BenchMark Quizzes by MDFT Pro

Virtual Machine Scale Set Auto Scaling Configuration

Mark works as a Cloud Infrastructure Manager at MDFT Pro, a technology training agency that provides Azure certification courses to students across multiple regions. Claire, the DevOps Training Coordinator, has been tasked with setting up scalable virtual infrastructure to support their growing student lab environments. As part of their Azure infrastructure optimization project, they need to implement virtual machine scale sets that can automatically adjust to varying student workloads throughout different training sessions and peak learning periods.

Mark has created a virtual machine scale set named Scale1 to host the training lab environments. The scale set configuration needs to handle the fluctuating demands as students connect and disconnect from lab sessions throughout the day. The current configuration shows specific autoscaling rules that will determine how many virtual machines run based on CPU utilization patterns.

Configuration	Value
Instance Count	4
Instance Size	DS1_v2
Deploy as Low Priority	No
Use Managed Disks	Yes

Autoscale Settings	Value
Autoscale	Enabled
Minimum VMs	2
Maximum VMs	20

Scale Out Rules	Value
CPU Threshold	80%
VMs to Increase By	2

Scale In Rules	Value
CPU Threshold	30%
VMs to Decrease By	4

The training environment experiences variable loads depending on class schedules. During a monitoring period, Scale1 shows 25% CPU utilization for six minutes, followed by 50% CPU utilization for another six minutes.

Based on the autoscaling configuration and these utilization patterns, how many virtual machines will Scale1 be running after this monitoring period?

Choose the correct answer from the options below.

Explanations for each answer:

2 virtual machines is correct. When CPU utilization drops to 25% (below the scale-in threshold of 30%), the scale set will scale down by 4 VMs from the initial 4, but it cannot go below the minimum of 2 VMs. When CPU increases to 50% (below the scale-out threshold of 80%), no scale-out occurs, so it remains at 2 VMs.
4 virtual machines is incorrect. This would only be correct if no scaling occurred, but since the CPU dropped to 25% (below the 30% scale-in threshold), scaling would occur to reduce the VM count.
6 virtual machines is incorrect. This count would require a scale-out event, but 50% CPU utilization is below the 80% threshold needed to trigger scaling out, so no additional VMs would be added.
10 virtual machines is incorrect. This would require significant scale-out activity, but neither 25% nor 50% CPU utilization reaches the 80% threshold required to trigger scale-out operations.
20 virtual machines is incorrect. This is the maximum VM limit, but would only be reached through multiple scale-out events triggered by sustained high CPU usage above 80%, which doesn't occur in this scenario.

Learn more about Virtual Machine Scale Sets autoscaling policies, thresholds, and scaling behaviors in Azure.:

Autoscale Overview

Exam Preparation Quiz

Virtual Machine Scale Set Auto Scaling Configuration