九.SpringCloud源码剖析-Eureka Server服务注册流程

妖狐艹你老母 2022-12-11 06:29 129阅读 0赞

### 系列文章目录 ###

[一.SpringCloud源码剖析-Eureka核心API][.SpringCloud_-Eureka_API]

[二.SpringCloud源码剖析-Eureka Client 初始化过程][.SpringCloud_-Eureka Client]

[三.SpringCloud源码剖析-Eureka服务注册][.SpringCloud_-Eureka]

[四.SpringCloud源码剖析-Eureka服务发现][.SpringCloud_-Eureka 1]

[五.SpringCloud源码剖析-Eureka Client服务续约][.SpringCloud_-Eureka Client 1]

[六.SpringCloud源码剖析-Eureka Client取消注册][.SpringCloud_-Eureka Client 2]

[七.SpringCloud源码剖析-Eureka Server的自动配置][.SpringCloud_-Eureka Server]

[八.SpringCloud源码剖析-Eureka Server初始化流程][.SpringCloud_-Eureka Server 1]

[九.SpringCloud源码剖析-Eureka Server服务注册流程][.SpringCloud_-Eureka Server 2]

[十.SpringCloud源码剖析-Eureka Server服务续约][.SpringCloud_-Eureka Server 3]

[十一.SpringCloud源码剖析-Eureka Server服务注册表拉取][.SpringCloud_-Eureka Server 4]

[十二.SpringCloud源码剖析-Eureka Server服务剔除][.SpringCloud_-Eureka Server 5]

[十三.SpringCloud源码剖析-Eureka Server服务下线][.SpringCloud_-Eureka Server 6]

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

## 前言 ##

本片文章的目的是分析Eureka Server的注册流程，您可以结合《[Eureka Client服务注册][.SpringCloud_-Eureka]》更容易理解

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

## Eureka Server服务注册流程 ##

在《[Eureka Server初始化流程][.SpringCloud_-Eureka Server 1]》 文章中我们知道，在EurekaServerAutoConfiguration中注册了JerseyFilter用来处理所有的/eureka开头的请求,当Eureka Client客户端发起注册请求，请求被该Filter接待

/** * Register the Jersey filter * 注册Jersey filter */
    	@Bean
    	public FilterRegistrationBean jerseyFilterRegistration(
    			javax.ws.rs.core.Application eurekaJerseyApp) { 
    		FilterRegistrationBean bean = new FilterRegistrationBean();
    		//ServletContainer 是核心处理类
    		bean.setFilter(new ServletContainer(eurekaJerseyApp));
    		bean.setOrder(Ordered.LOWEST_PRECEDENCE);
    		//处理的请求/eureka/**
    		bean.setUrlPatterns(
    				Collections.singletonList(EurekaConstants.DEFAULT_PREFIX + "/*"));
    
    		return bean;
    	}

具体的实现是在ServletContainer中完成

//处理请求
    private void doFilter(HttpServletRequest request, HttpServletResponse response, FilterChain chain, String requestURI, String servletPath, String queryString) throws IOException, ServletException { 
            Pattern p = this.getStaticContentPattern();
            //处理 ContextPath 上下文路径
            if (p != null && p.matcher(servletPath).matches()) { 
                chain.doFilter(request, response);
            } else { 
                if (this.filterContextPath != null) { 
                    if (!servletPath.startsWith(this.filterContextPath)) { 
                        throw new ContainerException("The servlet path, \"" + servletPath + "\", does not start with the filter context path, \"" + this.filterContextPath + "\"");
                    }
    
                    if (servletPath.length() == this.filterContextPath.length()) { 
                        if (this.webComponent.getResourceConfig().getFeature("com.sun.jersey.config.feature.Redirect")) { 
                            URI l = UriBuilder.fromUri(request.getRequestURL().toString()).path("/").replaceQuery(queryString).build(new Object[0]);
                            response.setStatus(307);
                            response.setHeader("Location", l.toASCIIString());
                            return;
                        }
    
