Azure Stack Hub and reliability
Azure Stack Hub is a hybrid cloud platform that lets you provide Azure services from your datacenter. It provides a way to run apps in an on-premises environment.
This service unlocks the following hybrid cloud use cases for customer-facing and internal line-of-business apps:
- Edge and disconnected solutions: Addresses latency and connectivity requirements by processing data locally.
- Cloud apps that meet varied regulations: Allows you to develop and deploy apps with full flexibility to meet regulatory or policy requirements.
- Cloud app model on-premises: Provides Azure services, containers, serverless, and microservice architectures to update and extend existing apps or build new ones.
For more information, reference Azure Stack Hub overview.
To understand how Azure Stack Hub supports resiliency for your application workload, reference the following articles:
- Capacity planning for Azure Stack Hub overview
- Storage Spaces Direct cache and capacity tiers
- Datacenter integration planning considerations for Azure Stack Hub integrated systems
The following sections include design considerations, a configuration checklist, and recommended configuration options specific to Azure Stack Hub and reliability.
Design considerations
Azure Stack Hub includes the following design considerations:
- Microsoft doesn't provide an SLA for Azure Stack Hub because Microsoft doesn't have control over customer datacenter reliability, people, and processes.
- Azure Stack Hub only supports a single Scale Unit (SU) within a single region, which consists of between four and 16 servers that use Hyper-V failover clustering. Each region serves as an independent Azure Stack Hub stamp with separate portal and API endpoints.
- Azure Stack Hub doesn't support Availability Zones because it consists of a single region or a single physical location. High availability to cope with outages of a single location should be implemented by using two Azure Stack Hub instances deployed in different physical locations.
- Azure Stack Hub supports premium storage to ensure compatibility. However, provisioning premium storage accounts or disks doesn't guarantee that storage objects will be allocated onto SSD or NVMe drives.
- Azure Stack Hub supports only a subset of VPN Gateway SKUs available in Azure with a limited bandwidth of
100or200Mbps. - Only one site-to-site (S2S) VPN connection can be created between two Azure Stack Hub deployments. This connection limit is because of a platform limitation that allows only a single VPN connection to the same IP address. Multiple S2S VPN connections with higher throughput can be established using third-party NVAs.
- Apply general Azure configuration recommendations for all Azure Stack Hub services.
Checklist
Have you configured Azure Stack Hub with reliability in mind?
- Treat Azure Stack Hub as a scale unit and deploy multiple instances to remove Azure Stack Hub as a single point of failure for encompassed workloads.
Configuration recommendations
Consider the following recommendation table to optimize your Azure Stack Hub configuration for reliability:
| Recommendation | Description |
|---|---|
| Treat Azure Stack Hub as a scale unit and deploy multiple instances to remove Azure Stack Hub as a single point of failure for encompassed workloads. | Deploy workloads in either an active-active or active-passive configuration across Azure Stack Hub stamps or Azure. |