Eureka集群和负载均衡

Eureka集群和负载均衡

#### 首先创建一个maven项目

1.先删除掉src，然后只留pom.xml

pom.xml

 <modules>
        <module>springcloud-api</module>
        <module>springcloud-provider-dept-8002</module>
        <module>springcloud-consumer-dept-80</module>
        <module>springcloud-eureka-7001</module>
        <module>springcloud-eurake-7002</module>
        <module>springcloud-eurake-7003</module>
        <module>springcloud-provider-dept-8003</module>
        <module>springcloud-provider-dept-8004</module>
        <module>springcloud-consumer-dept-feign</module>
        <module>springcloud-provider-dept-hystrix-8002</module>
​
    </modules>
    <!--打包方式-->
    <packaging>pom</packaging>
    <properties>
        <project.buile.sourceEncoding>UTF-8</project.buile.sourceEncoding>
        <maven-compiler-source>1.8</maven-compiler-source>
        <maven-compiler-target>1.8</maven-compiler-target>
        <junit.version>4.12</junit.version>
        <lombok.version>1.16.10</lombok.version>
        <log4j.version>1.2.17</log4j.version>
    </properties>
    <dependencyManagement>
        <dependencies>
            <!--springCloud的依赖-->
            <dependency>
                <groupId>org.springframework.cloud</groupId>
                <artifactId>spring-cloud-dependencies</artifactId>
                <version>Greenwich.SR1</version>
                <type>pom</type>
                <scope>import</scope>
            </dependency>
            <!--springboot-->
            <dependency>
                <groupId>org.springframework.boot</groupId>
                <artifactId>spring-boot-dependencies</artifactId>
                <version>2.1.4.RELEASE</version>
                <type>pom</type>
                <scope>import</scope>
            </dependency>
            <!--数据库的-->
            <dependency>
                <groupId>mysql</groupId>
                <artifactId>mysql-connector-java</artifactId>
                <version>5.1.47</version>
            </dependency>
            <dependency>
                <groupId>com.alibaba</groupId>
                <artifactId>druid</artifactId>
                <version>1.1.10</version>
            </dependency>
            <!--springboot启动器-->
            <dependency>
                <groupId>org.mybatis.spring.boot</groupId>
                <artifactId>mybatis-spring-boot-starter</artifactId>
                <version>1.3.4</version>
            </dependency>
            <!--junit-->
            <dependency>
                <groupId>junit</groupId>
                <artifactId>junit</artifactId>
                <version>${junit.version}</version>
            </dependency>
            <!--lombok-->
            <dependency>
                <groupId>org.projectlombok</groupId>
                <artifactId>lombok</artifactId>
                <version>${lombok.version}</version>
            </dependency>
            <!--log4j-->
            <dependency>
                <groupId>log4j</groupId>
                <artifactId>log4j</artifactId>
                <version>${log4j.version}</version>
            </dependency>
            <!--y用于日志和测试-->
            <dependency>
                <groupId>ch.qos.logback</groupId>
                <artifactId>logback-core</artifactId>
                <version>1.2.3</version>
            </dependency>
        </dependencies>
    </dependencyManagement>
</project>

创建springcloud-api

pom.xml

<?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">
    <parent>
        <artifactId>springcloud</artifactId>
        <groupId>com.liu</groupId>
        <version>1.0-SNAPSHOT</version>
    </parent>
    <modelVersion>4.0.0</modelVersion>
​
    <artifactId>springcloud-api</artifactId>
    <dependencies>
        <dependency>
            <groupId>org.projectlombok</groupId>
            <artifactId>lombok</artifactId>
        </dependency>
        <!--Feign做负载均衡时会在api里面加入fegin-->
        <dependency>
            <groupId>org.springframework.cloud</groupId>
            <artifactId>spring-cloud-starter-feign</artifactId>
            <version>1.4.6.RELEASE</version>
        </dependency>
    </dependencies>
​
</project>

创建Dept实体

package com.example.pojo;
​
import lombok.AllArgsConstructor;
import lombok.Data;
import lombok.NoArgsConstructor;
import lombok.experimental.Accessors;
​
import java.io.Serializable;
@Data
@NoArgsConstructor
@AllArgsConstructor
@Accessors(chain = true)
public class Dept implements Serializable {// 实体类
    private Long deptno;
    private String dname;
    // 这个数据存储在那个数据库的字段，为服务，一个服务对应一个数据库，
    // 同一个信息可能存在不同的数据库
    private String db_source;
​
    public Dept(String dname) {
        this.dname = dname;
    }
​
/*
    链式写法：
        Dept dept=new Dept();
        dept.setDeptNo(11).setDname('sss').setDb_source
 */
}
​

