| /* |
| * Licensed to the Apache Software Foundation (ASF) under one or more |
| * contributor license agreements. See the NOTICE file distributed with |
| * this work for additional information regarding copyright ownership. |
| * The ASF licenses this file to You under the Apache License, Version 2.0 |
| * (the "License"); you may not use this file except in compliance with |
| * the License. You may obtain a copy of the License at |
| * |
| * http://www.apache.org/licenses/LICENSE-2.0 |
| * |
| * Unless required by applicable law or agreed to in writing, software |
| * distributed under the License is distributed on an "AS IS" BASIS, |
| * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. |
| * See the License for the specific language governing permissions and |
| * limitations under the License. |
| */ |
| package org.apache.dubbo.registry.etcd; |
| |
| import org.apache.dubbo.common.URL; |
| import org.apache.dubbo.common.extension.ExtensionLoader; |
| import org.apache.dubbo.common.logger.Logger; |
| import org.apache.dubbo.common.logger.LoggerFactory; |
| import org.apache.dubbo.common.utils.CollectionUtils; |
| import org.apache.dubbo.common.utils.ConcurrentHashSet; |
| import org.apache.dubbo.event.EventDispatcher; |
| import org.apache.dubbo.event.EventListener; |
| import org.apache.dubbo.registry.client.AbstractServiceDiscovery; |
| import org.apache.dubbo.registry.client.DefaultServiceInstance; |
| import org.apache.dubbo.registry.client.ServiceInstance; |
| import org.apache.dubbo.registry.client.event.ServiceInstancesChangedEvent; |
| import org.apache.dubbo.registry.client.event.listener.ServiceInstancesChangedListener; |
| import org.apache.dubbo.remoting.etcd.ChildListener; |
| import org.apache.dubbo.remoting.etcd.EtcdClient; |
| import org.apache.dubbo.remoting.etcd.EtcdTransporter; |
| import org.apache.dubbo.remoting.etcd.StateListener; |
| import org.apache.dubbo.remoting.etcd.option.OptionUtil; |
| import org.apache.dubbo.rpc.RpcException; |
| |
| import com.google.gson.Gson; |
| |
| import java.io.File; |
| import java.util.ArrayList; |
| import java.util.Collections; |
| import java.util.List; |
| import java.util.Map; |
| import java.util.Optional; |
| import java.util.Set; |
| import java.util.concurrent.ConcurrentHashMap; |
| |
| /** |
| * 2019-07-08 |
| */ |
| public class EtcdServiceDiscovery extends AbstractServiceDiscovery implements EventListener<ServiceInstancesChangedEvent> { |
| |
| private final static Logger logger = LoggerFactory.getLogger(EtcdServiceDiscovery.class); |
| |
| private final String root = "/services"; |
| |
| private final Set<String> services = new ConcurrentHashSet<>(); |
| private final Map<String, ChildListener> childListenerMap = new ConcurrentHashMap<>(); |
| |
| EtcdClient etcdClient; |
| EventDispatcher dispatcher; |
| ServiceInstance serviceInstance; |
| |
| @Override |
| public void onEvent(ServiceInstancesChangedEvent event) { |
| registerServiceWatcher(event.getServiceName()); |
| } |
| |
| @Override |
| public void initialize(URL registryURL) throws Exception { |
| |
| EtcdTransporter etcdTransporter = ExtensionLoader.getExtensionLoader(EtcdTransporter.class).getAdaptiveExtension(); |
| |
| if (registryURL.isAnyHost()) { |
| throw new IllegalStateException("Service discovery address is invalid, actual: '" + registryURL.getHost() + "'"); |
| } |
| |
| etcdClient = etcdTransporter.connect(registryURL); |
| |
| etcdClient.addStateListener(state -> { |
| if (state == StateListener.CONNECTED) { |
| try { |
| recover(); |
| } catch (Exception e) { |
| logger.error(e.getMessage(), e); |
| } |
| } |
| }); |
| |
| this.dispatcher = EventDispatcher.getDefaultExtension(); |
| this.dispatcher.addEventListener(this); |
| } |
| |
| @Override |
| public void destroy() { |
| if (etcdClient != null && etcdClient.isConnected()) { |
| etcdClient.close(); |
| } |
| } |
| |
| @Override |
