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5-Layer Model

FaultRay organizes infrastructure components into five logical layers, each representing a distinct tier of the technology stack.

Layer Overview

┌─────────────────────────────────┐
│  Layer 5: Edge / CDN            │
├─────────────────────────────────┤
│  Layer 4: DNS / Routing         │
├─────────────────────────────────┤
│  Layer 3: Network / Load Bal.   │
├─────────────────────────────────┤
│  Layer 2: Compute / Application │
├─────────────────────────────────┤
│  Layer 1: Storage / Database    │
└─────────────────────────────────┘

Layer 1: Storage / Database

The foundation layer handles persistent data storage.

  • Databases (RDS, Cloud SQL, Cosmos DB)
  • Object storage (S3, GCS, Blob Storage)
  • File systems (EFS, Filestore)
  • Cache layers (ElastiCache, Memorystore)

Key resilience factors: Replication, backup frequency, cross-region failover.

Layer 2: Compute / Application

The application processing layer runs your business logic.

  • Virtual machines (EC2, Compute Engine, Azure VMs)
  • Containers (ECS, GKE, AKS)
  • Serverless (Lambda, Cloud Functions, Azure Functions)
  • Application servers

Key resilience factors: Auto-scaling, health checks, rolling deployments.

Layer 3: Network / Load Balancing

The networking layer routes traffic between components.

  • Load balancers (ALB/NLB, Cloud Load Balancing, Azure LB)
  • VPCs and subnets
  • Security groups and firewalls
  • Service mesh (Istio, Linkerd)

Key resilience factors: Multi-AZ distribution, health check intervals, connection draining.

Layer 4: DNS / Routing

The routing layer manages name resolution and traffic policies.

  • DNS services (Route 53, Cloud DNS, Azure DNS)
  • Traffic management (Global Accelerator, Traffic Manager)
  • API gateways

Key resilience factors: TTL settings, failover routing policies, health-checked endpoints.

Layer 5: Edge / CDN

The edge layer handles content delivery and DDoS protection.

  • CDN (CloudFront, Cloud CDN, Azure CDN)
  • WAF / DDoS protection (Shield, Cloud Armor)
  • Edge functions (CloudFront Functions, Workers)

Key resilience factors: PoP distribution, origin failover, cache hit ratios.

Cross-Layer Analysis

FaultRay evaluates failure impact across layers. A Layer 1 (database) failure might cascade through Layer 2 (application) and ultimately affect Layer 5 (CDN cache invalidation). The simulation engine traces these cross-layer dependencies to calculate true impact.

faultray simulate -m model.json --cascade-depth 5