Merge pull request #1286 from lcg72/master

Fixes #1259 #1260 #753 #1253 Solve the problem of meta data update

spring-cloud-alibaba-starters/spring-cloud-starter-dubbo/src/main/java/com/alibaba/cloud/dubbo/metadata/repository/DubboServiceMetadataRepository.java

@@ -22,6 +22,7 @@ import java.util.LinkedHashSet;
 import java.util.List;
 import java.util.Map;
 import java.util.Objects;
+import java.util.Optional;
 import java.util.Set;
 import java.util.stream.Collectors;
 import java.util.stream.Stream;
@@ -289,9 +290,11 @@ public class DubboServiceMetadataRepository
 							serviceName);
 				}
 
-				initSubscribedDubboMetadataService(serviceName);
+				if (initSubscribedDubboMetadataService(serviceName)) {
-				// mark this service name having been initialized
+					// mark this service name having been initialized
-				initializedServices.add(serviceName);
+					initializedServices.add(serviceName);
+				}
+
 			}
 		}
 	}
@@ -300,12 +303,19 @@ public class DubboServiceMetadataRepository
 	 * Remove the metadata and initialized service of Dubbo Services if no there is no
 	 * service instance.
 	 * @param serviceName the service name
+	 * @param url the meta service url
 	 */
-	public void removeMetadataAndInitializedService(String serviceName) {
+	public void removeMetadataAndInitializedService(String serviceName, URL url) {
 		synchronized (monitor) {
 			initializedServices.remove(serviceName);
 			dubboRestServiceMetadataRepository.remove(serviceName);
-			subscribedDubboMetadataServiceURLs.remove(serviceName);
+			// fix #1260 if the subscribedDubboMetadataServiceURLs removed fail，old meta
+			// information will be retained
+			if (DubboMetadataService.class.getName().equals(url.getServiceInterface())) {
+				String serviceKey = url.getServiceKey();
+				subscribedDubboMetadataServiceURLs.remove(serviceKey);
+			}
+
 		}
 	}
 
@@ -614,24 +624,47 @@ public class DubboServiceMetadataRepository
 		subscribedServices.remove(currentApplicationName);
 	}
 
-	protected void initSubscribedDubboMetadataService(String serviceName) {
+	protected Boolean initSubscribedDubboMetadataService(String serviceName) {
-		metadataServiceInstanceSelector.choose(discoveryClient.getInstances(serviceName))
+		// this need to judge whether the initialization is successful or not. The failed
-				.map(this::getDubboMetadataServiceURLs)
+		// initialization will not change the initializedServices
-				.ifPresent(dubboMetadataServiceURLs -> {
+		Optional<ServiceInstance> optionalServiceInstance = metadataServiceInstanceSelector
-					dubboMetadataServiceURLs.forEach(dubboMetadataServiceURL -> {
+				.choose(discoveryClient.getInstances(serviceName));
-						try {
+		if (!((Optional) optionalServiceInstance).isPresent()) {
-							initSubscribedDubboMetadataServiceURL(
+			return false;
-									dubboMetadataServiceURL);
+		}
-							initDubboMetadataServiceProxy(dubboMetadataServiceURL);
+		ServiceInstance serviceInstance = optionalServiceInstance.get();
-						}
+		if (null == serviceInstance) {
-						catch (Throwable e) {
+			return false;
-							if (logger.isErrorEnabled()) {
+		}
-								logger.error(e.getMessage(), e);
+		List<URL> dubboMetadataServiceURLs = getDubboMetadataServiceURLs(serviceInstance);
-							}
+		if (dubboMetadataServiceURLs.isEmpty()) {
-						}
+			return false;
-					});
+		}
-				});
+		for (URL dubboMetadataServiceURL : dubboMetadataServiceURLs) {
+			try {
+				initSubscribedDubboMetadataServiceURL(dubboMetadataServiceURL);
+				DubboMetadataService dubboMetadataService = dubboMetadataConfigServiceProxy
+						.getProxy(serviceName);
+				if (dubboMetadataService == null) {
+					dubboMetadataService = initDubboMetadataServiceProxy(
+							dubboMetadataServiceURL);
+				}
+
+				if (dubboMetadataService == null) {
+					removeMetadataAndInitializedService(serviceName,
+							dubboMetadataServiceURL);
+					return false;
+				}
+			}
+			catch (Throwable e) {
+				if (logger.isErrorEnabled()) {
+					logger.error(e.getMessage(), e);
+				}
+				return false;
+			}
+		}
 		initDubboRestServiceMetadataRepository(serviceName);
+		return true;
 	}
 
 	private void initSubscribedDubboMetadataServiceURL(URL dubboMetadataServiceURL) {
@@ -640,11 +673,13 @@ public class DubboServiceMetadataRepository
 		subscribedDubboMetadataServiceURLs.add(serviceKey, dubboMetadataServiceURL);
 	}
 
-	private void initDubboMetadataServiceProxy(URL dubboMetadataServiceURL) {
+	private DubboMetadataService initDubboMetadataServiceProxy(
+			URL dubboMetadataServiceURL) {
 		String serviceName = dubboMetadataServiceURL.getParameter(APPLICATION_KEY);
 		String version = dubboMetadataServiceURL.getParameter(VERSION_KEY);
 		// Initialize DubboMetadataService with right version
-		dubboMetadataConfigServiceProxy.initProxy(serviceName, version);
+		return dubboMetadataConfigServiceProxy.initProxy(serviceName, version);
+
 	}
 
