diff --git a/apm-protocol/apm-network/src/main/proto/Common.proto b/apm-protocol/apm-network/src/main/proto/Common.proto
new file mode 100644
index 000000000..9142490f3
--- /dev/null
+++ b/apm-protocol/apm-network/src/main/proto/Common.proto
@@ -0,0 +1,10 @@
+syntax = "proto3";
+
+option java_multiple_files = true;
+option java_package = "org.apache.skywalking.apm.network.proto";
+
+enum SpanType {
+    Entry = 0;
+    Exit = 1;
+    Local = 2;
+}
\ No newline at end of file
diff --git a/apm-protocol/apm-network/src/main/proto/DiscoveryService.proto b/apm-protocol/apm-network/src/main/proto/DiscoveryService.proto
index f2068f027..c4c06ca5c 100644
--- a/apm-protocol/apm-network/src/main/proto/DiscoveryService.proto
+++ b/apm-protocol/apm-network/src/main/proto/DiscoveryService.proto
@@ -3,6 +3,7 @@ syntax = "proto3";
 option java_multiple_files = true;
 option java_package = "org.apache.skywalking.apm.network.proto";
 
+import "Common.proto";
 import "Downstream.proto";
 
 service InstanceDiscoveryService {
@@ -67,4 +68,5 @@ message ServiceNameMappingElement {
 message ServiceNameElement {
     string serviceName = 1;
     int32 applicationId = 2;
+    SpanType srcSpanType = 3;
 }
diff --git a/apm-protocol/apm-network/src/main/proto/TraceSegmentService.proto b/apm-protocol/apm-network/src/main/proto/TraceSegmentService.proto
index 5ac1aba91..f58fbbf3f 100644
--- a/apm-protocol/apm-network/src/main/proto/TraceSegmentService.proto
+++ b/apm-protocol/apm-network/src/main/proto/TraceSegmentService.proto
@@ -3,6 +3,7 @@ syntax = "proto3";
 option java_multiple_files = true;
 option java_package = "org.apache.skywalking.apm.network.proto";
 
+import "Common.proto";
 import "Downstream.proto";
 import "KeyWithStringValue.proto";
 
@@ -66,12 +67,6 @@ enum RefType {
     CrossThread = 1;
 }
 
-enum SpanType {
-    Entry = 0;
-    Exit = 1;
-    Local = 2;
-}
-
 enum SpanLayer {
     Unknown = 0;
     Database = 1;
diff --git a/apm-sniffer/apm-agent-core/src/main/java/org/apache/skywalking/apm/agent/core/boot/ServiceManager.java b/apm-sniffer/apm-agent-core/src/main/java/org/apache/skywalking/apm/agent/core/boot/ServiceManager.java
index e1ca40ab0..33d189958 100644
--- a/apm-sniffer/apm-agent-core/src/main/java/org/apache/skywalking/apm/agent/core/boot/ServiceManager.java
+++ b/apm-sniffer/apm-agent-core/src/main/java/org/apache/skywalking/apm/agent/core/boot/ServiceManager.java
@@ -19,8 +19,9 @@
 
 package org.apache.skywalking.apm.agent.core.boot;
 
-import java.util.HashMap;
+import java.util.Collections;
 import java.util.Iterator;
+import java.util.LinkedHashMap;
 import java.util.Map;
 import java.util.ServiceLoader;
 import org.apache.skywalking.apm.agent.core.logging.api.LogManager;
@@ -36,7 +37,7 @@ public enum ServiceManager {
     INSTANCE;
 
     private static final ILog logger = LogManager.getLogger(ServiceManager.class);
-    private Map<Class, BootService> bootedServices = new HashMap<Class, BootService>();
+    private Map<Class, BootService> bootedServices = Collections.emptyMap();
 
     public void boot() {
         bootedServices = loadAllServices();
@@ -57,7 +58,7 @@ public enum ServiceManager {
     }
 
