diff --git a/apm-network/src/main/proto/DiscoveryService.proto b/apm-network/src/main/proto/DiscoveryService.proto
new file mode 100644
index 000000000..337e32e93
--- /dev/null
+++ b/apm-network/src/main/proto/DiscoveryService.proto
@@ -0,0 +1,50 @@
+syntax = "proto3";
+
+option java_multiple_files = true;
+option java_package = "org.skywalking.apm.network.trace.proto";
+
+import "Downstream.proto";
+
+//discovery service for application instance, this service is called when application starts
+//or http client connection switch to another collector server instance
+service InstanceDiscoveryService {
+    rpc register (ApplicationInstance) returns (ApplicationInstanceMapping) {
+    }
+
+    rpc registerRecover (ApplicationInstanceMapping) returns (Downstream) {
+    }
+}
+
+message ApplicationInstance {
+    string applicationCode = 1;
+}
+
+message ApplicationInstanceMapping {
+    int32 applicationInstanceId = 1;
+    int64 registerTime = 2;
+}
+
+//discovery service for ServiceName by Network address or application code
+service ServiceNameDiscoveryService {
+    rpc discovery (ServiceNameCollection) returns (ServiceNameMappingCollection) {
+    }
+}
+
+message ServiceNameCollection {
+    repeated ServiceNameElement elements = 1;
+}
+
+message ServiceNameMappingCollection {
+    repeated ServiceNameMappingElement elements = 1;
+}
+
+message ServiceNameMappingElement {
+    int32 serviceId = 1;
+    ServiceNameElement element = 1;
+}
+
+message ServiceNameElement {
+    ServiceName = 0;
+    ApplicationCode = 1;
+}
+
diff --git a/apm-network/src/main/proto/RegisterService.proto b/apm-network/src/main/proto/RegisterService.proto
index dff94a55d..109de2bd6 100644
--- a/apm-network/src/main/proto/RegisterService.proto
+++ b/apm-network/src/main/proto/RegisterService.proto
@@ -5,47 +5,16 @@ option java_package = "org.skywalking.apm.network.trace.proto";
 
 //register service for ApplicationCode, this service is called when service starts.
 service ApplicationRegisterService {
-    rpc register (ApplicationMetaInfo) returns (ApplicationRegiseredInfo) {
+    rpc register (Application) returns (ApplicationMapping) {
     }
 }
 
-message ApplicationMetaInfo {
+message Application {
     string applicationCode = 1;
 }
 
-message ApplicationRegiseredInfo {
+message ApplicationMapping {
     int32 applicationId = 1;
-    int32 applicationInstanceId = 2;
-}
-
-//register service for ServiceName, Network address
-service DictionaryRegisterService {
-    rpc register (DictionaryRegisterMetaInfo) returns (DictionaryRegiseredInfo) {
-    }
-}
-
-message DictionaryRegisterMetaInfo {
-    repeated DictionaryRegisterElement elements = 1;
-}
-
-message DictionaryRegisterElement {
-    RegisterElementType type = 1;
-    string name = 2;
-}
-
-message DictionaryRegiseredInfo {
-    repeated DictionaryRegiseredElement elements = 1;
-}
-
-message DictionaryRegiseredElement {
-    RegisterElementType type = 1;
-    string name = 2;
-    int32 id = 3;
-}
-
-
-enum RegisterElementType {
-    ServiceName = 0;
-    NetworkAddress = 1;
+    Application = 2;
 }