 	@Override

spring-cloud-alibaba-starters/spring-cloud-starter-dubbo/src/main/java/com/alibaba/cloud/dubbo/registry/AbstractSpringCloudRegistry.java

@@ -48,9 +48,11 @@ import static java.util.Collections.emptyList;
 import static org.apache.dubbo.common.URLBuilder.from;
 import static org.apache.dubbo.common.constants.CommonConstants.GROUP_KEY;
 import static org.apache.dubbo.common.constants.CommonConstants.PROTOCOL_KEY;
+import static org.apache.dubbo.common.constants.CommonConstants.PROVIDER;
 import static org.apache.dubbo.common.constants.CommonConstants.PROVIDER_SIDE;
 import static org.apache.dubbo.common.constants.CommonConstants.SIDE_KEY;
 import static org.apache.dubbo.common.constants.CommonConstants.VERSION_KEY;
+import static org.apache.dubbo.common.constants.RegistryConstants.CATEGORY_KEY;
 import static org.apache.dubbo.common.constants.RegistryConstants.EMPTY_PROTOCOL;
 import static org.apache.dubbo.registry.Constants.ADMIN_PROTOCOL;
 import static org.springframework.util.StringUtils.hasText;
@@ -161,6 +163,13 @@ public abstract class AbstractSpringCloudRegistry extends FailbackRegistry {
 		}
 		else if (isDubboMetadataServiceURL(url)) { // for DubboMetadataService
 			subscribeDubboMetadataServiceURLs(url, listener);
+			if (from(url).getParameter(CATEGORY_KEY) != null
+					&& from(url).getParameter(CATEGORY_KEY).contains(PROVIDER)) {
+				// Fix #1259 and #753 Listene meta service change events to remove useless
+				// clients
+				registerServiceInstancesChangedEventListener(url, listener);
+			}
+
 		}
 		else { // for general Dubbo Services
 			subscribeDubboServiceURLs(url, listener);
@@ -228,10 +237,13 @@ public abstract class AbstractSpringCloudRegistry extends FailbackRegistry {
 		// Re-obtain the latest list of available metadata address here, ip or port may
 		// change.
 		// by https://github.com/wangzihaogithub
-		dubboMetadataConfigServiceProxy.removeProxy(serviceName);
+		// When the last service provider is closed, 【fix 1259】while close the
-		repository.removeMetadataAndInitializedService(serviceName);
+		// channel，when up a new provider then repository.initializeMetadata(serviceName)
-		dubboGenericServiceFactory.destroy(serviceName);
+		// will throw Exception.
-		repository.initializeMetadata(serviceName);
+		// dubboMetadataConfigServiceProxy.removeProxy(serviceName);
+		// repository.removeMetadataAndInitializedService(serviceName);
+		// dubboGenericServiceFactory.destroy(serviceName);
+		// repository.initializeMetadata(serviceName);
 		if (CollectionUtils.isEmpty(serviceInstances)) {
 			if (logger.isWarnEnabled()) {
 				logger.warn(
@@ -239,6 +251,18 @@ public abstract class AbstractSpringCloudRegistry extends FailbackRegistry {
 								+ "available , please make sure the further impact",
 						serviceName, url.getServiceKey());
 			}
+			if (isDubboMetadataServiceURL(url)) {
+				// if meta service change, and serviceInstances is zero, will clean up
+				// information about this client
+				dubboMetadataConfigServiceProxy.removeProxy(serviceName);
+				repository.removeMetadataAndInitializedService(serviceName, url);
+				dubboGenericServiceFactory.destroy(serviceName);
+				String listenerId = generateId(url);
+				// The metaservice will restart the new listener. It needs to be optimized
+				// to see whether the original listener can be reused.
+				this.registerListeners.remove(listenerId);
+			}
+
 			/**
 			 * URLs with {@link RegistryConstants#EMPTY_PROTOCOL}
 			 */
@@ -250,6 +274,11 @@ public abstract class AbstractSpringCloudRegistry extends FailbackRegistry {
 			listener.notify(allSubscribedURLs);
 			return;
 		}
+		if (isDubboMetadataServiceURL(url)) {
+			// Prevent duplicate generation of DubboMetadataService
+			return;
+		}
+		repository.initializeMetadata(serviceName);
 
 		DubboMetadataService dubboMetadataService = dubboMetadataConfigServiceProxy
 				.getProxy(serviceName);
@@ -301,7 +330,11 @@ public abstract class AbstractSpringCloudRegistry extends FailbackRegistry {
 	}
 
 	private List<URL> emptyURLs(URL url) {
-		return asList(from(url).setProtocol(EMPTY_PROTOCOL).build());
+		// issue : When the last service provider is closed, the client still periodically
+		// connects to the last provider.n
+		// fix https://github.com/alibaba/spring-cloud-alibaba/issues/1259
+		return asList(from(url).setProtocol(EMPTY_PROTOCOL).removeParameter(CATEGORY_KEY)
+				.build());
 	}
 
 	private List<ServiceInstance> getServiceInstances(String serviceName) {