# Sprint-Ribbon与负载均衡
标签（空格分隔）： Java-Spring
---
![PNG 图像.png-276.1kB][1]
**Ribbon**是一个基于HTTP与TCP的客户端负载均衡器。
服务端列表去轮询访问以达到均衡负载的作用。当 Ribbon与 Eureka联合使用时, Ribbon 的服务实例清单 Ribbon Serverlist会被 Discoveryenabledniwsserverlist重写,扩展成从Eureka注册中心中获取服务端列表。同时它也会用 Niwsdiscoveryping来取代Ping,它将职责委托给Eureka来确定服务端是否已经启动。在本章中,我们对Ribbon不做详细的介绍,读者只需要理解它在Eureka服务发现的基础上,实现了一套对服务实例的选择策略,从而实现对服务的消费。下一章我们会对 Ribbon做详细的介绍和分析。
客户端示例：RestTemplate + Ribbon
```java
@SpringBootApplication
@EnableDiscoveryClient
@RestController
public class RibbonClient {
public static void main(String[] args) {
SpringApplication.run(RibbonClient.class, args);
}
@Bean
@LoadBalanced //实现负载均衡
RestTemplate restTemplate() {
return new RestTemplate();
}
@Autowired
private RestTemplate restTemplate;
@GetMapping("/ribbonInvoke")
private String ribbonInvoke() {
RibbonMessage msg = restTemplate.getForObject("http://TG-RIBBON-SERVICE/ribbonAccept", RibbonMessage.class);
System.out.println(msg);
return msg.toString();
}
}
```
调用后输出日志示例：
```java
2019-02-01 16:15:53.953 INFO 11404 --- [nio-8201-exec-1] c.n.l.DynamicServerListLoadBalancer : DynamicServerListLoadBalancer for client TG-RIBBON-SERVICE initialized: DynamicServerListLoadBalancer:{NFLoadBalancer:name=TG-RIBBON-SERVICE,current list of Servers=[192.168.14.196:8056],Load balancer stats=Zone stats: {defaultzone=[Zone:defaultzone; Instance count:1; Active connections count: 0; Circuit breaker tripped count: 0; Active connections per server: 0.0;]
},Server stats: [[Server:192.168.14.196:8056; Zone:defaultZone; Total Requests:0; Successive connection failure:0; Total blackout seconds:0; Last connection made:Thu Jan 01 08:00:00 CST 1970; First connection made: Thu Jan 01 08:00:00 CST 1970; Active Connections:0; total failure count in last (1000) msecs:0; average resp time:0.0; 90 percentile resp time:0.0; 95 percentile resp time:0.0; min resp time:0.0; max resp time:0.0; stddev resp time:0.0]
]}ServerList:org.springframework.cloud.netflix.ribbon.eureka.DomainExtractingServerList@53c23742
```
[1]: http://static.zybuluo.com/zero1036/afoqlykn1ujhynyr36if234h/PNG%20%E5%9B%BE%E5%83%8F.png
网友评论