Spring Cloud之Ribbon与Nginx区别

客户端负载均衡器

在SpringCloud中Ribbon负载均衡客户端，会从eureka注册中心服务器端上获取服务注册信息列表，缓存到本地。

让后在本地实现轮训负载均衡策略。

Ribbon与Nginx区别

1.服务器端负载均衡Nginx

nginx是客户端所有请求统一交给nginx，由nginx进行实现负载均衡请求转发，属于服务器端负载均衡。

既请求有nginx服务器端进行转发。

2.客户端负载均衡Ribbon

Ribbon是从eureka注册中心服务器端上获取服务注册信息列表，缓存到本地，让后在本地实现轮训负载均衡策略。

既在客户端实现负载均衡。

应用场景的区别：

Nginx适合于服务器端实现负载均衡比如Tomcat ，Ribbon适合与在微服务中RPC远程调用实现本地服务负载均衡，比如Dubbo、SpringCloud中都是采用本地负载均衡。

Ribbon是Spring Cloud （本地）客户端负载均衡器

Ribbon底层实现：

Member：

pom：

<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">

  <modelVersion>4.0.0</modelVersion>

  <groupId>com.toov5</groupId>

  <artifactId>member</artifactId>

  <version>0.0.1-SNAPSHOT</version>

	<parent>

		<groupId>org.springframework.boot</groupId>

		<artifactId>spring-boot-starter-parent</artifactId>

		<version>2.0.1.RELEASE</version>

	</parent>

	<!-- 管理依赖 -->

	<dependencyManagement>

		<dependencies>

			<dependency>

				<groupId>org.springframework.cloud</groupId>

				<artifactId>spring-cloud-dependencies</artifactId>

				<version>Finchley.M7</version>

				<type>pom</type>

				<scope>import</scope>

			</dependency>

		</dependencies>

	</dependencyManagement>

	<dependencies>

		<!-- SpringBoot整合Web组件 -->

		<dependency>

			<groupId>org.springframework.boot</groupId>

			<artifactId>spring-boot-starter-web</artifactId>

		</dependency>

		<!-- SpringBoot整合eureka客户端 -->

		<dependency>

			<groupId>org.springframework.cloud</groupId>

			<artifactId>spring-cloud-starter-netflix-eureka-client</artifactId>

		</dependency>

	</dependencies>

	<!-- 注意： 这里必须要添加， 否者各种依赖有问题 -->

	<repositories>

		<repository>

			<id>spring-milestones</id>

			<name>Spring Milestones</name>

			<url>https://repo.spring.io/libs-milestone</url>

			<snapshots>

				<enabled>false</enabled>

			</snapshots>

		</repository>

	</repositories>

</project>

　　yml：

###服务启动端口号

server:

  port: 8009

###服务名称(服务注册到eureka名称)

spring:

    application:

        name: app-toov5-member

###服务注册到eureka地址

eureka:

  client:

    service-url:

    ##当前会员注册到eureka服务  地址+端口号

           defaultZone: http://127.0.0.1:8100/eureka

###因为该应用为注册中心，不会注册自己

    register-with-eureka: true

###是否需要从eureka上获取注册信息

    fetch-registry: true

Controller类

package com.toov5.api.controller;

import org.springframework.beans.factory.annotation.Value;

import org.springframework.web.bind.annotation.RequestMapping;

import org.springframework.web.bind.annotation.RestController;

@RestController

public class MemberApiController {

    @Value("${server.port}")

    private String serverPort;

    @RequestMapping("/getMember")

  public String getMember() {

        return "会员服务"+serverPort;

  }

}

启动类：

package com.toov5.api;

import org.springframework.boot.SpringApplication;

import org.springframework.boot.autoconfigure.SpringBootApplication;

import org.springframework.cloud.netflix.eureka.EnableEurekaClient;

@SpringBootApplication

@EnableEurekaClient   //注册到eureka

public class AppMember {

    public static void main(String[] args) {

        SpringApplication.run(AppMember.class, args);

    }

}

Order

Controlller

package com.toov5.api.controller;

import java.util.List;

import org.springframework.beans.factory.annotation.Autowired;

import org.springframework.cloud.client.ServiceInstance;

import org.springframework.cloud.client.discovery.DiscoveryClient;

import org.springframework.web.bind.annotation.RequestMapping;

import org.springframework.web.bind.annotation.RestController;

import org.springframework.web.client.RestTemplate;

//纯手写Ribbon本地负载均衡

@RestController

public class ExtRibbonController {

    @Autowired

    private DiscoveryClient discoveryClient;

    @Autowired

    private RestTemplate restTemplate;

    //定义请求数

    private int reqCount;

@RequestMapping("/ribbonMember")

   public String ribbonMember() {

       //互殴去对应服务器远程调用地址

      String  instanceUrl =  getInstance()+"/getMember";

      System.out.println("instanceUrl"+instanceUrl);

        //直接使用httpclient远程调用。本次使用rest方式

      String result = restTemplate.getForObject(instanceUrl, String.class);  //底层使用httpclient实现的

       return result;

   }

   private String getInstance() {

       List<ServiceInstance> instances = discoveryClient.getInstances("app-toov5-member");

       if (instances==null || instances.size()==0) {

        return null;

