Use AWS Cost Anomaly Detection with an AWS services monitor to pinpoint waste

SAP-C02 By islever Editorial Last updated

Determine cost optimization and visibility strategies. Identify opportunities for cost optimizations.

Short answer

D Create an AWS services monitor in Cost Anomaly Detection and subscribe the operations team to daily cost summaries with a cost variance threshold.

Question

A company used AWS CloudFormation to create all new infrastructure in its AWS member accounts. The resources rarely change and are properly sized for the expected load. The monthly AWS bill is consistent. Occasionally, a developer creates a new resource for testing and forgets to remove the resource when the test is complete. Most of these tests last a few days before the resources are no longer needed. The company wants to automate the process of finding unused resources. A solutions architect needs to design a solution that determines whether the cost in the AWS bill is increasing. The solution must help identify resources that cause an increase in cost and must automatically notify the company's operations team. Which solution will meet these requirements?
  1. Turn on billing alerts. Use AWS Cost Explorer to determine the costs for the past month. Create an Amazon CloudWatch alarm for total estimated charges. Specify a cost threshold that is higher than the costs that Cost Explorer determined. Add a notification to alert the operations team if the alarm threshold is breached.
  2. Turn on billing alerts. Use AWS Cost Explorer to determine the average monthly costs for the past 3 months. Create an Amazon CloudWatch alarm for total estimated charges. Specify a cost threshold that is higher than the costs that Cost Explorer determined. Add a notification to alert the operations team if the alarm threshold is breached.
  3. Use AWS Cost Anomaly Detection to create a cost monitor that has a monitor type of Linked account. Create a subscription to send daily AWS cost summaries to the operations team. Specify a threshold for cost variance.
  4. Use AWS Cost Anomaly Detection to create a cost monitor that has a monitor type of AWS services. Create a subscription to send daily AWS cost summaries to the operations team. Specify a threshold for cost variance. Correct Answer

Key Takeaways

Cost Anomaly Detection with an AWS services monitor isolates the anomalous service in a linked account, while a Linked account monitor only reports that an account's total moved and leaves the investigation to the team.

A developer occasionally leaves test resources running, so the bill creeps up unpredictably. The operations team must be told which spend rose and roughly by how much, without manually reading a monthly Cost Explorer report.

Common mistake: Choosing a Linked account monitor. It flags anomalous totals per account but does not name the service responsible, so it cannot identify the specific unused resources causing the increase.

Expert Analysis

Why the Answer Is Correct

AWS Cost Anomaly Detection monitors spend and, with an AWS services monitor type, analyses each service inside a linked account. When a forgotten test resource drives spend up, the monitor names the service and the threshold for cost variance filters out normal noise. A daily email subscription alerts the operations team automatically, which is exactly the notification requirement.

Why the Other Options Are Wrong

A and B: CloudWatch billing alarms on total estimated charges only fire when an aggregate threshold is crossed and cannot attribute the increase to a service or resource, and a threshold set above the historical average cannot detect a small but real leak. C: A Linked account monitor reports the anomalous account total without identifying the service.

Community Comment Notes

The 80 to 20 vote split was driven by the Linked account versus AWS services distinction. Commenters confirmed that a Linked account monitor answers which account moved, not which service, so it fails the requirement to identify the resources causing the increase.

Official Reference

https://docs.aws.amazon.com/cost-management/latest/userguide/cost-anomaly-detection.html

This link opens the official vendor documentation in a new tab.

Community Votes

D
80%
C
20%

80% of anonymous learners picked answer D. Votes are pick records left by other test-takers — they are not the verified answer.

Discussion 18 contributions

Compiled from public community threads and reader submissions, lightly edited for clarity. Handles and vote tallies are shown as recorded, and comments reflect the views of individual contributors.

