SpirngCloud之Ribbon负载均衡(二)

一概念

Spring Cloud Ribbon是基于Netflix Ribbon实现的一套客户端负载均衡的工具。

简单的说，Ribbon是Netflix发布的开源项目，主要功能是提供客户端的软件负载均衡算法，将Netflix的中间层服务连接在一起。Ribbon客户端组件提供一系列完善的配置项如连接超时，重试等。简单的说，就是在配置文件中列出Load Balancer（简称LB）后面所有的机器，Ribbon会自动的帮助你基于某种规则（如简单轮询，随机连接等）去连接这些机器。我们也很容易使用Ribbon实现自定义的负载均衡算法。

LB，即负载均衡(Load Balance)，在微服务或分布式集群中经常用的一种应用。负载均衡简单的说就是将用户的请求平摊的分配到多个服务上，从而达到系统的HA。常见的负载均衡有软件Nginx，LVS，硬件 F5等。相应的在中间件，例如：dubbo和SpringCloud中均给我们提供了负载均衡，SpringCloud的负载均衡算法可以自定义。

二 Ribbon配置初步

启动一中的eureka-server项目和producer-service项目，然后再改producer-service的端口，启动2个客户端

修改producer-service的类

 1 @RestController
 2 @RequestMapping("/api/v1/product")
 3 public class ProductController {
 4 
 5 
 6 
 7     @Value("${server.port}")
 8     private String port;
 9 
10     @Autowired
11     private ProductService productService;
12 
13     /**
14      * 获取所有商品列表
15      * @return
16      */
17     @RequestMapping("list")
18     public Object list(){
19         return productService.listProduct();
20     }
21 
22 
23     /**
24      * 根据id查找商品详情
25      * @param id
26      * @return
27      */
28     @RequestMapping("find")
29     public Object findById(int id){
30 
31         Product product = productService.findById(id);
32 
33         Product result = new Product();
34         BeanUtils.copyProperties(product,result);
35         result.setName( result.getName() + " data from port="+port );
36         return result;
37     }

创建order-serveice项目

pom.xml

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

        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-test</artifactId>
            <scope>test</scope>
        </dependency>
    </dependencies>

启动类

 1 @SpringBootApplication
 2 public class OrderServiceApplication {
 3 
 4     public static void main(String[] args) {
 5         SpringApplication.run(OrderServiceApplication.class, args);
 6     }
 7 
 8 
 9     @Bean
10     @LoadBalanced
11     public RestTemplate restTemplate() {
12         return new RestTemplate();
13     }
14 
15 
16 }

Web层

@RestController
@RequestMapping("/api/v1/order")
public class OrderController {


    @Autowired(required = false)
    private ProductOrderServiceImpl productOrderService;


    @RequestMapping("/save")
    public Object save(@RequestParam("user_id")int userId, @RequestParam("product_id") int productId){

        return productOrderService.save(userId, productId);
    }




}

Service层

@Service
public class ProductOrderServiceImpl {


    @Autowired
    private RestTemplate restTemplate;

    public ProductOrder save(int userId, int productId) {
        System.out.println("123");

        Object obj = restTemplate.getForObject("http://product-service/api/v1/product/find?id="+productId, Object.class);

        System.out.println(obj);

        ProductOrder productOrder = new ProductOrder();
        productOrder.setCreateTime(new Date());
        productOrder.setUserId(userId);
        productOrder.setTradeNo(UUID.randomUUID().toString());

        return productOrder;
    }
}

Bo类

/**
 * 商品订单实体类
 */
public class ProductOrder implements Serializable {


    private int id;

    /**
     * 商品名称
     */
    private String productName;

    /**
     * 订单号
     */
    private  String tradeNo;

    /**
     * 价格,分
     */
    private int price;


    private Date createTime;


    private int userId;

    private String userName;


    public int getUserId() {
        return userId;
    }

    public void setUserId(int userId) {
        this.userId = userId;
    }

    public String getUserName() {
        return userName;
    }

    public void setUserName(String userName) {
        this.userName = userName;
    }

    public int getId() {
        return id;
    }

    public void setId(int id) {
        this.id = id;
    }

    public String getProductName() {
        return productName;
    }

    public void setProductName(String productName) {
        this.productName = productName;
    }

    public String getTradeNo() {
        return tradeNo;
    }

    public void setTradeNo(String tradeNo) {
        this.tradeNo = tradeNo;
    }

    public int getPrice() {
        return price;
    }

    public void setPrice(int price) {
        this.price = price;
    }

    public Date getCreateTime() {
        return createTime;
    }

    public void setCreateTime(Date createTime) {
        this.createTime = createTime;
    }
}

配置文件

server:
  port: 8781


#指定注册中心地址
eureka:
  client:
    serviceUrl:
      defaultZone: http://localhost:8761/eureka/

#服务的名称
spring:
  application:
    name: order-service

结果：2个结果在轮询

{id=1, name=iphonex data from port=8772, price=9999, store=10}{id=1, name=iphonex data from port=8771, price=9999, store=10}{id=1, name=iphonex data from port=8772, price=9999, store=10}{id=1, name=iphonex data from port=8771, price=9999, store=10}{id=1, name=iphonex data from port=8772, price=9999, store=10}{id=1, name=iphonex data from port=8771, price=9999, store=10}

来源：https://www.cnblogs.com/dalianpai/p/11687175.html

标签

负载均衡

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SpirngCloud之Ribbon负载均衡(二)

一 概念

二 Ribbon配置初步

一概念