Task Statement 4.2: Design cost-optimized compute solutions.
📘AWS Certified Solutions Architect – (SAA-C03)
AWS provides a set of tools that help you monitor, analyze, and control costs. Understanding how and when to use each tool is critical for designing cost-optimized compute solutions.
The main tools are:
- AWS Cost Explorer
- AWS Budgets
- AWS Cost and Usage Report (CUR)
1. AWS Cost Explorer
What it is:
- A visual tool that shows your AWS spending over time.
- Lets you analyze costs, identify trends, and find which services are costing more.
Key Features:
- View costs by service (e.g., EC2, S3, Lambda)
- Group costs by account, region, or tags (like project, environment, or department)
- Forecast future costs based on historical trends
Use Case Example (IT environment):
- You run multiple EC2 instances for different projects.
- Cost Explorer helps you see which project’s EC2 instances are most expensive.
- You notice the development environment has many idle instances, so you can stop or downsize them to save money.
Exam Tip:
- AWS may ask: “Which tool would you use to visualize monthly EC2 costs by environment?” → Answer: Cost Explorer.
2. AWS Budgets
What it is:
- A tool that lets you set custom cost or usage limits and get alerts when thresholds are crossed.
Key Features:
- Create cost budgets (e.g., max $500/month for EC2)
- Create usage budgets (e.g., max 1000 GB of storage in S3)
- Set alerts via email or SNS if thresholds are exceeded
Use Case Example (IT environment):
- Your team has a QA environment in AWS that shouldn’t exceed $200 per month.
- You create a budget and set an alert.
- If spending reaches $180, your team gets notified and can take action, like stopping unused instances.
Exam Tip:
- AWS may ask: “Which service can notify you when a monthly cost exceeds a limit?” → Answer: AWS Budgets.
3. AWS Cost and Usage Report (CUR)
What it is:
- The most detailed cost reporting tool in AWS.
- Provides raw, granular data about every AWS service used.
Key Features:
- Delivered in CSV or Parquet format to S3
- Contains line-by-line details of all usage and costs
- Can be used for deep analysis or integrating with BI tools (like QuickSight or Athena)
Use Case Example (IT environment):
- Your organization wants a full breakdown of EC2, S3, and Lambda usage for accounting.
- CUR provides every single API call, instance, and storage usage, which can then be analyzed in Amazon Athena to identify high-cost resources or unused instances.
Exam Tip:
- AWS may ask: “Which tool provides detailed, line-item data of all AWS service usage?” → Answer: AWS Cost and Usage Report (CUR).
How These Tools Work Together for Cost-Optimized Compute
When designing cost-optimized compute solutions, you often combine all three tools:
- Identify high-cost resources → Use Cost Explorer
- Set spending limits or alerts → Use AWS Budgets
- Do detailed auditing and reporting → Use Cost and Usage Report (CUR)
IT Scenario Example:
- Your company runs EC2, Lambda, and RDS for multiple applications.
- You use Cost Explorer to find EC2 instances that are over-provisioned.
- You set budgets for each environment (dev, QA, production) to avoid overspending.
- You use CUR to generate a monthly report showing exactly which instances were used, for how long, and at what cost.
- This helps in rightsizing compute resources, like switching from m5.large to t3.medium if possible, saving costs.
Key Points to Remember for the Exam
| Tool | Purpose | Example Question Scenario |
|---|---|---|
| Cost Explorer | Analyze and visualize costs | “See trends of EC2 usage per month” |
| AWS Budgets | Set alerts and limits for costs or usage | “Notify if spending exceeds $500” |
| Cost and Usage Report (CUR) | Detailed line-item report for auditing or BI | “Detailed report of every S3 PUT, GET, and Lambda invocation” |
- All tools complement each other.
- Cost Explorer is for analysis and trends, Budgets is for alerts, CUR is for deep, detailed reports.
- Tagging resources is important to make reports meaningful (like tagging EC2 instances by project or environment).
✅ Quick Tip:
For the exam, focus on when to use each tool and what problem it solves. AWS often frames questions around visualization, alerts, and detailed reporting.