| public void register(ServiceInstance serviceInstance) throws RuntimeException { |
| try { |
| this.serviceInstance = serviceInstance; |
| String path = toPath(serviceInstance); |
| // etcdClient.createEphemeral(path); |
| etcdClient.putEphemeral(path, new Gson().toJson(serviceInstance)); |
| services.add(serviceInstance.getServiceName()); |
| } catch (Throwable e) { |
| throw new RpcException("Failed to register " + serviceInstance + " to etcd " + etcdClient.getUrl() |
| + ", cause: " + (OptionUtil.isProtocolError(e) |
| ? "etcd3 registry may not be supported yet or etcd3 registry is not available." |
| : e.getMessage()), e); |
| } |
| } |
| |
| String toPath(ServiceInstance serviceInstance) { |
| return root + File.separator + serviceInstance.getServiceName() + File.separator + serviceInstance.getHost() |
| + ":" + serviceInstance.getPort(); |
| } |
| |
| String toParentPath(String serviceName) { |
| return root + File.separator + serviceName; |
| } |
| |
| @Override |
| public void update(ServiceInstance serviceInstance) throws RuntimeException { |
| try { |
| String path = toPath(serviceInstance); |
| etcdClient.putEphemeral(path, new Gson().toJson(serviceInstance)); |
| services.add(serviceInstance.getServiceName()); |
| } catch (Throwable e) { |
| throw new RpcException("Failed to register " + serviceInstance + " to etcd " + etcdClient.getUrl() |
| + ", cause: " + (OptionUtil.isProtocolError(e) |
| ? "etcd3 registry may not be supported yet or etcd3 registry is not available." |
| : e.getMessage()), e); |
| } |
| } |
| |
| @Override |
| public void unregister(ServiceInstance serviceInstance) throws RuntimeException { |
| try { |
| String path = toPath(serviceInstance); |
| etcdClient.delete(path); |
| services.remove(serviceInstance.getServiceName()); |
| this.serviceInstance = null; |
| } catch (Throwable e) { |
| throw new RpcException("Failed to unregister " + serviceInstance + " to etcd " + etcdClient.getUrl() + ", cause: " + e.getMessage(), e); |
| } |
| } |
| |
| @Override |
| public Set<String> getServices() { |
| return Collections.unmodifiableSet(services); |
| } |
| |
| @Override |
| public void addServiceInstancesChangedListener(ServiceInstancesChangedListener listener) throws NullPointerException, IllegalArgumentException { |
| listener.getServiceNames().forEach(serviceName -> registerServiceWatcher(serviceName)); |
| } |
| |
| @Override |
| public List<ServiceInstance> getInstances(String serviceName) { |
| List<String> children = etcdClient.getChildren(toParentPath(serviceName)); |
| if (CollectionUtils.isEmpty(children)) { |
| return Collections.EMPTY_LIST; |
| } |
| List<ServiceInstance> list = new ArrayList<>(children.size()); |
| for (String child : children) { |
| ServiceInstance serviceInstance = new Gson().fromJson(etcdClient.getKVValue(child), DefaultServiceInstance.class); |
| list.add(serviceInstance); |
| } |
| return list; |
| } |
| |
| |
| protected void registerServiceWatcher(String serviceName) { |
| String path = root + File.separator + serviceName; |
| /* |
| * if we have no category watcher listener, |
| * we find out the current listener or create one for the current category, put or get only once. |
| */ |
| ChildListener childListener = |
| Optional.ofNullable(childListenerMap.get(serviceName)) |
| .orElseGet(() -> { |
| ChildListener watchListener, prev; |
| prev = childListenerMap.putIfAbsent(serviceName, watchListener = (parentPath, currentChildren) -> |
| dispatchServiceInstancesChangedEvent(serviceName)); |
| return prev != null ? prev : watchListener; |
| }); |
| |
| etcdClient.create(path); |
| |
| etcdClient.addChildListener(path, childListener); |
| } |
| |
| private void recover() throws Exception { |
| // register |
| if (serviceInstance != null) { |
| if (logger.isInfoEnabled()) { |
| logger.info("Recover application register: " + serviceInstance); |
| } |
| register(serviceInstance); |
| } |
| } |
| } |