     private Map<Class, BootService> loadAllServices() {
-        HashMap<Class, BootService> bootedServices = new HashMap<Class, BootService>();
+        Map<Class, BootService> bootedServices = new LinkedHashMap<Class, BootService>();
         Iterator<BootService> serviceIterator = load().iterator();
         while (serviceIterator.hasNext()) {
             BootService bootService = serviceIterator.next();
diff --git a/apm-sniffer/apm-agent-core/src/main/java/org/apache/skywalking/apm/agent/core/context/TracingContext.java b/apm-sniffer/apm-agent-core/src/main/java/org/apache/skywalking/apm/agent/core/context/TracingContext.java
index 03a1900a7..f848502b7 100644
--- a/apm-sniffer/apm-agent-core/src/main/java/org/apache/skywalking/apm/agent/core/context/TracingContext.java
+++ b/apm-sniffer/apm-agent-core/src/main/java/org/apache/skywalking/apm/agent/core/context/TracingContext.java
@@ -296,7 +296,7 @@ public class TracingContext implements AbstractTracerContext {
         AbstractSpan parentSpan = peek();
         final int parentSpanId = parentSpan == null ? -1 : parentSpan.getSpanId();
         AbstractTracingSpan span = (AbstractTracingSpan)DictionaryManager.findOperationNameCodeSection()
-            .findOrPrepare4Register(segment.getApplicationId(), operationName)
+            .findOrPrepare4Register(segment.getApplicationId(), operationName, false, false)
             .doInCondition(new PossibleFound.FoundAndObtain() {
                 @Override
                 public Object doProcess(int operationId) {
diff --git a/apm-sniffer/apm-agent-core/src/main/java/org/apache/skywalking/apm/agent/core/context/trace/StackBasedTracingSpan.java b/apm-sniffer/apm-agent-core/src/main/java/org/apache/skywalking/apm/agent/core/context/trace/StackBasedTracingSpan.java
index 22a21fd8b..4ee8957c8 100644
--- a/apm-sniffer/apm-agent-core/src/main/java/org/apache/skywalking/apm/agent/core/context/trace/StackBasedTracingSpan.java
+++ b/apm-sniffer/apm-agent-core/src/main/java/org/apache/skywalking/apm/agent/core/context/trace/StackBasedTracingSpan.java
@@ -16,7 +16,6 @@
  *
  */
 
-
 package org.apache.skywalking.apm.agent.core.context.trace;
 
 import org.apache.skywalking.apm.agent.core.dictionary.DictionaryManager;
@@ -48,7 +47,7 @@ public abstract class StackBasedTracingSpan extends AbstractTracingSpan {
         if (--stackDepth == 0) {
             if (this.operationId == DictionaryUtil.nullValue()) {
                 this.operationId = (Integer)DictionaryManager.findOperationNameCodeSection()
-                    .findOrPrepare4Register(owner.getApplicationId(), operationName)
+                    .findOrPrepare4Register(owner.getApplicationId(), operationName, this.isEntry(), this.isExit())
                     .doInCondition(
                         new PossibleFound.FoundAndObtain() {
                             @Override public Object doProcess(int value) {
diff --git a/apm-sniffer/apm-agent-core/src/main/java/org/apache/skywalking/apm/agent/core/dictionary/OperationNameDictionary.java b/apm-sniffer/apm-agent-core/src/main/java/org/apache/skywalking/apm/agent/core/dictionary/OperationNameDictionary.java
index 18c8b35e6..7075f2860 100644
--- a/apm-sniffer/apm-agent-core/src/main/java/org/apache/skywalking/apm/agent/core/dictionary/OperationNameDictionary.java
+++ b/apm-sniffer/apm-agent-core/src/main/java/org/apache/skywalking/apm/agent/core/dictionary/OperationNameDictionary.java
@@ -16,7 +16,6 @@
  *
  */
 
-
 package org.apache.skywalking.apm.agent.core.dictionary;
 
 import io.netty.util.internal.ConcurrentSet;
@@ -28,6 +27,7 @@ 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.network.proto.ServiceNameMappingElement;
+import org.apache.skywalking.apm.network.proto.SpanType;
 
 import static org.apache.skywalking.apm.agent.core.conf.Config.Dictionary.OPERATION_NAME_BUFFER_SIZE;
 
@@ -39,19 +39,21 @@ public enum OperationNameDictionary {
     private Map<OperationNameKey, Integer> operationNameDictionary = new ConcurrentHashMap<OperationNameKey, Integer>();
     private Set<OperationNameKey> unRegisterOperationNames = new ConcurrentSet<OperationNameKey>();
 
-    public PossibleFound findOrPrepare4Register(int applicationId, String operationName) {
-        return find0(applicationId, operationName, true);
+    public PossibleFound findOrPrepare4Register(int applicationId, String operationName,
+        boolean isEntry, boolean isExit) {
+        return find0(applicationId, operationName, isEntry, isExit, true);
     }
 
     public PossibleFound findOnly(int applicationId, String operationName) {
-        return find0(applicationId, operationName, false);
+        return find0(applicationId, operationName, false, false, false);
     }
 
