Merge pull request #239 from nobodyiam/long-poll-improvement-merge

Add notification id for long poll

apollo-biz/src/main/java/com/ctrip/framework/apollo/biz/entity/ReleaseMessage.java

 package com.ctrip.framework.apollo.biz.entity;
 
+import com.google.common.base.MoreObjects;
+
 import java.util.Date;
 
 import javax.persistence.Column;
@@ -55,4 +57,14 @@ public class ReleaseMessage {
   public void setMessage(String message) {
     this.message = message;
   }
+
+  @Override
+  public String toString() {
+    return MoreObjects.toStringHelper(this)
+        .omitNullValues()
+        .add("id", id)
+        .add("message", message)
+        .add("dataChangeLastModifiedTime", dataChangeLastModifiedTime)
+        .toString();
+  }
 }

apollo-biz/src/main/java/com/ctrip/framework/apollo/biz/message/MessageListener.java → apollo-biz/src/main/java/com/ctrip/framework/apollo/biz/message/ReleaseMessageListener.java

 package com.ctrip.framework.apollo.biz.message;
 
+import com.ctrip.framework.apollo.biz.entity.ReleaseMessage;
+
 /**
  * @author Jason Song(song_s@ctrip.com)
  */
-public interface MessageListener {
-  void handleMessage(String message, String channel);
+public interface ReleaseMessageListener {
+  void handleMessage(ReleaseMessage message, String channel);
 }

apollo-biz/src/main/java/com/ctrip/framework/apollo/biz/message/ReleaseMessageScanner.java

@@ -33,7 +33,7 @@ public class ReleaseMessageScanner implements InitializingBean {
   @Autowired
   private ReleaseMessageRepository releaseMessageRepository;
   private int databaseScanInterval;
-  private List<MessageListener> listeners;
+  private List<ReleaseMessageListener> listeners;
   private ScheduledExecutorService executorService;
   private long maxIdScanned;
 
@@ -66,7 +66,7 @@ public class ReleaseMessageScanner implements InitializingBean {
    * add message listeners for release message
    * @param listener
    */
-  public void addMessageListener(MessageListener listener) {
+  public void addMessageListener(ReleaseMessageListener listener) {
     if (!listeners.contains(listener)) {
       listeners.add(listener);
     }
@@ -115,9 +115,9 @@ public class ReleaseMessageScanner implements InitializingBean {
    */
   private void fireMessageScanned(List<ReleaseMessage> messages) {
     for (ReleaseMessage message : messages) {
-      for (MessageListener listener : listeners) {
+      for (ReleaseMessageListener listener : listeners) {
         try {
-          listener.handleMessage(message.getMessage(), Topics.APOLLO_RELEASE_TOPIC);
+          listener.handleMessage(message, Topics.APOLLO_RELEASE_TOPIC);
         } catch (Throwable ex) {
           Cat.logError(ex);
           logger.error("Failed to invoke message listener {}", listener.getClass(), ex);

apollo-biz/src/main/java/com/ctrip/framework/apollo/biz/repository/ReleaseMessageRepository.java

@@ -4,6 +4,7 @@ import com.ctrip.framework.apollo.biz.entity.ReleaseMessage;
 
 import org.springframework.data.repository.PagingAndSortingRepository;
 
+import java.util.Collection;
 import java.util.List;
 
 /**
@@ -13,4 +14,6 @@ public interface ReleaseMessageRepository extends PagingAndSortingRepository<Rel
   List<ReleaseMessage> findFirst500ByIdGreaterThanOrderByIdAsc(Long id);
 
   ReleaseMessage findTopByOrderByIdDesc();
+
+  ReleaseMessage findTopByMessageInOrderByIdDesc(Collection<String> messages);
 }

apollo-biz/src/main/java/com/ctrip/framework/apollo/biz/service/ReleaseMessageService.java

+package com.ctrip.framework.apollo.biz.service;
+
+import com.ctrip.framework.apollo.biz.entity.ReleaseMessage;
+import com.ctrip.framework.apollo.biz.repository.ReleaseMessageRepository;
+
+import org.springframework.beans.factory.annotation.Autowired;
+import org.springframework.stereotype.Service;
+
+import java.util.Collection;
+
+/**
+ * @author Jason Song(song_s@ctrip.com)
+ */
+@Service
+public class ReleaseMessageService {
+  @Autowired
+  private ReleaseMessageRepository releaseMessageRepository;
+
+  public ReleaseMessage findLatestReleaseMessageForMessages(Collection<String> messages) {
+    return releaseMessageRepository.findTopByMessageInOrderByIdDesc(messages);
+  }
+}

apollo-biz/src/test/java/com/ctrip/framework/apollo/biz/message/ReleaseMessageScannerTest.java