                        requestURI = requestURI + "/";
                    }
                }
    
                UriBuilder absoluteUriBuilder = UriBuilder.fromUri(request.getRequestURL().toString());
                URI baseUri = this.filterContextPath == null ? absoluteUriBuilder.replacePath(request.getContextPath()).path("/").build(new Object[0]) : absoluteUriBuilder.replacePath(request.getContextPath()).path(this.filterContextPath).path("/").build(new Object[0]);
                URI requestUri = absoluteUriBuilder.replacePath(requestURI).replaceQuery(queryString).build(new Object[0]);
                //这里调用service方法
                int status = this.service(baseUri, requestUri, request, response);
                if (this.forwardOn404 && status == 404 && !response.isCommitted()) { 
                    response.setStatus(200);
                    chain.doFilter(request, response);
                }
    
            }
        }
    
    
    	// 处理请求，调用WebComponent的service方法
        public int service(URI baseUri, URI requestUri, HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException { 
            return this.webComponent.service(baseUri, requestUri, request, response);
        }

最终会调用ApplicationResource实现服务注册 ， Eureka Server对于Eureka client注册服务实例，获取服务实例的的REST请求的都交给ApplicationResource处理，其中用来服务注册的方法是addInstance,我们来看一下他的源码

/** 服务实例注册,InstanceInfo是服务注册信息，isReplicationd为true代表是从其他Eureka Server节点复制实例，如果是isReplication为false，代表是Eureka Client 注册的 * Registers information about a particular instance for an * {@link com.netflix.discovery.shared.Application}. * * @param info * {@link InstanceInfo} information of the instance. * @param isReplication * a header parameter containing information whether this is * replicated from other nodes. */
        @POST
        @Consumes({ "application/json", "application/xml"})
        public Response addInstance(InstanceInfo info,
                                    @HeaderParam(PeerEurekaNode.HEADER_REPLICATION) String isReplication) { 
            logger.debug("Registering instance {} (replication={})", info.getId(), isReplication);
            //验证instanceinfo包含所有必需的必填字段
            // validate that the instanceinfo contains all the necessary required fields
            if (isBlank(info.getId())) { 
                return Response.status(400).entity("Missing instanceId").build();
            } else if (isBlank(info.getHostName())) { 
                return Response.status(400).entity("Missing hostname").build();
            } else if (isBlank(info.getIPAddr())) { 
                return Response.status(400).entity("Missing ip address").build();
            } else if (isBlank(info.getAppName())) { 
                return Response.status(400).entity("Missing appName").build();
            } else if (!appName.equals(info.getAppName())) { 
                return Response.status(400).entity("Mismatched appName, expecting " + appName + " but was " + info.getAppName()).build();
            } else if (info.getDataCenterInfo() == null) { 
                return Response.status(400).entity("Missing dataCenterInfo").build();
            } else if (info.getDataCenterInfo().getName() == null) { 
                return Response.status(400).entity("Missing dataCenterInfo Name").build();
            }
    		//处理客户端可能在数据缺失的情况下向错误的DataCenterInfo注册的情况
            // handle cases where clients may be registering with bad DataCenterInfo with missing data
            DataCenterInfo dataCenterInfo = info.getDataCenterInfo();
            if (dataCenterInfo instanceof UniqueIdentifier) { 
                String dataCenterInfoId = ((UniqueIdentifier) dataCenterInfo).getId();
                if (isBlank(dataCenterInfoId)) { 
                    boolean experimental = "true".equalsIgnoreCase(serverConfig.getExperimental("registration.validation.dataCenterInfoId"));
                    if (experimental) { 
                        String entity = "DataCenterInfo of type " + dataCenterInfo.getClass() + " must contain a valid id";
                        return Response.status(400).entity(entity).build();
                    } else if (dataCenterInfo instanceof AmazonInfo) { 
                        AmazonInfo amazonInfo = (AmazonInfo) dataCenterInfo;
                        String effectiveId = amazonInfo.get(AmazonInfo.MetaDataKey.instanceId);
                        if (effectiveId == null) { 
                            amazonInfo.getMetadata().put(AmazonInfo.MetaDataKey.instanceId.getName(), info.getId());
                        }
                    } else { 
                        logger.warn("Registering DataCenterInfo of type {} without an appropriate id", dataCenterInfo.getClass());
                    }
                }
            }
    		//【重要】：这里在调用PeerAwareInstanceRegistry的register注册服务，使用的是实现类：InstanceRegistry
            registry.register(info, "true".equals(isReplication));
            return Response.status(204).build();  // 204 to be backwards compatible
        }

