springCloud3—ribbon

同一份代码，改变端口，就可以启动多个同名但是端口不一样的微服务。

客户端通过nginx来调用后面的多个用户微服务来实现负载均衡，这是服务端负载均衡。

客户端有一个组件，可以知道当前有几个用户微服务的ip和端口，客户端实现一个负载均衡算法，直接去调用用户微服务。Ribbon是实现了客户端负载均衡的组件。

Ribbon选择一个在同一个zone且负载少的eureka，从中拉取可用的服务提供者列表，放到客户端，然后在客户端实现一个负载均衡的算法，最后命中到某个节点。Ribbon提供了多种算法：轮询、随机、根据响应时间。默认负载均衡的策略是轮询。

通过代码自定义配置ribbon：

package com.itmuch.cloud;import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;
import org.springframework.cloud.client.loadbalancer.LoadBalanced;
import org.springframework.cloud.netflix.eureka.EnableEurekaClient;
import org.springframework.cloud.netflix.ribbon.RibbonClient;
import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.ComponentScan;
import org.springframework.context.annotation.FilterType;
import org.springframework.web.client.RestTemplate;@SpringBootApplication
@EnableEurekaClient
@RibbonClient(name = "microservice-provider-user", configuration = TestConfiguration.class)
//@ComponentScan扫的是他所在的包和子包
@ComponentScan(excludeFilters = { @ComponentScan.Filter(type = FilterType.ANNOTATION, value = ExcludeFromComponentScan.class) })
public class ConsumerMovieRibbonApplication {  @Bean
  @LoadBalanced//就一个注解。@LoadBalanced整合了ribbon,让RestTemplate具备负载均衡的能力
  public RestTemplate restTemplate() {
    return new RestTemplate();
  }  public static void main(String[] args) {
    SpringApplication.run(ConsumerMovieRibbonApplication.class, args);
  }
}

package com.itmuch.cloud;public @interface ExcludeFromComponentScan {}

package com.itmuch.cloud;import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;import com.netflix.loadbalancer.IRule;
import com.netflix.loadbalancer.RandomRule;@Configuration
@ExcludeFromComponentScan//否则所有的ribbon客户端都会使用RandomRule这个规则
public class TestConfiguration {
  //  @Autowired
  //  IClientConfig config;  @Bean
  public IRule ribbonRule() {
    return new RandomRule(); //随机选取一个微服务，也可以自己定义路由规则。
  }
}

package com.itmuch.cloud.controller;import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.cloud.client.ServiceInstance;
import org.springframework.cloud.client.loadbalancer.LoadBalancerClient;
import org.springframework.web.bind.annotation.GetMapping;
import org.springframework.web.bind.annotation.PathVariable;
import org.springframework.web.bind.annotation.RestController;
import org.springframework.web.client.RestTemplate;import com.itmuch.cloud.entity.User;@RestController
public class MovieController {
  @Autowired
  private RestTemplate restTemplate;
  @Autowired
  private LoadBalancerClient loadBalancerClient;  @GetMapping("/movie/{id}")
  public User findById(@PathVariable Long id) {
    // http://localhost:7900/simple/，microservice-provider-user是注册到eureka之后的一个虚拟主机名（页面有，microservice-provider-user工程的虚拟主机名）。
     //microservice-provider-user工程的配置文件中spring.application.name中定义。
    // VIP virtual IP。不再是通过服务提供者的ip和端口访问了。
    // HAProxy Heartbeat
    //spring:application:name:microservice-provider-user
    return this.restTemplate.getForObject("http://microservice-provider-user/simple/" + id, User.class);
  }  @GetMapping("/test")
  public String test() {
      //如果microservice-provider-user微服务有多个，可以看出命中的是哪个ip端口
    ServiceInstance serviceInstance = this.loadBalancerClient.choose("microservice-provider-user");
    System.out.println("111" + ":" + serviceInstance.getServiceId() + ":" + serviceInstance.getHost() + ":" + serviceInstance.getPort());    ServiceInstance serviceInstance2 = this.loadBalancerClient.choose("microservice-provider-user2");
    System.out.println("222" + ":" + serviceInstance2.getServiceId() + ":" + serviceInstance2.getHost() + ":" + serviceInstance2.getPort());    return "1";
  }
}

spring:
  application:
    name: microservice-consumer-movie-ribbon #自己的工程名字
server:
  port: 8010
eureka:
  client:
    healthcheck:
      enabled: true
    serviceUrl:
      defaultZone: http://user:password123@localhost:8761/eureka  #eureka server的地址
  instance:
    prefer-ip-address: true