@@ -44,8 +44,8 @@ public class ReleaseMessageScannerTest {
 
   @Test
   public void testScanMessageAndNotifyMessageListener() throws Exception {
-    SettableFuture<String> someListenerFuture = SettableFuture.create();
-    MessageListener someListener = (message, channel) -> someListenerFuture.set(message);
+    SettableFuture<ReleaseMessage> someListenerFuture = SettableFuture.create();
+    ReleaseMessageListener someListener = (message, channel) -> someListenerFuture.set(message);
     releaseMessageScanner.addMessageListener(someListener);
 
     String someMessage = "someMessage";
@@ -55,13 +55,14 @@ public class ReleaseMessageScannerTest {
     when(releaseMessageRepository.findFirst500ByIdGreaterThanOrderByIdAsc(0L)).thenReturn(
         Lists.newArrayList(someReleaseMessage));
 
-    String someListenerMessage =
+    ReleaseMessage someListenerMessage =
         someListenerFuture.get(5000, TimeUnit.MILLISECONDS);
 
-    assertEquals(someMessage, someListenerMessage);
+    assertEquals(someMessage, someListenerMessage.getMessage());
+    assertEquals(someId, someListenerMessage.getId());
 
-    SettableFuture<String> anotherListenerFuture = SettableFuture.create();
-    MessageListener anotherListener = (message, channel) -> anotherListenerFuture.set(message);
+    SettableFuture<ReleaseMessage> anotherListenerFuture = SettableFuture.create();
+    ReleaseMessageListener anotherListener = (message, channel) -> anotherListenerFuture.set(message);
     releaseMessageScanner.addMessageListener(anotherListener);
 
     String anotherMessage = "anotherMessage";
@@ -71,10 +72,11 @@ public class ReleaseMessageScannerTest {
     when(releaseMessageRepository.findFirst500ByIdGreaterThanOrderByIdAsc(someId)).thenReturn(
         Lists.newArrayList(anotherReleaseMessage));
 
-    String anotherListenerMessage =
+    ReleaseMessage anotherListenerMessage =
         anotherListenerFuture.get(5000, TimeUnit.MILLISECONDS);
 
-    assertEquals(anotherMessage, anotherListenerMessage);
+    assertEquals(anotherMessage, anotherListenerMessage.getMessage());
+    assertEquals(anotherId, anotherListenerMessage.getId());
 
   }
 

apollo-client/src/main/java/com/ctrip/framework/apollo/internals/RemoteConfigRepository.java

@@ -59,6 +59,7 @@ public class RemoteConfigRepository extends AbstractConfigRepository {
   private final AtomicBoolean m_longPollingStopped;
   private SchedulePolicy m_longPollSchedulePolicy;
   private AtomicReference<ServiceDTO> m_longPollServiceDto;
+  private AtomicReference<ApolloConfigNotification> m_longPollResult;
 
   /**
    * Constructor.
@@ -82,8 +83,9 @@ public class RemoteConfigRepository extends AbstractConfigRepository {
     m_executorService = Executors.newScheduledThreadPool(1,
         ApolloThreadFactory.create("RemoteConfigRepository", true));
     m_longPollingService = Executors.newFixedThreadPool(2,
-            ApolloThreadFactory.create("RemoteConfigRepository-LongPolling", true));
+        ApolloThreadFactory.create("RemoteConfigRepository-LongPolling", true));
     m_longPollServiceDto = new AtomicReference<>();
+    m_longPollResult = new AtomicReference<>();
     this.trySync();
     this.schedulePeriodicRefresh();
     this.scheduleLongPollingRefresh();
@@ -270,7 +272,7 @@ public class RemoteConfigRepository extends AbstractConfigRepository {
 
         String url =
             assembleLongPollRefreshUrl(lastServiceDto.getHomepageUrl(), appId, cluster,
-                m_namespace, dataCenter);
+                m_namespace, dataCenter, m_longPollResult.get());
 
         logger.debug("Long polling from {}", url);
         HttpRequest request = new HttpRequest(url);
@@ -286,6 +288,10 @@ public class RemoteConfigRepository extends AbstractConfigRepository {
         logger.debug("Long polling response: {}, url: {}", response.getStatusCode(), url);
         if (response.getStatusCode() == 200) {
           m_longPollServiceDto.set(lastServiceDto);
+          if (response.getBody() != null) {
+            m_longPollResult.set(response.getBody());
+            transaction.addData("Result", response.getBody().toString());
+          }
           longPollingService.submit(new Runnable() {
             @Override
             public void run() {
@@ -320,7 +326,8 @@ public class RemoteConfigRepository extends AbstractConfigRepository {
   }
 
   private String assembleLongPollRefreshUrl(String uri, String appId, String cluster,
-                                            String namespace, String dataCenter) {
+                                            String namespace, String dataCenter,
+                                            ApolloConfigNotification previousResult) {
     Escaper escaper = UrlEscapers.urlPathSegmentEscaper();
     Map<String, String> queryParams = Maps.newHashMap();
     queryParams.put("appId", escaper.escape(appId));
@@ -337,6 +344,11 @@ public class RemoteConfigRepository extends AbstractConfigRepository {
       queryParams.put("ip", escaper.escape(localIp));
     }
 