ApplicationResource.addInstance看方法名就能推测出他是用来注册实例的方法，其中参数InstanceInfo 是客户端提交的注册信息，请求头中isReplicationd为true代表是从其他Eureka Server节点复制实例，如果是isReplication为false，代表是Eureka Client 注册的

在做了一些列参数判断之后，这里在调用PeerAwareInstanceRegistry的register注册服务，使用的是实现类：InstanceRegistry，这个类在之前有介绍过，就是Eureak Server用来实现服务注册，服务发现，服务续约，取消注册等的具体实现，他的继承关系如下：  
![在这里插入图片描述][watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3UwMTQ0OTQxNDg_size_16_color_FFFFFF_t_70_pic_center]  
跟踪下去，InstanceRegistry .register方法源码如下

public class InstanceRegistry extends PeerAwareInstanceRegistryImpl implements ApplicationContextAware { 
    
        public void register(final InstanceInfo info, final boolean isReplication) { 
        	//调用handleRegistration方法，抛出事件：EurekaInstanceRegisteredEvent
            this.handleRegistration(info, this.resolveInstanceLeaseDuration(info), isReplication);
            //调用父类PeerAwareInstanceRegistryImpl的register方法
            super.register(info, isReplication);
        }
        //服务注册，抛出EurekaInstanceRegisteredEvent事件
        private void handleRegistration(InstanceInfo info, int leaseDuration, boolean isReplication) { 
            this.log("register " + info.getAppName() + ", vip " + info.getVIPAddress() + ", leaseDuration " + leaseDuration + ", isReplication " + isReplication);
            this.publishEvent(new EurekaInstanceRegisteredEvent(this, info, leaseDuration, isReplication));
        }
      ...省略...  
      }

这里在调用handleRegistration方法，抛出事件：EurekaInstanceRegisteredEvent后继续调用了super.register方法，即：PeerAwareInstanceRegistryImpl.register，继续跟踪下去：

@Singleton
    public class PeerAwareInstanceRegistryImpl extends AbstractInstanceRegistry implements PeerAwareInstanceRegistry { 
      /** 注册服务信息 InstanceInfo，并将此信息InstanceInfo复制到所有对等的eureka server节点。 如果这是来自其他副本节点的复制事件，则不会复制它。 * Registers the information about the {@link InstanceInfo} and replicates * this information to all peer eureka nodes. If this is replication event * from other replica nodes then it is not replicated. * * @param info * the {@link InstanceInfo} to be registered and replicated. * @param isReplication * true if this is a replication event from other replica nodes, * false otherwise. */
        @Override
        public void register(final InstanceInfo info, final boolean isReplication) { 
        	//租期失效时间 90 s
            int leaseDuration = Lease.DEFAULT_DURATION_IN_SECS;
            
            if (info.getLeaseInfo() != null && info.getLeaseInfo().getDurationInSecs() > 0) { 
            	//如果服务的租期失效时间大于默认的90s，则重新赋值租期时间
                leaseDuration = info.getLeaseInfo().getDurationInSecs();
            }
            //服务注册
            super.register(info, leaseDuration, isReplication);
            //把注册的服务信息复制到其他的Eureka Server 节点，注意这里是Action.Register
            replicateToPeers(Action.Register, info.getAppName(), info.getId(), info, null, isReplication);
        }
    }

该方法做了3个事情，

*  1是更新租期失效时间，
 *  2是调用super.register服务注册(AbstractInstanceRegistry.register)
 *  3是调用replicateToPeers把服务实例拷贝到其他的Eureak Server节点

