Ribbon

小灰灰 2023-07-21 06:16 75阅读 0赞

>  *  [https://github.com/Netflix/ribbon][https_github.com_Netflix_ribbon]
>  *  [https://cloud.spring.io/spring-cloud-static/spring-cloud-netflix/2.1.0.RC2/single/spring-cloud-netflix.html\#spring-cloud-ribbon][https_cloud.spring.io_spring-cloud-static_spring-cloud-netflix_2.1.0.RC2_single_spring-cloud-netflix.html_spring-cloud-ribbon]

>  *  Nacos：[https://blog.csdn.net/qq\_40794973/article/details/104593366][https_blog.csdn.net_qq_40794973_article_details_104593366]
>  *  Feign：[https://blog.csdn.net/qq\_40794973/article/details/105306096][https_blog.csdn.net_qq_40794973_article_details_105306096]

--------------------

# 1 负载均衡的两种方式 #

![watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3FxXzQwNzk0OTcz_size_16_color_FFFFFF_t_70][]

![watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3FxXzQwNzk0OTcz_size_16_color_FFFFFF_t_70 1][]

@Autowired
    private DiscoveryClient discoveryClient;
    //-------------------------------------------手写负载均衡----------------------------//
    @GetMapping("/hello")
    public String hello() {
        // 1.拿到用户中心所有的实例信息
        List<ServiceInstance> userInstances = discoveryClient.getInstances("user-center");
        // 2.所有用户中心实例的请求地址
        List<String> targetUrls = userInstances.stream()
                .map((instance) -> instance.getUri().toString() + "/user/hello")
                .collect(Collectors.toList());
        //随机请求
        int i = ThreadLocalRandom.current().nextInt(targetUrls.size());
        log.info("请求的目标地址：{}", targetUrls.get(i));
        return new RestTemplate().getForObject(targetUrls.get(i), String.class);
    }

--------------------

# 2 整合Ribbon #

![watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3FxXzQwNzk0OTcz_size_16_color_FFFFFF_t_70 2][]

## 2.1 加依赖 ##

> spring-cloud-starter-alibaba-nacos-discovery 已经依赖ribbon了所以无需单独引入

![20200402220555152.png][]

使用ribbon无需写注解，无需写配置（需要修改另说）

## 2.2 hello world ##

[https://cloud.spring.io/spring-cloud-static/Hoxton.SR3/reference/htmlsingle/\#rest-template-loadbalancer-client][https_cloud.spring.io_spring-cloud-static_Hoxton.SR3_reference_htmlsingle_rest-template-loadbalancer-client]

@Configuration
    public class RestTemplageConfig {
        @Bean
        @LoadBalanced
        public RestTemplate restTemplate(){
            return new RestTemplate();
        }
    }

@Autowired
    private RestTemplate restTemplate;
    @GetMapping("/hello")
    public String hello() {
        return restTemplate.getForObject("http://user-center/user/hello", String.class);
    }

--------------------

# 3 Ribbon组成 #

![watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3FxXzQwNzk0OTcz_size_16_color_FFFFFF_t_70 3][]

--------------------

# 4 Ribbon内置的负载均衡规则 #

![watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3FxXzQwNzk0OTcz_size_16_color_FFFFFF_t_70 4][]

--------------------

# 5 **Ribbon**细粒度配置 #

## 5.1 Java代码配置 ##

> Spring中的父子容器：[https://yuanyu.blog.csdn.net/article/details/105294435][https_yuanyu.blog.csdn.net_article_details_105294435]
> 
> [https://cloud.spring.io/spring-cloud-static/Greenwich.SR1/single/spring-cloud.html\#\_customizing\_the\_ribbon\_client][https_cloud.spring.io_spring-cloud-static_Greenwich.SR1_single_spring-cloud.html_customizing_the_ribbon_client]
> 
> **16.2 Customizing the Ribbon Client**
> 
> The `CustomConfiguration` clas must be a `@Configuration` class, but take care that it is not in a `@ComponentScan` for the main application context. Otherwise, it is shared by all the `@RibbonClients`. If you use `@ComponentScan` (or `@SpringBootApplication`), you need to take steps to avoid it being included (for instance, you can put it in a separate, non-overlapping package or specify the packages to scan explicitly in the `@ComponentScan`).