+    if (previousResult != null) {
+      //number doesn't need encode
+      queryParams.put("notificationId", String.valueOf(previousResult.getNotificationId()));
+    }
+
     String params = MAP_JOINER.join(queryParams);
     if (!uri.endsWith("/")) {
       uri += "/";

apollo-client/src/test/java/com/ctrip/framework/apollo/integration/ConfigIntegrationTest.java

@@ -234,6 +234,7 @@ public class ConfigIntegrationTest extends BaseIntegrationTest {
     final String someKey = "someKey";
     final String someValue = "someValue";
     final String anotherValue = "anotherValue";
+    long someNotificationId = 1;
 
     long pollTimeoutInMS = 50;
     Map<String, String> configurations = Maps.newHashMap();
@@ -242,7 +243,7 @@ public class ConfigIntegrationTest extends BaseIntegrationTest {
     ContextHandler configHandler = mockConfigServerHandler(HttpServletResponse.SC_OK, apolloConfig);
     ContextHandler pollHandler =
         mockPollNotificationHandler(pollTimeoutInMS, HttpServletResponse.SC_OK,
-            new ApolloConfigNotification(apolloConfig.getNamespaceName()), false);
+            new ApolloConfigNotification(apolloConfig.getNamespaceName(), someNotificationId), false);
 
     startServerWithHandlers(configHandler, pollHandler);
 

apollo-configservice/src/main/java/com/ctrip/framework/apollo/configservice/controller/NotificationController.java

@@ -10,9 +10,11 @@ import com.google.common.collect.Multimaps;
 import com.google.common.collect.Sets;
 
 import com.ctrip.framework.apollo.biz.entity.AppNamespace;
-import com.ctrip.framework.apollo.biz.message.MessageListener;
+import com.ctrip.framework.apollo.biz.entity.ReleaseMessage;
+import com.ctrip.framework.apollo.biz.message.ReleaseMessageListener;
 import com.ctrip.framework.apollo.biz.message.Topics;
 import com.ctrip.framework.apollo.biz.service.AppNamespaceService;
+import com.ctrip.framework.apollo.biz.service.ReleaseMessageService;
 import com.ctrip.framework.apollo.biz.utils.EntityManagerUtil;
 import com.ctrip.framework.apollo.core.ConfigConsts;
 import com.ctrip.framework.apollo.core.dto.ApolloConfigNotification;
@@ -38,7 +40,7 @@ import java.util.Set;
  */
 @RestController
 @RequestMapping("/notifications")
-public class NotificationController implements MessageListener {
+public class NotificationController implements ReleaseMessageListener {
   private static final Logger logger = LoggerFactory.getLogger(NotificationController.class);
   private static final long TIMEOUT = 30 * 1000;//30 seconds
   private final Multimap<String, DeferredResult<ResponseEntity<ApolloConfigNotification>>>
@@ -52,6 +54,9 @@ public class NotificationController implements MessageListener {
   @Autowired
   private AppNamespaceService appNamespaceService;
 
+  @Autowired
+  private ReleaseMessageService releaseMessageService;
+
   @Autowired
   private EntityManagerUtil entityManagerUtil;
 
@@ -61,6 +66,7 @@ public class NotificationController implements MessageListener {
       @RequestParam(value = "cluster") String cluster,
       @RequestParam(value = "namespace", defaultValue = ConfigConsts.NAMESPACE_DEFAULT) String namespace,
       @RequestParam(value = "dataCenter", required = false) String dataCenter,
+      @RequestParam(value = "notificationId", defaultValue = "-1") long notificationId,
       @RequestParam(value = "ip", required = false) String clientIp) {
     Set<String> watchedKeys = assembleWatchKeys(appId, cluster, namespace, dataCenter);
 
@@ -72,24 +78,42 @@ public class NotificationController implements MessageListener {
     DeferredResult<ResponseEntity<ApolloConfigNotification>> deferredResult =
         new DeferredResult<>(TIMEOUT, NOT_MODIFIED_RESPONSE);
 
-    //register all keys
-    for (String key : watchedKeys) {
-      this.deferredResults.put(key, deferredResult);
-    }
+    //check whether client is out-dated
+    ReleaseMessage latest = releaseMessageService.findLatestReleaseMessageForMessages(watchedKeys);
 