当Fegin做负载均衡时(会创建DeptClientService类进行接口传递)

package com.example.service;
​
import com.example.pojo.Dept;
import org.springframework.cloud.openfeign.FeignClient;
import org.springframework.stereotype.Component;
import org.springframework.web.bind.annotation.GetMapping;
import org.springframework.web.bind.annotation.PathVariable;
import org.springframework.web.bind.annotation.PostMapping;
​
import java.util.List;
​
@Component
@FeignClient(value = "SPRINGCLOUD-PROVIDER-DEPT")
public interface DeptClientService {
​
    @GetMapping("/dept/get/{id}")
    public Dept queryId(@PathVariable("id") Long id);
​
    @GetMapping("/dept/list")
    public List<Dept> queryAll();
​
    @PostMapping("/dept/add")
    public boolean addDept(Dept dept);
​
}
​

 

首先创建maven（springcloud-eureka-7001）

pom.xml

<dependencies>
        <dependency>
            <groupId>org.springframework.cloud</groupId>
            <artifactId>spring-cloud-starter-eureka-server</artifactId>
            <version>1.4.6.RELEASE</version>
        </dependency>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-devtools</artifactId>
        </dependency>
    </dependencies>

application.yml

server:
  port: 7001
#Eureka配置
eureka:
  instance:
    hostname: eureka7001.com #eureka服务端的实例名称
  client:
    register-with-eureka: false  #标识是否向服务端注册自己
    fetch-registry: false #如果为false，表示自己为注册中心
    service-url:  # 监控页面
      # 单机 defaultZone: http://${eureka.instance.hostname}:${server.port}/eureka/
      # 集群（关联） defaultZone: http://${eureka.instance.hostname}:${server.port}/eureka/
      defaultZone: http://eureka7002.com:7002/eureka/,http://eureka7003.com:7003/eureka/

启动类

package com.example;
​
import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;
import org.springframework.cloud.netflix.eureka.server.EnableEurekaServer;
​
@SpringBootApplication
@EnableEurekaServer // 启动之后访问http://localhost:7001
public class EurekaService_7001 {
    public static void main(String args[]){
        SpringApplication.run(EurekaService_7001.class,args);
    }
}

创建maven(springcloud-eurake-7002)

pom.xml和启动类和7001相同（启动类名称不能一样）

server:
  port: 7002
​
#Eureka配置
eureka:
  instance:
    hostname: eureka7002.com #eureka服务端的实例名称
  client:
    register-with-eureka: false  #标识是否向服务端注册自己
    fetch-registry: false #如果为false，表示自己为注册中心
    service-url:  # 监控页面
      defaultZone: http://eureka7001.com:7001/eureka/,http://eureka7003.com:7003/eureka/

 

创建maven(springcloud-eurake-70023

pom.xml和启动类和7001相同（启动类名称不能一样）

server:
  port: 7003
​
#Eureka配置
eureka:
  instance:
    hostname: eureka7003.com #eureka服务端的实例名称
  client:
    register-with-eureka: false  #标识是否向服务端注册自己
    fetch-registry: false #如果为false，表示自己为注册中心
    service-url:  # 监控页面
      defaultZone: http://eureka7001.com:7001/eureka/,http://eureka7002.com:7002/eureka/

创建maven（springcloud-provider-dept-8002）

pom.xml

 <dependencies>
        <!--加入eureka依赖-->
        <dependency>
            <groupId>org.springframework.cloud</groupId>
            <artifactId>spring-cloud-starter-eureka</artifactId>
            <version>1.4.6.RELEASE</version>
        </dependency>
        <!--增加Eureka监控用的配置依赖-->
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-actuator</artifactId>
        </dependency>
        <dependency>
            <groupId>com.liu</groupId>
            <artifactId>springcloud-api</artifactId>
            <version>1.0-SNAPSHOT</version>
        </dependency>
        <dependency>
            <groupId>junit</groupId>
            <artifactId>junit</artifactId>
        </dependency>
        <dependency>
            <groupId>mysql</groupId>
            <artifactId>mysql-connector-java</artifactId>
        </dependency>
        <dependency>
            <groupId>com.alibaba</groupId>
            <artifactId>druid</artifactId>
        </dependency>
        <dependency>
            <groupId>ch.qos.logback</groupId>
            <artifactId>logback-core</artifactId>
        </dependency>
        <dependency>
            <groupId>org.mybatis.spring.boot</groupId>
            <artifactId>mybatis-spring-boot-starter</artifactId>
        </dependency>
        <!--test-->
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-test</artifactId>
        </dependency>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-web</artifactId>
        </dependency>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-jetty</artifactId>
        </dependency>
        <!--热部署工具-->
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-devtools</artifactId>
        </dependency>
    </dependencies>