    }

       int instanceSize = instances.size();

       int serviceIndex = reqCount%instanceSize;

       reqCount++;

       return instances.get(serviceIndex).getUri().toString();

   }

}

启动类：

package com.toov5.api.controller;

import org.springframework.boot.SpringApplication;

import org.springframework.boot.autoconfigure.SpringBootApplication;

import org.springframework.cloud.netflix.eureka.EnableEurekaClient;

import org.springframework.context.annotation.Bean;

import org.springframework.web.client.RestTemplate;

@SpringBootApplication

@EnableEurekaClient

public class AppOrder {

  public static void main(String[] args) {

    SpringApplication.run(AppOrder.class, args);

}

  //解决RestTemplate找不到问题  把restTemplate注册到Spring Boot容器中

  @Bean

//  @LoadBalanced   手写的 不要去实现本地负载均衡效果了

  RestTemplate restTemplate() {

      return new RestTemplate();

  }

}

yml：

###服务启动端口号

server:

  port: 8002

###服务名称(服务注册到eureka名称)

spring:

    application:

        name: app-toov5-order

###服务注册到eureka地址

eureka:

  client:

    service-url:

           defaultZone: http://127.0.0.1:8100/eureka

###因为该应用为注册中心，不会注册自己

    register-with-eureka: true

###是否需要从eureka上获取注册信息

    fetch-registry: true

　　pom

<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">

  <modelVersion>4.0.0</modelVersion>

  <groupId>com.toov5</groupId>

  <artifactId>order</artifactId>

  <version>0.0.1-SNAPSHOT</version>

  <parent>

		<groupId>org.springframework.boot</groupId>

		<artifactId>spring-boot-starter-parent</artifactId>

		<version>2.0.1.RELEASE</version>

	</parent>

	<!-- 管理依赖 -->

	<dependencyManagement>

		<dependencies>

			<dependency>

				<groupId>org.springframework.cloud</groupId>

				<artifactId>spring-cloud-dependencies</artifactId>

				<version>Finchley.M7</version>

				<type>pom</type>

				<scope>import</scope>

			</dependency>

		</dependencies>

	</dependencyManagement>

	<dependencies>

		<!-- SpringBoot整合Web组件 -->

		<dependency>

			<groupId>org.springframework.boot</groupId>

			<artifactId>spring-boot-starter-web</artifactId>

		</dependency>

		<!-- SpringBoot整合eureka客户端 -->

		<dependency>

			<groupId>org.springframework.cloud</groupId>

			<artifactId>spring-cloud-starter-netflix-eureka-client</artifactId>

		</dependency>

	</dependencies>

	<!-- 注意： 这里必须要添加， 否者各种依赖有问题 -->

	<repositories>

		<repository>

			<id>spring-milestones</id>

			<name>Spring Milestones</name>

			<url>https://repo.spring.io/libs-milestone</url>

			<snapshots>

				<enabled>false</enabled>

			</snapshots>

		</repository>

	</repositories>

</project>

　　Eureka

pom

<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">

  <modelVersion>4.0.0</modelVersion>

  <groupId>com.toov5</groupId>

  <artifactId>SpringCloud-eureka-server</artifactId>

  <version>0.0.1-SNAPSHOT</version>

  <parent>

		<groupId>org.springframework.boot</groupId>

		<artifactId>spring-boot-starter-parent</artifactId>

		<version>2.0.1.RELEASE</version>

	</parent>

	<!-- 管理依赖 -->

	<dependencyManagement>

		<dependencies>

			<dependency>

				<groupId>org.springframework.cloud</groupId>

				<artifactId>spring-cloud-dependencies</artifactId>

				<version>Finchley.M7</version>

				<type>pom</type>

				<scope>import</scope>

			</dependency>

		</dependencies>

	</dependencyManagement>

	<dependencies>

		<!--SpringCloud eureka-server -->

		<dependency>

			<groupId>org.springframework.cloud</groupId>

			<artifactId>spring-cloud-starter-netflix-eureka-server</artifactId>

		</dependency>

	</dependencies>

	<!-- 注意： 这里必须要添加， 否者各种依赖有问题 -->

	<repositories>

		<repository>

			<id>spring-milestones</id>

			<name>Spring Milestones</name>

			<url>https://repo.spring.io/libs-milestone</url>

			<snapshots>

				<enabled>false</enabled>

			</snapshots>

		</repository>

	</repositories>

</project>

　　yml

###eureka 服务端口号

server:

  port: 8100

###服务注册名称

eureka:

  instance:

  ##注册中心ip地址

    hostname: 127.0.0.1

###客户端调用地址

  client:

    serviceUrl:

      defaultZone: http://${eureka.instance.hostname}:${server.port}/eureka/

###因为该应用为注册中心，不会注册自己 （集群设为true）

    register-with-eureka: false

###因为自己为注册中心 ,不会去在该应用中的检测服务

    fetch-registry: false

package com.toov5;

import org.springframework.boot.SpringApplication;

import org.springframework.boot.autoconfigure.SpringBootApplication;

import org.springframework.cloud.netflix.eureka.server.EnableEurekaServer;

@EnableEurekaServer   //开启注册中心

@SpringBootApplication

public class AppEureka {

     public static void main(String[] args) {

           SpringApplication.run(AppEureka.class, args);

    }

}

启动访问：

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