TOC Cloud Computing & Infrastructure 3 — Questions and Answers
Question 1: Which cloud cost optimization strategy involves committing to a specific resource capacity for one or three years in exchange for significantly discounted pricing?
- Spot instances
- Reserved instances (Correct answer)
- On-demand pricing
- Savings plans with auto-scaling
Correct answer: Reserved instances
Reserved instances (or equivalent commitment-based pricing) offer discounts of up to 72% compared to on-demand rates in exchange for a usage commitment.
Question 2: What does the term 'serverless computing' mean in the context of cloud infrastructure?
- Computing that requires no servers at all
- A model where the provider automatically manages server provisioning and scaling per function invocation (Correct answer)
- Running virtual machines without an operating system
- Deploying containers without a container orchestration platform
Correct answer: A model where the provider automatically manages server provisioning and scaling per function invocation
Serverless abstracts all server management from the developer; the provider runs code in response to events and bills per execution, not per server hour.
Question 3: Which Infrastructure as Code (IaC) practice ensures that applying the same configuration multiple times produces the same infrastructure state?
- Immutability
- Idempotency (Correct answer)
- Versioning
- Declarative syntax
Correct answer: Idempotency
Idempotency guarantees that re-running the same IaC template converges to the desired state without creating duplicate or conflicting resources.
Question 4: A company needs to run a batch job that can tolerate interruptions and requires the lowest possible compute cost. Which option is most appropriate?
- On-demand instances
- Spot/preemptible instances (Correct answer)
- Dedicated hosts
- Reserved instances
Correct answer: Spot/preemptible instances
Spot (AWS) or preemptible (GCP) instances use spare cloud capacity at steep discounts but can be reclaimed by the provider with short notice, suiting fault-tolerant batch workloads.
Question 5: Which cloud database category is best suited for applications that require flexible schemas, horizontal scaling, and high write throughput for unstructured data?
- Relational (SQL) database
- NoSQL database (Correct answer)
- Data warehouse
- In-memory cache
Correct answer: NoSQL database
NoSQL databases (e.g., DynamoDB, MongoDB Atlas) support schema-less documents or key-value pairs and scale horizontally to handle massive write volumes.
Question 6: In cloud networking, what is the function of a Network Access Control List (NACL)?
- It encrypts traffic between subnets
- It provides stateless traffic filtering at the subnet boundary (Correct answer)
- It routes traffic between VPCs
- It monitors DNS resolution queries
Correct answer: It provides stateless traffic filtering at the subnet boundary
NACLs are stateless subnet-level firewalls that evaluate inbound and outbound rules independently for each packet passing through the subnet boundary.
Question 7: An organization wants to automatically replace unhealthy EC2 instances (or equivalent VMs) without manual intervention. Which cloud feature enables this?
- Snapshot scheduling
- Auto Scaling group with health checks (Correct answer)
- Elastic Load Balancer access logs
- CloudTrail audit logging
Correct answer: Auto Scaling group with health checks
Auto Scaling groups continuously monitor instance health and automatically terminate and replace unhealthy instances to maintain the desired capacity.
TOC Cloud Computing & Infrastructure 3
Which cloud cost optimization strategy involves committing to a specific resource capacity for one or three years in exchange for significantly discounted pricing?