Alibaba Exam ACP-Cloud1 Topic 4 Question 55 Discussion

A new media company uses a mobile app to provide news and information services. They utilize Auto Scaling to add/reduce ECS instances dynamically to address service traffic spikes.

Based on the estimation of their service and technical personnel the company thinks they require 10 ECS instances during idle hours and 10 to 20 ECS instances (dynamically adjusted) during some busy hours, which are normally from 07:30 to 09:00 and from 18:30 to 20:00 In the scaling group; they set the "Minimum number of instances" to 10 and "Maximum number of instances" to 20.

To simplify deployment tasks and save costs, which of the following scaling modes should they choose?