N10-009 Question 43
Single answerScalability, Elasticity, MultitenancyA company is migrating its customer-facing web application from an on-premises data center to a public cloud provider. The application experiences large traffic spikes during monthly promotions, but usage returns to normal afterward. The security team also requires that the company's data and network traffic remain logically separated from other customers using the same cloud platform. Which solution BEST meets these requirements while controlling costs?
- A
Deploy the application on a fixed number of large virtual machines in a single subnet to guarantee performance during promotions
- B
Use auto-scaling resources that increase and decrease capacity based on demand, and place the application in the company's own logically isolated virtual network within the provider's shared environment
- C
Move the application to a dedicated physical server in the cloud so the company can take advantage of multitenancy without sharing infrastructure
- D
Use a peer-to-peer hosting model so client devices can contribute resources during promotions, reducing the need for elasticity
Show answer and explanation
Correct answer: B
Explanation
The best answer is to use elastic cloud resources with logical isolation. In Network+ terms, scalability refers to the ability to support growth, while elasticity refers more specifically to automatically or dynamically adjusting resource allocation up or down based on current demand. This is ideal for workloads with predictable spikes, such as monthly promotions. Multitenancy means multiple customers share the same provider infrastructure, but each tenant's data and network environment should remain logically separated through virtualized controls such as isolated virtual networks, security groups, routing boundaries, and tenant-specific policies. Major cloud providers document these patterns as standard design principles: scale based on demand, avoid overprovisioning, and use logically isolated tenant environments within shared infrastructure. This approach best satisfies performance, cost efficiency, and separation requirements.
- A. Incorrect.
This is incorrect because a fixed number of large virtual machines addresses neither elasticity nor cost control effectively. Overprovisioning for peak demand means the company pays for unused capacity during normal periods. A single subnet also does not specifically address logical isolation from other tenants beyond basic placement.
- B. Correct.
This is correct because elasticity allows cloud resources to scale out during promotion-driven traffic spikes and scale back in when demand falls, which aligns with cost-efficient cloud design. Using a logically isolated virtual network, such as a tenant-specific virtual private cloud or equivalent provider construct, supports multitenant cloud usage while keeping the company's traffic and resources separated from those of other customers. This reflects common cloud networking best practices.
- C. Incorrect.
This is incorrect because a dedicated physical server reduces or eliminates the shared-resource benefits typically associated with multitenant public cloud environments and is often more expensive than needed for this scenario. The statement is also internally flawed: dedicated physical hardware is generally used to avoid sharing infrastructure, not to take advantage of multitenancy.
- D. Incorrect.
This is incorrect because peer-to-peer hosting is not an appropriate enterprise solution for a customer-facing cloud web application that must meet security, performance, and isolation requirements. It does not provide the managed elasticity or tenant isolation expected in a public cloud deployment.