-    deferredResult.onTimeout(() -> logWatchedKeysToCat(watchedKeys, "Apollo.LongPoll.TimeOutKeys"));
+    /**
+     * Manually close the entity manager.
+     * Since for async request, Spring won't do so until the request is finished,
+     * which is unacceptable since we are doing long polling - means the db connection would be hold
+     * for a very long time
+     */
+    entityManagerUtil.closeEntityManager();
 
-    deferredResult.onCompletion(() -> {
-      //unregister all keys
+    if (latest != null && latest.getId() != notificationId) {
+      deferredResult.setResult(new ResponseEntity<>(
+          new ApolloConfigNotification(namespace, latest.getId()), HttpStatus.OK));
+    } else {
+      //register all keys
       for (String key : watchedKeys) {
-        deferredResults.remove(key, deferredResult);
+        this.deferredResults.put(key, deferredResult);
       }
-      logWatchedKeysToCat(watchedKeys, "Apollo.LongPoll.CompletedKeys");
-    });
 
-    logWatchedKeysToCat(watchedKeys, "Apollo.LongPoll.RegisteredKeys");
-    logger.info("Listening {} from appId: {}, cluster: {}, namespace: {}, datacenter: {}",
-        watchedKeys, appId, cluster, namespace, dataCenter);
+      deferredResult
+          .onTimeout(() -> logWatchedKeysToCat(watchedKeys, "Apollo.LongPoll.TimeOutKeys"));
+
+      deferredResult.onCompletion(() -> {
+        //unregister all keys
+        for (String key : watchedKeys) {
+          deferredResults.remove(key, deferredResult);
+        }
+        logWatchedKeysToCat(watchedKeys, "Apollo.LongPoll.CompletedKeys");
+      });
+
+      logWatchedKeysToCat(watchedKeys, "Apollo.LongPoll.RegisteredKeys");
+      logger.info("Listening {} from appId: {}, cluster: {}, namespace: {}, datacenter: {}",
+          watchedKeys, appId, cluster, namespace, dataCenter);
+    }
+
     return deferredResult;
   }
 
@@ -101,13 +125,6 @@ public class NotificationController implements MessageListener {
                                                String namespace,
                                                String dataCenter) {
     AppNamespace appNamespace = appNamespaceService.findByNamespaceName(namespace);
-    /**
-     * Manually close the entity manager.
-     * Since for async request, Spring won't do so until the request is finished,
-     * which is unacceptable since we are doing long polling - means the db connection would be hold
-     * for a very long time
-     */
-    entityManagerUtil.closeEntityManager();
 
     //check whether the namespace's appId equals to current one
     if (Objects.isNull(appNamespace) || Objects.equals(applicationId, appNamespace.getAppId())) {
@@ -140,27 +157,29 @@ public class NotificationController implements MessageListener {
   }
 
   @Override
-  public void handleMessage(String message, String channel) {
+  public void handleMessage(ReleaseMessage message, String channel) {
     logger.info("message received - channel: {}, message: {}", channel, message);
-    Cat.logEvent("Apollo.LongPoll.Messages", message);
-    if (!Topics.APOLLO_RELEASE_TOPIC.equals(channel) || Strings.isNullOrEmpty(message)) {
+
+    String content = message.getMessage();
+    Cat.logEvent("Apollo.LongPoll.Messages", content);
+    if (!Topics.APOLLO_RELEASE_TOPIC.equals(channel) || Strings.isNullOrEmpty(content)) {
       return;
     }
-    List<String> keys = STRING_SPLITTER.splitToList(message);
-    //message should be appId|cluster|namespace
+    List<String> keys = STRING_SPLITTER.splitToList(content);
+    //message should be appId+cluster+namespace
     if (keys.size() != 3) {
-      logger.error("message format invalid - {}", message);
+      logger.error("message format invalid - {}", content);
       return;
     }
 
     ResponseEntity<ApolloConfigNotification> notification =
         new ResponseEntity<>(
-            new ApolloConfigNotification(keys.get(2)), HttpStatus.OK);
+            new ApolloConfigNotification(keys.get(2), message.getId()), HttpStatus.OK);
 
     //create a new list to avoid ConcurrentModificationException
     List<DeferredResult<ResponseEntity<ApolloConfigNotification>>> results =
-        Lists.newArrayList(deferredResults.get(message));
-    logger.info("Notify {} clients for key {}", results.size(), message);
+        Lists.newArrayList(deferredResults.get(content));
+    logger.info("Notify {} clients for key {}", results.size(), content);
 
     for (DeferredResult<ResponseEntity<ApolloConfigNotification>> result : results) {
       result.setResult(notification);

apollo-configservice/src/test/java/com/ctrip/framework/apollo/configservice/controller/NotificationControllerTest.java