创建mapper

package com.example.mapper;
​
import com.example.pojo.Dept;
import org.apache.ibatis.annotations.Insert;
import org.apache.ibatis.annotations.Mapper;
import org.apache.ibatis.annotations.Param;
import org.apache.ibatis.annotations.Select;
import org.springframework.stereotype.Repository;
​
import java.util.List;
​
@Mapper
@Repository
public interface DeptMapper {
    @Insert(value = "insert into dept values(default,#{dept.dname},DATABASE())")
    public boolean addDept(@Param("dept") Dept dept);
    @Select("select * from dept where deptno=#{deptno}")
    public Dept queryById(@Param("deptno") Long id);
    @Select("select * from dept")
    public List<Dept> query();
}

创建service

package com.example.service;
​
import com.example.mapper.DeptMapper;
import com.example.pojo.Dept;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Service;
​
import java.util.List;
​
@Service
public class DeptService {
    @Autowired
    private DeptMapper deptMapper;
​
    public boolean addDept(Dept dept) {
        return deptMapper.addDept(dept);
    }
​
    public Dept queryById(Long id) {
        return deptMapper.queryById(id);
    }
​
    public List<Dept> query() {
        return deptMapper.query();
    }
}
​

创建Controller

package com.example.springcloud.controller;
​
import com.example.pojo.Dept;
import com.example.service.DeptService;
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.GetMapping;
import org.springframework.web.bind.annotation.PathVariable;
import org.springframework.web.bind.annotation.PostMapping;
import org.springframework.web.bind.annotation.RestController;
​
import java.util.List;
​
@RestController
public class DeptController {
    @Autowired
    private DeptService deptService;
​
    // 获取 一些配置信息，得到具体的微服务
    @Autowired
    private DiscoveryClient discoveryClient;
​
    @PostMapping("/dept/add")
    public boolean addDept(Dept dept) {
        return deptService.addDept(dept);
​
    }
​
    @GetMapping("/dept/get/{id}")
    public Dept get(@PathVariable("id") Long id) {
        Dept dept = deptService.queryById(id);
        if(dept==null){
            throw new RuntimeException("fail Please check you Code");
        }
        return dept;
​
    }
​
    @GetMapping("/dept/list")
    public List<Dept> addDept() {
        return deptService.query();
​
    }
​
    // 注册进来的微服务，获取一些信息‘ 这方法并非是业务代码，只是显示微服务的接口信息
    @GetMapping("/dept/discovery")
    public Object discovery() {
        // 获取到服务的列表清单
        List<String> services = discoveryClient.getServices();
        System.out.println("discovery=>services:" + services);
​
        List<ServiceInstance> instances = discoveryClient.getInstances("SPRINGCLOUD-PROVIDER-DEPT");
        for (ServiceInstance instance : instances) {
            System.out.println(
                    instance.getHost() + "	" +
                            instance.getPort() + "	" +
                            instance.getUri() + "	" +
                            instance.getServiceId()
            );
        }
        return this.discoveryClient;
    }
}
​

启动类

package com.example;
​
import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;
import org.springframework.cloud.client.discovery.EnableDiscoveryClient;
import org.springframework.cloud.netflix.eureka.EnableEurekaClient;
​
@SpringBootApplication
@EnableEurekaClient // 在服务开启之后会自动注册到eureka中
@EnableDiscoveryClient // 服务发现·
public class DeptProvider_8002 {
    public static void main(String args[]) {
        SpringApplication.run(DeptProvider_8002.class, args);
    }
}