<?xml version="1.0" encoding="UTF-8"?>
<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>    <artifactId>microservice-consumer-movie-ribbon</artifactId>
    <packaging>jar</packaging>    <parent>
        <groupId>com.itmuch.cloud</groupId>
        <artifactId>microservice-spring-cloud</artifactId>
        <version>0.0.1-SNAPSHOT</version>
    </parent>    <properties>
        <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
        <project.reporting.outputEncoding>UTF-8</project.reporting.outputEncoding>
        <java.version>1.8</java.version>
    </properties>    <dependencies>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-web</artifactId>
        </dependency>        <!-- ribbon注册到eureka上面去 -->
        <dependency>
            <groupId>org.springframework.cloud</groupId>
            <artifactId>spring-cloud-starter-eureka</artifactId>
        </dependency>        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-actuator</artifactId>
        </dependency>
    </dependencies>
</project>

通过配置文件自定义ribbon：

package com.itmuch.cloud;import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;
import org.springframework.cloud.client.loadbalancer.LoadBalanced;
import org.springframework.cloud.netflix.eureka.EnableEurekaClient;
import org.springframework.context.annotation.Bean;
import org.springframework.web.client.RestTemplate;@SpringBootApplication
@EnableEurekaClient
public class ConsumerMovieRibbonApplication {  @Bean
  @LoadBalanced//就一个注解。@LoadBalanced整合了ribbon,让RestTemplate具备负载均衡的能力
  public RestTemplate restTemplate() {
    return new RestTemplate();
  }  public static void main(String[] args) {
    SpringApplication.run(ConsumerMovieRibbonApplication.class, args);
  }
}

package com.itmuch.cloud.controller;import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.cloud.client.ServiceInstance;
import org.springframework.cloud.client.loadbalancer.LoadBalancerClient;
import org.springframework.web.bind.annotation.GetMapping;
import org.springframework.web.bind.annotation.PathVariable;
import org.springframework.web.bind.annotation.RestController;
import org.springframework.web.client.RestTemplate;import com.itmuch.cloud.entity.User;@RestController
public class MovieController {
  @Autowired
  private RestTemplate restTemplate;
  @Autowired
  private LoadBalancerClient loadBalancerClient;  @GetMapping("/movie/{id}")
  public User findById(@PathVariable Long id) {
    // http://localhost:7900/simple/
    // VIP virtual IP
    // HAProxy Heartbeat    ServiceInstance serviceInstance = this.loadBalancerClient.choose("microservice-provider-user");
    System.out.println("===" + ":" + serviceInstance.getServiceId() + ":" + serviceInstance.getHost() + ":" + serviceInstance.getPort());    return this.restTemplate.getForObject("http://microservice-provider-user/simple/" + id, User.class);
  }  @GetMapping("/test")
  public String test() {
    ServiceInstance serviceInstance = this.loadBalancerClient.choose("microservice-provider-user");
    System.out.println("111" + ":" + serviceInstance.getServiceId() + ":" + serviceInstance.getHost() + ":" + serviceInstance.getPort());    ServiceInstance serviceInstance2 = this.loadBalancerClient.choose("microservice-provider-user2");
    System.out.println("222" + ":" + serviceInstance2.getServiceId() + ":" + serviceInstance2.getHost() + ":" + serviceInstance2.getPort());    return "1";
  }
}

spring:
  application:
    name: microservice-consumer-movie-ribbon
server:
  port: 8010
eureka:
  client:
    healthcheck:
      enabled: true
    serviceUrl:
      defaultZone: http://user:password123@localhost:8761/eureka
  instance:
    prefer-ip-address: true
microservice-provider-user:   #请求这个微服务的时候
  ribbon:   #ribbon配置
    NFLoadBalancerRuleClassName: com.netflix.loadbalancer.RandomRule  #随机的rule去负载均衡