@@ -5,8 +5,10 @@ import com.google.common.collect.Lists;
 import com.google.common.collect.Multimap;
 
 import com.ctrip.framework.apollo.biz.entity.AppNamespace;
+import com.ctrip.framework.apollo.biz.entity.ReleaseMessage;
 import com.ctrip.framework.apollo.biz.message.Topics;
 import com.ctrip.framework.apollo.biz.service.AppNamespaceService;
+import com.ctrip.framework.apollo.biz.service.ReleaseMessageService;
 import com.ctrip.framework.apollo.biz.utils.EntityManagerUtil;
 import com.ctrip.framework.apollo.core.ConfigConsts;
 import com.ctrip.framework.apollo.core.dto.ApolloConfigNotification;
@@ -25,6 +27,8 @@ import java.util.List;
 
 import static org.junit.Assert.assertEquals;
 import static org.junit.Assert.assertTrue;
+import static org.mockito.Matchers.anyCollectionOf;
+import static org.mockito.Mockito.mock;
 import static org.mockito.Mockito.when;
 
 /**
@@ -39,10 +43,13 @@ public class NotificationControllerTest {
   private String defaultNamespace;
   private String somePublicNamespace;
   private String someDataCenter;
+  private long someNotificationId;
   private String someClientIp;
   @Mock
   private AppNamespaceService appNamespaceService;
   @Mock
+  private ReleaseMessageService releaseMessageService;
+  @Mock
   private EntityManagerUtil entityManagerUtil;
   private Multimap<String, DeferredResult<ResponseEntity<ApolloConfigNotification>>>
       deferredResults;
@@ -51,6 +58,7 @@ public class NotificationControllerTest {
   public void setUp() throws Exception {
     controller = new NotificationController();
     ReflectionTestUtils.setField(controller, "appNamespaceService", appNamespaceService);
+    ReflectionTestUtils.setField(controller, "releaseMessageService", releaseMessageService);
     ReflectionTestUtils.setField(controller, "entityManagerUtil", entityManagerUtil);
 
     someAppId = "someAppId";
@@ -59,6 +67,7 @@ public class NotificationControllerTest {
     defaultNamespace = ConfigConsts.NAMESPACE_DEFAULT;
     somePublicNamespace = "somePublicNamespace";
     someDataCenter = "someDC";
+    someNotificationId = 1;
     someClientIp = "someClientIp";
 
     deferredResults =
@@ -70,7 +79,8 @@ public class NotificationControllerTest {
   public void testPollNotificationWithDefaultNamespace() throws Exception {
     DeferredResult<ResponseEntity<ApolloConfigNotification>>
         deferredResult = controller
-        .pollNotification(someAppId, someCluster, defaultNamespace, someDataCenter, someClientIp);
+        .pollNotification(someAppId, someCluster, defaultNamespace, someDataCenter,
+            someNotificationId, someClientIp);
 
     List<String> clusters =
         Lists.newArrayList(someCluster, someDataCenter, ConfigConsts.CLUSTER_NAME_DEFAULT);
@@ -85,12 +95,35 @@ public class NotificationControllerTest {
     }
   }
 
+  @Test
+  public void testPollNotificationWithDefaultNamespaceWithNotificationIdOutDated() throws Exception {
+    long notificationId = someNotificationId + 1;
+    ReleaseMessage someReleaseMessage = mock(ReleaseMessage.class);
+
+    when(someReleaseMessage.getId()).thenReturn(notificationId);
+    when(releaseMessageService.findLatestReleaseMessageForMessages(anyCollectionOf(String.class)))
+        .thenReturn(someReleaseMessage);
+
+    DeferredResult<ResponseEntity<ApolloConfigNotification>>
+        deferredResult = controller
+        .pollNotification(someAppId, someCluster, defaultNamespace, someDataCenter,
+            someNotificationId, someClientIp);
+
+    ResponseEntity<ApolloConfigNotification> result =
+        (ResponseEntity<ApolloConfigNotification>) deferredResult.getResult();
+
+    assertEquals(HttpStatus.OK, result.getStatusCode());
+    assertEquals(defaultNamespace, result.getBody().getNamespaceName());
+    assertEquals(notificationId, result.getBody().getNotificationId());
+  }
+
   @Test
   public void testPollNotificationWithDefaultNamespaceWithDefaultClusterWithDataCenter()
       throws Exception {
     DeferredResult<ResponseEntity<ApolloConfigNotification>>
         deferredResult = controller
-        .pollNotification(someAppId, defaultCluster, defaultNamespace, someDataCenter, someClientIp);
+        .pollNotification(someAppId, defaultCluster, defaultNamespace, someDataCenter,
+            someNotificationId, someClientIp);
 
     List<String> clusters =
         Lists.newArrayList(someDataCenter, defaultCluster);
@@ -110,7 +143,7 @@ public class NotificationControllerTest {
       throws Exception {
     DeferredResult<ResponseEntity<ApolloConfigNotification>>
         deferredResult = controller
-        .pollNotification(someAppId, defaultCluster, defaultNamespace, null, someClientIp);
+        .pollNotification(someAppId, defaultCluster, defaultNamespace, null, someNotificationId, someClientIp);
 
