SOA-C02 Question 76
Select 3Your company runs a high-traffic web application on an Amazon EC2 instance with an auto-scaling group. During a traffic spike, the application becomes unresponsive. A junior administrator suggests upgrading the EC2 instance type to a larger instance, while another suggests increasing the number of instances in the auto-scaling group. Which of the following statements correctly differentiate horizontal and vertical scaling in this scenario?
- A
Horizontal scaling involves adding more EC2 instances to the auto-scaling group to handle increased traffic.
- B
Vertical scaling involves upgrading the EC2 instance type to a larger instance for better performance.
- C
Horizontal scaling is always more cost-effective than vertical scaling.
- D
Vertical scaling requires changes to the application to distribute the workload across multiple resources.
- E
Horizontal scaling is typically used for stateless applications that can easily distribute traffic across multiple instances.
Show answer and explanation
Correct answers: A, B, E
Explanation
Horizontal scaling (scaling out) involves adding more resources, such as EC2 instances, to handle increased traffic and is often used for stateless applications. Vertical scaling (scaling up) involves upgrading the hardware of an existing instance to better handle demand. Both approaches have their pros and cons, but understanding the differences is critical for implementing the right solution in a given scenario.
- A. Correct.
Correct. Horizontal scaling involves adding more instances to distribute the traffic load across multiple resources.
- B. Correct.
Correct. Vertical scaling involves upgrading the instance type to a larger one to provide more CPU, memory, or network performance for the application.
- C. Incorrect.
Incorrect. Horizontal scaling is not always more cost-effective; it depends on the application's requirements, workload, and scaling needs.
- D. Incorrect.
Incorrect. Vertical scaling does not require changes to the application; it simply upgrades the existing instance's capacity.
- E. Correct.
Correct. Horizontal scaling is better suited for stateless applications, as they can easily distribute the workload across multiple instances without maintaining session or state information.