-account role trust must identify the intended caller and mitigate confused-deputy risk where applicable.
B:This principle concerns the different situation in which developers may create IAM roles for their applications but must never grant themselves organization administrator rights. It explains the alternative control to attach an appropriately scoped IAM permissions boundary to roles they create and restrict boundary removal. For the present workload, an external CI provider must deploy into an AWS account, but its role trust policy allows every account belonging to the provider. the design rationale is instead that cross-account role trust must identify the intended caller and mitigate confused-deputy risk where applicable.
D:This principle concerns the different situation in which a production database password is copied into EC2 user data and rotated manually by editing every application server. It explains the alternative control to store the credential in Secrets Manager with supported rotation and use authorized application retrieval. For the present workload, an external CI provider must deploy into an AWS account, but its role trust policy allows every account belonging to the provider. the design rationale is instead that cross-account role trust must identify the intended caller and mitigate confused-deputy risk where applicable.
Question 244
An AWS DevOps engineer must address this situation: A remediation Lambda invokes several dependent services, but transient failures cause duplicate deletions and no reliable execution history. Which implementation choice BEST meets the main operational requirement?
- Use AWS AppConfig deployment strategies and validators with monitors to roll out configuration changes gradually.
- Manage approved automation documents through version control, least-privilege execution and logged Systems Manager operations.
- Apply Systems Manager State Manager associations for supported recurring desired-state tasks and detect noncompliance.
- Use AWS Step Functions to orchestrate retries, state transitions, idempotent actions and failure paths.
Explanation
Correct Answer
D:This response directly addresses the stated requirement: Use AWS Step Functions to orchestrate retries, state transitions, idempotent actions and failure paths. The relevant technical mechanism is that stateful workflows make multi-step operational automation observable and allow controlled retries and compensation. Without this design, an automatic retry can repeat a destructive change or leave dependent systems inconsistent. An operational acceptance check should confirm that a forced transient error follows the documented retry policy and completes without duplicated side effects.
Incorrect Answers
A:This design is appropriate for another AWS operational requirement: A team deploys one feature-flag value to every application node instantly and causes a sudden spike in transaction failures. In that situation the corresponding response would be to use AWS AppConfig deployment strategies and validators with monitors to roll out configuration changes gradually. It does not directly mitigate the current failure mode, where an automatic retry can repeat a destructive change or leave dependent systems inconsistent. The current requirement instead calls for use AWS Step Functions to orchestrate retries, state transitions, idempotent actions and failure paths.
B:This design is appropriate for another AWS operational requirement: Operators collect manual troubleshooting commands into unversioned shell scripts on a shared bastion server. In that situation the corresponding response would be to manage approved automation documents through version control, least-privilege execution and logged Systems Manager operations. It does not directly mitigate the current failure mode, where an automatic retry can repeat a destructive change or leave dependent systems inconsistent. The current requirement instead calls for use AWS Step Functions to orchestrate retries, state transitions, idempotent actions and failure paths.
C:This design is appropriate for another AWS operational requirement: Production EC2 instances drift from their approved operating-system configuration after ad hoc troubleshooting. In that situation the corresponding response would be to apply Systems Manager State Manager associations for supported recurring desired-state tasks and detect noncompliance. It does not directly mitigate the current failure mode, where an automatic retry can repeat a destructive change or leave dependent systems inconsistent. The current requirement instead calls for use AWS Step Functions to orchestrate retries, state transitions, idempotent actions and failure paths.
Question 245
An AWS DevOps engineer must address this situation: Several VPCs require standardized outbound network inspection, but each workload account builds its own inconsistent firewall rule set. Which implementation choice BEST meets the main operational requirement?
- Design supported centrally governed AWS Network Firewall policy deployment with routing and logging validation.
- Use AWS Certificate Manager managed certificates and supported renewal validation for eligible endpoints.
- Use Amazon Macie or approved sensitive-data discovery workflows with centralized findings and remediation ownership.
- Enforce relevant S3 Block Public Access settings at an approved account or organization-controlled boundary.
Explanation
Correct Answer
A:This response directly addresses the stated requirement: Design supported centrally governed AWS Network Firewall policy deployment with routing and logging validation. The relevant technical mechanism is that network inspection must enforce centrally approved policy without leaving bypass routes in distributed VPC topologies. Without this design, a workload can evade required inspection or break connectivity because routing and firewall policy are inconsistent. An operational acceptance check should confirm that a controlled prohibited flow is blocked and logged from each intended VPC while authorized flows succeed.
Incorrect Answers
B:This design is appropriate for another AWS operational requirement: An HTTPS service repeatedly suffers certificate expiry because its team copies certificate files manually across load balancers. In that situation the corresponding response would be to use AWS Certificate Manager managed certificates and supported renewal validation for eligible endpoints. It does not directly mitigate the current failure mode, where a workload can evade required inspection or break connectivity because routing and firewall policy are inconsistent. The current requirement instead calls for design supported centrally governed AWS Network Firewall policy deployment with routing and logging validation.
