AZ-305 Question 152
Single answerA financial services company has a batch-processing workload that runs for several hours each night, utilizing high CPU resources. During daytime business hours, the application must remain online but only requires moderate CPU and memory resources. How should you recommend structuring the virtual machines in Azure to ensure cost-effectiveness while maintaining consistent performance during the day?
- A
Deploy a single set of standard Pay-As-You-Go VMs running continuously for both daytime and nighttime workloads.
- B
Use Azure Spot VMs for the daytime workload and automatically shut them down at night to reduce costs.
- C
Implement separate Virtual Machine Scale Sets: one with Pay-As-You-Go VMs for daytime processing and another with Spot VMs for batch-processing during off-peak hours.
- D
Configure all workloads on burstable B-series VMs so they can adapt to both daytime and nighttime resource demands.
Show answer and explanation
Correct answer: C
Explanation
In this scenario, splitting workloads by their operational requirements leads to both performance consistency and cost efficiency. The standard Pay-As-You-Go VMs guarantee availability during peak business hours, while the Spot VMs accommodate batch-processing workloads that can tolerate interruptions. Using a Virtual Machine Scale Set for the Spot VMs automates provisioning and scaling based on demand. For reference, consult Azure documentation on using Virtual Machine Scale Sets with Spot VMs for cost optimization (https://learn.microsoft.com/azure/virtual-machine-scale-sets/use-spot).
- A. Incorrect.
Option 1 is incorrect because running a single set of standard VMs 24/7 ignores potential cost savings from more flexible solutions, especially for the high-resource nighttime batch jobs.
- B. Incorrect.
Option 2 is incorrect because Spot VMs can be interrupted at any time for capacity reasons. This would jeopardize the consistent availability needed during daytime business hours.
- C. Correct.
Option 3 is correct. It separates workloads based on their resource and availability needs: Pay-As-You-Go VMs for steady daytime requirements, and Spot VMs in a scale set for cost-effective, batch-processing tasks at night that can tolerate interruptions.
- D. Incorrect.
Option 4 is incorrect because although B-series burstable VMs can handle short bursts of increased demand, they are generally not ideal for heavy nighttime batch-processing where large CPU utilization is needed for extended periods.