文章目录
- 1.InstanceController#list()
- 2.InstanceController#doSrvIpxt()
- 3.总结
1.InstanceController#list()
Nacos Server处理订阅请求
主要还是从请求中获取参数, 比如namespceId、serviceName、agent(指定提交请求的客户端是哪种类型)、clusters、clusterIP、udpPort(后续UDP通信会使用)、app、tenant, 最后调用方法对参数进行处理
2.InstanceController#doSrvIpxt()
对请求进行详细处理
public ObjectNode doSrvIpxt(String namespaceId, String serviceName, String agent, String clusters, String clientIP,int udpPort, String env, boolean isCheck, String app, String tid, boolean healthyOnly) throws Exception {// 不同agent,生成不同的clientInfoClientInfo clientInfo = new ClientInfo(agent);// 创建一个JSON Node,其就是当前方法返回的结果。后续代码就是对这个Node的各种初始化ObjectNode result = JacksonUtils.createEmptyJsonNode();// 从注册表中获取当前服务Service service = serviceManager.getService(namespaceId, serviceName);long cacheMillis = switchDomain.getDefaultCacheMillis();// now try to enable the pushtry {if (udpPort > 0 && pushService.canEnablePush(agent)) {// 创建当前发出订阅请求的Nacos client的UDP Client, PushClient// 注意,在Nacos的UDP通信中,Nacos Server充当的是UDP Client,Nacos Client充当的是UDP ServerpushService.addClient(namespaceId, serviceName, clusters, agent, new InetSocketAddress(clientIP, udpPort),pushDataSource, tid, app);cacheMillis = switchDomain.getPushCacheMillis(serviceName);}} catch (Exception e) {Loggers.SRV_LOG.error("[NACOS-API] failed to added push client {}, {}:{}", clientInfo, clientIP, udpPort, e);cacheMillis = switchDomain.getDefaultCacheMillis();}// 若注册表中没有该服务,则直接结束if (service == null) {if (Loggers.SRV_LOG.isDebugEnabled()) {Loggers.SRV_LOG.debug("no instance to serve for service: {}", serviceName);}result.put("name", serviceName);result.put("clusters", clusters);result.put("cacheMillis", cacheMillis);// 注意,hosts为空result.replace("hosts", JacksonUtils.createEmptyArrayNode());return result;}// 代码直到这里,说明注册表中存在该服务// 检测该服务是否被禁。若是被禁的服务,直接抛出异常checkIfDisabled(service);List<Instance> srvedIPs;// 获取到当前服务的所有实例,包含所有持久/临时实例srvedIPs = service.srvIPs(Arrays.asList(StringUtils.split(clusters, ",")));// filter ips using selector:// 若选择器不空,则根据选择算法选择可用的intance列表,默认情况下,选择器不做任何过滤if (service.getSelector() != null && StringUtils.isNotBlank(clientIP)) {srvedIPs = service.getSelector().select(clientIP, srvedIPs);}// 若最终选择的结果为空,则直接结束if (CollectionUtils.isEmpty(srvedIPs)) {if (Loggers.SRV_LOG.isDebugEnabled()) {Loggers.SRV_LOG.debug("no instance to serve for service: {}", serviceName);}if (clientInfo.type == ClientInfo.ClientType.JAVA&& clientInfo.version.compareTo(VersionUtil.parseVersion("1.0.0")) >= 0) {result.put("dom", serviceName);} else {result.put("dom", NamingUtils.getServiceName(serviceName));}result.put("name", serviceName);result.put("cacheMillis", cacheMillis);result.put("lastRefTime", System.currentTimeMillis());result.put("checksum", service.getChecksum());result.put("useSpecifiedURL", false);result.put("clusters", clusters);result.put("env", env);// 注意,hosts为空result.set("hosts", JacksonUtils.createEmptyArrayNode());result.set("metadata", JacksonUtils.transferToJsonNode(service.getMetadata()));return result;}// 代码走到这里,说明具有可用的instanceMap<Boolean, List<Instance>> ipMap = new HashMap<>(2);// 这个map只有两个key,True与False// key为true的value中存放的是所有健康的instance// key为false的value存放的是所有不健康的instanceipMap.put(Boolean.TRUE, new ArrayList<>());ipMap.put(Boolean.FALSE, new ArrayList<>());// 根据instance的健康状态,将所有instance分流放入map的不同key的value中for (Instance ip : srvedIPs) {// 这个语句写的非常好// 健康加入健康的列表, 不健康的加入不健康的列表ipMap.get(ip.isHealthy()).add(ip);}// isCheck为true,表示需要检测instance的保护阈值if (isCheck) {// reachProtectThreshold 是否达到了保护阈值, false 为没有达到result.put("reachProtectThreshold", false);}// 获取服务的保护阈值double threshold = service.getProtectThreshold();// 若 "健康instance数量/instance总数" <= 保护阈值,则说明需要启动保护机制了if ((float) ipMap.get(Boolean.TRUE).size() / srvedIPs.size() <= threshold) {Loggers.SRV_LOG.warn("protect threshold reached, return all ips, service: {}", serviceName);if (isCheck) {// true表示启动保护机制result.put("reachProtectThreshold", true);}// 健康数量小于阈值, 则从所有实例中调用, 可能会有不健康实例, 可以保证健康实例不被压崩溃// 将所有不健康的instance添加到的key为true的instance列表,// 即key为true的value中(instance列表)存放的是所有instance实例// 包含所有健康的与不健康的instanceipMap.get(Boolean.TRUE).addAll(ipMap.get(Boolean.FALSE));// 清空key为false的value(不健康的instance列表)ipMap.get(Boolean.FALSE).clear();}if (isCheck) {result.put("protectThreshold", service.getProtectThreshold());result.put("reachLocalSiteCallThreshold", false);return JacksonUtils.createEmptyJsonNode();}ArrayNode hosts = JacksonUtils.createEmptyArrayNode();// 注意,这个ipMap中存放着所有健康与不健康的instance列表for (Map.Entry<Boolean, List<Instance>> entry : ipMap.entrySet()) {List<Instance> ips = entry.getValue();// 若客户端只要健康的instance,且当前遍历的map的key为false,则跳过if (healthyOnly && !entry.getKey()) {continue;}// 遍历的这个ips可能是所有不健康的instance列表,// 也可能是所有健康的instance列表,// 也可能是所有健康与不健康的instance列表总和for (Instance instance : ips) {// 跳过禁用的instanceif (!instance.isEnabled()) {continue;}ObjectNode ipObj = JacksonUtils.createEmptyJsonNode();// 将当前遍历的instance转换为JSONipObj.put("ip", instance.getIp());ipObj.put("port", instance.getPort());// deprecated since nacos 1.0.0:ipObj.put("valid", entry.getKey());ipObj.put("healthy", entry.getKey());ipObj.put("marked", instance.isMarked());ipObj.put("instanceId", instance.getInstanceId());ipObj.set("metadata", JacksonUtils.transferToJsonNode(instance.getMetadata()));ipObj.put("enabled", instance.isEnabled());ipObj.put("weight", instance.getWeight());ipObj.put("clusterName", instance.getClusterName());if (clientInfo.type == ClientInfo.ClientType.JAVA&& clientInfo.version.compareTo(VersionUtil.parseVersion("1.0.0")) >= 0) {ipObj.put("serviceName", instance.getServiceName());} else {ipObj.put("serviceName", NamingUtils.getServiceName(instance.getServiceName()));}ipObj.put("ephemeral", instance.isEphemeral());hosts.add(ipObj);} // end-for} // end-forresult.replace("hosts", hosts);if (clientInfo.type == ClientInfo.ClientType.JAVA&& clientInfo.version.compareTo(VersionUtil.parseVersion("1.0.0")) >= 0) {result.put("dom", serviceName);} else {result.put("dom", NamingUtils.getServiceName(serviceName));}result.put("name", serviceName);result.put("cacheMillis", cacheMillis);result.put("lastRefTime", System.currentTimeMillis());result.put("checksum", service.getChecksum());result.put("useSpecifiedURL", false);result.put("clusters", clusters);result.put("env", env);result.replace("metadata", JacksonUtils.transferToJsonNode(service.getMetadata()));return result;}
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不同agent,生成不同的clientInfo, java、c、c++、go、nginx、dnsf
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pushService.addClient(): 创建当前发出订阅请求的Nacos client的UDP Client, PushClient, Nacos Server充当的是UDP Client,Nacos Client充当的是UDP Server
获取到了UDP通信客户端PushClient, 并写入到一个缓存map中
public void addClient(PushClient client) {// client is stored by key 'serviceName' because notify event is driven by serviceName changeString serviceKey = UtilsAndCommons.assembleFullServiceName(client.getNamespaceId(), client.getServiceName());// clientMap是一个缓存map,用于存放当前Nacos Server中所有instance对应的UDP Client// 其是一个双层map,外层map的key为 namespaceId##groupId@@微服务名称,value为内层map// 内层map的key为代表一个instance的字符串,value为该instance对应的UDP Client,即PushClientConcurrentMap<String, PushClient> clients = clientMap.get(serviceKey);// 若当前服务的内层map为null,则创建一个并放入到缓存mapif (clients == null) {clientMap.putIfAbsent(serviceKey, new ConcurrentHashMap<>(1024));clients = clientMap.get(serviceKey);}PushClient oldClient = clients.get(client.toString());// 从内层map中获取当前instance对应的的PushClient,// 若该PushClient不为null,则更新一个最后引用时间戳;// 若该PushClient为null,则将当前这个PushClient作为PushClient// 写入到内层map,即写入到了缓存mapif (oldClient != null) {// 更新最后引用时间戳oldClient.refresh();} else {PushClient res = clients.putIfAbsent(client.toString(), client);if (res != null) {Loggers.PUSH.warn("client: {} already associated with key {}", res.getAddrStr(), res.toString());}Loggers.PUSH.debug("client: {} added for serviceName: {}", client.getAddrStr(), client.getServiceName());}}
- 获取当前服务的所有实例, 包括持久和临时
public List<Instance> srvIPs(List<String> clusters) {if (CollectionUtils.isEmpty(clusters)) {clusters = new ArrayList<>();clusters.addAll(clusterMap.keySet());}// 获取到当前服务的所有cluster中的所有instancereturn allIPs(clusters);}public List<Instance> allIPs(List<String> clusters) {List<Instance> result = new ArrayList<>();for (String cluster : clusters) {Cluster clusterObj = clusterMap.get(cluster);if (clusterObj == null) {continue;}// 将当前遍历cluster的所有instance添加到result集合// 包含所有持久实例与临时实例result.addAll(clusterObj.allIPs());}return result;}public List<Instance> allIPs() {List<Instance> allInstances = new ArrayList<>();// 持久实例allInstances.addAll(persistentInstances);// 临时实例allInstances.addAll(ephemeralInstances);return allInstances;}
3.总结
Nacos Server处理订阅请求的主要任务:
- 创建了Nacos Client对应的UDP通信客户端PushClient, 并写入一个缓存map
- 从注册表中获取到指定服务的所有可用的instance, 并封装为Json