标签：ble .com 优先 pack server eureka 技术分享 cat can
在dubbo项目中, zookeeper即注册中心帮我们实现了调度和负载均衡的能力, 这种方式被称为服务器端的负载均衡, springcloud中, 使用ribben实现的客户端负载均衡
Ribbon是Netflix发布的云中间层服务开源项目，其主要功能是提供客户端侧负载均衡算法。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，Ribbon是一个客户端负载均衡器，我们可以在配置文件中列出Load Balancer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。
eureka使用ribbon的大致架构
Ribbon工作时分为两步：第一步先选择 Eureka Server, 它优先选择在同一个Zone且负载较少的Server；第二步再根据用户指定的策略，在从Server取到的服务注册列表中选择一个地址。其中Ribbon提供了多种策略，例如轮询round robin、随机Random、根据响应时间加权等。
将刚才的cosumer-movie改造成ribbon的项目
添加一个注解类, 需要放置在mainClass扫描不到的包下, 或者在mainClass中通过@COmponentScan进行过滤
这儿使用的是注解过滤, 所以首先需要一个注解:
package com.wenbronk.cosumer.ribben.annotation; /** * 自定义注解, 排除不想被扫描到的内容 * Created by wenbronk on 2017/5/18. */ public @interface ExcudeAnnotation { }
然后是一个ribbon的注解声明类:
package com.wenbronk.cosumer.ribben.config; import com.netflix.loadbalancer.IRule; import com.netflix.loadbalancer.RandomRule; import com.wenbronk.cosumer.ribben.annotation.ExcudeAnnotation; import org.springframework.context.annotation.Bean; import org.springframework.context.annotation.Configuration; /** * 默认规则为轮询, 这个为随机规则 * 该类必须放置在扫描不到的包下, 或者添加排除, 虽然他必须有注解 * Created by wenbronk on 2017/5/18. */ @Configuration @ExcudeAnnotation public class MyRibbonConfig { @Bean public IRule ribbonRule() { return new RandomRule(); } }
在mainClass中进行过滤
package com.wenbronk.cosumer.ribben; import com.wenbronk.cosumer.ribben.annotation.ExcudeAnnotation; import com.wenbronk.cosumer.ribben.config.MyRibbonConfig; 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; /** * 通过RIbbonClient自定义ribbon客户端 * Created by root on 2017/5/18. */ @SpringBootApplication @EnableEurekaClient // 使用此规则不可放在 可扫描的路径下, 如果非要放置, 需要加自定义注解 @RibbonClient(name = "microserver-provider-user", configuration = MyRibbonConfig.class) @ComponentScan(excludeFilters = {@ComponentScan.Filter(type = FilterType.ANNOTATION, value = {ExcudeAnnotation.class})}) public class MovieRibbenApplication { /** * 使用LoadBalanced开启客户端负载均衡的功能 * @return */ @Bean @LoadBalanced public RestTemplate restTemplate() { return new RestTemplate(); } public static void main(String[] args) { SpringApplication.run(MovieRibbenApplication.class, args); } }
通过配置端口, 将user服务启动4个实例, 并注册为2个服务, 在movie-ribbon的controller中加入如下代码
package com.wenbronk.cosumer.ribben.controller; import com.wenbronk.cosumer.ribben.entity.User; 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.RequestMapping; import org.springframework.web.bind.annotation.RestController; import org.springframework.web.client.RestTemplate; /** * Created by root on 2017/5/18. */ @RestController public class MovieRibbenController { @Autowired private RestTemplate restTemplate; @Autowired private LoadBalancerClient loadBalancerClient; @RequestMapping("/movie/{id}") public User findById(@PathVariable Long id) { return restTemplate.getForObject("http://microservice-provider-user/simple/" + id, User.class); } @GetMapping("/test") public void test() { ServiceInstance instance = this.loadBalancerClient.choose("MICROSERVICE-PROVIDER-USER"); System.out.println("111: " + instance.getServiceId() + ": " + instance.getHost() + ": " + instance.getPort()); // System.out.println(instance.toString()); ServiceInstance instance1 = this.loadBalancerClient.choose("MICROSERVICE-PROVIDER-USER-1"); System.out.println("222: " + instance1.getServiceId() + ": " + instance1.getHost() + ": " + instance1.getPort()); // System.out.println(instance1); // System.out.println(instance == instance1); } }
通过浏览器重复的发送请求, 在控制台可看到只有provide-user 使用了我们自定义的规则, user-1 仍然使用的ribbon的默认规则轮询
从版本1.2.0开始，Spring Cloud Netflix现在支持使用属性与Ribbon文档兼容来自定义Ribbon客户端。
配置的优先级: 配置文件 > java代码 > springcloud default
users:
ribbon:
NFLoadBalancerRuleClassName: com.netflix.loadbalancer.WeightedResponseTimeRule
NFLoadBalancerRuleClassName 是规则, 除了此规则 springcloud还有
每个规则可添加的类也有很多
package com.wenbronk.cosumer.ribbon.yml; 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; /** * Created by wenbronk on 2017/5/20. */ @SpringBootApplication @EnableEurekaClient public class MoveiRibbonYmlApplicatoin { @Bean public RestTemplate restTemplate() { return new RestTemplate(); } public static void main(String[] args) { SpringApplication.run(MoveiRibbonYmlApplicatoin.class, args); } }
MovieRibbonController
package com.wenbronk.cosumer.ribbon.yml.controller;
import com.wenbronk.cosumer.ribbon.yml.entity.User;
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.RequestMapping;
import org.springframework.web.bind.annotation.RestController;
import org.springframework.web.client.RestTemplate;
/**
* Created by root on 2017/5/18.
*/
@RestController
public class MovieRibbenController {
@Autowired
private RestTemplate restTemplate;
@Autowired
private LoadBalancerClient loadBalancerClient;
@RequestMapping("/movie/{id}")
public User findById(@PathVariable Long id) {
return restTemplate.getForObject("http://microservice-provider-user/simple/" + id, User.class);
}
@GetMapping("/test")
public void test() {
ServiceInstance instance = this.loadBalancerClient.choose("MICROSERVICE-PROVIDER-USER");
System.out.println("111: " + instance.getServiceId() + ": " + instance.getHost() + ": " + instance.getPort());
// System.out.println(instance.toString());
ServiceInstance instance1 = this.loadBalancerClient.choose("MICROSERVICE-PROVIDER-USER-1");
System.out.println("222: " + instance1.getServiceId() + ": " + instance1.getHost() + ": " + instance1.getPort());
// System.out.println(instance1);
// System.out.println(instance == instance1);
}
}
标签：ble .com 优先 pack server eureka 技术分享 cat can
原文地址：http://www.cnblogs.com/wenbronk/p/6881643.html
