Cost Optimization — AWS Cloud Practitioner (CLF-C02)
Utilization pattern determines the right commitment tier
Savings Plans offer flexible compute discounts across instance families and regions. Reserved Instances offer deeper discounts tied to a specific instance type and region. Spot Instances provide steep discounts for interruption-tolerant workloads. CLF-C02 signals the right answer through workload description — "steady-state, predictable" points to Reserved Instances or Savings Plans; "batch, fault-tolerant" points to Spot. Cost Explorer surfaces utilization data to inform that choice.
What This Pattern Tests
The exam presents a running workload and asks you to reduce costs. Spot Instances save 60-90% but require fault tolerance. Savings Plans save 20-40% with 1-year or 3-year commitment to a consistent compute spend (flexible across instance families with Compute Savings Plans). Reserved Instances save similarly but lock to specific instance types and regions. Graviton (ARM) instances offer ~20% better price-performance than x86. The trap is recommending Spot for a latency-sensitive web API (interruptions cause errors) or Reserved Instances for a workload that runs 2 hours per day (break-even requires ~40% utilization).
Decision Axis
Workload characteristics (fault tolerance, utilization pattern, flexibility needs) determine which pricing model applies — not just the discount percentage.
Associated Traps
More Top Traps on This Exam
Decision Rules
Which AWS service provides utilization-based rightsizing recommendations for EC2 instances, versus a service that offers general best-practice checks or retrospective spending visibility?
When persistent low utilization signals over-provisioned compute after migration, choose the service that produces machine-learning-backed instance rightsizing recommendations (AWS Compute Optimizer) rather than services that display historical cost trends (AWS Cost Explorer), alert on budget thresholds (AWS Budgets), or estimate future pricing (AWS Pricing Calculator).
Does the scenario require proactive threshold-based alerting on variable spend (AWS Budgets) or reactive historical cost analysis and forecasting (AWS Cost Explorer)?
Domain Coverage
Difficulty Breakdown