From public community threads 18

  1. titi_r 👍 13 Answered D
    Ans "D" - more granular. Q: What is the difference between a linked account monitor in a payer account, and a services monitor in a linked account? A linked account monitor in a payer account will monitor the spend of all services, in total, for that linked account. A services monitor in a linked account will monitor the individual spend for each service for that linked account. For example, if there is a spike in S3 spending, but a dip in EC2 spending of the same amount (net neutral change), the linked account monitor in the payer account will not detect this because it is monitoring the total account spend across all services. However, the services monitor in the linked account would detect the S3 spike since it is monitoring each service spend individually.
  2. Dgix 👍 5 Answered D
    On reconsideration: D, as it deals with the individual services in an account, not just the total cost.
  3. pangchn 👍 4 Answered D
    D seems more granular to detect thich resource in which account generated the bill. C seem only care about the balance across accounts as below "linked account monitor can track up to 10 different linked accounts. A linked account monitor tracks spending aggregated across all of the designated linked accounts. For example, if a linked account monitor tracks Account A and Account B, and then Account A’s usage spikes while Account B’s usage dips by the same amount, there will be no anomaly detected because it is a net neutral change" https://aws.amazon.com/aws-cost-management/aws-cost-anomaly-detection/faqs/
  4. CMMC 👍 3 Answered C
    AWS Cost Anomaly Detection is specifically designed to detect unusual spending patterns or anomalies in AWS costs. By creating a cost monitor with a monitor type of Linked account, the solution focuses on the entire AWS account's spending, which is suitable for identifying unexpected increases in costs due to unused resources. Setting a threshold for cost variance allows the operations team to receive notifications when there are significant deviations from the expected spending pattern.
  5. pangchn 👍 3 Answered D
    vote D here A linked account monitor can track up to 10 different linked accounts. A linked account monitor tracks spending aggregated across all of the designated linked accounts. For example, if a linked account monitor tracks Account A and Account B, and then Account A’s usage spikes while Account B’s usage dips by the same amount, there will be no anomaly detected because it is a net neutral change. ref https://aws.amazon.com/aws-cost-management/aws-cost-anomaly-detection/faqs/
Show 13 more comments
  1. gustori99 👍 3 Answered D
    Answer is between C and D. Choosing monitor type AWS Services is more appropriate than Linked Account because the monitor AWS Services monitors all resources including resources from all member accounts of the organization. Also with Linked Accounts you can only add max 10 accounts to a single monitor. Therefore answer D is correct.
  2. thotwielder 👍 3 Answered D
    c: identify abnormal accounts d: identify abnormal service, which is desired.
  3. Dgix 👍 2 Answered C
    C is the correct answer. D is not granular enough.
  4. 0b43291 👍 1 Answered D
    By creating a cost monitor with the monitor type set to "AWS services," Cost Anomaly Detection will monitor the individual spend for each service within the linked account. This would allow the company to detect anomalies or spikes in spending for specific services, even if there is a corresponding decrease in another service that offsets the overall account spend. Given the requirement to identify resources that cause an increase in cost, monitoring at the service level would provide more granular visibility and enable the company to pinpoint the specific services or resources responsible for cost increases. Creating a subscription to send daily AWS cost summaries to the operations team and specifying a threshold for cost variance would ensure that the team is notified when the cost increase for any individual service exceeds the defined threshold.
  5. AzureDP900 👍 1
    Option D: Using AWS Cost Anomaly Detection to create a cost monitor with a monitor type of AWS services: This option focuses on individual AWS services, making it easier to identify which specific resource is causing the increase in costs. This approach provides detailed insights into each service's contribution to your company's overall expenses, making it easier to pinpoint the issue and take corrective action. Considering all options, Option D seems to be the most suitable solution for identifying resources that cause an increase in costs and automatically notifying the company's operations team. This approach offers real-time monitoring, detailed insights into individual services' contributions, and automatic notifications when costs exceed specified thresholds.
  6. TonytheTiger 👍 1 Answered C
    Option C and Not Option D : Linked account - This monitor evaluates the total spend of an individual, or group of, member accounts. If your Organizations need to segment spend by team, product, services, or environment, this monitor is useful. The maximum number of member accounts that you can select for each monitor is 10. https://docs.aws.amazon.com/cost-management/latest/userguide/getting-started-ad.html#monitor-type-def
  7. tushar321 👍 1
    D. An AWS service monitor will be applicable to all customers since it tracks and detects anomalies across any service they deploy https://aws.amazon.com/aws-cost-management/aws-cost-anomaly-detection/faqs/#:~:text=An%20AWS%20service%20monitor%20will%20be%20applicable%20to%20all%20customers%20since%20it%20tracks%20and%20detects%20anomalies%20across%20any%20service%20they%20deploy
  8. salekali01 👍 1 Answered C
    Monitoring at the AWS service level can be useful, but it may not provide the same comprehensive view of costs across accounts as the linked account monitor type. Therefore, option C provides a more adaptive and comprehensive solution for detecting cost anomalies and notifying the operations team.
  9. JoeTromundo 👍 1 Answered D
    For those who think the correct answer is C: A Linked Account monitor detects anomalies at the account level. While it can identify which account has unusual spending, it does NOT pinpoint the SPECIFIC SERVICES or RESOURCES causing the increase, as the statement requires.
  10. VerRi 👍 1 Answered C
    I will go with C because the scenario says, "to create all new infrastructure in its AWS member accounts."
  11. kgpoj 👍 1 Answered D
    "identify resources that cause an increase in cost " D for sure
  12. steed47 👍 1 Answered C
    C more granular
  13. seetpt 👍 1 Answered D
    D for me

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