C:This design is appropriate for another AWS operational requirement: An enterprise stores regulated identifiers in thousands of S3 buckets and cannot tell which new datasets contain personal information. In that situation the corresponding response would be to use Amazon Macie or approved sensitive-data discovery workflows with centralized findings and remediation ownership. It does not directly mitigate the current failure mode, where a workload can evade required inspection or break connectivity because routing and firewall policy are inconsistent. The current requirement instead calls for design supported centrally governed AWS Network Firewall policy deployment with routing and logging validation.
D:This design is appropriate for another AWS operational requirement: An organization wants to reduce accidental public S3 access even when a bucket owner adds an overly broad bucket policy. In that situation the corresponding response would be to enforce relevant S3 Block Public Access settings at an approved account or organization-controlled boundary. It does not directly mitigate the current failure mode, where a workload can evade required inspection or break connectivity because routing and firewall policy are inconsistent. The current requirement instead calls for design supported centrally governed AWS Network Firewall policy deployment with routing and logging validation.
Question 246
The team has omitted the measure to use suitable dimensional custom metrics or CloudWatch Contributor Insights rules for high-cardinality traffic patterns. It operates in this setting: An application uses Amazon SQS and one noisy producer dominates message backlog, but aggregate queue metrics do not identify top contributors. Which resulting risk is MOST direct?
- Alert fatigue may cause operators to disregard a genuinely abnormal production failure.
- Engineers may scale every consumer instead of fixing one anomalous high-volume producer.
- A critical business process can be broken even while hosts and root endpoints appear healthy.
- An incident can remain unresolved while engineers read logs that are unrelated to the failing transaction.
Explanation
Correct Answer
B:The omitted control leaves this direct failure exposure: Engineers may scale every consumer instead of fixing one anomalous high-volume producer. This follows from the specific situation: An application uses Amazon SQS and one noisy producer dominates message backlog, but aggregate queue metrics do not identify top contributors. The proposed safeguard would be to use suitable dimensional custom metrics or CloudWatch Contributor Insights rules for high-cardinality traffic patterns. The governing engineering reason is that operational analysis sometimes requires attributing load to distinct producers or dimensions, not just aggregate totals. A test would check that the dashboard identifies the abnormal producing identity and records the queue traffic concentration.
Incorrect Answers
A:This failure could arise in a related but different scenario: A nightly batch varies naturally with business volume and a hardcoded CloudWatch threshold creates constant false alerts. There the appropriate mitigation is to use CloudWatch anomaly detection or workload-normalized thresholds with suitable evaluation periods. The current environment is specifically an application uses Amazon SQS and one noisy producer dominates message backlog, but aggregate queue metrics do not identify top contributors. Its omitted safeguard creates the more direct consequence: Engineers may scale every consumer instead of fixing one anomalous high-volume producer.
C:This failure could arise in a related but different scenario: A public ordering endpoint returns 200 from an internal health check but its user checkout flow fails intermittently. There the appropriate mitigation is to use CloudWatch Synthetics canaries to exercise representative transaction steps and alert on failed end-user workflows. The current environment is specifically an application uses Amazon SQS and one noisy producer dominates message backlog, but aggregate queue metrics do not identify top contributors. Its omitted safeguard creates the more direct consequence: Engineers may scale every consumer instead of fixing one anomalous high-volume producer.
D:This failure could arise in a related but different scenario: A developer searches thousands of CloudWatch log streams manually to find one request correlation identifier. There the appropriate mitigation is to use CloudWatch Logs Insights queries with structured fields, narrow time windows and reusable filters. The current environment is specifically an application uses Amazon SQS and one noisy producer dominates message backlog, but aggregate queue metrics do not identify top contributors. Its omitted safeguard creates the more direct consequence: Engineers may scale every consumer instead of fixing one anomalous high-volume producer.
Question 247
The team has omitted the measure to bind deployments to the reviewed source revision and require artifact provenance checks before release. It operates in this setting: A release pipeline tests only the current branch head while allowing production deploys from arbitrary manually uploaded files. Which resulting risk is MOST direct?
- An undocumented console-only pipeline can be rebuilt with different permissions or skipped security stages.
- Pipeline logs or archived build specifications can expose credentials that authorize production package publication.
- A caller can replace an approved build with a binary unrelated to the pull request that passed review.
- An unapproved build might reach production despite policy requiring independent release authorization.
