Budgets and cost anomaly detection in AWS - Practice Problems & Coding Challenges

Challenge - 5 Problems

🧠 Conceptual

intermediate

Understanding AWS Budgets Thresholds

You set an AWS budget with a threshold of 80% for your monthly cost. What happens when your actual cost reaches 85% of the budget?

A Your budget resets immediately to zero and starts a new cycle.

B You receive a notification alerting you that you have exceeded 80% of your budget.

C AWS automatically stops all running resources to prevent overspending.

D No action occurs until the budget reaches 100%.

💡 Hint

Think about what AWS Budgets are designed to do regarding notifications.

AWS Budgets send alerts when thresholds are crossed but do not stop resources or reset budgets automatically.

❓ service_behavior

intermediate

AWS Cost Anomaly Detection Behavior

You have enabled AWS Cost Anomaly Detection for your account. What is the primary behavior of this service?

A It automatically fixes cost anomalies by shutting down resources.

B It deletes unused resources to reduce costs.

C It detects unusual spending patterns and sends alerts for investigation.

D It increases your budget limits automatically when anomalies are detected.

💡 Hint

Consider what anomaly detection tools usually do in monitoring systems.

AWS Cost Anomaly Detection identifies unusual spending and notifies you; it does not take automatic corrective actions.

❓ Configuration

advanced

Configuring an AWS Budget with Multiple Thresholds

You want to create an AWS budget that sends notifications at 50%, 80%, and 100% of your monthly cost limit. Which JSON snippet correctly defines these thresholds in the AWS Budgets configuration?

A { "BudgetLimit": { "Amount": "1000", "Unit": "USD" }, "Notifications": [ { "Threshold": 50, "ComparisonOperator": "GREATER_THAN", "NotificationType": "ACTUAL" }, { "Threshold": 80, "ComparisonOperator": "GREATER_THAN", "NotificationType": "ACTUAL" }, { "Threshold": 100, "ComparisonOperator": "GREATER_THAN", "NotificationType": "ACTUAL" } ] }

B { "BudgetLimit": { "Amount": "1000", "Unit": "USD" }, "Notifications": [ { "Threshold": "50%", "ComparisonOperator": "GREATER_THAN", "NotificationType": "ACTUAL" }, { "Threshold": "80%", "ComparisonOperator": "GREATER_THAN", "NotificationType": "ACTUAL" }, { "Threshold": "100%", "ComparisonOperator": "GREATER_THAN", "NotificationType": "ACTUAL" } ] }

C { "BudgetLimit": { "Amount": "1000", "Unit": "USD" }, "Notifications": [ { "Threshold": 0.5, "ComparisonOperator": "GREATER_THAN", "NotificationType": "ACTUAL" }, { "Threshold": 0.8, "ComparisonOperator": "GREATER_THAN", "NotificationType": "ACTUAL" }, { "Threshold": 1.0, "ComparisonOperator": "GREATER_THAN", "NotificationType": "ACTUAL" } ] }

D { "BudgetLimit": { "Amount": "1000", "Unit": "USD" }, "Notifications": [ { "Threshold": 50, "ComparisonOperator": "LESS_THAN", "NotificationType": "ACTUAL" }, { "Threshold": 80, "ComparisonOperator": "LESS_THAN", "NotificationType": "ACTUAL" }, { "Threshold": 100, "ComparisonOperator": "LESS_THAN", "NotificationType": "ACTUAL" } ] }

💡 Hint

Threshold values should be numbers representing percentages without symbols, and comparison operator should detect when cost exceeds the threshold.

Thresholds are numeric percentages without percent signs. The comparison operator 'GREATER_THAN' triggers alerts when costs exceed thresholds.

❓ security

advanced

IAM Permissions for AWS Cost Anomaly Detection

Which IAM policy permission is required to allow a user to view AWS Cost Anomaly Detection findings but not modify them?

A "ce:DeleteAnomalySubscription"

B "ce:GetAnomalySubscriptions"

C "ce:UpdateAnomalySubscription"

D "ce:GetAnomalies"

💡 Hint

Think about permissions that allow reading data but not changing it.

"ce:GetAnomalies" allows viewing anomaly detection findings. Update or delete permissions allow modifications.

✅ Best Practice

expert

Optimizing Cost Anomaly Detection for Multiple Linked Accounts

You manage a consolidated billing family with multiple linked AWS accounts. To optimize cost anomaly detection across all accounts, which approach is best?

A Enable Cost Anomaly Detection only in the payer account to monitor all linked accounts centrally.

B Enable Cost Anomaly Detection separately in each linked account to get detailed alerts per account.

C Disable Cost Anomaly Detection and rely on manual cost reviews for linked accounts.

D Enable Cost Anomaly Detection in the payer account and also in each linked account for redundancy.

💡 Hint

Consider how consolidated billing and central monitoring work together.

Enabling Cost Anomaly Detection in the payer account allows centralized monitoring of all linked accounts efficiently.

Practice

1. What is the main purpose of AWS Budgets in cloud cost management?

easy

A. To automatically reduce cloud service prices

B. To create backups of billing data

C. To set spending limits and receive alerts when costs approach those limits

D. To monitor network traffic between AWS services

Solution

1. Step 1: Understand AWS Budgets function

   AWS Budgets allow users to set cost or usage limits and get alerts when those limits are near or exceeded.

2. Step 2: Compare options to this function

   Only To set spending limits and receive alerts when costs approach those limits describes setting limits and alerts, which matches AWS Budgets' purpose.

