Architecting on AWS Certification Architecting on AWS Certification Cost Optimization & Performance Efficiency 1 — Questions and Answers
Question 1: Which EC2 purchasing option offers up to 90% discount compared to On-Demand pricing in exchange for a flexible one- or three-year commitment to a specific instance family and Region?
- Spot Instances
- Reserved Instances
- Compute Savings Plans (Correct answer)
- Dedicated Hosts
Correct answer: Compute Savings Plans
Compute Savings Plans offer up to 66% savings (EC2 Instance Savings Plans up to 72%) by committing to a consistent compute usage ($/hour) for 1 or 3 years with flexibility across instance families, sizes, and Regions.
Question 2: Which S3 storage class is the most cost-effective for data that is accessed infrequently but must be retrieved within milliseconds?
- S3 Standard
- S3 Standard-Infrequent Access (Correct answer)
- S3 Glacier Instant Retrieval
- S3 One Zone-IA
Correct answer: S3 Standard-Infrequent Access
S3 Standard-IA offers lower storage costs than S3 Standard with millisecond retrieval, designed for data accessed less than once a month.
Question 3: An architect wants to right-size EC2 instances based on historical CPU and memory utilization. Which AWS service provides these recommendations?
- AWS Trusted Advisor
- AWS Compute Optimizer (Correct answer)
- AWS Cost Explorer
- Amazon Inspector
Correct answer: AWS Compute Optimizer
AWS Compute Optimizer analyzes CloudWatch metrics and machine learning models to recommend optimal EC2 instance types based on actual utilization.
Question 4: Which caching strategy reduces database read load by storing frequently queried results in memory, improving application throughput and reducing cost?
- Write-through caching with ElastiCache
- Read-through caching with ElastiCache
- Lazy-loading caching with ElastiCache
- All of the above are valid strategies (Correct answer)
Correct answer: All of the above are valid strategies
Write-through, read-through, and lazy-loading are all valid ElastiCache caching strategies that reduce database read pressure and improve performance.
Question 5: An application serves static assets globally. Which AWS service reduces latency for users worldwide by caching content at edge locations?
- AWS Global Accelerator
- Amazon CloudFront (Correct answer)
- Elastic Load Balancing
- Amazon API Gateway
Correct answer: Amazon CloudFront
Amazon CloudFront is a CDN that caches content at 400+ Points of Presence globally, reducing origin load and delivering assets from the nearest edge location.
Question 6: Which EC2 instance purchasing model is best suited for a batch processing workload that can tolerate interruptions in exchange for the lowest possible cost?
- On-Demand Instances
- Reserved Instances
- Spot Instances (Correct answer)
- Dedicated Instances
Correct answer: Spot Instances
EC2 Spot Instances use spare AWS capacity at up to 90% discount; they can be interrupted with a 2-minute warning, making them ideal for fault-tolerant batch jobs.
Architecting on AWS Certification Architecting on AWS Certification Cost Optimization & Performance Efficiency 1
Which EC2 purchasing option offers up to 90% discount compared to On-Demand pricing in exchange for a flexible one- or three-year commitment to a specific instance family and Region?