我们先看下super.register方法即：AbstractInstanceRegistry.register方法的源码

/** * Registers a new instance with a given duration. * * @see com.netflix.eureka.lease.LeaseManager#register(java.lang.Object, int, boolean) */
        public void register(InstanceInfo registrant, int leaseDuration, boolean isReplication) { 
            try { 
            	//获取锁：ReentrantReadWriteLock.lock()
                read.lock();
                //根据注册的服务的名字取本地服务注册表中获取服务注册信息，如果该服务已经被注册了，那么registry中将会存在它
                Map<String, Lease<InstanceInfo>> gMap = registry.get(registrant.getAppName());
                REGISTER.increment(isReplication);
                if (gMap == null) { 
                //如果该服务实例没被注册，就把服务实例注册到本地的registry中，本质是一个Map
                    final ConcurrentHashMap<String, Lease<InstanceInfo>> gNewMap = new ConcurrentHashMap<String, Lease<InstanceInfo>>();
                    //没有的话就添加到registry中
                    gMap = registry.putIfAbsent(registrant.getAppName(), gNewMap);
                    if (gMap == null) { 
                        gMap = gNewMap;
                    }
                }
                //根据服务实例id获取服务的租约对象
                Lease<InstanceInfo> existingLease = gMap.get(registrant.getId());
                // Retain the last dirty timestamp without overwriting it, if there is already a lease
                //如果已经有租约，则保留最后的脏时间戳而不覆盖它
                if (existingLease != null && (existingLease.getHolder() != null)) { 
                	//registry中已经存在的当前服务的最后修改时间的时间戳
                    Long existingLastDirtyTimestamp = existingLease.getHolder().getLastDirtyTimestamp();
                    //提交注册的当前服务的最后修改时间
                    Long registrationLastDirtyTimestamp = registrant.getLastDirtyTimestamp();
                    logger.debug("Existing lease found (existing={}, provided={}", existingLastDirtyTimestamp, registrationLastDirtyTimestamp);
    			//因为如果时间戳相等，我们仍然采用远程传输的InstanceInfo而不是服务器本地副本
                    // this is a > instead of a >= because if the timestamps are equal, we still take the remote transmitted
                    // InstanceInfo instead of the server local copy.
                    //如果已存在的该服务的修改时间 大于 当前提交注册的该服务的最后修改时间，
                    //则采用registy中已存在的服务为准,因为要选择修改时间靠后的
                    
                    if (existingLastDirtyTimestamp > registrationLastDirtyTimestamp) { 
                        logger.warn("There is an existing lease and the existing lease's dirty timestamp {} is greater" +
                                " than the one that is being registered {}", existingLastDirtyTimestamp, registrationLastDirtyTimestamp);
                        logger.warn("Using the existing instanceInfo instead of the new instanceInfo as the registrant");
                        //使用现有的instanceInfo代替新的instanceInfo作为注册者
                        registrant = existingLease.getHolder();
                    }
                } else { 
                	//执行到这里，说明该服务是新注册
                    // The lease does not exist and hence it is a new registration
                    synchronized (lock) { 
                    //这里在计算服务的续约频率值
                        if (this.expectedNumberOfRenewsPerMin > 0) { 
                            // Since the client wants to cancel it, reduce the threshold
                            // (1
                            // for 30 seconds, 2 for a minute)
    						//(expectedNumberOfRenewsPerMin)期待的每分钟续订次数,默认是30s/个，给他增加到2，每分钟2个请求
                            this.expectedNumberOfRenewsPerMin = this.expectedNumberOfRenewsPerMin + 2;
                            //修改numberOfRenewsPerMinThreshold每分钟续约阀值 = 2 *（85%），
                            //RenewalPercentThreshold是获取续订阈值百分比 
                            this.numberOfRenewsPerMinThreshold =
                                    (int) (this.expectedNumberOfRenewsPerMin * serverConfig.getRenewalPercentThreshold());
                        }
                    }
                    logger.debug("No previous lease information found; it is new registration");
                }
                //创建租约对象，把注册实例和租期放进去
                Lease<InstanceInfo> lease = new Lease<InstanceInfo>(registrant, leaseDuration);
                if (existingLease != null) { 
                	//设置服务上线时间
                    lease.setServiceUpTimestamp(existingLease.getServiceUpTimestamp());
                }
                //以注册的实例的ID为key把服务实例存封装到 Map
                gMap.put(registrant.getId(), lease);
                //添加到注册队列
                synchronized (recentRegisteredQueue) { 
                    recentRegisteredQueue.add(new Pair<Long, String>(
                            System.currentTimeMillis(),
                            registrant.getAppName() + "(" + registrant.getId() + ")"));
                }
                // This is where the initial state transfer of overridden status happens
                if (!InstanceStatus.UNKNOWN.equals(registrant.getOverriddenStatus())) { 
                    logger.debug("Found overridden status {} for instance {}. Checking to see if needs to be add to the "
                                    + "overrides", registrant.getOverriddenStatus(), registrant.getId());
                    if (!overriddenInstanceStatusMap.containsKey(registrant.getId())) { 
                        logger.info("Not found overridden id {} and hence adding it", registrant.getId());
                        //添加服务的OverriddenStatus
                        overriddenInstanceStatusMap.put(registrant.getId(), registrant.getOverriddenStatus());
                    }
                }
                InstanceStatus overriddenStatusFromMap = overriddenInstanceStatusMap.get(registrant.getId());
                if (overriddenStatusFromMap != null) { 
                    logger.info("Storing overridden status {} from map", overriddenStatusFromMap);
                    registrant.setOverriddenStatus(overriddenStatusFromMap);
                }
    