<?xml version="1.0" encoding="UTF-8"?>
<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>    <artifactId>microservice-consumer-movie-ribbon-properties-customizing</artifactId>
    <packaging>jar</packaging>    <parent>
        <groupId>com.itmuch.cloud</groupId>
        <artifactId>microservice-spring-cloud</artifactId>
        <version>0.0.1-SNAPSHOT</version>
    </parent>    <properties>
        <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
        <project.reporting.outputEncoding>UTF-8</project.reporting.outputEncoding>
        <java.version>1.8</java.version>
    </properties>    <dependencies>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-web</artifactId>
        </dependency>        <dependency>
            <groupId>org.springframework.cloud</groupId>
            <artifactId>spring-cloud-starter-eureka</artifactId>
        </dependency>        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-actuator</artifactId>
        </dependency>
    </dependencies>
</project>

Ribbon禁止eureka：

package com.itmuch.cloud;import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;
import org.springframework.cloud.client.loadbalancer.LoadBalanced;
import org.springframework.cloud.netflix.eureka.EnableEurekaClient;
import org.springframework.context.annotation.Bean;
import org.springframework.web.client.RestTemplate;@SpringBootApplication
@EnableEurekaClient
public class ConsumerMovieRibbonApplication {  @Bean
  @LoadBalanced
  public RestTemplate restTemplate() {
    return new RestTemplate();
  }  public static void main(String[] args) {
    SpringApplication.run(ConsumerMovieRibbonApplication.class, args);
  }
}

package com.itmuch.cloud.controller;import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.cloud.client.ServiceInstance;
import org.springframework.cloud.client.loadbalancer.LoadBalancerClient;
import org.springframework.web.bind.annotation.GetMapping;
import org.springframework.web.bind.annotation.PathVariable;
import org.springframework.web.bind.annotation.RestController;
import org.springframework.web.client.RestTemplate;import com.itmuch.cloud.entity.User;@RestController
public class MovieController {
  @Autowired
  private RestTemplate restTemplate;
  @Autowired
  private LoadBalancerClient loadBalancerClient;  @GetMapping("/movie/{id}")
  public User findById(@PathVariable Long id) {
    // http://localhost:7900/simple/
    // VIP virtual IP
    // HAProxy Heartbeat    ServiceInstance serviceInstance = this.loadBalancerClient.choose("microservice-provider-user");
    System.out.println("===" + ":" + serviceInstance.getServiceId() + ":" + serviceInstance.getHost() + ":" + serviceInstance.getPort());    return this.restTemplate.getForObject("http://microservice-provider-user/simple/" + id, User.class);
  }  @GetMapping("/test")
  public String test() {
    ServiceInstance serviceInstance = this.loadBalancerClient.choose("microservice-provider-user");
    System.out.println("111" + ":" + serviceInstance.getServiceId() + ":" + serviceInstance.getHost() + ":" + serviceInstance.getPort());    ServiceInstance serviceInstance2 = this.loadBalancerClient.choose("microservice-provider-user2");
    System.out.println("222" + ":" + serviceInstance2.getServiceId() + ":" + serviceInstance2.getHost() + ":" + serviceInstance2.getPort());    return "1";
  }
}

spring:
  application:
    name: microservice-consumer-movie-ribbon
server:
  port: 8010
eureka:
  client:
    healthcheck:
      enabled: true
    serviceUrl:
      defaultZone: http://user:password123@localhost:8761/eureka
  instance:
    prefer-ip-address: true
ribbon:
  eureka:
   enabled: false    #禁止ribbon中的eureka
microservice-provider-user: #请求这个微服务的时候（此时这个微服务有7900.7901.7904三个微服务），只访问7900
  ribbon:
    listOfServers: localhost:7900

<?xml version="1.0" encoding="UTF-8"?>
<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>    <artifactId>microservice-consumer-movie-ribbon-without-eureka</artifactId>
    <packaging>jar</packaging>    <parent>
        <groupId>com.itmuch.cloud</groupId>
        <artifactId>microservice-spring-cloud</artifactId>
        <version>0.0.1-SNAPSHOT</version>
    </parent>    <properties>
        <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
        <project.reporting.outputEncoding>UTF-8</project.reporting.outputEncoding>
        <java.version>1.8</java.version>
    </properties>    <dependencies>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-web</artifactId>
        </dependency>        <dependency>
            <groupId>org.springframework.cloud</groupId>
            <artifactId>spring-cloud-starter-eureka</artifactId>
        </dependency>        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-actuator</artifactId>
        </dependency>
    </dependencies>
</project>