application.yml配置

server:
  port: 8002
spring:
  application:
    name: springcloud-provider-dept
  datasource:
    url: jdbc:mysql://localhost:3306/mytest?serverTimezone=UTC&useUnicode=true&characterEncoding=utf8&useSSL=false
    username: root
    password: root
    driver-class-name: com.mysql.jdbc.Driver
    type: com.alibaba.druid.pool.DruidDataSource
mybatis:
  # model的包
  type-aliases-package: com.example.pojo
  configuration:
#  　　 开启驼峰uName自动映射到u_name
      map-underscore-to-camel-case: true
​
# eureka的配置
eureka:
  client:
    service-url:
      defaultZone: http://localhost:7001/eureka/,http://localhost:7002/eureka/,http://localhost:7003/eureka/
  instance:
    instance-id: springcloud-provider-dept-8002
    prefer-ip-address: true # true可以显示服务的IP地址
​
# info 配置
info:
  app.name: liuli-springcloud
  company.name: baidu.com

如果需要创建多个负责均衡的话，则创建的maven项目和springcloud-provider-dept-8002相似，不过需要改端口号，数据库名，instance-id:

=======================================================================================

创建消费客户端maven(springcloud-consumer-dept-80)(带有Ribbon负载均衡)

pom.xml

 <build>
        <plugins>
            <plugin>
                <groupId>org.apache.maven.plugins</groupId>
                <artifactId>maven-compiler-plugin</artifactId>
                <configuration>
                    <source>7</source>
                    <target>7</target>
                </configuration>
            </plugin>
        </plugins>
    </build>
​
    <!--实体类+web-->
    <dependencies>
        <!--Ribbon-->
        <dependency>
            <groupId>org.springframework.cloud</groupId>
            <artifactId>spring-cloud-starter-ribbon</artifactId>
            <version>1.4.6.RELEASE</version>
        </dependency>
        <!--Eurake-->
        <dependency>
            <groupId>org.springframework.cloud</groupId>
            <artifactId>spring-cloud-starter-eureka</artifactId>
            <version>1.4.6.RELEASE</version>
        </dependency>
​
        <dependency>
            <groupId>com.liu</groupId>
            <artifactId>springcloud-api</artifactId>
            <version>1.0-SNAPSHOT</version>
        </dependency>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-web</artifactId>
        </dependency>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-devtools</artifactId>
        </dependency>
    </dependencies>

application.yml

server:
  port: 80
​
#Eurake配置
eureka:
  client:
    register-with-eureka: false # 不向eurake注册自己
    service-url:
      defaultZone: http://eureka7001.com:7001/eureka/,http://eureka7002.com:7002/eureka/,http://eureka7003.com:7003/eureka/
​

创建DeptConsumerController

package com.example.springcloud.controller;
​
import com.example.pojo.Dept;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.web.bind.annotation.PathVariable;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RestController;
import org.springframework.web.client.RestTemplate;
​
import java.util.List;
​
@RestController
public class DeptConsumerController {
​
​
    @Autowired
    private RestTemplate restTemplate;
​
    // Ribbon 我们这里的地址，应该是一个变量，通过服务者来访问
//    private static final String REST_URL_PREFIX="http://localhost:8002";
    private static final String REST_URL_PREFIX="http://SPRINGCLOUD-PROVIDER-DEPT";
​
    @RequestMapping("/consumer/dept/get/{id}")
    public Dept get(@PathVariable("id")Long id){
        return restTemplate.getForObject(REST_URL_PREFIX+"/dept/get/"+id,Dept.class);
    }
    @RequestMapping("/consumer/dept/add")
    public boolean add(Dept dept){
        System.out.println("客户端的信息=>"+dept);
        return restTemplate.postForObject(REST_URL_PREFIX+"/dept/add?",dept,Boolean.class);
    }
    @RequestMapping("/consumer/dept/list")
    public List<Dept> get(){
        return restTemplate.getForObject(REST_URL_PREFIX+"/dept/list",List.class);
    }
}

创建config配置类

package com.example.springcloud.config;
​
import org.springframework.cloud.client.loadbalancer.LoadBalanced;
import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;
import org.springframework.web.client.RestTemplate;
​
@Configuration
public class ConfigBean {
    // 配置负载均衡实现RestTemplate
    @Bean
    @LoadBalanced // Ribbon
    public RestTemplate getRestTemplate(){
        return  new RestTemplate();
    }
​
}

创建Ribbon负载均衡类（tip：这个类的位置不可以和启动类同级，放在启动类的上一级目录）

package com.example.myrule;
​
import com.netflix.loadbalancer.IRule;
import com.netflix.loadbalancer.RandomRule;
import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;
​
@Configuration
public class RibbonRuleDemo {
    @Bean
    public IRule myRule() {
        return new RandomRule();
    }
}