    			//根据覆盖的状态规则设置状态
                // Set the status based on the overridden status rules
                InstanceStatus overriddenInstanceStatus = getOverriddenInstanceStatus(registrant, existingLease, isReplication);
                registrant.setStatusWithoutDirty(overriddenInstanceStatus);
    
                // If the lease is registered with UP status, set lease service up timestamp
                //如果租约已注册为UP状态，请设置租约服务启动时间戳记
                if (InstanceStatus.UP.equals(registrant.getStatus())) { 
    	            //更新服务上线时间戳
                    lease.serviceUp();
                }
                //服务动作：ADDED添加，MODIFIED修改，DELETED删除
                registrant.setActionType(ActionType.ADDED);
                //添加到最近更改的队列
                recentlyChangedQueue.add(new RecentlyChangedItem(lease));
                //最后更新时间
                registrant.setLastUpdatedTimestamp();
                //使当前应用的ResponseCache失效
                invalidateCache(registrant.getAppName(), registrant.getVIPAddress(), registrant.getSecureVipAddress());
                logger.info("Registered instance {}/{} with status {} (replication={})",
                        registrant.getAppName(), registrant.getId(), registrant.getStatus(), isReplication);
            } finally { 
                read.unlock();
            }
        }

总结一下，这个方法做了什么呢

1.  判断当前服务是否已经被注册，如果是，则以最后更新时间为准，选择更新时间靠后的服务实例进行注册
2.  维护实例的租约信息Lease，并放到Eureka Server本地维护维护的registry注册表中，本质是一个Map（ConcurrentHashMap<String, Map<String, Lease>>）
3.  如果是服务是新注册的，把注册的实例封装成Leaset存储到registry注册表中，并更新每分钟续约阀值numberOfRenewsPerMinThreshold
4.  维护了两个队列，recentRegisteredQueue最近注册队列，recentlyChangedQueue最近更改队列，这个队列可以用来获取最近操作的信息。
5.  维护当前实例的OverriddenStatus
6.  更新服务实例的最后更新时间戳
7.  使ResponseCache缓存失效

