Microsoft Certified: Azure Solutions Architect ExpertDesign business continuity solutionsMedium
A company is designing a highly available solution for a stateless web application running on Azure Virtual Machine Scale Sets. The application must remain available even if an entire Azure Availability Zone fails. Which high availability strategy should be implemented?
- ADeploy the Virtual Machine Scale Set across multiple Azure regions using Azure Traffic Manager.
- BDeploy the Virtual Machine Scale Set within a single Availability Set.
- CDeploy the Virtual Machine Scale Set in a single region without any redundancy.
- DDeploy the Virtual Machine Scale Set across multiple Availability Zones.
Show answer & explanationAnswer & explanation
Correct answer: D. Deploy the Virtual Machine Scale Set across multiple Availability Zones.
Deploying a Virtual Machine Scale Set across multiple Availability Zones ensures that instances are distributed across physically separate data centers within a region, providing resilience against a single Availability Zone failure.
Why the other options are wrong
- A. Deploying across multiple Azure regions using Azure Traffic Manager provides disaster recovery and global load balancing, which is for regional outages, but the question specifically asks for resilience against an 'entire Azure Availability Zone' failure within a region.
- B. Deploying within a single Availability Set provides fault domain and update domain isolation within a single data center, but does not protect against an entire Availability Zone failure.
- C. Deploying without redundancy offers no high availability against any failure, including an Availability Zone failure.
Azure Availability Zones
Azure Availability Zones are physically separate locations within an Azure region, each with independent power, cooling, and networking, providing resilience against data center failures.
- Protects against data center failures within a region.
- Distributes resources across independent physical locations.
- Requires services to be zone-aware to function across zones.
Memory trick: Zones: Keep apps alive, even if one zone dies.