Infrastructure Overview

The multi-region shopping mall platform uses Terraform to manage AWS infrastructure as code. It provisions over 260 resources across two regions: us-east-1 (primary) and us-west-2 (secondary).

Architecture Diagram

State Management

Terraform state is centrally managed using S3 backend with DynamoDB locking.

Component	Value
S3 Bucket	multi-region-mall-terraform-state
DynamoDB Table	terraform-state-lock
Region	us-east-1
Encryption	AES-256 Server-Side Encryption

terraform {
  backend "s3" {
    bucket         = "multi-region-mall-terraform-state"
    key            = "environments/production/us-east-1/terraform.tfstate"
    region         = "us-east-1"
    dynamodb_table = "terraform-state-lock"
    encrypt        = true
  }
}

Module Dependency Diagram

Resource Status by Region

us-east-1 (Primary Region)

Category	Resource Count	Key Components
Networking	~30	VPC, Subnets, NAT GW, Transit Gateway
Compute	~45	EKS Cluster, Node Groups, ALB
Data	~80	Aurora, DocumentDB, ElastiCache, MSK, OpenSearch
Security	~35	KMS, Secrets Manager, IAM, Security Groups
Edge	~20	CloudFront, WAF, Route53
Observability	~50	CloudWatch, X-Ray, Tempo Storage
Total	~260

us-west-2 (Secondary Region)

Category	Resource Count	Key Components
Networking	~30	VPC, Subnets, NAT GW, Transit Gateway
Compute	~45	EKS Cluster, Node Groups, ALB
Data	~75	Aurora (Read), DocumentDB, ElastiCache, MSK, OpenSearch
Security	~35	KMS, Secrets Manager, IAM, Security Groups
Observability	~50	CloudWatch, X-Ray, Tempo Storage
Total	~235

Environment Structure

terraform/
├── environments/
│   └── production/
│       ├── us-east-1/          # Primary Region
│       │   ├── main.tf
│       │   ├── variables.tf
│       │   ├── outputs.tf
│       │   └── terraform.tfvars
│       └── us-west-2/          # Secondary Region
│           ├── main.tf
│           ├── variables.tf
│           ├── outputs.tf
│           └── terraform.tfvars
├── global/                     # Global Resources
│   ├── route53/
│   └── iam/
└── modules/                    # Reusable Modules
    ├── compute/
    ├── data/
    ├── edge/
    ├── networking/
    ├── observability/
    └── security/

Provisioning Order

When deploying to multiple regions, resources must be provisioned in the following order considering dependencies:

1. Global Resources: Route53 Hosted Zone, IAM Roles
2. us-east-1 Primary: Full infrastructure (including global database primary)
3. us-west-2 Secondary: Full infrastructure (joining global databases as secondary)

Important Notes

• Running terraform apply simultaneously in both regions may cause state conflicts
• Always deploy the primary region first, then the secondary region
• Global databases (Aurora, DocumentDB, ElastiCache) are created in the primary region first, then joined by the secondary

Tagging Strategy

All resources have the following tags applied:

default_tags {
  tags = {
    Environment = "production"
    Region      = var.region
    ManagedBy   = "terraform"
    Project     = "multi-region-mall"
  }
}

Next Steps

• Terraform Modules - Detailed description of 17 modules
• EKS Cluster - Kubernetes cluster configuration
• Databases - Global database configuration