该方法结束，我们回到PeerAwareInstanceRegistryImpl.register方法中，继续跟踪replicateToPeers 方法

@Singleton
    public class PeerAwareInstanceRegistryImpl extends AbstractInstanceRegistry implements PeerAwareInstanceRegistry { 
      /** * Replicates all eureka actions to peer eureka nodes except for replication * traffic to this node. * 将所有eureka操作复制到对等eureka节点 */
        private void replicateToPeers(Action action, String appName, String id,
                                      InstanceInfo info /* optional */,
                                      InstanceStatus newStatus /* optional */, boolean isReplication) { 
             //开始计时
            Stopwatch tracer = action.getTimer().start();
            try { 
            	//是否是其他节点复制过来的
                if (isReplication) { 
                	//最后一分钟的复制次数+1
                    numberOfReplicationsLastMin.increment();
                }
                // If it is a replication already, do not replicate again as this will create a poison replication
                //如果已经是复制，则不要再次复制
                if (peerEurekaNodes == Collections.EMPTY_LIST || isReplication) { 
                    return;
                }
    			//遍历集群所有节点
                for (final PeerEurekaNode node : peerEurekaNodes.getPeerEurekaNodes()) { 
                    // If the url represents this host, do not replicate to yourself.
                    //如果该URL代表此主机，请不要复制到您自己，当前节点不复制
                    if (peerEurekaNodes.isThisMyUrl(node.getServiceUrl())) { 
                        continue;
                    }
                    //复制实例到其他某个Eureka
                    replicateInstanceActionsToPeers(action, appName, id, info, newStatus, node);
                }
            } finally { 
                tracer.stop();
            }
        }

继续跟踪replicateInstanceActionsToPeers的源码

/** * Replicates all instance changes to peer eureka nodes except for * replication traffic to this node. * */
        private void replicateInstanceActionsToPeers(Action action, String appName,
                                                     String id, InstanceInfo info, InstanceStatus newStatus,
                                                     PeerEurekaNode node) { 
            try { 
                InstanceInfo infoFromRegistry = null;
                CurrentRequestVersion.set(Version.V2);
                //判断请求的是什么操作
                switch (action) { 
                	//取消注册，调用 PeerEurekaNode.cancel
                    case Cancel:
                        node.cancel(appName, id);
                        break;
                    //心跳请求，调用PeerEurekaNode.heartbeat
                    case Heartbeat:
                        InstanceStatus overriddenStatus = overriddenInstanceStatusMap.get(id);
                        infoFromRegistry = getInstanceByAppAndId(appName, id, false);
                        node.heartbeat(appName, id, infoFromRegistry, overriddenStatus, false);
                        break;
                    //服务注册调用PeerEurekaNode.register
                    case Register:
                        node.register(info);
                        break;
                     //状态修改调用PeerEurekaNode.statusUpdate
                    case StatusUpdate:
                        infoFromRegistry = getInstanceByAppAndId(appName, id, false);
                        node.statusUpdate(appName, id, newStatus, infoFromRegistry);
                        break;
                      //状态删除调用PeerEurekaNode.deleteStatusOverride
                    case DeleteStatusOverride:
                        infoFromRegistry = getInstanceByAppAndId(appName, id, false);
                        node.deleteStatusOverride(appName, id, infoFromRegistry);
                        break;
                }
            } catch (Throwable t) { 
                logger.error("Cannot replicate information to {} for action {}", node.getServiceUrl(), action.name(), t);
            }
        }

这里在根据请求的动作类型选择PeerEurekaNode的不同方法，我们这里是服务注册.register，调用的是 PeerEurekaNode.register ，源码如下：

/** * Sends the registration information of {@link InstanceInfo} receiving by * this node to the peer node represented by this class. * * @param info * the instance information {@link InstanceInfo} of any instance * that is send to this instance. * @throws Exception */
        public void register(final InstanceInfo info) throws Exception { 
        	//到期时间当，前时间加上30s过期
            long expiryTime = System.currentTimeMillis() + getLeaseRenewalOf(info);
            //封装InstanceReplicationTask 实例赋值任务到调度器中
            batchingDispatcher.process(
                    taskId("register", info),
                    new InstanceReplicationTask(targetHost, Action.Register, info, null, true) { 				
                        public EurekaHttpResponse<Void> execute() { 
                            //复制器客户端 HttpReplicationClient(JerseyReplicationClient)，执行注册
                            //调用AbstractJerseyEurekaHttpClient#register
                            return replicationClient.register(info);
                        }
                    },
                    expiryTime
            );
        }