Explanation
Correct Answer
C:The omitted control leaves this direct failure exposure: A caller can replace an approved build with a binary unrelated to the pull request that passed review. This follows from the specific situation: A release pipeline tests only the current branch head while allowing production deploys from arbitrary manually uploaded files. The proposed safeguard would be to bind deployments to the reviewed source revision and require artifact provenance checks before release. The governing engineering reason is that source-to-artifact traceability is an essential chain of custody in a trustworthy delivery system. A test would check that release metadata proves the exact committed revision, build execution and signed or hashed artifact used in production.
Incorrect Answers
A:This failure could arise in a related but different scenario: A microservice team stores a CodePipeline definition only in the console, and rebuilding the production pipeline after an outage is manual. There the appropriate mitigation is to version and provision the pipeline and its supporting roles through reviewed infrastructure-as-code templates. The current environment is specifically a release pipeline tests only the current branch head while allowing production deploys from arbitrary manually uploaded files. Its omitted safeguard creates the more direct consequence: A caller can replace an approved build with a binary unrelated to the pull request that passed review.
B:This failure could arise in a related but different scenario: A pipeline downloads third-party package credentials from plaintext environment variables visible to build log readers. There the appropriate mitigation is to resolve protected build secrets at execution time through Secrets Manager or encrypted Systems Manager parameters with least-privilege roles. The current environment is specifically a release pipeline tests only the current branch head while allowing production deploys from arbitrary manually uploaded files. Its omitted safeguard creates the more direct consequence: A caller can replace an approved build with a binary unrelated to the pull request that passed review.
D:This failure could arise in a related but different scenario: A production release requires compliance approval, yet the pipeline advances automatically from integration tests to the production stage. There the appropriate mitigation is to insert an authorized CodePipeline manual approval action before production with bounded notification and review procedures. The current environment is specifically a release pipeline tests only the current branch head while allowing production deploys from arbitrary manually uploaded files. Its omitted safeguard creates the more direct consequence: A caller can replace an approved build with a binary unrelated to the pull request that passed review.
Question 248
An operations team deploys the following safeguard: Inspect CodeBuild phase status, logs, buildspec commands and service-role permissions to identify the failing step. Which observed result is the STRONGEST validation that the safeguard works?
- A controlled test shows the bottleneck and revised timeout or downstream handling reduces retries and message age.
- Service events isolate a placement or image-pull permission error and the corrected task starts healthy.
- The incident timeline identifies the actual dependency failure and a verified recovery condition rather than coincidence.
- A failed build is traced to a specific missing dependency or IAM denial and passes after the targeted fix.
Explanation
Correct Answer
D:The best verification result is: A failed build is traced to a specific missing dependency or IAM denial and passes after the targeted fix. It specifically demonstrates that the implemented safeguard to inspect CodeBuild phase status, logs, buildspec commands and service-role permissions to identify the failing step. is effective. This control matters where a CodeBuild action fails at the package stage but engineers immediately restart the entire pipeline without reading stage logs. Without suitable evidence, the outstanding exposure is that blind retries can waste capacity and conceal repeatable dependency or permission defects.
Incorrect Answers
A:This measurement validates a different AWS control: Correlate Lambda duration, timeout, invocation errors, dependency latency and queue age before modifying concurrency. It is most relevant where a Lambda event-processing function times out during downstream database calls, triggering retries and a growing SQS backlog. It would not establish whether the current safeguard is effective; the required acceptance evidence is specifically that a failed build is traced to a specific missing dependency or IAM denial and passes after the targeted fix.
B:This measurement validates a different AWS control: Inspect ECS service events, stopped task reasons, capacity and task execution role permissions. It is most relevant where an ECS service cannot reach desired count after release even though the task image exists in ECR. It would not establish whether the current safeguard is effective; the required acceptance evidence is specifically that a failed build is traced to a specific missing dependency or IAM denial and passes after the targeted fix.
C:This measurement validates a different AWS control: Correlate AWS Health, CloudWatch service metrics and deployment history to distinguish platform events from workload defects. It is most relevant where an application failure starts during an AWS service disruption, but the team treats every instance restart as the root cause. It would not establish whether the current safeguard is effective; the required acceptance evidence is specifically that a failed build is traced to a specific missing dependency or IAM denial and passes after the targeted fix.
Question 249
The team has omitted the measure to apply suitable pipeline execution controls and release-version checks before promoting a candidate artifact. It operates in this setting: Multiple feature branches share one deployment stage, and an older pipeline run occasionally overwrites the newest tested build. Which resulting risk is MOST direct?
- An older successful pipeline execution can roll production back accidentally without a controlled rollback decision.
- A caller can replace an approved build with a binary unrelated to the pull request that passed review.
- Pipeline logs or archived build specifications can expose credentials that authorize production package publication.
- Long-lived deployment keys can be reused to compromise production outside approved release activity.
