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SAP-C03 · LESSON 3

Cost-Optimized Architecture Design15% · 4 topics

Separate steady and variable demand when choosing commitments, scaling and storage tiers. Compare NAT, endpoint and inter-Region transfer costs. For AI, measure tokens, latency and quality, assess batching and authorization-aware caching, and attribute usage to departments.

3.1Optimize cost from usage and constraints

Concept

Separate steady and variable demand when choosing commitments, scaling and storage tiers. Compare NAT, endpoint and inter-Region transfer costs. For AI, measure tokens, latency and quality, assess batching and authorization-aware caching, and attribute usage to departments.

How it works / steps

  1. Write requirements and success criteria first.
  2. Use a test environment and retain success and failure evidence.
  3. Review the result, then check your decisions with domain practice below.

Workplace example

Hold performance targets constant and compare usage and monthly estimates.

Common confusions and exam tips

Mini quiz

Q1. Cost Anomaly Detection reported a sudden increase in data transfer costs for an account. What is the most appropriate next step?

  1. Judge the alert a false positive and disable Cost Anomaly Detection monitoring from now on
  2. Without confirming the cause, stop all EC2 and RDS in that account to halt the cost increase
  3. Wait for next month's invoice, then consult Accounting and start investigating
  4. Filter that account's usage types and resources in Cost Explorer to identify the cause
Show answer and explanation

Answer: D Filter that account's usage types and resources in Cost Explorer to identify the cause

First identify which usage type and resources increased. Misconfigurations (replication loops, unintended exposure and so on) are sometimes the cause.

Q2. Which statement about Savings Plans is incorrect?

  1. Usage exceeding the committed hourly amount is also all billed at discounted prices
  2. Compute Savings Plans apply to EC2, Fargate and Lambda usage regardless of instance family or Region
  3. Discounted prices apply to usage up to the committed amount
  4. You commit to an hourly spend for a 1- or 3-year term
Show answer and explanation

Answer: A Usage exceeding the committed hourly amount is also all billed at discounted prices

Usage beyond the committed amount is billed at regular On-Demand rates.

Reference links

3.2Determine cost optimization and visibility strategies

Concept

For organization-wide cost visibility, use consolidated billing, cost allocation tags (standardized with tag policies), AWS Cost Categories (classifying costs by rules such as department or product), and the Cost and Usage Report (CUR) analyzed with Athena and QuickSight. Savings Plans and Reserved Instance discounts are shared in the organization, and AWS Budgets and Cost Anomaly Detection detect overruns and anomalies.

How it works / steps

  1. Define tag standards (cost-center, env and so on) and enforce them with tag policies
  2. Define per-department costs from accounts and tags with Cost Categories
  3. Export CUR to S3 and analyze it with Athena and QuickSight
  4. Purchase Savings Plans in the management account and share them in the organization (restrict sharing if needed)
  5. Notify with Budgets and Cost Anomaly Detection

Workplace example

To allocate AWS costs to each business unit monthly, define Cost Categories with account and tag rules and share a QuickSight dashboard with each division head.

Common confusions and exam tips

Mini quiz

Q1. You are choosing how to visualize and manage costs. You want to group costs by business unit using rules on combinations of accounts and tags, for monthly internal chargeback. Which is the most suitable?

  1. AWS Cost Categories
  2. AWS Cost Anomaly Detection
  3. AWS Pricing Calculator
  4. AWS Budgets
Show answer and explanation

Answer: A AWS Cost Categories

Cost Categories group costs into your own categories using rules on accounts, tags, services and so on, usable in Cost Explorer and billing data.

Reference links

3.3Determine a cost optimization strategy

Concept

In new systems, reduce operating costs by adopting managed and serverless services, and build purchase options (Savings Plans, Spot), storage classes, low-data-transfer architectures and right-sizing into the design stage. Compare cost estimates per requirement so you can explain the trade-offs.

How it works / steps

  1. Determine the minimum configuration the requirements need
  2. Reduce operational effort and idle costs with managed and serverless services
  3. Use Savings Plans for steady parts and Spot for interruptible processing
  4. Review data transfer paths (NAT, cross-Region)
  5. Set up tags and budgets from the start

Workplace example

Design an internal request system used only a few times a month as serverless with API Gateway, Lambda and DynamoDB instead of always-on EC2, cutting costs by 90%.

Common confusions and exam tips

Mini quiz

Q1. You are choosing a compute purchase option. EC2, Fargate and Lambda incur steady monthly costs, and you may change instance families or Regions in the future. Which is the most suitable?

  1. Compute Savings Plans
  2. On-Demand Instances
  3. Spot Instances
  4. EC2 Instance Savings Plans
Show answer and explanation

Answer: A Compute Savings Plans

Compute Savings Plans apply discounts to EC2, Fargate and Lambda usage regardless of instance family, Region or OS.

Q2. You are choosing how to visualize and manage costs. You want to email department heads when each department's forecast for this month is about to exceed its budget. Which is the most suitable?

  1. AWS Cost Categories
  2. AWS Cost Anomaly Detection
  3. AWS Pricing Calculator
  4. AWS Budgets
Show answer and explanation

Answer: D AWS Budgets

AWS Budgets notifies when actual or forecast costs exceed budget thresholds, and actions can also automate measures such as restricting permissions.

Reference links

3.4Identify opportunities for cost optimization

Concept

Find cost reduction opportunities in existing environments with Compute Optimizer (right-sizing EC2, EBS, Lambda), S3 Storage Lens (storage usage and lifecycle recommendations), Cost Explorer Savings Plans recommendations and Trusted Advisor (idle resources). Unused Elastic IPs, EBS volumes, snapshots and previous-generation instances are also targets.

How it works / steps

  1. Identify the highest-cost services and accounts with Cost Explorer
  2. Downsize based on Compute Optimizer recommendations
  3. Find buckets without lifecycle configuration with Storage Lens
  4. Review Savings Plans recommendations and utilization before purchasing
  5. Build a mechanism to regularly delete unused resources

Workplace example

Storage Lens finds a bucket with 50 TB of incomplete multipart uploads; delete them with a lifecycle rule to lower the monthly bill.

Common confusions and exam tips

Mini quiz

Q1. You want to review S3 usage across the organization and find, across the board, which buckets have no lifecycle configured and are accumulating incomplete multipart uploads. Which method is most appropriate?

  1. Have each account's staff export object lists of all buckets as CSV every month and send them
  2. Enable S3 Storage Lens organization-wide and review per-bucket metrics and recommendations in the dashboard
  3. Enable S3 access logs on all buckets and delete buckets in order of log volume
  4. Consolidate all buckets into one account and set all storage classes to Standard
Show answer and explanation

Answer: B Enable S3 Storage Lens organization-wide and review per-bucket metrics and recommendations in the dashboard

S3 Storage Lens aggregates storage usage and activity across the organization and shows improvements for cost and data protection.

Q2. You are choosing a compute purchase option. You have decided to keep using a specific instance family in the Tokyo Region for 3 years and want the largest possible discount. Which is the most suitable?

  1. Compute Savings Plans
  2. On-Demand Instances
  3. Spot Instances
  4. EC2 Instance Savings Plans
Show answer and explanation

Answer: D EC2 Instance Savings Plans

EC2 Instance Savings Plans fix the Region and family in exchange for a larger discount than Compute Savings Plans (size and OS can change).

Reference links

Lessons are written by this site based on public information and do not guarantee exam content. Product specifications change, so check the latest information at the reference links.

Notes (unofficial, original questions, no pass guarantee)