AZ-305 Question 132
Single answerA mission-critical financial application running on Azure Virtual Machines must remain operational even if an entire Azure region becomes unavailable. The application stores stateful data that requires minimal downtime and data loss in the event of a regional outage. Which design best meets these high availability requirements?
- A
Deploy two VMs in an Availability Set within a single region, and replicate data using Azure Backup
- B
Deploy a VM Scale Set across multiple Availability Zones in the same region, and use zone-redundant storage for data replication
- C
Deploy mirrored VMs in two separate Azure regions, fronted by Azure Traffic Manager, and replicate data asynchronously with geo-redundant storage
- D
Deploy a VM Scale Set across Availability Zones in two separate regions, and use Azure Load Balancer to distribute traffic across both regions
Show answer and explanation
Correct answer: C
Explanation
For mission-critical workloads that must remain operational even if an entire Azure region fails, cross-region redundancy is essential. Option 3 follows Microsoft’s recommended best practices for achieving high availability and disaster recovery by leveraging multiple Azure regions and global load balancing with Azure Traffic Manager. Refer to Microsoft’s documentation (https://learn.microsoft.com/azure/architecture/resiliency) for more details on designing highly available multi-region architectures.
- A. Incorrect.
Option 1: Incorrect. While an Availability Set provides protection against host-level failures within a single data center, it does not protect against a full region outage. Azure Backup is for data backups, not for immediate failover capabilities when a region is down.
- B. Incorrect.
Option 2: Incorrect. Using multiple Availability Zones in one region can mitigate data center failures, but a full region outage would still impact the application. Zone-redundant storage also does not ensure cross-region failover.
- C. Correct.
Option 3: Correct. Deploying mirrored VMs (or equivalent workloads) in two separate Azure regions, fronted by Traffic Manager, ensures cross-region failover. Traffic Manager directs clients to the secondary region if the primary region becomes unavailable. Using geo-redundant storage allows asynchronous data replication, minimizing downtime and data loss.
- D. Incorrect.
Option 4: Incorrect. Azure Load Balancer is typically scoped to a single region and cannot distribute traffic across multiple regions directly. You would still need a global load balancing solution like Azure Traffic Manager or Azure Front Door for cross-region failover.