diff --git a/apm-collector/apm-collector-agent/agent-grpc/agent-grpc-provider/src/main/java/org/apache/skywalking/apm/collector/agent/grpc/provider/handler/InstanceDiscoveryServiceHandler.java b/apm-collector/apm-collector-agent/agent-grpc/agent-grpc-provider/src/main/java/org/apache/skywalking/apm/collector/agent/grpc/provider/handler/InstanceDiscoveryServiceHandler.java
index cde3e4c69ef4fa02df4244cc7e55efef38a7d68f..2b20ce3911893748318fc03fa28e342571a5791f 100644
--- a/apm-collector/apm-collector-agent/agent-grpc/agent-grpc-provider/src/main/java/org/apache/skywalking/apm/collector/agent/grpc/provider/handler/InstanceDiscoveryServiceHandler.java
+++ b/apm-collector/apm-collector-agent/agent-grpc/agent-grpc-provider/src/main/java/org/apache/skywalking/apm/collector/agent/grpc/provider/handler/InstanceDiscoveryServiceHandler.java
@@ -66,6 +66,8 @@ public class InstanceDiscoveryServiceHandler extends InstanceDiscoveryServiceGrp
         int instanceId = request.getApplicationInstanceId();
         long heartBeatTime = request.getHeartbeatTime();
         this.instanceHeartBeatService.heartBeat(instanceId, heartBeatTime);
+        responseObserver.onNext(Downstream.getDefaultInstance());
+        responseObserver.onCompleted();
     }
 
     private String buildOsInfo(OSInfo osinfo) {
diff --git a/apm-collector/apm-collector-agent/agent-grpc/agent-grpc-provider/src/test/java/org/apache/skywalking/apm/collector/agent/grpc/provider/handler/mock/RegisterMock.java b/apm-collector/apm-collector-agent/agent-grpc/agent-grpc-provider/src/test/java/org/apache/skywalking/apm/collector/agent/grpc/provider/handler/mock/RegisterMock.java
index 6bf5d16909d47233e990eb882d776c3fd6c8a792..11c7f070aaada95c646503d161f78b9b44ce29dd 100644
--- a/apm-collector/apm-collector-agent/agent-grpc/agent-grpc-provider/src/test/java/org/apache/skywalking/apm/collector/agent/grpc/provider/handler/mock/RegisterMock.java
+++ b/apm-collector/apm-collector-agent/agent-grpc/agent-grpc-provider/src/test/java/org/apache/skywalking/apm/collector/agent/grpc/provider/handler/mock/RegisterMock.java
@@ -20,8 +20,12 @@ package org.apache.skywalking.apm.collector.agent.grpc.provider.handler.mock;
 
 import io.grpc.ManagedChannel;
 import java.util.UUID;
+import java.util.concurrent.Executors;
+import java.util.concurrent.TimeUnit;
 import org.apache.skywalking.apm.network.proto.Application;
 import org.apache.skywalking.apm.network.proto.ApplicationInstance;
+import org.apache.skywalking.apm.network.proto.ApplicationInstanceHeartbeat;
+import org.apache.skywalking.apm.network.proto.ApplicationInstanceMapping;
 import org.apache.skywalking.apm.network.proto.ApplicationMapping;
 import org.apache.skywalking.apm.network.proto.ApplicationRegisterServiceGrpc;
 import org.apache.skywalking.apm.network.proto.InstanceDiscoveryServiceGrpc;
@@ -29,18 +33,24 @@ import org.apache.skywalking.apm.network.proto.OSInfo;
 import org.apache.skywalking.apm.network.proto.ServiceNameCollection;
 import org.apache.skywalking.apm.network.proto.ServiceNameDiscoveryServiceGrpc;
 import org.apache.skywalking.apm.network.proto.ServiceNameElement;
+import org.apache.skywalking.apm.network.proto.ServiceNameMappingCollection;
+import org.apache.skywalking.apm.util.RunnableWithExceptionProtection;
 import org.joda.time.DateTime;
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
 
