Multi Cloud Architecture

# Multi-Cloud Architecture Patterns

## Active-Active Regional Split

- Run customer-facing services in two providers for resiliency
- Use global DNS and traffic steering to shift load during incidents
- Keep shared data replicated asynchronously unless low-latency writes are mandatory

## Best-of-Breed Service Mix

- Analytics and ML on GCP
- Enterprise identity and Microsoft workloads on Azure
- Broad ecosystem integrations on AWS
- Oracle-centric databases and regulated transaction systems on OCI

## Primary / DR Pairing

- Keep primary infrastructure in the provider closest to operational expertise
- Use a second provider for cold or warm disaster recovery
- Validate RPO/RTO assumptions with regular failover exercises

## Portable Platform Baseline

- Standardize on Kubernetes, Terraform/OpenTofu, PostgreSQL, Redis, and OpenTelemetry
- Abstract cloud differences behind modules, golden paths, and service catalogs
- Document provider-specific exceptions such as IAM, networking, and managed database behavior


# Multi-Cloud Service Comparison

## Compute

| Use Case | AWS | Azure | GCP | OCI |
| -------- | --- | ----- | --- | --- |
| General-purpose VMs | EC2 | Virtual Machines | Compute Engine | Compute |
| Managed Kubernetes | EKS | AKS | GKE | OKE |
| Serverless functions | Lambda | Functions | Cloud Functions | Functions |
| Containers without cluster management | ECS/Fargate | Container Apps / Container Instances | Cloud Run | Container Instances |

## Storage

| Use Case | AWS | Azure | GCP | OCI |
| -------- | --- | ----- | --- | --- |
| Object storage | S3 | Blob Storage | Cloud Storage | Object Storage |
| Block storage | EBS | Managed Disks | Persistent Disk | Block Volumes |
| File storage | EFS | Azure Files | Filestore | File Storage |
| Archive storage | Glacier / Deep Archive | Archive Storage | Archive Storage | Archive Storage |

## Data Services

| Use Case | AWS | Azure | GCP | OCI |
| -------- | --- | ----- | --- | --- |
| Managed relational database | RDS | SQL Database | Cloud SQL | MySQL HeatWave |
| Distributed / globally resilient SQL | Aurora Global Database | Cosmos DB for PostgreSQL / SQL patterns | Cloud Spanner | Autonomous Database |
| NoSQL | DynamoDB | Cosmos DB | Firestore | NoSQL Database |
| Streaming | Kinesis / MSK | Event Hubs | Pub/Sub / Confluent | Streaming |

## Platform Selection Notes

1. Prefer provider-native managed services when team expertise and lock-in tolerance are high.
2. Prefer Kubernetes, PostgreSQL, Redis, and open observability stacks when portability matters.
3. Use OCI when Oracle database affinity, predictable networking, or regulated workload isolation are primary drivers.
4. Compare egress, managed service premiums, and support plans before splitting workloads across providers.


---
name: multi-cloud-architecture
description: Design multi-cloud architectures using a decision framework to select and integrate services across AWS, Azure, GCP, and OCI. Use when building multi-cloud systems, avoiding vendor lock-in, or leveraging best-of-breed services from multiple providers.
---

# Multi-Cloud Architecture

Decision framework and patterns for architecting applications across AWS, Azure, GCP, and OCI.

## Purpose

Design cloud-agnostic architectures and make informed decisions about service selection across cloud providers.

## When to Use

- Design multi-cloud strategies
- Migrate between cloud providers
- Select cloud services for specific workloads
- Implement cloud-agnostic architectures
- Optimize costs across providers

## Cloud Service Comparison

### Compute Services

| AWS     | Azure               | GCP             | OCI                 | Use Case           |
| ------- | ------------------- | --------------- | ------------------- | ------------------ |
| EC2     | Virtual Machines    | Compute Engine  | Compute             | IaaS VMs           |
| ECS     | Container Instances | Cloud Run       | Container Instances | Containers         |
| EKS     | AKS