     List<String> clusters =
         Lists.newArrayList(defaultCluster);
@@ -137,7 +170,8 @@ public class NotificationControllerTest {
 
     DeferredResult<ResponseEntity<ApolloConfigNotification>>
         deferredResult = controller
-        .pollNotification(someAppId, someCluster, somePublicNamespace, someDataCenter, someClientIp);
+        .pollNotification(someAppId, someCluster, somePublicNamespace, someDataCenter,
+            someNotificationId, someClientIp);
 
     List<String> clusters =
         Lists.newArrayList(someCluster, someDataCenter, ConfigConsts.CLUSTER_NAME_DEFAULT);
@@ -159,17 +193,50 @@ public class NotificationControllerTest {
     }
   }
 
+  @Test
+  public void testPollNotificationWithPublicNamespaceWithNotificationIdOutDated() throws Exception {
+    long notificationId = someNotificationId + 1;
+    ReleaseMessage someReleaseMessage = mock(ReleaseMessage.class);
+
+    when(someReleaseMessage.getId()).thenReturn(notificationId);
+    when(releaseMessageService.findLatestReleaseMessageForMessages(anyCollectionOf(String.class)))
+        .thenReturn(someReleaseMessage);
+
+    String somePublicAppId = "somePublicAppId";
+    AppNamespace somePublicAppNamespace =
+        assmbleAppNamespace(somePublicAppId, somePublicNamespace);
+
+    when(appNamespaceService.findByNamespaceName(somePublicNamespace))
+        .thenReturn(somePublicAppNamespace);
+
+    DeferredResult<ResponseEntity<ApolloConfigNotification>>
+        deferredResult = controller
+        .pollNotification(someAppId, someCluster, somePublicNamespace, someDataCenter,
+            someNotificationId, someClientIp);
+
+    ResponseEntity<ApolloConfigNotification> result =
+        (ResponseEntity<ApolloConfigNotification>) deferredResult.getResult();
+
+    assertEquals(HttpStatus.OK, result.getStatusCode());
+    assertEquals(somePublicNamespace, result.getBody().getNamespaceName());
+    assertEquals(notificationId, result.getBody().getNotificationId());
+  }
+
   @Test
   public void testPollNotificationWithDefaultNamespaceAndHandleMessage() throws Exception {
     DeferredResult<ResponseEntity<ApolloConfigNotification>>
         deferredResult = controller
-        .pollNotification(someAppId, someCluster, defaultNamespace, someDataCenter, someClientIp);
+        .pollNotification(someAppId, someCluster, defaultNamespace, someDataCenter,
+            someNotificationId, someClientIp);
 
     String key =
         Joiner.on(ConfigConsts.CLUSTER_NAMESPACE_SEPARATOR)
             .join(someAppId, someCluster, defaultNamespace);
+    long someId = 1;
+    ReleaseMessage someReleaseMessage = new ReleaseMessage(key);
+    someReleaseMessage.setId(someId);
 
-    controller.handleMessage(key, Topics.APOLLO_RELEASE_TOPIC);
+    controller.handleMessage(someReleaseMessage, Topics.APOLLO_RELEASE_TOPIC);
 
     ResponseEntity<ApolloConfigNotification> response =
         (ResponseEntity<ApolloConfigNotification>) deferredResult.getResult();
@@ -177,6 +244,7 @@ public class NotificationControllerTest {
 
     assertEquals(HttpStatus.OK, response.getStatusCode());
     assertEquals(defaultNamespace, notification.getNamespaceName());
+    assertEquals(someId, notification.getNotificationId());
   }
 
   @Test
@@ -190,13 +258,17 @@ public class NotificationControllerTest {
 
     DeferredResult<ResponseEntity<ApolloConfigNotification>>
         deferredResult = controller
-        .pollNotification(someAppId, someCluster, somePublicNamespace, someDataCenter, someClientIp);
+        .pollNotification(someAppId, someCluster, somePublicNamespace, someDataCenter,
+            someNotificationId, someClientIp);
 
     String key =
         Joiner.on(ConfigConsts.CLUSTER_NAMESPACE_SEPARATOR)
             .join(somePublicAppId, someDataCenter, somePublicNamespace);
+    long someId = 1;
+    ReleaseMessage someReleaseMessage = new ReleaseMessage(key);
+    someReleaseMessage.setId(someId);
 
-    controller.handleMessage(key, Topics.APOLLO_RELEASE_TOPIC);
+    controller.handleMessage(someReleaseMessage, Topics.APOLLO_RELEASE_TOPIC);
 