> 注意： UserCenterRibbonConfiguration需要被扫描到，RibbonConfiguration不能被扫描到，否则会成为全局配置。@SpringBootApplication会扫描当前包和子包

@Configuration
    @RibbonClient(name = "user-center",configuration = RibbonConfiguration.class)
    public class UserCenterRibbonConfiguration {}

@Configuration
    public class RibbonConfiguration {
        @Bean
        public IRule ribbonRule() {
            return new RandomRule();
        }
    }

## 5.2 用配置属性配置 ##

<clientName>.ribbon.NFLoadBalancerRuleClassName

>  *  com.netflix.loadbalancer.RandomRule
>  *  com.nobug.client.config.NacosSameClusterWeightedRule

user-center:
      ribbon:
        NFLoadBalancerRuleClassName: com.netflix.loadbalancer.RandomRule

## 5.3 最佳实践总结 ##

<table>  代码配置方式 vs 属性配置方式  
 <thead> 
  <tr> 
   <th style="width:216px;">配置方式</th> 
   <th style="width:340px;">优点</th> 
   <th>缺点</th> 
  </tr> 
 </thead> 
 <tbody> 
  <tr> 
   <td style="width:216px;">代码配置</td> 
   <td style="width:340px;">基于代码，更加灵活</td> 
   <td>有小坑(父子上下文)&nbsp;<br> 线上修改得重新打包、发布</td> 
  </tr> 
  <tr> 
   <td style="width:216px;">属性配置【优先级更高】</td> 
   <td style="width:340px;">易上手<br> 配置更加直观<br> 线上修改无需重新打包、发布<br><span style="color:#f33b45;">优先级更高</span></td> 
   <td>极端场景下没有代码配置方式灵活</td> 
  </tr> 
 </tbody> 
</table>

>  *  尽量使用属性配置，属性方式实现不了的情况下再考虑用代码配置
>  *  在同一个微服务内尽量保持单一性，比如统一使用属性配置，不要两种方式混用，增加定位代码的复杂性

--------------------

# 6 Ribbon全局配置  #

>  *  方式一 : 让ComponentScan上下文重叠（强烈不建议使用）
>  *  方式二【唯一正确的途径】 : @RibbonClients(defaultConfiguration=xxx.class)

>  RibbonConfiguration需要被@SpringBootApplication扫描

@Configuration
    @RibbonClients(defaultConfiguration = RibbonConfiguration.class) 
    public class RibbonConfiguration {
    }

--------------------

# 7 Ribbon支持的配置项 #

@Configuration
    public class RibbonConfiguration {
        @Bean
        public IRule ribbonRule() {
            return new RandomRule();
        }
        @Bean
        public IPing ping(){
            return new PingUrl();
        }
        //...
    }

> [https://cloud.spring.io/spring-cloud-static/Greenwich.SR1/single/spring-cloud.html\#\_customizing\_the\_ribbon\_client\_by\_setting\_properties][https_cloud.spring.io_spring-cloud-static_Greenwich.SR1_single_spring-cloud.html_customizing_the_ribbon_client_by_setting_properties]
> 
> **16.4 Customizing the Ribbon Client by Setting Properties**
> 
>  *  `<clientName>.ribbon.NFLoadBalancerClassName`: Should implement `ILoadBalancer`
>  *  `<clientName>.ribbon.NFLoadBalancerRuleClassName`: Should implement `IRule`
>  *  `<clientName>.ribbon.NFLoadBalancerPingClassName`: Should implement `IPing`
>  *  `<clientName>.ribbon.NIWSServerListClassName`: Should implement `ServerList`
>  *  `<clientName>.ribbon.NIWSServerListFilterClassName`: Should implement `ServerListFilter`

xxx-center:
      ribbon:
        NFLoadBalancerClassName: ILoadBalancer实现类
        NFLoadBalancerRuleClassName: IRule实现类
        NFLoadBalancerPingClassName: IPing实现类
        NIWSServerListClassName: ServerList实现类
        NIWSServerListFilterClassName: ServerListFilter实现类

