Architecting on AWS Certification Welding Procedures & Techniques 4 — Questions and Answers
Question 1: A company runs a batch job that processes data for 6 hours every night and can tolerate interruption. Which EC2 purchasing option minimizes cost?
- On-Demand Instances
- Reserved Instances (1-year term)
- Spot Instances (Correct answer)
- Dedicated Hosts
Correct answer: Spot Instances
Spot Instances offer up to 90% discount compared to On-Demand and are ideal for fault-tolerant batch workloads.
Question 2: Which S3 feature automatically moves objects to cheaper storage classes based on access patterns without predefined rules?
- S3 Lifecycle Policies
- S3 Intelligent-Tiering (Correct answer)
- S3 Replication
- S3 Object Lock
Correct answer: S3 Intelligent-Tiering
S3 Intelligent-Tiering monitors access and moves objects between tiers automatically, optimizing cost without retrieval fees.
Question 3: An architect wants to reduce NAT Gateway data-processing costs for EC2 instances that frequently access S3. What is the best solution?
- Move all EC2 instances to public subnets
- Create a VPC Gateway Endpoint for S3 (Correct answer)
- Enable S3 Transfer Acceleration
- Use an Application Load Balancer as a proxy
Correct answer: Create a VPC Gateway Endpoint for S3
A VPC Gateway Endpoint for S3 routes traffic over AWS's private network, bypassing the NAT Gateway and eliminating its cost.
Question 4: Which AWS Compute Optimizer metric indicates that an EC2 instance is over-provisioned and should be downsized?
- High network throughput utilization
- Consistently low CPU and memory utilization over the lookback period (Correct answer)
- Elevated disk I/O wait times
- High number of CPU credits earned
Correct answer: Consistently low CPU and memory utilization over the lookback period
Consistently low CPU and memory utilization signals that the instance is larger than the workload requires.
Question 5: A team wants to share a single Amazon RDS instance across multiple development environments to save cost. What is a key risk of this approach?
- RDS does not support multiple databases on one instance
- A noisy workload in one environment can degrade performance for all others (Correct answer)
- IAM roles cannot be scoped per database on a shared RDS instance
- Shared RDS instances do not support Multi-AZ
Correct answer: A noisy workload in one environment can degrade performance for all others
Shared compute resources mean one environment's heavy queries can starve CPU and I/O for all other environments.
Question 6: What AWS feature lets you set a monthly cost threshold and receive an email notification when projected spend exceeds it?
- AWS Cost Explorer anomaly detection
- AWS Budgets alert (Correct answer)
- Trusted Advisor cost check
- CloudWatch billing alarm
Correct answer: AWS Budgets alert
AWS Budgets allows you to set cost or usage thresholds and sends alerts via SNS or email when they are breached.
Question 7: Which pricing model offers the highest discount on AWS Lambda compared to paying per invocation at on-demand rates?
- Provisioned Concurrency flat rate
- Lambda Compute Savings Plans (Correct answer)
- Reserved Concurrency
- AWS Free Tier credits
Correct answer: Lambda Compute Savings Plans
Compute Savings Plans cover Lambda compute usage and provide discounts up to 17% compared to on-demand rates.
Architecting on AWS Certification Welding Procedures & Techniques 4
A company runs a batch job that processes data for 6 hours every night and can tolerate interruption.
Which EC2 purchasing option minimizes cost?