     ResponseEntity<ApolloConfigNotification> response =
         (ResponseEntity<ApolloConfigNotification>) deferredResult.getResult();
@@ -204,7 +276,7 @@ public class NotificationControllerTest {
 
     assertEquals(HttpStatus.OK, response.getStatusCode());
     assertEquals(somePublicNamespace, notification.getNamespaceName());
-
+    assertEquals(someId, notification.getNotificationId());
   }
 
   private AppNamespace assmbleAppNamespace(String appId, String namespace) {

apollo-configservice/src/test/java/com/ctrip/framework/apollo/configservice/integration/NotificationControllerIntegrationTest.java

@@ -21,6 +21,7 @@ import java.util.concurrent.TimeUnit;
 import java.util.concurrent.atomic.AtomicBoolean;
 
 import static org.junit.Assert.assertEquals;
+import static org.junit.Assert.assertNotEquals;
 
 /**
  * @author Jason Song(song_s@ctrip.com)
@@ -45,7 +46,7 @@ public class NotificationControllerIntegrationTest extends AbstractBaseIntegrati
     executorService = Executors.newSingleThreadExecutor();
   }
 
-  @Test
+  @Test(timeout = 5000L)
   public void testPollNotificationWithDefaultNamespace() throws Exception {
     AtomicBoolean stop = new AtomicBoolean();
     perodicSendMessage(assembleKey(someAppId, someCluster, defaultNamespace), stop);
@@ -60,6 +61,39 @@ public class NotificationControllerIntegrationTest extends AbstractBaseIntegrati
     ApolloConfigNotification notification = result.getBody();
     assertEquals(HttpStatus.OK, result.getStatusCode());
     assertEquals(defaultNamespace, notification.getNamespaceName());
+    assertNotEquals(0, notification.getNotificationId());
+  }
+
+  @Test(timeout = 5000L)
+  @Sql(scripts = "/integration-test/test-release-message.sql", executionPhase = Sql.ExecutionPhase.BEFORE_TEST_METHOD)
+  @Sql(scripts = "/integration-test/cleanup.sql", executionPhase = Sql.ExecutionPhase.AFTER_TEST_METHOD)
+  public void testPollNotificationWithDefaultNamespaceWithNotificationIdNull() throws Exception {
+    ResponseEntity<ApolloConfigNotification> result = restTemplate.getForEntity(
+        "{baseurl}/notifications?appId={appId}&cluster={clusterName}&namespace={namespace}",
+        ApolloConfigNotification.class,
+        getHostUrl(), someAppId, someCluster, defaultNamespace);
+
+    ApolloConfigNotification notification = result.getBody();
+    assertEquals(HttpStatus.OK, result.getStatusCode());
+    assertEquals(defaultNamespace, notification.getNamespaceName());
+    assertEquals(10, notification.getNotificationId());
+  }
+
+  @Test(timeout = 5000L)
+  @Sql(scripts = "/integration-test/test-release.sql", executionPhase = Sql.ExecutionPhase.BEFORE_TEST_METHOD)
+  @Sql(scripts = "/integration-test/test-release-message.sql", executionPhase = Sql.ExecutionPhase.BEFORE_TEST_METHOD)
+  @Sql(scripts = "/integration-test/cleanup.sql", executionPhase = Sql.ExecutionPhase.AFTER_TEST_METHOD)
+  public void testPollNotificationWithDefaultNamespaceWithNotificationIdOutDated() throws Exception {
+    long someOutDatedNotificationId = 1;
+    ResponseEntity<ApolloConfigNotification> result = restTemplate.getForEntity(
+        "{baseurl}/notifications?appId={appId}&cluster={clusterName}&namespace={namespace}&notificationId={notificationId}",
+        ApolloConfigNotification.class,
+        getHostUrl(), someAppId, someCluster, defaultNamespace, someOutDatedNotificationId);
+
+    ApolloConfigNotification notification = result.getBody();
+    assertEquals(HttpStatus.OK, result.getStatusCode());
+    assertEquals(defaultNamespace, notification.getNamespaceName());
+    assertEquals(10, notification.getNotificationId());
   }
 
   @Test(timeout = 5000L)
@@ -82,6 +116,7 @@ public class NotificationControllerIntegrationTest extends AbstractBaseIntegrati
     ApolloConfigNotification notification = result.getBody();
     assertEquals(HttpStatus.OK, result.getStatusCode());
     assertEquals(somePublicNamespace, notification.getNamespaceName());
+    assertNotEquals(0, notification.getNotificationId());
   }
 