启动类

package com.example.springcloud;
​
import com.example.myrule.RibbonRuleDemo;
import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;
import org.springframework.cloud.netflix.eureka.EnableEurekaClient;
import org.springframework.cloud.netflix.ribbon.RibbonClient;
​
// Ribbon 和 Eureka整合以后，客户端可以直接调用
@SpringBootApplication
@EnableEurekaClient
@RibbonClient(name = "SPRINGCLOUD-PROVIDER-DEPT",configuration = RibbonRuleDemo.class)
public class DeptConsumer_80 {
public  static void main(String args[]){
    SpringApplication.run(DeptConsumer_80.class,args);
}
}
​

Fegin做负载均衡时

创建maven项目（springcloud-consumer-dept-feign）

<?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">
    <parent>
        <artifactId>springcloud</artifactId>
        <groupId>com.liu</groupId>
        <version>1.0-SNAPSHOT</version>
    </parent>
    <modelVersion>4.0.0</modelVersion>
​
    <artifactId>springcloud-consumer-dept-feign</artifactId>
    <!--实体类+web-->
    <dependencies>
        <!--Feign-->
        <dependency>
            <groupId>org.springframework.cloud</groupId>
            <artifactId>spring-cloud-starter-feign</artifactId>
            <version>1.4.6.RELEASE</version>
        </dependency>
        <!--Ribbon-->
        <dependency>
            <groupId>org.springframework.cloud</groupId>
            <artifactId>spring-cloud-starter-ribbon</artifactId>
            <version>1.4.6.RELEASE</version>
        </dependency>
        <!--Eurake-->
        <dependency>
            <groupId>org.springframework.cloud</groupId>
            <artifactId>spring-cloud-starter-eureka</artifactId>
            <version>1.4.6.RELEASE</version>
        </dependency>
​
        <dependency>
            <groupId>com.liu</groupId>
            <artifactId>springcloud-api</artifactId>
            <version>1.0-SNAPSHOT</version>
        </dependency>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-web</artifactId>
        </dependency>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-devtools</artifactId>
        </dependency>
    </dependencies>
​
</project>

application.yml

server:
  port: 80
​
#Eurake配置
eureka:
  client:
    register-with-eureka: false # 不向eurake注册自己
    service-url:
      defaultZone: http://eureka7001.com:7001/eureka/,http://eureka7002.com:7002/eureka/,http://eureka7003.com:7003/eureka/
​
​

创建config配置类

package com.example.springcloud.config;
​
import org.springframework.cloud.client.loadbalancer.LoadBalanced;
import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;
import org.springframework.web.client.RestTemplate;
​
@Configuration
public class ConfigBean {
    // 配置负载均衡实现RestTemplate
    @Bean
    @LoadBalanced // Ribbon
    public RestTemplate getRestTemplate(){
        return  new RestTemplate();
    }
​
​
}
​

创建controller类（DeptConsumerController）

package com.example.springcloud.controller;
​
import com.example.pojo.Dept;
import com.example.service.DeptClientService;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.web.bind.annotation.PathVariable;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RestController;
​
import java.util.List;
​
@RestController
public class DeptConsumerController {
​
​
    @Autowired
    private DeptClientService deptClientService;
​
    @RequestMapping("/consumer/dept/get/{id}")
    public Dept get(@PathVariable("id") Long id) {
        return deptClientService.queryId(id);
    }
​
    @RequestMapping("/consumer/dept/add")
    public boolean add(Dept dept) {
        return deptClientService.addDept(dept);
    }
​
    @RequestMapping("/consumer/dept/list")
    public List<Dept> get() {
        return deptClientService.queryAll();
    }
}
​

启动类

package com.example.springcloud;
​
import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;
import org.springframework.cloud.netflix.eureka.EnableEurekaClient;
import org.springframework.cloud.openfeign.EnableFeignClients;
import org.springframework.context.annotation.ComponentScan;
​
// Ribbon 和 Eureka整合以后，客户端可以直接调用
@SpringBootApplication
@EnableEurekaClient
@EnableFeignClients(basePackages = "com.example")
@ComponentScan("com.example")
public class FeignDeptConsumer_80 {
public  static void main(String args[]){
    SpringApplication.run(FeignDeptConsumer_80.class,args);
}
}
​

 

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原文地址：https://www.cnblogs.com/liuli-warriors/p/12669026.html