Multi-Site Azure Local Architectures

Table of Contents

  1. Overview
  2. Multi-Site vs. Rack-Aware Clustering
  3. Multi-Site Topology Patterns
    1. Distributed Hub-and-Spoke
    2. Peer-to-Peer Federation
    3. Tiered Architecture
  4. Multi-Site Architecture Comparison
  5. Synchronization Mechanisms
    1. Management Synchronization
    2. Data Replication
    3. Workload Distribution
  6. Failover and Recovery
  7. Operational Considerations

Overview

Deploy Azure Local clusters across multiple physical sites with synchronized operations, failover capabilities, and coordinated governance.

📝 Key Distinction: Azure Local does NOT support stretch clusters (single cluster spanning multiple sites). This page covers multi-cluster architectures where each site has its own Azure Local cluster, connected through replication and Arc management.

For rack-level high availability within a single cluster, see Rack-Aware Clustering.

View Diagram: Multi-Site Replication Topology

Azure Local Multi-Site Architecture showing primary, DR, and edge sites with replication topology Figure 1: Azure Local multi-site deployment with synchronous and asynchronous replication across datacenters

Multi-Site vs. Rack-Aware Clustering

Feature Rack-Aware Clustering Multi-Site Architecture
Cluster Count Single cluster Multiple clusters
Physical Scope 2 racks (same campus, ≤1ms latency) Multiple sites (any distance)
Storage Single pool, synchronous Separate pools, replicated
Replication Built-in (Storage Spaces Direct) Azure Site Recovery or Storage Replica
Failover Automatic (zone-aware) Manual or ASR-automated
Use Case Room/building-level HA Geographic DR
Status Preview GA

Multi-Site Topology Patterns 

graph TB
    subgraph Pattern1[Hub-and-Spoke]
        Hub[Central Hub Site<br/>Control Plane]
        Spoke1[Spoke Site 1<br/>Workloads]
        Spoke2[Spoke Site 2<br/>Workloads]
        Spoke3[Spoke Site 3<br/>Workloads]

        Hub --> Spoke1
        Hub --> Spoke2
        Hub --> Spoke3
    end

    subgraph Pattern2[Peer-to-Peer]
        Site1[Site 1]
        Site2[Site 2]
        Site3[Site 3]

        Site1 <--> Site2
        Site2 <--> Site3
        Site3 <--> Site1
    end

    subgraph Pattern3[Tiered]
        Primary[Primary Site<br/>Control & Data]
        Secondary1[Secondary Site 1<br/>Replicas]
        Secondary2[Secondary Site 2<br/>Replicas]
        Tertiary[Tertiary Site<br/>DR & Archive]

        Primary --> Secondary1
        Primary --> Secondary2
        Secondary1 --> Tertiary
        Secondary2 --> Tertiary
    end

    style Pattern1 fill:#E8F4FD,stroke:#0078D4,stroke-width:2px,color:#000
    style Pattern2 fill:#FFF4E6,stroke:#FF8C00,stroke-width:2px,color:#000
    style Pattern3 fill:#F3E8FF,stroke:#7B3FF2,stroke-width:2px,color:#000

Distributed Hub-and-Spoke

  • Central hub site (primary control plane)
  • Spoke sites (application workloads)
  • Replicated management
  • Site-specific data residency

Peer-to-Peer Federation

  • No central hub
  • Direct site-to-site communication
  • Distributed quorum
  • Equal governance rights

Tiered Architecture

  • Primary site (control plane & data)
  • Secondary sites (read replicas, compute)
  • Tertiary sites (DR & archival)
  • Cascading replication

Multi-Site Architecture Comparison

Synchronization Mechanisms

Management Synchronization

  • Cluster configuration sync
  • Policy and governance distribution
  • Certificate management coordination
  • Update and patch orchestration

Data Replication

  • Application data sync
  • Database replication
  • Storage synchronization
  • Consistency requirements

Workload Distribution

  • VM placement policies
  • Traffic routing across sites
  • Load balancing strategies
  • Site affinity rules

Failover and Recovery

  • Site failure scenarios
    • Single site outage
    • Network partition
    • Complete data center failure
  • Recovery procedures
    • Failover automation
    • Manual intervention points
    • Data consistency verification
    • Service restoration order

Operational Considerations

  • Monitoring across sites
  • Log aggregation and correlation
  • Remote support coordination
  • Maintenance scheduling
  • Update deployment sequence
See also: Connected Mode Architecture Networking Deep Dive Lab Exercise