不懂Ribbon原理的可以进来看看哦，分析RibbonClientConfiguration完成了哪些核心初始操作

Myth丶恋晨 2022-09-04 13:51 105阅读 0赞

![在这里插入图片描述][watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3FxXzM4NTI2NTcz_size_16_color_FFFFFF_t_70_pic_center]  本文在前一篇文章的基础上来继续分析Ribbon的核心内容。  
[不懂Ribbon原理的可以进来看看哦，分析SpringBoot自动装配完成了Ribbon哪些核心操作][Ribbon_SpringBoot_Ribbon]

# RibbonClientConfiguration #

RibbonClientConfiguration是一个非常中的Ribbon配置类，在第一个发起Ribbon请求的时候会完成对应的初始化操作。会完成多个相关的默认设置。

<table> 
 <thead> 
  <tr> 
   <th>接口</th> 
   <th>默认实现</th> 
   <th>描述</th> 
  </tr> 
 </thead> 
 <tbody> 
  <tr> 
   <td>IClientConfig</td> 
   <td>DefaultClientConfigImpl</td> 
   <td>管理配置接口</td> 
  </tr> 
  <tr> 
   <td>IRule</td> 
   <td>ZoneAvoidanceRule</td> 
   <td>均衡策略接口</td> 
  </tr> 
  <tr> 
   <td>IPing</td> 
   <td>DummyPing</td> 
   <td>检查服务可用性接口</td> 
  </tr> 
  <tr> 
   <td>ServerList&lt;Server&gt;</td> 
   <td>ConfigurationBasedServerList</td> 
   <td>获取服务列表接口</td> 
  </tr> 
  <tr> 
   <td>ILoadBalancer</td> 
   <td>ZoneAwareLoadBalancer</td> 
   <td>负载均衡接口</td> 
  </tr> 
  <tr> 
   <td>ServerListUpdater</td> 
   <td>PollingServerListUpdater</td> 
   <td>定时更新服务列表接口</td> 
  </tr> 
  <tr> 
   <td>ServerIntrospector</td> 
   <td>DefaultServerIntrospector</td> 
   <td>安全端口接口</td> 
  </tr> 
 </tbody> 
</table>

@Bean
        @ConditionalOnMissingBean
        public IClientConfig ribbonClientConfig() { 
            DefaultClientConfigImpl config = new DefaultClientConfigImpl();
            config.loadProperties(this.name);
            config.set(CommonClientConfigKey.ConnectTimeout, 1000);
            config.set(CommonClientConfigKey.ReadTimeout, 1000);
            config.set(CommonClientConfigKey.GZipPayload, true);
            return config;
        }
    
        @Bean
        @ConditionalOnMissingBean
        public IRule ribbonRule(IClientConfig config) { 
            if (this.propertiesFactory.isSet(IRule.class, this.name)) { 
                return (IRule)this.propertiesFactory.get(IRule.class, config, this.name);
            } else { 
                ZoneAvoidanceRule rule = new ZoneAvoidanceRule();
                rule.initWithNiwsConfig(config);
                return rule;
            }
        }
    
        @Bean
        @ConditionalOnMissingBean
        public IPing ribbonPing(IClientConfig config) { 
            return (IPing)(this.propertiesFactory.isSet(IPing.class, this.name) ? (IPing)this.propertiesFactory.get(IPing.class, config, this.name) : new DummyPing());
        }
    
        @Bean
        @ConditionalOnMissingBean
        public ServerList<Server> ribbonServerList(IClientConfig config) { 
            if (this.propertiesFactory.isSet(ServerList.class, this.name)) { 
                return (ServerList)this.propertiesFactory.get(ServerList.class, config, this.name);
            } else { 
                ConfigurationBasedServerList serverList = new ConfigurationBasedServerList();
                serverList.initWithNiwsConfig(config);
                return serverList;
            }
        }
    
        @Bean
        @ConditionalOnMissingBean
        public ServerListUpdater ribbonServerListUpdater(IClientConfig config) { 
            return new PollingServerListUpdater(config);
        }
    
        @Bean
        @ConditionalOnMissingBean
        public ILoadBalancer ribbonLoadBalancer(IClientConfig config, ServerList<Server> serverList, ServerListFilter<Server> serverListFilter, IRule rule, IPing ping, ServerListUpdater serverListUpdater) { 
            return (ILoadBalancer)(this.propertiesFactory.isSet(ILoadBalancer.class, this.name) ? (ILoadBalancer)this.propertiesFactory.get(ILoadBalancer.class, config, this.name) : new ZoneAwareLoadBalancer(config, rule, ping, serverList, serverListFilter, serverListUpdater));

