Plan migration to Azure App Service from Azure Stack Hub

To successfully migrate from Azure App Service on Azure Stack Hub to Azure App Service, start with a comprehensive assessment of your existing environment. Evaluate application architecture, platform dependencies, operational requirements, compliance constraints, and business objectives before selecting a migration strategy.

Assess application suitability

Identify all applications hosted on Azure App Service on Azure Stack Hub and classify them according to complexity and criticality.

For each application, document:

  • Application owners and stakeholders
  • Business criticality
  • Runtime and framework versions
  • External service dependencies
  • Authentication providers
  • Network connectivity requirements
  • Performance and scale requirements
  • Availability and disaster recovery requirements

Applications with minimal dependencies might be suitable for direct migration. Applications that rely on platform-specific integrations or legacy infrastructure might require modernization activities before migration.

Evaluate application dependencies

Many applications depend on services outside of App Service itself. Understanding these dependencies is critical to migration planning.

Assess:

  • SQL Server databases
  • File shares and storage systems
  • Internal APIs
  • Active Directory or Microsoft Entra ID integrations
  • Message queues and event systems
  • SMTP services
  • Third-party services
  • Monitoring and logging platforms

Determine whether dependencies:

  • Remain on-premises
  • Remain on Azure Stack Hub
  • Are migrated to Azure
  • Are replaced with Azure-native services

Applications with significant on-premises dependencies might require VPN, ExpressRoute, private endpoint, or hybrid networking configurations following migration.

Evaluate hosting model options

Migration provides an opportunity to reassess how you host applications.

The recommended migration approach depends on application type and complexity.

Application Type Recommended Target
ASP.NET Core applications Azure App Service (Windows or Linux)
Java applications Azure App Service for Linux
Node.js applications Azure App Service for Linux
Python applications Azure App Service for Linux
PHP applications Azure App Service for Linux
Existing Windows-based ASP.NET Framework applications Azure App Service (Windows)
Containerized applications Azure App Service Containers, Azure Container Apps, or Azure Kubernetes Service (AKS)

Plan for networking changes

Networking architecture in Azure can differ significantly from Azure Stack Hub deployments.

Review requirements for:

  • Private application access
  • Inbound internet traffic
  • Hybrid connectivity
  • Internal DNS resolution
  • Network isolation
  • Regulatory requirements

Determine whether Azure networking capabilities such as:

  • Virtual Network integration
  • Private endpoints
  • Azure Application Gateway
  • Azure Front Door
  • Azure Firewall

are required as part of the target architecture.

Review identity and security requirements

When you migrate to Azure App Service, you get access to more identity and security capabilities. You might be able to simplify your existing security architectures.

Consider adopting:

  • Microsoft Entra ID authentication
  • Managed identities
  • Azure Key Vault references
  • Azure RBAC
  • Private endpoints
  • Conditional access policies
  • Microsoft Defender for Cloud

Organizations should also review certificate management, secrets management, and compliance requirements before designing the target environment.

Select an appropriate migration strategy

Different applications might need different migration approaches.

Strategy Description Typical Use Case
Rehost Move application with minimal modification Modern applications already compatible with Azure App Service
Replatform Update configuration or supporting services during migration Applications requiring infrastructure modernization
Refactor Modify application architecture to take advantage of Azure services Strategic applications with long-term investment plans
Modernize Rebuild portions of the application using cloud-native services Applications requiring significant transformation

Not every workload requires modernization during migration. Some organizations choose to migrate first, then modernize incrementally after the application is operating successfully in Azure.

Validate regional deployment requirements

You can deploy Azure App Service across a broad range of Azure regions. By using multiple regions, your organization can improve latency, resiliency, and compliance outcomes compared to a single Azure Stack Hub deployment.

Evaluate:

  • Data residency requirements
  • User proximity
  • Disaster recovery requirements
  • Availability zone support
  • Service availability by region

For business-critical workloads, consider multi-region or zone-redundant architectures where appropriate.

Assess scale and capacity requirements

Migration should include a review of current and future growth requirements.

Document:

  • Current instance counts
  • Peak traffic patterns
  • CPU and memory utilization
  • Seasonal demand fluctuations
  • Growth forecasts

This assessment helps determine the appropriate Azure App Service plan and whether advanced capabilities.

Establish a migration approach and timeline

Define the following elements for your migration project:

  • Migration waves
  • Testing milestones
  • Rollback procedures
  • User acceptance criteria
  • Production cutover plans

For large estates, use a phased migration approach:

  1. Pilot applications
  2. Non-production environments
  3. Low-risk production applications
  4. Business-critical production workloads

This approach helps your team gain operational experience with Azure App Service before migrating mission-critical applications.

Define success criteria

Before migration begins, establish measurable success criteria.

Examples include:

  • Successful deployment to Azure App Service
  • No critical functionality regressions
  • Performance equal to or better than the source environment
  • Security and compliance validation completed
  • Monitoring and alerting configured
  • Operational runbooks updated

Clearly defined success criteria help ensure migration activities stay aligned with business objectives and reduce deployment risk.

Tip

View migration as both a platform transition and a modernization opportunity. While you can often migrate applications with minimal changes, evaluating capabilities such as Linux hosting, private endpoints, managed identities, Azure Front Door, availability zones.

Next steps

Migrate to Azure App Service from Azure App Service on Azure Stack Hub

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