把InstanceInfo注册实例封装成InstanceReplicationTask实例复制任务，交给batchingDispatcher批量任务调度器去执行，replicationClient是HttpReplicationClient它的默认实现是JerseyEurekaHttpClient，底层会调用AbstractJerseyEurekaHttpClient\#register的方法完成实例的注册，这里其实就和当时我们分析Eureka Client 服务注册的最后注册请求一样了

public abstract class AbstractJerseyEurekaHttpClient implements EurekaHttpClient { 
     public EurekaHttpResponse<Void> register(InstanceInfo info) { 
    		 //请求地址
            String urlPath = "apps/" + info.getAppName();
            ClientResponse response = null;
    
            EurekaHttpResponse var5;
            try { 
                Builder resourceBuilder = this.jerseyClient.resource(this.serviceUrl).path(urlPath).getRequestBuilder();
                this.addExtraHeaders(resourceBuilder);
                //把InstanceInfo作为参数，发送post请求提交服务注册
                response = (ClientResponse)((Builder)((Builder)((Builder)resourceBuilder.header("Accept-Encoding", "gzip")).type(MediaType.APPLICATION_JSON_TYPE)).accept(new String[]{ "application/json"})).post(ClientResponse.class, info);
                var5 = EurekaHttpResponse.anEurekaHttpResponse(response.getStatus()).headers(headersOf(response)).build();
            } finally { 
                if (logger.isDebugEnabled()) { 
                    logger.debug("Jersey HTTP POST {}/{} with instance {}; statusCode={}", new Object[]{ this.serviceUrl, urlPath, info.getId(), response == null ? "N/A" : response.getStatus()});
                }
    
                if (response != null) { 
                    response.close();
                }
    
            }
    
            return var5;
        }

到这里就结束了，在PeerEurekaNode中封装InstanceReplicationTask实例服务任务，通过EurekaHttpClient去发起请求(JerseyEurekaHttpClient)，最终通过JerseyEurekaHttpClient父类AbstractJerseyEurekaHttpClient\#register方法注册，方法中把InstanceInfo作为参数使用POST提交请求。

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

# 总结 #

![提示：这里对文章进行总结：例如：以上就是今天要讲的内容，本文仅仅简单介绍了pandas的使用，而pandas提供了大量能使我们快速便捷地处理数据的函数和方法。][pandas_pandas]

[.SpringCloud_-Eureka_API]: https://blog.csdn.net/u014494148/article/details/107904301
[.SpringCloud_-Eureka Client]: https://blog.csdn.net/u014494148/article/details/107982920
[.SpringCloud_-Eureka]: https://blog.csdn.net/u014494148/article/details/106907911
[.SpringCloud_-Eureka 1]: https://blog.csdn.net/u014494148/article/details/108217656
[.SpringCloud_-Eureka Client 1]: https://blog.csdn.net/u014494148/article/details/108315405
[.SpringCloud_-Eureka Client 2]: https://blog.csdn.net/u014494148/article/details/108319815
[.SpringCloud_-Eureka Server]: https://blog.csdn.net/u014494148/article/details/108351827
[.SpringCloud_-Eureka Server 1]: https://blog.csdn.net/u014494148/article/details/108469231
[.SpringCloud_-Eureka Server 2]: https://blog.csdn.net/u014494148/article/details/108861409
[.SpringCloud_-Eureka Server 3]: https://blog.csdn.net/u014494148/article/details/108884210
[.SpringCloud_-Eureka Server 4]: https://blog.csdn.net/u014494148/article/details/108895557
[.SpringCloud_-Eureka Server 5]: https://blog.csdn.net/u014494148/article/details/108900884
[.SpringCloud_-Eureka Server 6]: https://blog.csdn.net/u014494148/article/details/108905727
[watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3UwMTQ0OTQxNDg_size_16_color_FFFFFF_t_70_pic_center]: /images/20221123/9a5e4ec900064b42b0877b7eeff14a95.png
[pandas_pandas]: /images/20221123/3810f48555f34e90963dd0c2e448c794.png