Nacos - 客戶端註冊已經講過了，那這裡講一下服務端是怎麼處理請求的。
處理客戶的請求在InstanceController裡，我們看看register方法。
InstanceController#register
這裡主要是封裝Instance，並呼叫serviceManager的registerInstance方法進行服務註冊。
public String register(HttpServletRequest request) throws Exception {
// 獲取namespaceId
final String namespaceId = WebUtils
.optional(request, CommonParams.NAMESPACE_ID, Constants.DEFAULT_NAMESPACE_ID);
// 獲取serviceName
final String serviceName = WebUtils.required(request, CommonParams.SERVICE_NAME);
// 驗證serviceName的合法性
NamingUtils.checkServiceNameFormat(serviceName);
// 封裝並驗證Instance的合法性
final Instance instance = parseInstance(request);
// 服務註冊
serviceManager.registerInstance(namespaceId, serviceName, instance);
return "ok";
}ServiceManager#registerInstance
判斷是否已經註冊過，如果沒有註冊，則建立一個Service並註冊，然後再新增例項。
public void registerInstance(String namespaceId, String serviceName, Instance instance) throws NacosException {
// 是否已經註冊過，如果沒有註冊，則建立一個Service並註冊
createEmptyService(namespaceId, serviceName, instance.isEphemeral());
// 從註冊的服務中取Service
Service service = getService(namespaceId, serviceName);
if (service == null) {
throw new NacosException(NacosException.INVALID_PARAM,
"service not found, namespace: " + namespaceId + ", service: " + serviceName);
}
// 新增例項
addInstance(namespaceId, serviceName, instance.isEphemeral(), instance);
}ServiceManager#createEmptyService
直接呼叫createServiceIfAbsent方法。
public void createEmptyService(String namespaceId, String serviceName, boolean local) throws NacosException {
createServiceIfAbsent(namespaceId, serviceName, local, null);
}ServiceManager#createServiceIfAbsent
public void createServiceIfAbsent(String namespaceId, String serviceName, boolean local, Cluster cluster)
throws NacosException {
// 獲取Service
Service service = getService(namespaceId, serviceName);
if (service == null) {
// 沒有獲取到則建立
Loggers.SRV_LOG.info("creating empty service {}:{}", namespaceId, serviceName);
service = new Service();
service.setName(serviceName);
service.setNamespaceId(namespaceId);
service.setGroupName(NamingUtils.getGroupName(serviceName));
// now validate the service. if failed, exception will be thrown
service.setLastModifiedMillis(System.currentTimeMillis());
// checksum用於校驗的
service.recalculateChecksum();
if (cluster != null) {
// 加入到叢集
cluster.setService(service);
service.getClusterMap().put(cluster.getName(), cluster);
}
// 驗證服務和叢集名稱的合法性
service.validate();
// 放入快取並檢查心跳
putServiceAndInit(service);
if (!local) {
// 一致性協議儲存
addOrReplaceService(service);
}
}
}ServiceManager#putServiceAndInit
Service存入serviceMap快取，並每5秒健康檢查
private void putServiceAndInit(Service service) throws NacosException {
// 存入serviceMap快取
putService(service);
// 每5秒健康檢查，包括service和cluster
service.init();
// 新增監聽，包括臨時和永久
consistencyService
.listen(KeyBuilder.buildInstanceListKey(service.getNamespaceId(), service.getName(), true), service);
consistencyService
.listen(KeyBuilder.buildInstanceListKey(service.getNamespaceId(), service.getName(), false), service);
Loggers.SRV_LOG.info("[NEW-SERVICE] {}", service.toJson());
}ServiceManager#getService
從serviceMap快取中取值。
public Service getService(String namespaceId, String serviceName) {
if (serviceMap.get(namespaceId) == null) {
return null;
}
return chooseServiceMap(namespaceId).get(serviceName);
}
public Map<String, Service> chooseServiceMap(String namespaceId) {
return serviceMap.get(namespaceId);
}ServiceManager#addInstance
儲存例項
public void addInstance(String namespaceId, String serviceName, boolean ephemeral, Instance... ips)
throws NacosException {
// 獲取例項key
String key = KeyBuilder.buildInstanceListKey(namespaceId, serviceName, ephemeral);
// 從快取serviceMap獲取Service
Service service = getService(namespaceId, serviceName);
synchronized (service) {
// 獲取service的所有例項
List<Instance> instanceList = addIpAddresses(service, ephemeral, ips);
Instances instances = new Instances();
instances.setInstanceList(instanceList);
// 一致性儲存，實際呼叫DistroConsistencyServiceImpl#put
consistencyService.put(key, instances);
}
}ServiceManager#addIpAddresses
直接呼叫updateIpAddresses方法
private List<Instance> addIpAddresses(Service service, boolean ephemeral, Instance... ips) throws NacosException {