在众多的默认实现中比较重要的是【ILoadBalancer】对象的实现。即【ZoneAwareLoadBalancer】的实现。实现的原理图为：  
![请添加图片描述][watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3FxXzM4NTI2NTcz_size_16_color_FFFFFF_t_70]  
在【ZoneAwareLoadBalancer】里面完成了服务地址动态获取和服务地址更新定时任务的配置。首先会进入【ZoneAwareLoadBalancer】的构造方法中

public ZoneAwareLoadBalancer(IClientConfig clientConfig, IRule rule,
                                     IPing ping, ServerList<T> serverList, ServerListFilter<T> filter,
                                     ServerListUpdater serverListUpdater) { 
            super(clientConfig, rule, ping, serverList, filter, serverListUpdater);
        }

通过源码能够发现会调用父类中的构造方法。

public DynamicServerListLoadBalancer(IClientConfig clientConfig, IRule rule, IPing ping,
                                             ServerList<T> serverList, ServerListFilter<T> filter,
                                             ServerListUpdater serverListUpdater) { 
            // 继续调用父类中的方法
            super(clientConfig, rule, ping);
            this.serverListImpl = serverList;
            this.filter = filter;
            this.serverListUpdater = serverListUpdater;
            if (filter instanceof AbstractServerListFilter) { 
                ((AbstractServerListFilter) filter).setLoadBalancerStats(getLoadBalancerStats());
            }
            // 完成相关的初始操作 服务地址获取和更新
            restOfInit(clientConfig);
        }

在上面的源码中我们先继续跟踪父类中的方法。

void initWithConfig(IClientConfig clientConfig, IRule rule, IPing ping, LoadBalancerStats stats) { 
            this.config = clientConfig;
            String clientName = clientConfig.getClientName();
            this.name = clientName;
            // 设置了定时任务的间隔时间为30秒。
            int pingIntervalTime = Integer.parseInt(""
                    + clientConfig.getProperty(
                            CommonClientConfigKey.NFLoadBalancerPingInterval,
                            Integer.parseInt("30")));
            int maxTotalPingTime = Integer.parseInt(""
                    + clientConfig.getProperty(
                            CommonClientConfigKey.NFLoadBalancerMaxTotalPingTime,
                            Integer.parseInt("2")));
    
            setPingInterval(pingIntervalTime);
            setMaxTotalPingTime(maxTotalPingTime);
    
            // cross associate with each other
            // i.e. Rule,Ping meet your container LB
            // LB, these are your Ping and Rule guys ...
            setRule(rule);
            setPing(ping);
    
            setLoadBalancerStats(stats);
            rule.setLoadBalancer(this);
            if (ping instanceof AbstractLoadBalancerPing) { 
                ((AbstractLoadBalancerPing) ping).setLoadBalancer(this);
            }
            logger.info("Client: {} instantiated a LoadBalancer: {}", name, this);
            boolean enablePrimeConnections = clientConfig.get(
                    CommonClientConfigKey.EnablePrimeConnections, DefaultClientConfigImpl.DEFAULT_ENABLE_PRIME_CONNECTIONS);
    
            if (enablePrimeConnections) { 
                this.setEnablePrimingConnections(true);
                PrimeConnections primeConnections = new PrimeConnections(
                        this.getName(), clientConfig);
                this.setPrimeConnections(primeConnections);
            }
            init();
    
        }

在initWithConfig方法中比较中的就是设置了定时任务的间隔时间。然后我们再回到restOfInit方法中。

void restOfInit(IClientConfig clientConfig) { 
            boolean primeConnection = this.isEnablePrimingConnections();
            // turn this off to avoid duplicated asynchronous priming done in BaseLoadBalancer.setServerList()
            this.setEnablePrimingConnections(false);
            // 设置定时任务
            enableAndInitLearnNewServersFeature();
    		// 获取并更新服务地址
            updateListOfServers();
            if (primeConnection && this.getPrimeConnections() != null) { 
                this.getPrimeConnections()
                        .primeConnections(getReachableServers());
            }
            this.setEnablePrimingConnections(primeConnection);
            LOGGER.info("DynamicServerListLoadBalancer for client {} initialized: {}", clientConfig.getClientName(), this.toString());
        }

先看enableAndInitLearnNewServersFeature方法

public void enableAndInitLearnNewServersFeature() { 
            LOGGER.info("Using serverListUpdater {}", serverListUpdater.getClass().getSimpleName());
            serverListUpdater.start(updateAction);
        }

start方法的实现有多种，根据我们的服务选择对应的选择即可。比如本地就使用PollingServerListUpdater,如果是Eureka注册中心就选择EurekaNotificationServerListUpdater.  
![请添加图片描述][a5e88e0567974b0ebc5a3f651b14561a.png]  
以本地为例：