--------------------

# 8  Ribbon的饥饿加载  #

> 开启饥饿加载

ribbon:
      eager-load:
        enabled: true
        clients: user-service ,xxx # 细粒度指定哪些具体的服务【多个使用逗号分隔，不在这个名单上的依然使用懒加载】

--------------------

# 9 nacos && Ribbon #

## 9.1 扩展Ribbon支持Nacos权重 ##

[http://www.imooc.com/article/288660][http_www.imooc.com_article_288660]

![watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3FxXzQwNzk0OTcz_size_16_color_FFFFFF_t_70 5][]

/**
     * 扩展Ribbon支持Nacos权重
     */
    //IRule
    @Slf4j
    public class NacosWeightedRule extends AbstractLoadBalancerRule {
        @Autowired
        private NacosDiscoveryProperties nacosDiscoveryProperties;
        @Override
        public void initWithNiwsConfig(IClientConfig iClientConfig) {
            //读取配置文件,并初始化NacosWeightedRule
        }
        @Override
        public Server choose(Object o) {
            try {
                BaseLoadBalancer loadBalancer = (BaseLoadBalancer) this.getLoadBalancer();
                log.info("lb={}",loadBalancer);
                //想要请求的微服务的名称
                String name = loadBalancer.getName();
                //拿到服务发现的相关API
                NamingService namingService = nacosDiscoveryProperties.namingServiceInstance();
                //nacos client自动通过基于权重的负载均衡算法,给我们选择一个实例
                Instance instance = namingService.selectOneHealthyInstance(name);
                log.info("选择的实例是: port={},instance={}", instance.getPort(), instance);
                return new NacosServer(instance);
            } catch (NacosException e) {
                //e.printStackTrace();
                log.error(e.getErrMsg());
            }
            return null;
        }
    }

## 9.2 扩展Ribbon同一集群优先调用 ##

>  *  [https://blog.csdn.net/lilizhou2008/article/details/94517599][https_blog.csdn.net_lilizhou2008_article_details_94517599]
>  *  [http://www.itmuch.com/spring-cloud-alibaba/ribbon-nacos-weight-cluster/][http_www.itmuch.com_spring-cloud-alibaba_ribbon-nacos-weight-cluster]

/**
     * 扩展Ribbon-同一集群优先调用
     */
    @Slf4j
    public class NacosSameClusterWeightedRule extends AbstractLoadBalancerRule {
        @Autowired
        private NacosDiscoveryProperties nacosDiscoveryProperties;
        @Override
        public void initWithNiwsConfig(IClientConfig iClientConfig) {}
        @Override
        public Server choose(Object o) {
            //1.找到指定服务的所有实例 A
            //2.过滤出相同集群下的所有实例 B
            //3.如果B是空,就用A
            //4.基于权重的负载均衡算法,返回1个实例
            try {
                //获取到配置中的集群名称 SH
                //spring.cloud.nacos.discovery.cluster-name=SH
                String clusterName = nacosDiscoveryProperties.getClusterName();
                BaseLoadBalancer loadBalancer = (BaseLoadBalancer) this.getLoadBalancer();
                //想要请求的微服务的名称
                String name = loadBalancer.getName();
                //拿到服务发现的相关API
                NamingService namingService = nacosDiscoveryProperties.namingServiceInstance();
                //1.找到指定服务的所有实例
                List<Instance> instances = namingService.selectInstances(name, true);
    
                //2.过滤出相同集群下的所有实例
                List<Instance> sameClusterInstances = instances.stream()
                        .filter(instance -> Objects.equals(instance.getClusterName(), clusterName))
                        .collect(Collectors.toList());
                // 3.如果上述2为空，就用1
                List<Instance> instancesToBeChosen;
                if (CollectionUtils.isEmpty(sameClusterInstances)) {
                    instancesToBeChosen = instances;
                    log.warn("发生了跨集群的调用，name = {}, clusterName = {}, instances = {}", name, clusterName, instances);
                } else {
                    instancesToBeChosen = sameClusterInstances;
                    log.info("同一集群调用，name = {}, clusterName = {}, instances = {}", name, clusterName, instances);
                }
                //4.基于权重的负载均衡算法，返回一个实例
                Instance instance = ExtendsBalancer.getHostByRandomWeightExtends(instancesToBeChosen);
                log.info("选择的实例是  instance = {}", instance);
                return new NacosServer(instance);
            } catch (Exception e) {
                //e.printStackTrace();
                log.error(e.getMessage());
                return null;
            }
        }
    }
    /**
     *
     */
    class ExtendsBalancer extends Balancer {
        public static Instance getHostByRandomWeightExtends(List<Instance> hosts) {
            return getHostByRandomWeight(hosts);
        }
    }