 /**
  * @author peng-yongsheng
  */
 class RegisterMock {
 
+    private static final Logger logger = LoggerFactory.getLogger(RegisterMock.class);
+
     private ApplicationRegisterServiceGrpc.ApplicationRegisterServiceBlockingStub applicationRegisterServiceBlockingStub;
     private InstanceDiscoveryServiceGrpc.InstanceDiscoveryServiceBlockingStub instanceDiscoveryServiceBlockingStub;
     private ServiceNameDiscoveryServiceGrpc.ServiceNameDiscoveryServiceBlockingStub serviceNameDiscoveryServiceBlockingStub;
 
-    void mock(ManagedChannel channel) {
+    void mock(ManagedChannel channel) throws InterruptedException {
         applicationRegisterServiceBlockingStub = ApplicationRegisterServiceGrpc.newBlockingStub(channel);
         instanceDiscoveryServiceBlockingStub = InstanceDiscoveryServiceGrpc.newBlockingStub(channel);
         serviceNameDiscoveryServiceBlockingStub = ServiceNameDiscoveryServiceGrpc.newBlockingStub(channel);
@@ -48,10 +58,17 @@ class RegisterMock {
         registerProvider();
     }
 
-    private void registerConsumer() {
+    private void registerConsumer() throws InterruptedException {
         Application.Builder application = Application.newBuilder();
         application.setApplicationCode("dubbox-consumer");
-        ApplicationMapping applicationMapping = applicationRegisterServiceBlockingStub.applicationCodeRegister(application.build());
+
+        ApplicationMapping applicationMapping;
+        do {
+            applicationMapping = applicationRegisterServiceBlockingStub.applicationCodeRegister(application.build());
+            logger.debug("application id: {}", applicationMapping.getApplication().getValue());
+            Thread.sleep(20);
+        }
+        while (applicationMapping.getApplication().getValue() == 0);
 
         ApplicationInstance.Builder instance = ApplicationInstance.newBuilder();
         instance.setApplicationId(applicationMapping.getApplication().getValue());
@@ -65,20 +82,37 @@ class RegisterMock {
         osInfo.addIpv4S("10.0.0.3");
         osInfo.addIpv4S("10.0.0.4");
         instance.setOsinfo(osInfo);
-        instanceDiscoveryServiceBlockingStub.registerInstance(instance.build());
+
+        ApplicationInstanceMapping instanceMapping;
+        do {
+            instanceMapping = instanceDiscoveryServiceBlockingStub.registerInstance(instance.build());
+            logger.debug("instance id: {}", instanceMapping.getApplicationInstanceId());
+            Thread.sleep(20);
+        }
+        while (instanceMapping.getApplicationInstanceId() == 0);
 
         ServiceNameCollection.Builder serviceNameCollection = ServiceNameCollection.newBuilder();
         ServiceNameElement.Builder serviceNameElement = ServiceNameElement.newBuilder();
         serviceNameElement.setApplicationId(applicationMapping.getApplication().getValue());
         serviceNameElement.setServiceName("org.skywaking.apm.testcase.dubbo.services.GreetService.doBusiness()");
         serviceNameCollection.addElements(serviceNameElement);
-        serviceNameDiscoveryServiceBlockingStub.discovery(serviceNameCollection.build());
+
+        registerServiceName(serviceNameCollection);
+
+        heartBeatScheduled(instanceMapping.getApplicationInstanceId());
     }
 
-    private void registerProvider() {
+    private void registerProvider() throws InterruptedException {
         Application.Builder application = Application.newBuilder();
         application.setApplicationCode("dubbox-provider");
-        ApplicationMapping applicationMapping = applicationRegisterServiceBlockingStub.applicationCodeRegister(application.build());
+
+        ApplicationMapping applicationMapping;
+        do {
+            applicationMapping = applicationRegisterServiceBlockingStub.applicationCodeRegister(application.build());
+            logger.debug("application id: {}", applicationMapping.getApplication().getValue());
+            Thread.sleep(20);
+        }
+        while (applicationMapping.getApplication().getValue() == 0);
 
