Budgets and cost anomaly detection in AWS - Commands & Configuration

Introduction

Managing cloud costs can be tricky because expenses can grow unexpectedly. Budgets help you set spending limits, and cost anomaly detection alerts you when costs change in unusual ways. This helps you avoid surprises and control your cloud spending.

When you want to set a monthly spending limit for your cloud resources to avoid overspending.

When you need alerts if your cloud costs suddenly increase due to unexpected usage.

When you want to track your cloud spending against a planned budget for a project.

When you want to find unusual cost patterns that might indicate errors or security issues.

When you want to receive notifications before your cloud costs exceed a certain threshold.

Commands

This command creates a monthly budget named 'MyMonthlyBudget' with a limit of 100 USD for the AWS account. It helps you track and control your monthly cloud spending.

Terminal

aws budgets create-budget --account-id 123456789012 --budget '{"BudgetName":"MyMonthlyBudget","BudgetLimit":{"Amount":"100","Unit":"USD"},"TimeUnit":"MONTHLY","BudgetType":"COST","CostFilters":{},"CostTypes":{"IncludeTax":true,"IncludeSubscription":true,"UseBlended":false},"TimePeriod":{"Start":"2024-06-01T00:00:00Z"}}'

Expected Output

{"Budget":{"BudgetName":"MyMonthlyBudget","BudgetLimit":{"Amount":"100","Unit":"USD"},"TimeUnit":"MONTHLY","BudgetType":"COST","CostFilters":{},"CostTypes":{"IncludeTax":true,"IncludeSubscription":true,"UseBlended":false},"TimePeriod":{"Start":"2024-06-01T00:00:00Z"}}}

→

--budget - Defines the budget details in JSON format

→

--account-id - Specifies the AWS account ID where the budget is created

This command lists all budgets for the specified AWS account so you can verify your budget was created correctly.

Terminal

aws budgets describe-budgets --account-id 123456789012

Expected Output

{"Budgets":[{"BudgetName":"MyMonthlyBudget","BudgetLimit":{"Amount":"100","Unit":"USD"},"TimeUnit":"MONTHLY","BudgetType":"COST"}]}

→

--account-id - Specifies the AWS account ID to list budgets for

This command lists your current cost anomaly detection subscriptions, which define who gets alerts when unusual cost changes happen.

Terminal

aws ce get-anomaly-subscriptions

Expected Output

{"AnomalySubscriptions":[]}

This command creates a cost anomaly detection subscription named 'MyCostAlerts' that sends daily email alerts to [e-mail] when anomalies are detected.

Terminal

aws ce create-anomaly-subscription --subscription '{"SubscriptionName":"MyCostAlerts","Frequency":"DAILY","Subscribers":[{"Type":"EMAIL","Address":"[e-mail]"}],"MonitorArnList":["arn:aws:ce::123456789012:anomalymonitor/abcdef12-3456-7890-abcd-ef1234567890"]}'

Expected Output

{"Subscription":{"SubscriptionName":"MyCostAlerts","Frequency":"DAILY","Subscribers":[{"Type":"EMAIL","Address":"[e-mail]"}],"MonitorArnList":["arn:aws:ce::123456789012:anomalymonitor/abcdef12-3456-7890-abcd-ef1234567890"]}}

→

--subscription - Defines the anomaly subscription details in JSON format

This command lists all anomaly monitors in your account, which watch for unusual cost patterns.

Terminal

aws ce list-anomaly-monitors

Expected Output

{"AnomalyMonitors":[{"MonitorArn":"arn:aws:ce::123456789012:anomalymonitor/abcdef12-3456-7890-abcd-ef1234567890","MonitorName":"DefaultMonitor"}]}

Key Concept

If you remember nothing else from this pattern, remember: setting budgets and enabling cost anomaly detection helps you catch unexpected cloud costs early and stay in control.

Common Mistakes

Not specifying the correct AWS account ID when creating or listing budgets.

The commands will fail or show no results because budgets are account-specific.

Always include the correct --account-id flag with your AWS account number.

Creating anomaly subscriptions without linking to a valid anomaly monitor ARN.

Without a monitor ARN, the subscription cannot track anomalies and will not send alerts.

First list or create anomaly monitors and use their ARNs when creating subscriptions.

Ignoring the budget time period start date or setting it incorrectly.

Budgets won't track costs properly if the time period is wrong or missing.

Set the TimePeriod Start date to the current or future date in ISO 8601 format.

Summary

Create a budget with aws budgets create-budget to set spending limits.

Verify budgets with aws budgets describe-budgets to check your settings.

Use aws ce list-anomaly-monitors and aws ce create-anomaly-subscription to set up cost anomaly detection alerts.

These tools help you monitor and control unexpected cloud cost changes.

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