@Override
        public synchronized void start(final UpdateAction updateAction) { 
            if (isActive.compareAndSet(false, true)) { 
                // 定时任务的 任务体
                final Runnable wrapperRunnable = new Runnable() { 
                    @Override
                    public void run() { 
                        if (!isActive.get()) { 
                            if (scheduledFuture != null) { 
                                scheduledFuture.cancel(true);
                            }
                            return;
                        }
                        try { 
                            // doUpdate()的方法体要注意
                            updateAction.doUpdate();
                            lastUpdated = System.currentTimeMillis();
                        } catch (Exception e) { 
                            logger.warn("Failed one update cycle", e);
                        }
                    }
                };
    			// 设置定时任务 10秒开始第一次检查，间隔时间是30秒
                scheduledFuture = getRefreshExecutor().scheduleWithFixedDelay(
                        wrapperRunnable,
                        initialDelayMs,
                        refreshIntervalMs,
                        TimeUnit.MILLISECONDS
                );
            } else { 
                logger.info("Already active, no-op");
            }
        }

此处要注意定时任务的具体内容，以本地为例。  
![请添加图片描述][watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3FxXzM4NTI2NTcz_size_16_color_FFFFFF_t_70 1]  
 所以定时任务执行的方法也就是【updateListOfServers】方法，也就是：  
![请添加图片描述][watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3FxXzM4NTI2NTcz_size_16_color_FFFFFF_t_70 2]  
emsp; 所以我们继续来看看【updateListOfServers】方法中的逻辑

@VisibleForTesting
        public void updateListOfServers() { 
            List<T> servers = new ArrayList<T>();
            if (serverListImpl != null) { 
                // 从本地或者Eureka或者Nacos等各个配置中心中获取对应的服务地址信息
                servers = serverListImpl.getUpdatedListOfServers();
                LOGGER.debug("List of Servers for {} obtained from Discovery client: {}",
                        getIdentifier(), servers);
    
                if (filter != null) { 
                    servers = filter.getFilteredListOfServers(servers);
                    LOGGER.debug("Filtered List of Servers for {} obtained from Discovery client: {}",
                            getIdentifier(), servers);
                }
            }
            // 更新服务地址信息
            updateAllServerList(servers);
        }

上面代码中重要的方法是【getUpdatedListOfServers】和【updateAllServerList】，先来看【getUpdatedListOfServers】方法  
![请添加图片描述][5c216de05fec4f0e82eb332da434a3de.png]  
  查看本地的逻辑，Eureka的自行查看

@Override
    	public List<Server> getUpdatedListOfServers() { 
            // 从本地配置中获取
            String listOfServers = clientConfig.get(CommonClientConfigKey.ListOfServers);
            return derive(listOfServers);
    	}

然后就是【updateAllServerList】方法

protected void updateAllServerList(List<T> ls) { 
            // other threads might be doing this - in which case, we pass
            // 通过CAS保证操作的原子性
            if (serverListUpdateInProgress.compareAndSet(false, true)) { 
                try { 
                    for (T s : ls) { 
                        s.setAlive(true); // set so that clients can start using these
                                          // servers right away instead
                                          // of having to wait out the ping cycle.
                    }
                    // 更新服务地址信息
                    setServersList(ls);
                    // 强制ping服务地址
                    super.forceQuickPing();
                } finally { 
                    serverListUpdateInProgress.set(false);
                }
            }
        }

以上的操作流程图为：  
![请添加图片描述][watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3FxXzM4NTI2NTcz_size_16_color_FFFFFF_t_70]

好了~【RibbonClientConfiguration】这个配置类的内容就给大家介绍到这里，欢迎大家一键三连!!!

[watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3FxXzM4NTI2NTcz_size_16_color_FFFFFF_t_70_pic_center]: /images/20220829/20b773df1c824d2f89e014f85e27aa17.png
[Ribbon_SpringBoot_Ribbon]: https://blog.csdn.net/qq_38526573/article/details/119581706?spm=1001.2014.3001.5501
[watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3FxXzM4NTI2NTcz_size_16_color_FFFFFF_t_70]: /images/20220829/cfb26610171b48cc947485d1a3286c45.png
[a5e88e0567974b0ebc5a3f651b14561a.png]: /images/20220829/ccdd9ed740ac4e7dbf8cc7f69d7a5908.png
[watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3FxXzM4NTI2NTcz_size_16_color_FFFFFF_t_70 1]: /images/20220829/366f3a8506cf40cda0507cfd73c42f7b.png
[watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3FxXzM4NTI2NTcz_size_16_color_FFFFFF_t_70 2]: /images/20220829/9c175784636043bb97a59f638f913735.png
[5c216de05fec4f0e82eb332da434a3de.png]: /images/20220829/9d350bbe882a4cfc81d1b06b665f23a0.png