   @Test(timeout = 5000L)
@@ -105,6 +140,24 @@ public class NotificationControllerIntegrationTest extends AbstractBaseIntegrati
     ApolloConfigNotification notification = result.getBody();
     assertEquals(HttpStatus.OK, result.getStatusCode());
     assertEquals(somePublicNamespace, notification.getNamespaceName());
+    assertNotEquals(0, notification.getNotificationId());
+  }
+
+  @Test(timeout = 5000L)
+  @Sql(scripts = "/integration-test/test-release.sql", executionPhase = Sql.ExecutionPhase.BEFORE_TEST_METHOD)
+  @Sql(scripts = "/integration-test/test-release-message.sql", executionPhase = Sql.ExecutionPhase.BEFORE_TEST_METHOD)
+  @Sql(scripts = "/integration-test/cleanup.sql", executionPhase = Sql.ExecutionPhase.AFTER_TEST_METHOD)
+  public void testPollNotificationWithPublicNamespaceWithNotificationIdOutDated() throws Exception {
+    long someOutDatedNotificationId = 1;
+    ResponseEntity<ApolloConfigNotification> result = restTemplate.getForEntity(
+        "{baseurl}/notifications?appId={appId}&cluster={clusterName}&namespace={namespace}&notificationId={notificationId}",
+        ApolloConfigNotification.class,
+        getHostUrl(), someAppId, someCluster, somePublicNamespace, someOutDatedNotificationId);
+
+    ApolloConfigNotification notification = result.getBody();
+    assertEquals(HttpStatus.OK, result.getStatusCode());
+    assertEquals(somePublicNamespace, notification.getNamespaceName());
+    assertEquals(20, notification.getNotificationId());
   }
 
   private String assembleKey(String appId, String cluster, String namespace) {

apollo-configservice/src/test/resources/integration-test/cleanup.sql

@@ -3,4 +3,5 @@ DELETE FROM Namespace;
 DELETE FROM AppNamespace;
 DELETE FROM Cluster;
 DELETE FROM App;
+DELETE FROM ReleaseMessage;
 

apollo-configservice/src/test/resources/integration-test/test-release-message.sql

+INSERT INTO `releasemessage` (`Id`, `Message`)
+VALUES
+	(10, 'someAppId+default+application');
+INSERT INTO `releasemessage` (`Id`, `Message`)
+VALUES
+	(20, 'somePublicAppId+default+somePublicNamespace');

apollo-core/src/main/java/com/ctrip/framework/apollo/core/dto/ApolloConfigNotification.java

@@ -5,20 +5,30 @@ package com.ctrip.framework.apollo.core.dto;
  */
 public class ApolloConfigNotification {
   private String namespaceName;
+  private long notificationId;
 
   //for json converter
   public ApolloConfigNotification() {
   }
 
-  public ApolloConfigNotification(String namespaceName) {
+  public ApolloConfigNotification(String namespaceName, long notificationId) {
     this.namespaceName = namespaceName;
+    this.notificationId = notificationId;
   }
 
   public String getNamespaceName() {
     return namespaceName;
   }
 
-  public void setNamespaceName(String namespaceName) {
-    this.namespaceName = namespaceName;
+  public long getNotificationId() {
+    return notificationId;
+  }
+
+  @Override
+  public String toString() {
+    return "ApolloConfigNotification{" +
+        "namespaceName='" + namespaceName + '\'' +
+        ", notificationId=" + notificationId +
+        '}';
   }
 }

apollo-core/src/main/java/com/ctrip/framework/apollo/core/utils/ClassLoaderUtil.java

@@ -18,7 +18,7 @@ public class ClassLoaderUtil {
 
   static {
     if (loader == null) {
-      logger.info("Using system class loader");
+      logger.warn("Using system class loader");
       loader = ClassLoader.getSystemClassLoader();
     }
 

apollo-core/src/main/java/com/ctrip/framework/apollo/core/utils/ResourceUtils.java

@@ -19,7 +19,7 @@ public class ResourceUtils {
   @SuppressWarnings("unchecked")
   public static Properties readConfigFile(String configPath, Properties defaults) {
     InputStream in = ClassLoaderUtil.getLoader().getResourceAsStream(configPath);
-    logger.info("Reading config from resource {}", configPath);
+    logger.debug("Reading config from resource {}", configPath);
     Properties props = new Properties();
     try {
       if (in == null) {
@@ -27,9 +27,9 @@ public class ResourceUtils {
         Path path = new File(System.getProperty("user.dir") + configPath).toPath();
         if (Files.isReadable(path)) {
           in = new FileInputStream(path.toFile());
-          logger.info("Reading config from file {} ", path);
+          logger.debug("Reading config from file {} ", path);
         } else {
-          logger.info("Could not find available config file");
+          logger.warn("Could not find available config file");
         }
       }
       if (defaults != null) {
@@ -59,9 +59,9 @@ public class ResourceUtils {
       sb.append(key).append('=').append(val).append('\n');
     }
     if (sb.length() > 0) {
-      logger.info("Reading properties: \n" + sb.toString());
+      logger.debug("Reading properties: \n" + sb.toString());
     } else {
-      logger.info("No available properties");
+      logger.warn("No available properties");
     }
     return props;
   }