3. Final Answer:

   To set spending limits and receive alerts when costs approach those limits -> Option C

4. Quick Check:

   AWS Budgets = Spending limits and alerts [OK]

Hint: Budgets set limits and alert you before overspending [OK]

Common Mistakes:

• Thinking Budgets automatically reduce costs
• Confusing Budgets with backup or network tools
• Assuming Budgets monitor traffic instead of costs

2. Which of the following is the correct way to create a cost anomaly detection monitor using AWS CLI?

easy

A. aws ec2 create-anomaly-monitor --name MyMonitor

B. aws ce create-budget --name MyMonitor

C. aws ce start-anomaly-monitor --monitor-name MyMonitor

D. aws ce create-anomaly-monitor --monitor-name MyMonitor

Solution

1. Step 1: Identify correct AWS CLI command for anomaly monitor

   The AWS Cost Explorer (ce) service uses 'create-anomaly-monitor' to create anomaly monitors.

2. Step 2: Check options for correct syntax and service

   aws ce create-anomaly-monitor --monitor-name MyMonitor uses 'aws ce create-anomaly-monitor' with correct parameter '--monitor-name'. Others use wrong commands or services.

3. Final Answer:

   aws ce create-anomaly-monitor --monitor-name MyMonitor -> Option D

4. Quick Check:

   Correct CLI command for anomaly monitor creation = aws ce create-anomaly-monitor --monitor-name MyMonitor [OK]

Hint: Use 'aws ce create-anomaly-monitor' to create monitors [OK]

Common Mistakes:

• Using 'create-budget' instead of anomaly monitor command
• Using EC2 service commands for cost anomaly detection
• Incorrect parameter names like '--name' instead of '--monitor-name'

3. Given this AWS CLI command output snippet for a cost anomaly detection alert:

{
  "AnomalyId": "12345",
  "AnomalyScore": 85,
  "Service": "Amazon S3",
  "StartTime": "2024-05-01T00:00:00Z",
  "EndTime": "2024-05-01T23:59:59Z"
}

What does the AnomalyScore of 85 indicate?

medium

A. A high likelihood of cost anomaly

B. A moderate likelihood of cost anomaly

C. A low likelihood of cost anomaly

D. An error in anomaly detection

Solution

1. Step 1: Understand AnomalyScore meaning

   AnomalyScore ranges from 0 to 100; higher scores mean higher likelihood of unusual cost behavior.

2. Step 2: Interpret score 85

   Score 85 is close to 100, indicating a high likelihood of a cost anomaly.

3. Final Answer:

   A high likelihood of cost anomaly -> Option A

4. Quick Check:

   High AnomalyScore means high anomaly chance [OK]

Hint: Higher AnomalyScore means stronger anomaly signal [OK]

Common Mistakes:

• Thinking 85 is low or moderate score
• Confusing AnomalyScore with error codes
• Ignoring the score scale from 0 to 100

4. You created a budget with this AWS CLI command:

aws budgets create-budget --account-id 123456789012 --budget '{"BudgetName":"MyBudget","BudgetLimit":{"Amount":"100","Unit":"USD"},"TimeUnit":"MONTHLY","BudgetType":"COST"}'

But you receive an error. What is the most likely cause?

medium

A. Missing required parameter --notifications-with-subscribers

B. Incorrect JSON format for the budget parameter

C. Using --account-id instead of --account-id is invalid

D. BudgetLimit Amount must be an integer, not a string

Solution

1. Step 1: Check JSON format in --budget parameter

   The JSON string uses double quotes inside single quotes but may have formatting issues or missing escapes.

2. Step 2: Identify common CLI JSON errors

   Incorrect JSON formatting or missing escapes cause CLI errors; the command likely fails due to this.

3. Final Answer:

   Incorrect JSON format for the budget parameter -> Option B

4. Quick Check:

   JSON format errors cause CLI command failures [OK]

Hint: Validate JSON syntax carefully in CLI commands [OK]

Common Mistakes:

• Assuming missing notifications cause errors
• Confusing parameter names like --account-id
• Thinking Amount must be integer, but string is allowed

5. You want to monitor your AWS costs and get notified only when unusual spending spikes happen in specific services tagged with Environment=Production. Which combination of AWS features should you use?

hard

A. Create a cost anomaly detection monitor filtered by tag and set SNS notifications for alerts

B. Create a budget with a fixed limit and enable email alerts for all costs

C. Use AWS CloudTrail to track cost changes and send alerts via Lambda

D. Set up AWS Config rules to monitor cost and trigger alarms

Solution

1. Step 1: Identify feature for unusual spending spikes

   Cost anomaly detection monitors unusual cost spikes, suitable for this use case.

2. Step 2: Use tags to filter specific services and set notifications

   Filtering by tag 'Environment=Production' and using SNS notifications matches the requirement.

3. Final Answer:

   Create a cost anomaly detection monitor filtered by tag and set SNS notifications for alerts -> Option A

4. Quick Check:

   Cost anomaly + tag filter + SNS alerts = Create a cost anomaly detection monitor filtered by tag and set SNS notifications for alerts [OK]

Hint: Use anomaly detection with tag filters and SNS for targeted alerts [OK]

Common Mistakes:

• Using budgets which alert on fixed limits, not anomalies
• Confusing CloudTrail or Config with cost anomaly detection
• Ignoring tag filtering for specific environment costs