Spring Cloud - Introduction

Before we look at Spring Cloud, let’s have a brief overview on Microservice Architecture and the role of Spring Boot in creating microservices.

Microservice Architecture

Microservice architecture is a style of application development where the application is broken down into small services and these services have loose coupling among them. Following are the major advantages of using microservice architecture −

  • Easy to maintain − Microservices are small in size and are supposed to handle only single business task. So, they are simple to develop and maintain.
  • Independent Scaling & Deployment − Microservices have their individual deployment pattern and cadence. So, each service can be scaled based on the load which that service is supposed to cater to. Each service can be deployed based on its schedule.
  • Independent Technology Usage − Microservices have their code base segregated from the deployment environment, so the language and the technology that a microservice needs to use can be decided based on the use-case. There is no need to have a common stack to be used in all microservices.

More details about Microservice Architecture can be found at Microservice Architecture

Spring Boot

Spring Boot is a Java-based framework which is used to create microservices which are used in microservice architecture. It further brings down the time needed to develop a Spring application. Following are the major benefits it provides −

  • It is easy to understand and develop a Spring application
  • Increases productivity
  • Reduces the development time

More info on Spring Boot can be found at −Spring Boot

Spring Cloud

Spring Cloud provides a collection of components which are useful in building distributed applications in cloud. We can develop these components on our own, however that would waste time in developing and maintaining this boilerplate code.

That is where Spring Cloud comes into picture. It provides ready-to-use cloud patterns for common problems which are observed in a distributed environment. Some of the patterns which it attempts to address are −

  • Distributed Messaging
  • Load Balancing
  • Circuit Breakers
  • Routing
  • Distributed Logging
  • Service Registration
  • Distributed Lock
  • Centralized Configuration

That is why, it becomes a very useful framework in developing applications which require high scalability, performance, and availability.

In this tutorial, we are going to cover the above-listed components of Spring Cloud.

Benefits of Using Spring Cloud

  • Developers focus on Business Logic − Spring Cloud provides all the boilerplate code to implement common design patterns of the cloud. Developers thus can focus on the business logic without the need to develop and maintain this boilerplate code.
  • Quick Development Time − As the developers get the boilerplate for free, they can quickly deliver on the required projects while maintaining code quality.
  • Easy to use − Spring Cloud projects can easily be integrated with existing Spring Projects.
  • Active Project − Spring Cloud is actively maintained by Pivotal that is the company behind Spring. So, we get all the new features and bug-fixes for free just by upgrading the Spring Cloud version.

Microservice architecture has multiple advantages; however, one of its most critical drawbacks is its deployment in a distributed environment. And with the distributed systems, we have some common problems that frequently creep up, for example −

  • How does service A know where to contact service B, i.e., address of service B?
  • How do multiple services communicate with each other, i.e., what protocol to use?
  • How do we monitor various services in our environment?
  • How do we distribute the configuration of the service with the service instance?
  • How do we link the calls which travel across services for debugging purposes?
  • and so on…

These are the set of problems which Spring Cloud tries to address and provide common solution to.

While Spring Boot is used for quick application development, using it along with Spring Cloud can reduce time to integrate our microservices which we develop and deploy in a distributed environment.

Spring Cloud Components

Let us now take a look at the various components which Spring Cloud provides and the problems these components solve

Problem                                         Components

Distributed Cloud Configuration Spring Cloud Configuration, Spring Cloud Zookeeper, Spring Consul Config
Distributed Messaging                 Spring Stream with Kafka, Spring Stream with RabbitMQ
Service Discovery                         Spring Cloud Eureka, Spring Cloud Consul, Spring Cloud                                                                         Zookeeper
Logging                                         Spring Cloud Zipkin, Spring Cloud Sleuth
Spring Service Communication Spring Hystrix, Spring Ribbon, Spring Feign, Spring Zuul

We will look at a few of these components in the upcoming chapters.

Difference between Spring Cloud and Spring Boot

This a very common question that arises when starting with Spring Cloud. Actually, there is no comparison here. Both Spring Cloud and Spring Boot are used to achieve different goals.

Spring Boot is a Java framework which is used for quicker application development, and is specifically used in Microservice architecture.

Spring cloud is used for integrating these micro-services so that they can easily work together in a distributed environment and can communicate with each other

In fact, to avail maximum benefits like less development time, it is recommended to use Spring Boot along with Spring Cloud.