SpringCloud 实战六：Eureka集群负载均衡

• 项目结构

说明：

cloud-eureka-server7001模块、cloud-eureka-server7002模块两个组成eureka注册中心集群

cloud-provider-payment8001模块、cloud-provider-payment8002模块两个组成支付模块服务集群

实现负载均衡：

1、配置

cloud-provider-payment8001：

server:
  port: 8001

spring:
  application:
    name: cloud-payment-service
  datasource:
    type: com.alibaba.druid.pool.DruidDataSource
    driver-class-name: org.gjt.mm.mysql.Driver
    url: jdbc:mysql://106.54.196.44:3306/test?useUnicode=true&characterEncoding=utf-8&useSSL=false
    username: root
    password: password

eureka:
  client:
    # 将自己注册进eureka中心
    register-with-eureka: true
    # 是否抓取注册信息，默认为true
    fetch-registry: true
    service-url:
      defaultZone: http://eureka7001.com:7001/eureka, http://eureka7002.com:7002/eureka

mybatis:
  mapper-locations: classpath:mapper/*.xml
  type-aliases-package: com.laoxu.springcloud.entities

cloud-provider-payment8002：

server:
  port: 8002

spring:
  application:
    name: cloud-payment-service
  datasource:
    type: com.alibaba.druid.pool.DruidDataSource
    driver-class-name: org.gjt.mm.mysql.Driver
    url: jdbc:mysql://106.54.196.44:3306/test?useUnicode=true&characterEncoding=utf-8&useSSL=false
    username: root
    password: password

eureka:
  client:
    # 将自己注册进eureka中心
    register-with-eureka: true
    # 是否抓取注册信息，默认为true
    fetch-registry: true
    service-url:
      defaultZone: http://eureka7001.com:7001/eureka, http://eureka7002.com:7002/eureka

mybatis:
  mapper-locations: classpath:mapper/*.xml
  type-aliases-package: com.laoxu.springcloud.entities

集群的spring.application.name必须要一致

2、修改消费微服务端restTemplate请求地址为注册中心服务即  spring.application.name

package com.laoxu.springcloud.controller;

import com.laoxu.springcloud.entities.CommonResult;
import com.laoxu.springcloud.entities.Payment;
import lombok.extern.slf4j.Slf4j;
import org.springframework.beans.factory.annotation.Autowired;
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 org.springframework.web.client.RestTemplate;

@RestController
@Slf4j
public class OrderController {

    @Autowired
    private RestTemplate restTemplate;

//    private static final String PAYMENT_URL = "http://localhost:8001";
    private static final String PAYMENT_URL = "http://CLOUD-PAYMENT-SERVICE";
    @PostMapping("/consumer/payment/create")
    public CommonResult<Payment> create(Payment payment){
        return restTemplate.postForObject(PAYMENT_URL + "/payment/create", payment, CommonResult.class);
    }

    @GetMapping("/consumer/payment/get/{id}")
    public CommonResult<Payment> getPaymentById(@PathVariable("id") Long id){
        return restTemplate.getForObject(PAYMENT_URL + "/payment/get/" +id, CommonResult.class);
    }

}

3、为restTemplate方法添加负载均衡注解

package com.laoxu.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 ApplicationContextConfig {
    @Bean
    @LoadBalanced
    public RestTemplate getRestTemplate(){
        return new RestTemplate();
    }
}

4、全部启动

5、测试

可以看到消费者在请求时注册中心会做负载均衡，默认的负载均衡机制为轮询访问所有的集群