You have a Standard Azure App Service plan named Plan1. You need to ensure that Plan1 will scale automatically when the CPU usage of the web app exceeds 80 percent. What should you select for Plan1?

To automatically scale an Azure App Service plan based on a performance metric like CPU

usage, you must configure autoscale rules. This is achieved within the "Scale out (App

Service plan)" settings by selecting the custom autoscale option, which allows you to define

rules. A rule can be set to trigger a scale-out action (adding more instances) when the CPU

percentage exceeds a specified threshold, such as 80%. This ensures the application has

more resources to handle the increased load automatically.

A. Automatic in the Scale out method settings: While the goal is automatic scaling, the

specific configuration method in Azure for metric-based scaling is defined by rules. "Rules

Based" is the more precise term for this mechanism.

C. Premium P1 in the Scale up (App Service plan) settings: This is a "scale up" operation,

which changes the size and capabilities (CPU, memory) of the instances, not the number of

instances. It does not provide automatic scaling based on load.

D. Standard S1 in the Scale up (App Service plan) settings: This is a "scale up" setting. The

plan is already Standard, and this action does not configure automatic scaling based on

performance metrics.

E. Manual in the Scale out method settings: This requires an administrator to manually

change the instance count and is the opposite of the "automatic" scaling requirement.

Microsoft Azure Documentation: "Get started with autoscale in Azure". This document

explains that custom autoscale operates based on rules that you define. It states, "You can

configure autoscale rules that are based on metrics... For example, you can increase the

number of instances when CPU usage is above 80%."

URL: https://learn.microsoft.com/en-us/azure/azure-monitor/autoscale/autoscale-get-started

Microsoft Azure Documentation: "Scale instance count manually or automatically". This

guide details the process for App Services, showing that to scale based on a metric, you

must select "Custom autoscale" and "Add a rule".

URL: https://learn.microsoft.com/en-us/azure/app-service/manage-scale-up#scale-instancecount-manually-or-automatically