AWS (Amazon Web Services) Certification Practice Exam

Which of the following describes the concept of scaling in/out?

1. Adding or removing physical servers

2. Increasing or decreasing the power of virtual machines

3. Adding or removing virtual machines in resources

4. Expanding physical data center space

The correct answer is: Adding or removing virtual machines in resources

The concept of scaling in/out primarily refers to the ability to add or remove virtual machines within a cloud infrastructure. This is a fundamental aspect of cloud computing, allowing organizations to adjust their resources based on current demand. When demand increases, additional virtual machines can be deployed quickly to handle the load, which is known as scaling out. Conversely, when demand decreases, unnecessary virtual machines can be removed to save on costs, referred to as scaling in. This flexibility enables businesses to optimize their resource usage while ensuring they meet performance requirements, all without the need for significant upfront investments in physical hardware or data center space. The other concepts, while related to scaling, do not accurately capture the essence of scaling in/out. Adding or removing physical servers or expanding physical data center space involves more permanent, capital-intensive changes and does not provide the same dynamic response to workload fluctuations. Increasing or decreasing the power of virtual machines pertains to vertical scaling, which modifies the existing instances rather than adjusting the quantity of instances available to meet demand.