Monolithic vs Microservices

What is Monolithic?

What is SOA?

What is Microservices?

Advantages of Microservices

Feature	Monolithic Architecture	SOA (Service-Oriented Architecture)	Microservices Architecture
Architecture Style	Single, unified codebase for the entire application.	Decoupled services, typically using an Enterprise Service Bus (ESB) for communication.	Independent, small services that communicate via lightweight protocols like HTTP/REST.
Size and Complexity	Large, tightly coupled application.	Modular but often larger services compared to microservices.	Fine-grained, small, loosely coupled services.
Communication	Internal method calls within the same process.	Typically uses ESB for messaging and service coordination.	Communicates via lightweight mechanisms such as REST or messaging queues.
Deployment	Entire application must be redeployed for changes.	Individual services can be deployed independently, but ESB may require coordination.	Independent services can be deployed and scaled independently.
Scalability	Limited scalability; scaling involves duplicating the whole application.	Scalable, but can be bottlenecked by ESB.	Highly scalable; individual services can be scaled based on demand.
Maintenance	Harder to maintain; any change may affect the entire application.	Easier to maintain due to modularity but complexity in ESB management.	Easier to maintain as services are smaller and focused on specific tasks.
Fault Isolation	Failure in one part can bring down the entire system.	Better fault isolation but complex ESB can affect recovery.	Failures are isolated to specific services; the rest of the system remains unaffected.
Data Management	Centralized database shared by the entire application.	Shared databases but with some service-specific schemas.	Each service manages its own database, promoting data isolation.
Performance	Faster within a single process, but can become slow as the application grows.	Slower due to ESB overhead and service orchestration.	Can be slower due to network communication, but scales well under load.
Pros	Simple to develop and deploy in small applications.	Modular services, better reusability, flexibility with ESB integration.	Highly scalable, fault-tolerant, technology agnostic, and easy to maintain.
Cons	Difficult to scale, maintain, and deploy in large systems; tightly coupled components.	ESB can become a bottleneck; increased complexity in managing service dependencies.	More complex to develop due to distributed nature; requires good management of service communication and data consistency.

Frameworks to Develop Microservices

Spring Boot (Java)
Micronaut (Java)
Quarkus (Java)
DropWizard (Java)
Flask (Python)
Django (Python)
Go Micro (Golang)
Node.js with Express.js
Lagom (Scala)

Why spring boot for microservices?

Rapid Development: Spring Boot simplifies the development process by providing a set of conventions and auto-configuration,
Spring Ecosystem Integration: Spring Boot is part of the larger Spring Framework, which means it seamlessly integrates with other Spring modules like Spring Data, Spring Security, Spring Cloud, and Spring Batch.
Spring Cloud for Microservices: Spring Cloud adds a rich set of tools specifically for microservice development, including:
- Service discovery (Eureka)
- Load balancing (Ribbon)
- Configuration management (Spring Cloud Config)
- API Gateway (Zuul)
- Distributed tracing (Zipkin)
- Circuit breakers (Hystrix)
Mature Ecosystem and Community Support: Spring Boot has a mature, well-documented ecosystem with a large and active community. This results in extensive learning resources, tutorials, and third-party libraries to support development.
Production-Ready Features: Inbuilt support for production-ready features like health checks, metrics, and distributed tracing. These features make it easy to monitor and manage microservices.
Scalability and Cloud-Native Capabilities: Well suited for cloud-native development with support for containerization and orchestration tools like Docker and Kubernetes.