Examkin

Question

Difficulty: MediumScale Azure App Service Web Apps

You manage an inventory synchronization service named InventoryProcessor that runs on an Azure App Service Web App. The web app currently uses a Basic (B1) App Service plan.

The application experiences intermittent CPU spikes during inventory updates. You must configure the application to automatically scale out when CPU utilization exceeds 80%80\%, and scale in when CPU utilization drops. You must also ensure that the autoscale configuration does not cause rapid, repeated scale-out and scale-in actions (flapping).

Which two actions should you perform to meet these requirements?

  1. Scale up the App Service plan to the Standard (S1) tier.Answer
  2. Configure a scale-out rule with a CPU threshold of 80%80\% and a scale-in rule with a CPU threshold of 30%30\%.Answer
  3. C
    Enable autoscaling directly on the Basic (B1) plan using the Azure CLI.
  4. D
    Configure a scale-out rule with a CPU threshold of 80%80\% and a scale-in rule with a CPU threshold of 75%75\%.

Answer

Scale up the App Service plan to the Standard (S1) tier, and configure a scale-out rule with a CPU threshold of 80%80\% and a scale-in rule with a CPU threshold of 30%30\%.
Scaling up the App Service plan to the Standard (S1) tier is necessary because autoscale rules are not supported on the Basic tier. Additionally, configuring the scale-out rule at 80%80\% and the scale-in rule at 30%30\% ensures that the thresholds are separated by a margin wide enough to prevent autoscale flapping.

Step-by-Step Solution

1
Determine the minimum App Service tier required for autoscale rules.
The Basic (B1) tier does not support autoscale rules. Scaling up to the Standard (S1) tier or higher is required to configure scale-out and scale-in rules.
Autoscale features in App Service are only available in Standard, Premium, and Isolated pricing tiers.
2
Define autoscale rules to handle load and prevent flapping.
Create a scale-out rule at 80%80\% CPU and a scale-in rule at a significantly lower value, such as 30%30\%.
Keeping a wide margin between the scale-out and scale-in thresholds prevents the system from entering an loop of constant scaling actions (flapping) when capacity changes.

Key Concept

App Service plan pricing tiers and autoscale flapping prevention
Rate this question

Topics

Scale Azure App Service Web Apps

More questions from this topic