return updateIpAddresses(service, UtilsAndCommons.UPDATE_INSTANCE_ACTION_ADD, ephemeral, ips);
}ServiceManager#updateIpAddresses
獲取service的所有例項，這裡會更新老資料
public List<Instance> updateIpAddresses(Service service, String action, boolean ephemeral, Instance... ips)
throws NacosException {
// 獲取舊資料
Datum datum = consistencyService
.get(KeyBuilder.buildInstanceListKey(service.getNamespaceId(), service.getName(), ephemeral));
// 獲取叢集中所有的例項
List<Instance> currentIPs = service.allIPs(ephemeral);
Map<String, Instance> currentInstances = new HashMap<>(currentIPs.size());
Set<String> currentInstanceIds = Sets.newHashSet();
// 遍歷所有例項，key為ip+埠
for (Instance instance : currentIPs) {
currentInstances.put(instance.toIpAddr(), instance);
currentInstanceIds.add(instance.getInstanceId());
}
// 定義新資料
Map<String, Instance> instanceMap;
if (datum != null && null != datum.value) {
// 如果有老資料，透過currentInstances來更新健康狀態和心跳時間
instanceMap = setValid(((Instances) datum.value).getInstanceList(), currentInstances);
} else {
// 沒有就建立一個
instanceMap = new HashMap<>(ips.length);
}
for (Instance instance : ips) {
// 不存在，就建立一個Cluster叢集，並開啟健康檢查
if (!service.getClusterMap().containsKey(instance.getClusterName())) {
// 重新建立一個
Cluster cluster = new Cluster(instance.getClusterName(), service);
// 開啟健康檢查
cluster.init();
service.getClusterMap().put(instance.getClusterName(), cluster);
Loggers.SRV_LOG
.warn("cluster: {} not found, ip: {}, will create new cluster with default configuration.",
instance.getClusterName(), instance.toJson());
}
// 刪除操作的話，就刪除例項
if (UtilsAndCommons.UPDATE_INSTANCE_ACTION_REMOVE.equals(action)) {
instanceMap.remove(instance.getDatumKey());
} else {
// 新增例項，設定唯一id
instance.setInstanceId(instance.generateInstanceId(currentInstanceIds));
instanceMap.put(instance.getDatumKey(), instance);
}
}
if (instanceMap.size() <= 0 && UtilsAndCommons.UPDATE_INSTANCE_ACTION_ADD.equals(action)) {
throw new IllegalArgumentException(
"ip list can not be empty, service: " + service.getName() + ", ip list: " + JacksonUtils
.toJson(instanceMap.values()));
}
// 返回所有例項
return new ArrayList<>(instanceMap.values());
}DistroConsistencyServiceImpl#put
如果是臨時，則加入快取，並放入阻塞佇列。
public void put(String key, Record value) throws NacosException {
onPut(key, value);
// 一致性服務
distroProtocol.sync(new DistroKey(key, KeyBuilder.INSTANCE_LIST_KEY_PREFIX), DataOperation.CHANGE,
globalConfig.getTaskDispatchPeriod() / 2);
}
public void onPut(String key, Record value) {
// 臨時加入dataStore快取
if (KeyBuilder.matchEphemeralInstanceListKey(key)) {
Datum<Instances> datum = new Datum<>();
datum.value = (Instances) value;
datum.key = key;
datum.timestamp.incrementAndGet();
dataStore.put(key, datum);
}
if (!listeners.containsKey(key)) {
return;
}
// 在notifier的阻塞佇列加入ArrayBlockingQueue
notifier.addTask(key, DataOperation.CHANGE);
}DistroConsistencyServiceImp.Notifierl#run
呼叫handle方法
@Override
public void run() {
Loggers.DISTRO.info("distro notifier started");
for (; ; ) {
try {
Pair<String, DataOperation> pair = tasks.take();
handle(pair);
} catch (Throwable e) {
Loggers.DISTRO.error("[NACOS-DISTRO] Error while handling notifying task", e);
}
}
}DistroConsistencyServiceImp.Notifierl#handle
對事件進行通知
private void handle(Pair<String, DataOperation> pair) {
try {
String datumKey = pair.getValue0();
DataOperation action = pair.getValue1();
services.remove(datumKey);
int count = 0;
// 沒有監聽，返回
if (!listeners.containsKey(datumKey)) {
return;
}
for (RecordListener listener : listeners.get(datumKey)) {
count++;
try {
if (action == DataOperation.CHANGE) {
// 處理變更事件
listener.onChange(datumKey, dataStore.get(datumKey).value);
continue;
}
if (action == DataOperation.DELETE) {
// 處理刪除事件
listener.onDelete(datumKey);
continue;
}
} catch (Throwable e) {
Loggers.DISTRO.error("[NACOS-DISTRO] error while notifying listener of key: {}", datumKey, e);
}
}
if (Loggers.DISTRO.isDebugEnabled()) {
Loggers.DISTRO
.debug("[NACOS-DISTRO] datum change notified, key: {}, listener count: {}, action: {}",
datumKey, count, action.name());
}
} catch (Throwable e) {
Loggers.DISTRO.error("[NACOS-DISTRO] Error while handling notifying task", e);
}
}總結
- 服務、叢集如果不存在，則建立，並註冊監聽事件。
- 開啟服務、叢集的健康檢查。
- 如果有舊服務資料，則更新健康狀態和心跳時間。
- 節點的資料一致性。
- 呼叫監聽。
