Azure Spot VMs for cost savings - Practice Problems & Coding Challenges

Challenge - 5 Problems

🧠 Conceptual

intermediate

Understanding Azure Spot VM eviction behavior

You deploy an Azure Spot VM to save costs. What happens when Azure needs the capacity back?

A The VM is converted automatically to a standard pay-as-you-go VM.

B The VM is immediately deleted without warning.

C The VM continues running but with reduced performance.

D The VM is stopped and deallocated, allowing you to restart it later.

💡 Hint

Think about how Azure handles temporary resources and your ability to restart.

Azure Spot VMs are evicted by stopping and deallocating them, not deleting. This allows you to restart the VM later if capacity is available.

❓ Architecture

intermediate

Designing a fault-tolerant application using Azure Spot VMs

You want to use Azure Spot VMs for a batch processing job that can tolerate interruptions. Which architecture best supports this?

A Use a Virtual Machine Scale Set with Spot VMs and automatic reimaging on eviction.

B Deploy Spot VMs behind a load balancer with no autoscaling.

C Deploy a single Spot VM with no backup and manually restart if evicted.

D Use only standard VMs with reserved instances for guaranteed uptime.

💡 Hint

Consider how to handle VM evictions automatically and scale out.

Using a VM Scale Set with Spot VMs and automatic reimaging helps maintain capacity by replacing evicted VMs automatically, supporting fault tolerance.

❓ security

advanced

Security considerations for Azure Spot VMs

Which security risk is most relevant when using Azure Spot VMs for sensitive workloads?

A Spot VMs do not support encryption at rest.

B Spot VMs cannot be joined to Azure Active Directory.

C Spot VMs can be evicted unexpectedly, risking data loss if not properly backed up.

D Spot VMs expose public IPs by default, increasing attack surface.

💡 Hint

Think about what happens when a Spot VM is evicted suddenly.

Because Spot VMs can be evicted without notice, any data stored only on the VM's temporary disk can be lost. Proper backup and state management is essential.

❓ service_behavior

advanced

Spot VM pricing and eviction policy behavior

You set a maximum price for your Azure Spot VM. What happens if the current Spot price exceeds your max price?

A Your VM continues running until Azure evicts it for capacity reasons only.

B Your VM is immediately evicted because the price exceeded your max price.

C Azure automatically lowers your max price to keep the VM running.

D Your VM price is capped at your max price and continues running.

💡 Hint

Consider how Spot VM pricing controls eviction.

If the current Spot price rises above your max price, Azure evicts your VM immediately to avoid charging more than your set limit.

✅ Best Practice

expert

Optimizing cost and availability with Azure Spot VMs

You want to minimize costs using Azure Spot VMs but keep your application highly available. Which strategy is best?

A Combine Spot VMs with standard VMs across scale sets and configure automatic fallback to standard VMs on eviction.

B Use only Spot VMs with no fallback to standard VMs.

C Use Spot VMs and manually redeploy when evicted to save costs.

D Use standard VMs with reserved instances and avoid Spot VMs for availability.

💡 Hint

Think about balancing cost savings with uptime guarantees.

Combining Spot and standard VMs with automatic fallback ensures cost savings while maintaining availability during Spot VM evictions.