Explanation
Correct Answer
A:The omitted control leaves this direct failure exposure: An older successful pipeline execution can roll production back accidentally without a controlled rollback decision. This follows from the specific situation: Multiple feature branches share one deployment stage, and an older pipeline run occasionally overwrites the newest tested build. The proposed safeguard would be to apply suitable pipeline execution controls and release-version checks before promoting a candidate artifact. The governing engineering reason is that concurrent delivery must preserve artifact-to-version ordering so a stale execution does not replace a newer approved revision. A test would check that parallel-trigger testing demonstrates that only the intended approved artifact version is promoted to production.
Incorrect Answers
B:This failure could arise in a related but different scenario: A release pipeline tests only the current branch head while allowing production deploys from arbitrary manually uploaded files. There the appropriate mitigation is to bind deployments to the reviewed source revision and require artifact provenance checks before release. The current environment is specifically multiple feature branches share one deployment stage, and an older pipeline run occasionally overwrites the newest tested build. Its omitted safeguard creates the more direct consequence: An older successful pipeline execution can roll production back accidentally without a controlled rollback decision.
C:This failure could arise in a related but different scenario: A pipeline downloads third-party package credentials from plaintext environment variables visible to build log readers. There the appropriate mitigation is to resolve protected build secrets at execution time through Secrets Manager or encrypted Systems Manager parameters with least-privilege roles. The current environment is specifically multiple feature branches share one deployment stage, and an older pipeline run occasionally overwrites the newest tested build. Its omitted safeguard creates the more direct consequence: An older successful pipeline execution can roll production back accidentally without a controlled rollback decision.
D:This failure could arise in a related but different scenario: A company deploys services into development and production AWS accounts, but the build account has permanent administrator credentials for both. There the appropriate mitigation is to use an AWS CodePipeline deployment role that assumes narrowly scoped target-account roles through IAM trust policies. The current environment is specifically multiple feature branches share one deployment stage, and an older pipeline run occasionally overwrites the newest tested build. Its omitted safeguard creates the more direct consequence: An older successful pipeline execution can roll production back accidentally without a controlled rollback decision.
Question 250
The team has omitted the measure to monitor Application Load Balancer error and target-response-time metrics alongside business-level availability indicators. It operates in this setting: An ALB-backed application has healthy EC2 hosts but clients experience increased 5xx responses and unacceptable response time. Which resulting risk is MOST direct?
- An incident can remain unresolved while engineers read logs that are unrelated to the failing transaction.
- Operators can miss an application-layer outage because host CPU and status checks remain nominal.
- Alert fatigue may cause operators to disregard a genuinely abnormal production failure.
- Engineers may scale every consumer instead of fixing one anomalous high-volume producer.
Explanation
Correct Answer
B:The omitted control leaves this direct failure exposure: Operators can miss an application-layer outage because host CPU and status checks remain nominal. This follows from the specific situation: An ALB-backed application has healthy EC2 hosts but clients experience increased 5xx responses and unacceptable response time. The proposed safeguard would be to monitor Application Load Balancer error and target-response-time metrics alongside business-level availability indicators. The governing engineering reason is that infrastructure health does not prove end-to-end application response quality under customer traffic. A test would check that synthetic requests and ALB metrics detect a simulated backend regression before the business SLO is breached.
Incorrect Answers
A:This failure could arise in a related but different scenario: A developer searches thousands of CloudWatch log streams manually to find one request correlation identifier. There the appropriate mitigation is to use CloudWatch Logs Insights queries with structured fields, narrow time windows and reusable filters. The current environment is specifically an ALB-backed application has healthy EC2 hosts but clients experience increased 5xx responses and unacceptable response time. Its omitted safeguard creates the more direct consequence: Operators can miss an application-layer outage because host CPU and status checks remain nominal.
C:This failure could arise in a related but different scenario: A nightly batch varies naturally with business volume and a hardcoded CloudWatch threshold creates constant false alerts. There the appropriate mitigation is to use CloudWatch anomaly detection or workload-normalized thresholds with suitable evaluation periods. The current environment is specifically an ALB-backed application has healthy EC2 hosts but clients experience increased 5xx responses and unacceptable response time. Its omitted safeguard creates the more direct consequence: Operators can miss an application-layer outage because host CPU and status checks remain nominal.
D:This failure could arise in a related but different scenario: An application uses Amazon SQS and one noisy producer dominates message backlog, but aggregate queue metrics do not identify top contributors. There the appropriate mitigation is to use suitable dimensional custom metrics or CloudWatch Contributor Insights rules for high-cardinality traffic patterns. The current environment is specifically an ALB-backed application has healthy EC2 hosts but clients experience increased 5xx responses and unacceptable response time. Its omitted safeguard creates the more direct consequence: Operators can miss an application-layer outage because host CPU and status checks remain nominal.