Merge pull request #204 from nobodyiam/long-polling-server-stick

apollo-client/src/main/java/com/ctrip/apollo/internals/ConfigServiceLocator.java

 package com.ctrip.apollo.internals;
 
+import com.google.common.base.Joiner;
 import com.google.common.collect.Lists;
+import com.google.common.collect.Maps;
+import com.google.common.escape.Escaper;
+import com.google.common.net.UrlEscapers;
 import com.google.gson.reflect.TypeToken;
 
 import com.ctrip.apollo.core.dto.ServiceDTO;
@@ -19,9 +23,11 @@ import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
 import org.unidal.lookup.annotation.Inject;
 import org.unidal.lookup.annotation.Named;
+import org.unidal.net.Networks;
 
 import java.lang.reflect.Type;
 import java.util.List;
+import java.util.Map;
 import java.util.concurrent.Executors;
 import java.util.concurrent.ScheduledExecutorService;
 import java.util.concurrent.TimeUnit;
@@ -37,6 +43,7 @@ public class ConfigServiceLocator implements Initializable {
   private AtomicReference<List<ServiceDTO>> m_configServices;
   private Type m_responseType;
   private ScheduledExecutorService m_executorService;
+  private static final Joiner.MapJoiner MAP_JOINER = Joiner.on("&").withKeyValueSeparator("=");
 
   /**
    * Create a config service locator.
@@ -95,10 +102,8 @@ public class ConfigServiceLocator implements Initializable {
         m_configUtil.getRefreshTimeUnit());
   }
 
-  //TODO periodically update config services
   private synchronized void updateConfigServices() {
-    String domainName = m_configUtil.getMetaServerDomainName();
-    String url = domainName + "/services/config";
+    String url = assembleMetaServiceUrl();
 
     HttpRequest request = new HttpRequest(url);
     int maxRetries = 5;
@@ -131,6 +136,19 @@ public class ConfigServiceLocator implements Initializable {
     throw new RuntimeException("Get config services failed", exception);
   }
 
+  private String assembleMetaServiceUrl() {
+    String domainName = m_configUtil.getMetaServerDomainName();
+    String appId = m_configUtil.getAppId();
+    String localIp = Networks.forIp().getLocalHostAddress();
+
+    Escaper escaper = UrlEscapers.urlPathSegmentEscaper();
+    Map<String, String> queryParams = Maps.newHashMap();
+    queryParams.put("appId", escaper.escape(appId));
+    queryParams.put("ip", escaper.escape(localIp));
+
+    return domainName + "/services/config?" + MAP_JOINER.join(queryParams);
+  }
+
   private void logConfigServicesToCat(List<ServiceDTO> serviceDtos) {
     for (ServiceDTO serviceDto : serviceDtos) {
       Cat.logEvent("Apollo.Config.Services", serviceDto.getHomepageUrl());

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

@@ -57,6 +57,7 @@ public class RemoteConfigRepository extends AbstractConfigRepository {
   private final ScheduledExecutorService m_executorService;
   private final AtomicBoolean m_longPollingStopped;
   private SchedulePolicy m_longPollSchedulePolicy;
+  private AtomicReference<ServiceDTO> m_longPollServiceDto;
 
   /**
    * Constructor.
@@ -79,6 +80,7 @@ public class RemoteConfigRepository extends AbstractConfigRepository {
     m_longPollingStopped = new AtomicBoolean(false);
     m_executorService = Executors.newScheduledThreadPool(1,
         ApolloThreadFactory.create("RemoteConfigRepository", true));
+    m_longPollServiceDto = new AtomicReference<>();
     this.trySync();
     this.schedulePeriodicRefresh();
     this.scheduleLongPollingRefresh();
@@ -148,8 +150,12 @@ public class RemoteConfigRepository extends AbstractConfigRepository {
 
     List<ServiceDTO> configServices = getConfigServices();
     for (int i = 0; i < maxRetries; i++) {
-      List<ServiceDTO> randomConfigServices = Lists.newArrayList(configServices);
+      List<ServiceDTO> randomConfigServices = Lists.newLinkedList(configServices);
       Collections.shuffle(randomConfigServices);
+      //Access the server which notifies the client first
+      if (m_longPollServiceDto.get() != null) {
+        randomConfigServices.add(0, m_longPollServiceDto.getAndSet(null));
+      }
 
       for (ServiceDTO configService : randomConfigServices) {
         String url =
@@ -272,6 +278,7 @@ public class RemoteConfigRepository extends AbstractConfigRepository {
 
         logger.debug("Long polling response: {}, url: {}", response.getStatusCode(), url);
         if (response.getStatusCode() == 200) {
+          m_longPollServiceDto.set(lastServiceDto);
           longPollingService.submit(new Runnable() {
             @Override
             public void run() {

apollo-configservice/src/main/java/com/ctrip/apollo/metaservice/controller/ServiceController.java

@@ -6,6 +6,7 @@ import com.netflix.appinfo.InstanceInfo;
 
 import org.springframework.beans.factory.annotation.Autowired;
 import org.springframework.web.bind.annotation.RequestMapping;
+import org.springframework.web.bind.annotation.RequestParam;
 import org.springframework.web.bind.annotation.RestController;
 
 import java.util.List;
@@ -39,7 +40,9 @@ public class ServiceController {
   }
 
   @RequestMapping("/config")
-  public List<ServiceDTO> getConfigService() {
+  public List<ServiceDTO> getConfigService(
+      @RequestParam(value = "appId", defaultValue = "") String appId,
+      @RequestParam(value = "ip", defaultValue = "") String clientIp) {
     List<InstanceInfo> instances = discoveryService.getConfigServiceInstances();
     List<ServiceDTO> result = instances.stream().map(new Function<InstanceInfo, ServiceDTO>() {