Reference: PRD Sections 4.3-4.5 - Multi-Region Architecture

This directory contains configuration samples for implementing multi-region deployments on the HelpDev platform.

Defines the phased rollout strategy for deploying services across multiple regions:

• ConfigMap with rollout configuration defining:

  • Regional deployment order (primary → secondary)
  • Phase definitions with validation criteria
  • Rollback triggers and strategy
  • Service tier overrides

• Argo Rollout example for canary deployments within a region:

  • Progressive traffic shifting (10% → 25% → 50% → 75% → 100%)
  • Integration with Istio for traffic routing
  • Analysis-driven promotion

• AnalysisTemplate for deployment validation:

  • Success rate monitoring
  • Latency threshold enforcement

Terraform configuration for DNS-based failover:

• Health Checks for each region monitoring /healthz endpoint
• Failover Routing - Primary (us-east-1) with automatic failover to secondary (sa-east-1)
• Latency-based Routing - Route users to nearest healthy region
• Weighted Routing - For controlled regional canary deployments
• CloudWatch Alarms for health check failures

Terraform configuration for cross-region data replication:

• ECR Replication - Automatic container image replication
• S3 Replication - Artifact and backup replication with versioning
• Secrets Manager Replication - Infrastructure secret synchronization

                    ┌──────────────────┐
                    │    Route53       │
                    │  Health Checks   │
                    └────────┬─────────┘
                             │
              ┌──────────────┴──────────────┐
              │                             │
              ▼                             ▼
    ┌─────────────────┐          ┌─────────────────┐
    │  us-east-1      │          │  sa-east-1      │
    │  (Primary)      │          │  (Secondary)    │
    │                 │          │                 │
    │  ┌───────────┐  │          │  ┌───────────┐  │
    │  │ EKS       │  │          │  │ EKS       │  │
    │  │ eks-prod- │  │          │  │ eks-prod- │  │
    │  │ use1      │  │          │  │ sae1      │  │
    │  └───────────┘  │          │  └───────────┘  │
    │                 │          │                 │
    │  ┌───────────┐  │   ◄───►  │  ┌───────────┐  │
    │  │ ECR       │──┼──────────┼──│ ECR       │  │
    │  │ Replicated│  │          │  │ Replica   │  │
    │  └───────────┘  │          │  └───────────┘  │
    │                 │          │                 │
    │  ┌───────────┐  │   ◄───►  │  ┌───────────┐  │
    │  │ Secrets   │──┼──────────┼──│ Secrets   │  │
    │  │ Manager   │  │          │  │ Replica   │  │
    │  └───────────┘  │          │  └───────────┘  │
    │                 │          │                 │
    │  ┌───────────┐  │   ◄───►  │  ┌───────────┐  │
    │  │ S3        │──┼──────────┼──│ S3        │  │
    │  │ Artifacts │  │          │  │ Replica   │  │
    │  └───────────┘  │          │  └───────────┘  │
    └─────────────────┘          └─────────────────┘

1. Deploy to us-east-1 (primary)
2. Run smoke tests
3. Monitor for 15 minutes
4. Validate success criteria:
   • 100% pod health
   • <0.1% error rate
   • p95 latency <500ms

1. Deploy to sa-east-1 (secondary)
2. Run smoke tests
3. Monitor for 10 minutes
4. Final validation across all regions

• Error rate >1% for 5 minutes
• Pod health <80%
• p95 latency >2 seconds

cd samples/multi-region

terraform init
terraform plan -var="environment=prod" \
  -var="primary_alb_dns=k8s-prod-use1-xxxx.us-east-1.elb.amazonaws.com" \
  -var="primary_alb_zone_id=Z35SXDOTRQ7X7K" \
  -var="secondary_alb_dns=k8s-prod-sae1-xxxx.sa-east-1.elb.amazonaws.com" \
  -var="secondary_alb_zone_id=Z2P70J7HTTTPLU"
terraform apply

# Apply from primary region
terraform apply -target=aws_ecr_replication_configuration.cross_region

Apply the ConfigMap to the Argo CD namespace:

kubectl apply -f phased-rollout-config.yaml -n argocd

1. Region Isolation: Per PRD, regions are isolated - services do NOT communicate across regions
2. Data Locality: Databases are regional; use Global Tables for DynamoDB if needed
3. ECR Replication: Automatic for all helpdev-* prefixed repositories
4. Secrets Replication: Only infrastructure secrets are replicated; application secrets are regional
5. Health Checks: Use multiple Route53 health checker regions for reliability

• terraform/environments/ - Environment-specific configurations
• argocd/ - Argo CD ApplicationSets for multi-region
• observability/dashboards/multi-region.json - Multi-region dashboard