想了解详解spring cloud中使用Ribbon实现客户端的软负载均衡的相关内容吗,牛奋lch在本文为您仔细讲解spring cloud Ribbon 软负载均衡的相关知识和一些Code实例,欢迎阅读和指正,我们先划重点:spring,cloud,Ribbon,软负载均衡,springcloud,负载均衡,下面大家一起来学习吧。
开篇
本例是在springboot整合H2内存数据库,实现单元测试与数据库无关性和使用RestTemplate消费springhttps://m.qb5200.com/boot的Restful服务两个示例的基础上改造而来
在使用RestTemplate来消费springhttps://m.qb5200.com/boot的Restful服务示例中,我们提到,调用springhttps://m.qb5200.com/boot服务的时候,需要将服务的URL写死或者是写在配置文件中,但这两种方式,无论哪一种,一旦ip地址发生了变化,都需要改动程序,并重新部署服务,使用Ribbon的时候,可以有效的避免这个问题。
前言:
软负载均衡的实现方式有两种,分别是服务端的负载均衡和客户端的负载均衡
服务端负载均衡:当浏览器向后台发出请求的时候,会首先向反向代理服务器发送请求,反向代理服务器会根据客户端部署的ip:port映射表以及负载均衡策略,来决定向哪台服务器发送请求,一般会使用到nginx反向代理技术。
客户端负载均衡:当浏览器向后台发出请求的时候,客户端会向服务注册器(例如:Eurekahttps://m.qb5200.com/Server),拉取注册到服务器的可用服务信息,然后根据负载均衡策略,直接命中哪台服务器发送请求。这整个过程都是在客户端完成的,并不需要反向代理服务器的参与。
一、启动Eurekahttps://m.qb5200.com/Server
请参考该例:springhttps://m.qb5200.com/cloud中启动Eurekahttps://m.qb5200.com/Serverhttps://m.qb5200.com/
二、启动微服务,并注册到Eurekahttps://m.qb5200.com/Server上
springhttps://m.qb5200.com/cloud-将springhttps://m.qb5200.com/boot服务注册到Eurekahttps://m.qb5200.com/Server上
为了演示负载均衡的效果,再启动一个为服务,注意需要将端口号改成不一致
三、添加Ribbon支持
1、添加Ribbon的依赖
2、添加负载均衡支持
packagehttps://m.qb5200.com/com.chhliu.springboot.restful;https://m.qb5200.com/
importhttps://m.qb5200.com/org.springframework.beans.factory.annotation.Autowired;https://m.qb5200.com/
importhttps://m.qb5200.com/org.springframework.boot.SpringApplication;https://m.qb5200.com/
importhttps://m.qb5200.com/org.springframework.boot.autoconfigure.SpringBootApplication;https://m.qb5200.com/
importhttps://m.qb5200.com/org.springframework.boot.web.client.RestTemplateBuilder;https://m.qb5200.com/
importhttps://m.qb5200.com/org.springframework.cloud.client.loadbalancer.LoadBalanced;https://m.qb5200.com/
importhttps://m.qb5200.com/org.springframework.cloud.netflix.eureka.EnableEurekaClient;https://m.qb5200.com/
importhttps://m.qb5200.com/org.springframework.context.annotation.Bean;https://m.qb5200.com/
importhttps://m.qb5200.com/org.springframework.web.client.RestTemplate;https://m.qb5200.com/
@SpringBootApplicationhttps://m.qb5200.com/
@EnableEurekaClienthttps://m.qb5200.com/
publichttps://m.qb5200.com/classhttps://m.qb5200.com/SpringbootRestTemplateApplicationhttps://m.qb5200.com/{https://m.qb5200.com/
https://m.qb5200.com/https://m.qb5200.com/https://m.qb5200.com/
https://m.qb5200.com/https://m.qb5200.com/@Autowiredhttps://m.qb5200.com/
https://m.qb5200.com/https://m.qb5200.com/privatehttps://m.qb5200.com/RestTemplateBuilderhttps://m.qb5200.com/builder;https://m.qb5200.com/
https://m.qb5200.com/
https://m.qb5200.com/https://m.qb5200.com/@Beanhttps://m.qb5200.com/
https://m.qb5200.com/https://m.qb5200.com/@LoadBalancedhttps://m.qb5200.com///https://m.qb5200.com/添加负载均衡支持,很简单,只需要在RestTemplate上添加@LoadBalanced注解,那么RestTemplate即具有负载均衡的功能,如果不加@LoadBalanced注解的话,会报java.net.UnknownHostException:springboot-h2异常,此时无法通过注册到Eurekahttps://m.qb5200.com/Server上的服务名来调用服务,因为RestTemplate是无法从服务名映射到ip:port的,映射的功能是由LoadBalancerClient来实现的。https://m.qb5200.com/
https://m.qb5200.com/https://m.qb5200.com/publichttps://m.qb5200.com/RestTemplatehttps://m.qb5200.com/restTemplate()https://m.qb5200.com/{https://m.qb5200.com/
https://m.qb5200.com/https://m.qb5200.com/https://m.qb5200.com/https://m.qb5200.com/returnhttps://m.qb5200.com/builder.build();https://m.qb5200.com/
https://m.qb5200.com/https://m.qb5200.com/}https://m.qb5200.com/
https://m.qb5200.com/
https://m.qb5200.com/https://m.qb5200.com/publichttps://m.qb5200.com/statichttps://m.qb5200.com/voidhttps://m.qb5200.com/main(String[]https://m.qb5200.com/args)https://m.qb5200.com/{https://m.qb5200.com/
https://m.qb5200.com/https://m.qb5200.com/https://m.qb5200.com/https://m.qb5200.com/SpringApplication.run(SpringbootRestTemplateApplication.class,https://m.qb5200.com/args);https://m.qb5200.com/
https://m.qb5200.com/https://m.qb5200.com/}https://m.qb5200.com/
}https://m.qb5200.com/