AWS Certified Solutions Architect – Professional — Question 587

A sys admin is maintaining an application on AWS. The application is installed on EC2 and user has configured ELB and Auto Scaling. Considering future load increase, the user is planning to launch new servers proactively so that they get registered with ELB.
How can the user add these instances with Auto Scaling?

Answer options

• A. Decrease the minimum limit of the Auto Scaling group
• B. Increase the maximum limit of the Auto Scaling group
• C. Launch an instance manually and register it with ELB on the fly
• D. Increase the desired capacity of the Auto Scaling group

Correct answer: D

Explanation

To proactively launch new instances and register them with the ELB, the administrator should increase the desired capacity of the Auto Scaling group, which instructs AWS to provision the extra instances immediately. Raising the maximum limit or lowering the minimum limit does not trigger an immediate launch of new servers. Manually launching instances and registering them bypasses the automation benefits of the Auto Scaling group.