         ApplicationInstance.Builder instance = ApplicationInstance.newBuilder();
         instance.setApplicationId(applicationMapping.getApplication().getValue());
@@ -92,13 +126,51 @@ class RegisterMock {
         osInfo.addIpv4S("10.0.0.1");
         osInfo.addIpv4S("10.0.0.2");
         instance.setOsinfo(osInfo);
-        instanceDiscoveryServiceBlockingStub.registerInstance(instance.build());
+
+        ApplicationInstanceMapping instanceMapping;
+        do {
+            instanceMapping = instanceDiscoveryServiceBlockingStub.registerInstance(instance.build());
+            logger.debug("instance id: {}", instanceMapping.getApplicationInstanceId());
+            Thread.sleep(20);
+        }
+        while (instanceMapping.getApplicationInstanceId() == 0);
 
         ServiceNameCollection.Builder serviceNameCollection = ServiceNameCollection.newBuilder();
         ServiceNameElement.Builder serviceNameElement = ServiceNameElement.newBuilder();
         serviceNameElement.setApplicationId(applicationMapping.getApplication().getValue());
         serviceNameElement.setServiceName("org.skywaking.apm.testcase.dubbo.services.GreetService.doBusiness()");
         serviceNameCollection.addElements(serviceNameElement);
-        serviceNameDiscoveryServiceBlockingStub.discovery(serviceNameCollection.build());
+
+        registerServiceName(serviceNameCollection);
+
+        heartBeatScheduled(instanceMapping.getApplicationInstanceId());
+    }
+
+    private void registerServiceName(ServiceNameCollection.Builder serviceNameCollection) throws InterruptedException {
+        ServiceNameMappingCollection serviceNameMappingCollection;
+        do {
+            serviceNameMappingCollection = serviceNameDiscoveryServiceBlockingStub.discovery(serviceNameCollection.build());
+            logger.debug("service name mapping collection size: {}", serviceNameMappingCollection.getElementsCount());
+            if (serviceNameMappingCollection.getElementsCount() > 0) {
+                logger.debug("service id: {}", serviceNameMappingCollection.getElements(0).getServiceId());
+            }
+            Thread.sleep(20);
+        }
+        while (serviceNameMappingCollection.getElementsCount() == 0 || serviceNameMappingCollection.getElements(0).getServiceId() == 0);
+    }
+
+    private void heartBeatScheduled(int instanceId) {
+        Executors.newSingleThreadScheduledExecutor().scheduleAtFixedRate(
+            new RunnableWithExceptionProtection(() -> heartBeat(instanceId),
+                t -> logger.error("instance heart beat scheduled error.", t)), 4, 1, TimeUnit.SECONDS);
+    }
+
+    private void heartBeat(int instanceId) {
+        long now = System.currentTimeMillis();
+        logger.debug("instance heart beat, instance id: {}, time: {}", instanceId, now);
+        ApplicationInstanceHeartbeat.Builder heartbeat = ApplicationInstanceHeartbeat.newBuilder();
+        heartbeat.setApplicationInstanceId(instanceId);
+        heartbeat.setHeartbeatTime(now);
+        instanceDiscoveryServiceBlockingStub.heartbeat(heartbeat.build());
     }
 }
diff --git a/apm-collector/apm-collector-agent/agent-grpc/agent-grpc-provider/src/test/java/org/apache/skywalking/apm/collector/agent/grpc/provider/handler/mock/TraceSegmentMock.java b/apm-collector/apm-collector-agent/agent-grpc/agent-grpc-provider/src/test/java/org/apache/skywalking/apm/collector/agent/grpc/provider/handler/mock/TraceSegmentMock.java
index 8fe9ee82a095d6826412b246572cf44948b3677c..c290bd30ad26727745fe6f5dc23d5fb37439d784 100644
--- a/apm-collector/apm-collector-agent/agent-grpc/agent-grpc-provider/src/test/java/org/apache/skywalking/apm/collector/agent/grpc/provider/handler/mock/TraceSegmentMock.java
+++ b/apm-collector/apm-collector-agent/agent-grpc/agent-grpc-provider/src/test/java/org/apache/skywalking/apm/collector/agent/grpc/provider/handler/mock/TraceSegmentMock.java
@@ -83,6 +83,8 @@ public class TraceSegmentMock {
         while (sleeping.getValue()) {
             Thread.sleep(200);
         }
+
+        Thread.sleep(200000);
     }
 
     static class Sleeping {