Cloud Native – Reactive Accelarator

Cloud-Native Architecture

1. What is Cloud-Native Architecture?

Cloud-Native Architecture হলো এমন একটা design approach যেখানে application গুলো মূলত cloud environment এর জন্য বানানো হয়। এখানে প্রধান লক্ষ্য হলো: scalability, resilience, flexibility, এবং automation।

Application গুলো cloud-এর সুবিধা (auto-scaling, managed services, distributed storage) ব্যবহার করে।
Stateless & distributed design preferred।
DevOps practices (CI/CD, monitoring, automation) integral।

সহজভাবে: Cloud-native app হলো এমন app যা cloud এ born করে এবং cloud-এর সুবিধা পুরোপুরি ব্যবহার করে।

2. Core Principles of Cloud-Native

Microservices → ছোট, independent services।
Containerization → Docker বা container runtime এ deploy করা।
Dynamic Orchestration → Kubernetes / ECS / Docker Swarm দিয়ে services manage করা।
DevOps Automation → CI/CD, Infrastructure as Code (Terraform, CloudFormation)।
Observability → Logging, Monitoring, Tracing (Prometheus, Grafana, ELK)।
Resilience & Self-Healing → Auto-restart, failover, distributed system design।

3. Structure of a Cloud-Native Application

Cloud-native application মূলত layers বা components এ divide করা যায়:

API Gateway / Load Balancer → Traffic routing & single entry point।
Microservices / Functions → Business logic, stateless, independent।
Containers → Packaging & runtime environment।
Service Discovery → কোন service কোথায় চলছে খুঁজে বের করা।
Message Queue / Event Bus → Async communication (Kafka, RabbitMQ)।
Databases / Storage → Cloud-managed DBs (RDS, DynamoDB, S3)।

Example: E-commerce App

User Service → Authentication, Profile → Docker container → Kubernetes pod
Order Service → Order processing → Pod → Autoscaled
Payment Service → Payment gateway → Cloud-managed service (e.g., Stripe)
Notification Service → Email/SMS → Event-driven (Kafka)

4. How Cloud-Native Apps Work

ধরা যাক আপনি online product কিনতে যাচ্ছেন:

User → Browser থেকে request → API Gateway
API Gateway → Order Service pod call করে
Order Service → Product Service check করে availability
Payment Service integrate করে cloud-managed payment
Notification Service → Kafka event consume করে email/sms পাঠায়
Kubernetes auto-scale করে heavy traffic handle করে

সার্বিকভাবে, system distributed, resilient, scalable এবং cloud resource optimized।

5. Advantages of Cloud-Native Architecture

✅ Scalability → Auto-scaling, only required services scale ✅ Resilience → Pods auto-restart, failover, distributed DB ✅ Faster Deployment → CI/CD, automated pipelines ✅ Cost Optimization → Pay-as-you-use cloud resources ✅ Technology Flexibility → Mixed tech stacks, polyglot services ✅ Global Distribution → Cloud regions, multi-AZ deployment possible

6. Disadvantages

❌ Complexity → Requires expertise in Kubernetes, containers, cloud infra ❌ DevOps Dependency → Automation, CI/CD, monitoring required ❌ Latency → Distributed services & cloud network may add delays ❌ Cost Management → Misconfigured scaling/storage can increase cost ❌ Security Overhead → Multi-tenant cloud, API security, secrets management

7. When to Use Cloud-Native

Large scale apps with high traffic
Apps requiring resilience & zero downtime
Frequent deployment / CI/CD pipelines
Multi-region / global access needed
Microservices or event-driven architecture

8. When NOT to Use

Small MVP or prototype
Team lacks DevOps expertise
Simple CRUD apps without heavy scaling requirement

9. Real-Life Examples

Netflix → Cloud-native, auto-scaled streaming, recommendation, billing
Spotify → Microservices, event-driven, global deployment
Uber → Multi-region, distributed services, resilient system
Airbnb → Cloud-native with containerized microservices

10. Scaling in Cloud-Native

Pod-level Scaling → Only the overloaded service scales
Auto-scaling → CPU/memory/network based scaling
Global Scaling → Multi-region deployment for latency reduction

11. Deployment in Cloud-Native

Containers → Docker / Podman
Orchestration → Kubernetes, Docker Swarm
CI/CD → Jenkins, GitHub Actions, GitLab CI
Infrastructure as Code → Terraform, CloudFormation

12. Important Concepts

API Gateway → Single entry point, routing, auth, caching
Service Mesh (Istio, Linkerd) → Service-to-service communication, observability
Event-Driven Architecture → Kafka, RabbitMQ for async events
Immutable Infrastructure → No manual changes on runtime servers
Observability → Metrics, logs, tracing for monitoring

13. Diagram (Textual Representation)

                 API Gateway
                      |
 ------------------------------------------------------
|      |           |             |             |       |
| User | Product   |   Order     |  Payment    |Notification|
|Service|Service  |  Service    |  Service    |  Service   |
| Docker| Pod      | Pod         | Cloud svc  | Pod       |
|  DB   | DB       | DB          | Managed DB | DB        |
 ------------------------------------------------------
        ^                 ^
        |                 |
   Event Bus / Message Queue (Kafka/RabbitMQ)

14. Developer Experience

Beginners → Initial setup complex (containers, Kubernetes, cloud infra)
Experienced DevOps + Dev Team → Productivity high, auto-scaling, resilience
Continuous Deployment → Small, frequent, safe deployments

15. Summary

Cloud-Native = Cloud-Optimized Application
Microservices + Containers + Automation + Resilience
Perfect for scalable, distributed, global apps
Requires DevOps, monitoring, orchestration expertise

Event-driven Architecture Serverless Architecture