Spring Cloud microservice architecture: achieving seamless collaboration in distributed systems

Article directory

- - 1. What is microservice architecture?
  - 2. Introduction to Spring Cloud
  - 3. Build microservices using Spring Cloud
  - - 3.1 Create Spring Boot application
    - 3.2 Add Spring Cloud dependency
    - 3.3 Configuring the application
    - 3.4 Create REST endpoint
    - 3.5 Connecting various services
    - 3.6 Start the Eureka server
  - 4. Build a distributed system
  - - 4.1 Service registration and discovery
    - 4.2 Load balancing
    - 4.3 Configuration management
    - 4.4 Circuit breaker mode
    - 4.5 Gateway
    - 4.6 Distributed Tracing
  - 5. Summary

Welcome to the architecture design column ~ Spring Cloud microservice architecture: achieving seamless collaboration in distributed systems

☆* o(≧▽≦)o *☆Hi~I am IT·Chen Han

?Blog homepage: IT·Chen Han’s blog

Column of this series of articles: Architecture design

Other columns: Java learning route, Java interview skills, Java practical projects, AIGC artificial intelligence, data structure learning

The author of the article has limited skills and level. If there are errors in the article, I hope everyone can correct them

Welcome everyone to pay attention!

The rise of distributed systems has changed the face of software development. As applications continue to grow in size, monolithic architectures can no longer meet the needs of modern applications. Microservices architecture emerged as an ideal choice for building scalable, highly available, and easy-to-maintain distributed systems. As a complete microservice architecture solution, Spring Cloud provides developers with tools and frameworks for seamless collaboration. This article will delve into the core concepts and components of Spring Cloud microservice architecture and how to build a complete distributed system.

1. What is microservice architecture?

Before diving into Spring Cloud, let us first understand what microservice architecture is. Microservices architecture is a software architecture pattern that splits an application into a set of small, independent services. Each service has its own database and business logic and can be deployed and scaled independently. The main goal of this architectural pattern is to improve the scalability, maintainability, and extensibility of the system.

Key features of microservices architecture include:

Split services: Split a large application into multiple smaller services, each responsible for a specific business area.
Independent deployment: Each microservice can be deployed independently without affecting other services.
Loose coupling: Microservices communicate through APIs, and the degree of coupling between them is low.
Independent technology stack: Each microservice can use a different technology stack, choosing the tools and languages that best suit its needs.
Easy to scale: Each microservice can be scaled independently as needed without scaling the entire application.
Fault tolerance: Microservice architecture can provide fault tolerance, so even if a certain service fails, the system can still continue to run.

2. Introduction to Spring Cloud

Spring Cloud is a project in the Spring ecosystem that aims to simplify the task of building distributed systems. It provides a set of tools and frameworks for handling common problems in distributed systems, such as service discovery, load balancing, configuration management, circuit breaker pattern, etc. Spring Cloud is built on Spring Boot and takes advantage of Spring Boot’s automatic configuration and rapid development capabilities.

The core components of Spring Cloud include:

Service registration and discovery: Through service registration and discovery components (such as Eureka, Consul, etc.), microservices can automatically register and discover other services, thereby realizing communication between services.
Load balancing: Through a load balancer (such as Ribbon), requests can be evenly distributed to multiple instances, improving system availability and performance.
Configuration Management: Spring Cloud Config allows the application’s configuration to be stored in one place and distributed to individual microservices.
Circuit breaker mode: Hystrix is a library that implements the circuit breaker mode, which can prevent fault propagation between services and improve the stability of the system.
Gateway: Zuul is a microservice gateway that can handle inbound and outbound traffic of all microservices and provides routing, filtering and other functions.
Distributed Tracing: Spring Cloud Sleuth and Zipkin can be used to track the flow of requests between different microservices for performance monitoring and troubleshooting.

3. Build microservices using Spring Cloud

Next, we will demonstrate how to use Spring Cloud to build a simple microservice system. Suppose we are developing an e-commerce platform, including product catalog, shopping cart and order service. Each service is an independent microservice and they can collaborate through HTTP communication.

3.1 Create Spring Boot application

First, we will create three Spring Boot applications, representing the product catalog service, shopping cart service, and order service. Every application can use Spring Initializr for fast initialization.