> 扩展Ribbon支持基于元数据的版本管理：[http://www.imooc.com/article/288674][http_www.imooc.com_article_288674]

[https_github.com_Netflix_ribbon]: https://github.com/Netflix/ribbon
[https_cloud.spring.io_spring-cloud-static_spring-cloud-netflix_2.1.0.RC2_single_spring-cloud-netflix.html_spring-cloud-ribbon]: https://cloud.spring.io/spring-cloud-static/spring-cloud-netflix/2.1.0.RC2/single/spring-cloud-netflix.html#spring-cloud-ribbon
[https_blog.csdn.net_qq_40794973_article_details_104593366]: https://blog.csdn.net/qq_40794973/article/details/104593366
[https_blog.csdn.net_qq_40794973_article_details_105306096]: https://blog.csdn.net/qq_40794973/article/details/105306096
[watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3FxXzQwNzk0OTcz_size_16_color_FFFFFF_t_70]: /images/20230528/68629741f4b74f3abc777d4522442a14.png
[watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3FxXzQwNzk0OTcz_size_16_color_FFFFFF_t_70 1]: /images/20230528/56349cd08bcd4fa78a352bca20370be1.png
[watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3FxXzQwNzk0OTcz_size_16_color_FFFFFF_t_70 2]: /images/20230528/fe195b8ebb6a41929c130353825576ec.png
[20200402220555152.png]: /images/20230528/3c1ca598dee5454082138a923bed7a0b.png
[https_cloud.spring.io_spring-cloud-static_Hoxton.SR3_reference_htmlsingle_rest-template-loadbalancer-client]: https://cloud.spring.io/spring-cloud-static/Hoxton.SR3/reference/htmlsingle/#rest-template-loadbalancer-client
[watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3FxXzQwNzk0OTcz_size_16_color_FFFFFF_t_70 3]: /images/20230528/de42c0a420784fc894142544f159ee99.png
[watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3FxXzQwNzk0OTcz_size_16_color_FFFFFF_t_70 4]: /images/20230528/79493e4436fb4618af8dc334a8efa4d4.png
[https_yuanyu.blog.csdn.net_article_details_105294435]: https://yuanyu.blog.csdn.net/article/details/105294435
[https_cloud.spring.io_spring-cloud-static_Greenwich.SR1_single_spring-cloud.html_customizing_the_ribbon_client]: https://cloud.spring.io/spring-cloud-static/Greenwich.SR1/single/spring-cloud.html#_customizing_the_ribbon_client
[https_cloud.spring.io_spring-cloud-static_Greenwich.SR1_single_spring-cloud.html_customizing_the_ribbon_client_by_setting_properties]: https://cloud.spring.io/spring-cloud-static/Greenwich.SR1/single/spring-cloud.html#_customizing_the_ribbon_client_by_setting_properties
[http_www.imooc.com_article_288660]: http://www.imooc.com/article/288660
[watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3FxXzQwNzk0OTcz_size_16_color_FFFFFF_t_70 5]: /images/20230528/a5fdf17e9ce64863a535b29aecfeb572.png
[https_blog.csdn.net_lilizhou2008_article_details_94517599]: https://blog.csdn.net/lilizhou2008/article/details/94517599
[http_www.itmuch.com_spring-cloud-alibaba_ribbon-nacos-weight-cluster]: http://www.itmuch.com/spring-cloud-alibaba/ribbon-nacos-weight-cluster/
[http_www.imooc.com_article_288674]: http://www.imooc.com/article/288674