6.13.2: Review Questions

Review Questions

Multiple Choice

1. In the layered cloud architecture, which layer does PaaS correspond to?
   • a) Physical layer
   • b) Infrastructure/virtualization layer
   • c) Platform/middleware layer
   • d) Application layer
2. Which of the following is NOT an extended cloud service model?
   • a) FaaS
   • b) CaaS
   • c) NaaS (Network as a Service)
   • d) All of the above are extended models
3. At which OSI layer do cloud security groups and network load balancers primarily operate?
   • a) Layer 1 (Physical)
   • b) Layer 3 (Network) and Layer 4 (Transport)
   • c) Layer 5 (Session)
   • d) Layer 7 (Application)

Short Answer

4. Create a comparison of IaaS, PaaS, and SaaS showing what the provider manages versus what the customer manages for each model. Include at least five stack components (hardware, OS, middleware, application, data).
5. Explain how a serverless architecture "compresses" the traditional layered view. Which layers does the cloud provider manage, and what does the developer focus on?
6. Describe the three-tier architecture pattern (presentation, business logic, data). How would you implement each tier using cloud services from either AWS or GCP?
7. Explain how the OSI model remains relevant in cloud computing. Give an example of a cloud service or concept that operates at Layer 3, Layer 4, and Layer 7.

True/False

8. True or False: In a SaaS model, the customer is responsible for managing the operating system and runtime environment.
9. True or False: DBaaS eliminates the need for database administrators entirely because the cloud provider handles everything.
10. True or False: Microservices primarily reside at the application layer but leverage services across multiple layers of the cloud stack.

Answer Key:

1. c
2. d (all are extended models — trick question; NaaS is also valid)
3. b
4. Table should show: Physical HW (provider for all), OS (customer IaaS, provider PaaS/SaaS), Middleware/Runtime (customer IaaS, provider PaaS/SaaS), Application (customer IaaS/PaaS, provider SaaS), Data (customer all three, but SaaS provider manages underlying DB).
5. Serverless hides layers 1-6 (physical through platform). Provider manages all infrastructure. Developer only provides application logic (Layer 7). The FaaS runtime is effectively a specialized PaaS.
6. Presentation: S3 + CloudFront (static), or App Engine frontend. Business logic: Lambda functions or ECS containers behind API Gateway. Data: RDS or Cloud SQL for relational, DynamoDB or Firestore for NoSQL.
7. Layer 3: VPC, IP subnets, routing tables. Layer 4: Security groups (port-based rules), network load balancers. Layer 7: Application load balancers (URL-based routing), API gateways, WAFs.
8. False
9. False (customer still designs schemas, writes queries, manages data access)
10. True