3.2 Add Spring Cloud dependency

In each application’s pom.xml file, add the Spring Cloud dependency. For example, for the product catalog service, you can add the following dependency:

<dependency>
    <groupId>org.springframework.cloud</groupId>
    <artifactId>spring-cloud-starter-netflix-eureka-client</artifactId>
</dependency>

This will allow the service to register with the Eureka server and become one of the discoverable services.

3.3 Configuring Applications

In each application’s configuration file, configure the Eureka client to connect to the Eureka server. An example configuration is as follows:

spring:
  application:
    name: product-service
eureka:
  client:
    serviceUrl:
      defaultZone: http://eureka-server:8761/eureka/

This will tell the product catalog service to register itself at http://eureka-server:8761/eureka/.

3.4 Create REST endpoint

In each application, create REST endpoints to provide services. For example, a product catalog service might have an endpoint for getting product information:

@RestController
@RequestMapping("/products")
public class ProductController {<!-- -->
    
    @GetMapping("/{productId}")
    public Product getProduct(@PathVariable Long productId) {<!-- -->
        //Business logic for querying product information
    }
}

3.5 Connecting various services

Now, we can establish connections between various services by using RestTemplate or Feign. For example, the shopping cart service can call the product catalog service to add products to the shopping cart.

@FeignClient(name = "product-service")
public interface ProductServiceClient {<!-- -->
    
    @GetMapping("/products/{productId}")
    Product getProduct(@PathVariable Long productId);
}

The shopping cart service can use ProductServiceClient to call the getProduct method of the product catalog service.

3.6 Start Eureka server

Finally, we need to start the Eureka server so that all microservices can be registered and discovered. You can use the following code to start the Eureka server:

@EnableEurekaServer
@SpringBootApplication
public class EurekaServerApplication {<!-- -->
    
    public static void main(String[] args) {<!-- -->
        SpringApplication.run(EurekaServerApplication.class, args);
    }
}

4. Building a distributed system

Through the above steps, we have created three microservices: product catalog service, shopping cart service and order service, and used Eureka for service registration and discovery. Now, let’s see how to build a distributed system.

4.1 Service registration and discovery

When we start individual microservices, they will automatically register with the Eureka server. This means that each microservice knows the location of other microservices and can call them by their service name. For example, the shopping cart service can call the product catalog service in the following ways:

Product product = productServiceClient.getProduct(productId);

4.2 Load Balancing

Spring Cloud also provides load balancing support. Through Ribbon, we can distribute requests among multiple service instances, thereby improving system availability and performance. By default, Ribbon uses a round-robin algorithm to select target instances.

4.3 Configuration Management

Spring Cloud Config allows us to store the application’s configuration in one place and distribute it to individual microservices. This means we can change the configuration without redeploying the service, thus enabling dynamic configuration.

4.4 Circuit breaker mode

Using Hystrix, we can implement a circuit breaker pattern to prevent fault propagation between services. If a service becomes unavailable, Hystrix will provide an alternate response or perform degradation logic instead of failing.

4.5 Gateway

As a microservices gateway, Zuul can handle inbound and outbound traffic for all microservices. It can perform functions such as routing, filtering, authentication, etc. to protect our microservices.

4.6 Distributed Tracing

Spring Cloud Sleuth and Zipkin can be used to track the flow of requests between different microservices. This is useful for performance monitoring and troubleshooting.

5. Summary

Spring Cloud provides a wealth of tools and frameworks for building microservice architecture, allowing developers to easily build distributed systems. Spring Cloud simplifies the development and management of distributed systems through functions such as service registration and discovery, load balancing, configuration management, circuit breaker mode, gateways, and distributed tracing.

If you are considering adopting a microservices architecture, Spring Cloud is a powerful choice that can help you build scalable, highly available, and easy-to-maintain distributed systems. Whether you are a beginner or an experienced developer, mastering Spring Cloud will become an important skill for developing distributed systems.

So, let’s embark on the journey of microservices and build a more powerful distributed system!

End Thank you for your support and encouragement!
Content you may be interested in:

[Java Interview Skills] Java Interview Eight-Part Essay – Mastering the Essential Knowledge for Interviews (Contents)

[Java Learning Roadmap] 2023 Full Version Java Learning Roadmap

[AIGC Artificial Intelligence] What is Chat GPT? How do beginners use Chat GPT? What should you pay attention to?

[Java Practical Project] SpringBoot + SSM Practical: Create an efficient and convenient enterprise-level Java takeout ordering system

[Data Structure Learning] Starting from Scratch: The Complete Path to Learning Data Structures