Polish apache#4050 : Dubbo Cloud Native : Add a mechanism to upgrade …

…Dubbo services smoothly
mercyblitz · Jun 4, 2019 · 9702156 · 9702156
1 parent 9208a34
commit 9702156
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Showing 3 changed files with 51 additions and 21 deletions.
diff --git a/dubbo-config/dubbo-config-api/src/test/java/org/apache/dubbo/config/api/DemoService.java b/dubbo-config/dubbo-config-api/src/test/java/org/apache/dubbo/config/api/DemoService.java
@@ -34,7 +34,7 @@ public interface DemoService {
 
     int echo(int i);
 
-    default String name() {
-        return getClass().getSimpleName();
-    }
+//    default String name() {
+//        return getClass().getSimpleName();
+//    }
 }
diff --git a/...org/apache/dubbo/registry/client/metadata/ExportedServicesRevisionMetadataCustomizer.java b/...org/apache/dubbo/registry/client/metadata/ExportedServicesRevisionMetadataCustomizer.java
@@ -33,6 +33,8 @@
 
 /**
  * The customizer to a add the metadata that the reversion of Dubbo exported services calculates.
+ * <p>
+ * The reversion is calculated on the methods that all Dubbo exported interfaces declare
  *
  * @since 2.7.3
  */
@@ -48,17 +50,20 @@ protected String buildMetadataValue(ServiceInstance serviceInstance) {
         LocalMetadataService localMetadataService = LocalMetadataService.getDefaultExtension();
         List<String> exportedURLs = localMetadataService.getExportedURLs();
         Object[] data = exportedURLs.stream()
-                .map(URL::valueOf)
-                .map(URL::getServiceInterface)
-                .filter(name -> !MetadataService.class.getName().equals(name))
-                .map(ClassUtils::forName)
-                .map(Class::getMethods)
-                .map(Arrays::asList)
-                .flatMap(Collection::stream)
-                .map(Object::toString)
-                .sorted()
-                .toArray();
+                .map(URL::valueOf)                       // String to URL
+                .map(URL::getServiceInterface)           // get the service interface
+                .filter(this::isNotMetadataService)      // filter not MetadataService interface
+                .map(ClassUtils::forName)                // load business interface class
+                .map(Class::getMethods)                  // get all public methods from business interface
+                .map(Arrays::asList)                     // Array to List
+                .flatMap(Collection::stream)             // flat Stream<Stream> to be Stream
+                .map(Object::toString)                   // Method to String
+                .sorted()                                // sort methods marking sure the calculation of reversion is stable
+                .toArray();                              // Stream to Array
+        return valueOf(hash(data));                      // calculate the hash code as reversion
+    }
 
-        return valueOf(hash(data));
+    private boolean isNotMetadataService(String serviceInterface) {
+        return !MetadataService.class.getName().equals(serviceInterface);
     }
 }
diff --git a/...registry-api/src/main/java/org/apache/dubbo/registry/support/ServiceOrientedRegistry.java b/...registry-api/src/main/java/org/apache/dubbo/registry/support/ServiceOrientedRegistry.java
@@ -42,6 +42,7 @@
 import java.util.Set;
 import java.util.stream.Collectors;
 
+import static java.lang.String.format;
 import static java.util.Collections.emptyList;
 import static java.util.Collections.emptySet;
 import static java.util.Collections.unmodifiableSet;
@@ -142,11 +143,11 @@ public void doRegister(URL url) {
         }
         if (localMetadataService.exportURL(url)) {
             if (logger.isInfoEnabled()) {
-                logger.info(String.format("The URL[%s] registered successfully.", url.toString()));
+                logger.info(format("The URL[%s] registered successfully.", url.toString()));
             }
         } else {
             if (logger.isWarnEnabled()) {
-                logger.info(String.format("The URL[%s] has been registered.", url.toString()));
+                logger.info(format("The URL[%s] has been registered.", url.toString()));
             }
         }
     }
@@ -158,11 +159,11 @@ public void doUnregister(URL url) {
         }
         if (localMetadataService.unexportURL(url)) {
             if (logger.isInfoEnabled()) {
-                logger.info(String.format("The URL[%s] deregistered successfully.", url.toString()));
+                logger.info(format("The URL[%s] deregistered successfully.", url.toString()));
             }
         } else {
             if (logger.isWarnEnabled()) {
-                logger.info(String.format("The URL[%s] has been deregistered.", url.toString()));
+                logger.info(format("The URL[%s] has been deregistered.", url.toString()));
             }
         }
     }
@@ -194,11 +195,12 @@ public void destroy() {
 
     protected void subscribeURLs(URL url, NotifyListener listener) {
 
+        localMetadataService.subscribeURL(url);
+
         Set<String> serviceNames = getServices(url);
 
         serviceNames.forEach(serviceName -> subscribeURLs(url, listener, serviceName));
 
-        localMetadataService.subscribeURL(url);
     }
 
     protected void subscribeURLs(URL url, NotifyListener listener, String serviceName) {
@@ -217,7 +219,7 @@ protected void subscribeURLs(URL subscribedURL, NotifyListener listener, String
                                  Collection<ServiceInstance> serviceInstances) {
 
         if (isEmpty(serviceInstances)) {
-            logger.warn(String.format("There is no instance in service[name : %s]", serviceName));
+            logger.warn(format("There is no instance in service[name : %s]", serviceName));
             return;
         }
 
@@ -350,7 +352,30 @@ protected List<URL> getTemplateURLs(URL subscribedURL, ServiceInstance selectedI
                                         Map<String, List<URL>> revisionURLsCache) {
         // get the revision from the specified {@link ServiceInstance}
         String revision = getExportedServicesRevision(selectedInstance);
-        return revisionURLsCache.computeIfAbsent(revision, key -> getProviderExportedURLs(subscribedURL, selectedInstance));
+        // try to get templateURLs from cache
+        List<URL> templateURLs = revisionURLsCache.get(revision);
+
+        if (isEmpty(templateURLs)) { // not exists or getting failed last time
+
+            if (!revisionURLsCache.isEmpty()) { // it's not first time
+                if (logger.isWarnEnabled()) {
+                    logger.warn(format("The ServiceInstance[id: %s, host : %s , port : %s] has different revision : %s" +
+                                    ", please make sure the service [name : %s] is changing or not.",
+                            selectedInstance.getId(),
+                            selectedInstance.getHost(),
+                            selectedInstance.getPort(),
+                            revision,
+                            selectedInstance.getServiceName()
+                    ));
+                }
+            }
+            // get or get again
+            templateURLs = getProviderExportedURLs(subscribedURL, selectedInstance);
+            // put into cache
+            revisionURLsCache.put(revision, templateURLs);
+        }
+
+        return templateURLs;
     }
 
     /**