Introduction to Spring Cloud
Spring Boot helps you build a single application. Spring Cloud helps you build a system of applications that work together — what the industry calls microservices architecture.
In this chapter, you’ll learn what Spring Cloud is, when you need it, and when a monolith is actually the better choice.
What is Spring Cloud?
Spring Cloud is a collection of tools for building distributed systems on top of Spring Boot:
| Problem | Spring Cloud Solution |
|---|---|
| How do services find each other? | Eureka (Service Discovery) |
| How does traffic enter the system? | Spring Cloud Gateway (API Gateway) |
| What if a service is down? | Resilience4j (Circuit Breaker) |
| How do we manage config across services? | Spring Cloud Config |
| How do we trace requests across services? | Micrometer + Zipkin (Distributed Tracing) |
| How do services communicate asynchronously? | Spring Cloud Stream (Kafka/RabbitMQ) |
Monolith vs Microservices
| Monolith | Microservices | |
|---|---|---|
| Deploy | Single deployment unit | Each service deployed independently |
| Scale | Scale everything together | Scale individual services |
| Complexity | Simple to start | Complex (networking, data consistency) |
| Team size | Small teams | Large organizations |
| Best for | Most startups, small teams | Large-scale systems with multiple teams |
Start with a well-structured monolith. Decompose into microservices only when you have a real scaling or organizational need.
What’s Next?
In the next chapter, you’ll learn microservices architecture patterns and build your first multi-service system.