-    private PossibleFound find0(int applicationId, String operationName, boolean registerWhenNotFound) {
+    private PossibleFound find0(int applicationId, String operationName,
+        boolean isEntry, boolean isExit, boolean registerWhenNotFound) {
         if (operationName == null || operationName.length() == 0) {
             return new NotFound();
         }
-        OperationNameKey key = new OperationNameKey(applicationId, operationName);
+        OperationNameKey key = new OperationNameKey(applicationId, operationName, isEntry, isExit);
         Integer operationId = operationNameDictionary.get(key);
         if (operationId != null) {
             return new Found(operationId);
@@ -78,9 +80,12 @@ public enum OperationNameDictionary {
             ServiceNameMappingCollection serviceNameMappingCollection = serviceNameDiscoveryServiceBlockingStub.discovery(builder.build());
             if (serviceNameMappingCollection.getElementsCount() > 0) {
                 for (ServiceNameMappingElement serviceNameMappingElement : serviceNameMappingCollection.getElementsList()) {
+                    ServiceNameElement element = serviceNameMappingElement.getElement();
                     OperationNameKey key = new OperationNameKey(
-                        serviceNameMappingElement.getElement().getApplicationId(),
-                        serviceNameMappingElement.getElement().getServiceName());
+                        element.getApplicationId(),
+                        element.getServiceName(),
+                        SpanType.Entry.equals(element.getSrcSpanType()),
+                        SpanType.Exit.equals(element.getSrcSpanType()));
                     unRegisterOperationNames.remove(key);
                     operationNameDictionary.put(key, serviceNameMappingElement.getServiceId());
                 }
@@ -91,10 +96,14 @@ public enum OperationNameDictionary {
     private class OperationNameKey {
         private int applicationId;
         private String operationName;
+        private boolean isEntry;
+        private boolean isExit;
 
-        public OperationNameKey(int applicationId, String operationName) {
+        public OperationNameKey(int applicationId, String operationName, boolean isEntry, boolean isExit) {
             this.applicationId = applicationId;
             this.operationName = operationName;
+            this.isEntry = isEntry;
+            this.isExit = isExit;
         }
 
         public int getApplicationId() {
@@ -123,5 +132,13 @@ public enum OperationNameDictionary {
             result = 31 * result + operationName.hashCode();
             return result;
         }
+
+        boolean isEntry() {
+            return isEntry;
+        }
+
+        boolean isExit() {
+            return isExit;
+        }
     }
 }
diff --git a/apm-sniffer/apm-agent-core/src/main/java/org/apache/skywalking/apm/agent/core/remote/CollectorDiscoveryService.java b/apm-sniffer/apm-agent-core/src/main/java/org/apache/skywalking/apm/agent/core/remote/CollectorDiscoveryService.java
index f7910f71d..b5d4f442e 100644
--- a/apm-sniffer/apm-agent-core/src/main/java/org/apache/skywalking/apm/agent/core/remote/CollectorDiscoveryService.java
+++ b/apm-sniffer/apm-agent-core/src/main/java/org/apache/skywalking/apm/agent/core/remote/CollectorDiscoveryService.java
@@ -44,13 +44,15 @@ public class CollectorDiscoveryService implements BootService {
 
     @Override
     public void boot() throws Throwable {
+        DiscoveryRestServiceClient discoveryRestServiceClient = new DiscoveryRestServiceClient();
+        discoveryRestServiceClient.run();
         future = Executors.newSingleThreadScheduledExecutor(new DefaultNamedThreadFactory("CollectorDiscoveryService"))
-            .scheduleAtFixedRate(new RunnableWithExceptionProtection(new DiscoveryRestServiceClient(),
+            .scheduleAtFixedRate(new RunnableWithExceptionProtection(discoveryRestServiceClient,
                     new RunnableWithExceptionProtection.CallbackWhenException() {
                         @Override public void handle(Throwable t) {
                             logger.error("unexpected exception.", t);
                         }
-                    }), 0,
+                    }), Config.Collector.DISCOVERY_CHECK_INTERVAL,
                 Config.Collector.DISCOVERY_CHECK_INTERVAL, TimeUnit.SECONDS);
     }
 
diff --git a/apm-sniffer/apm-sdk-plugin/kafka-v1-plugin/src/main/java/org/apache/skywalking/apm/plugin/kafka/v1/define/CallbackInstrumentation.java b/apm-sniffer/apm-sdk-plugin/kafka-v1-plugin/src/main/java/org/apache/skywalking/apm/plugin/kafka/v1/define/CallbackInstrumentation.java
index e478d6204..1744ce702 100644
--- a/apm-sniffer/apm-sdk-plugin/kafka-v1-plugin/src/main/java/org/apache/skywalking/apm/plugin/kafka/v1/define/CallbackInstrumentation.java
+++ b/apm-sniffer/apm-sdk-plugin/kafka-v1-plugin/src/main/java/org/apache/skywalking/apm/plugin/kafka/v1/define/CallbackInstrumentation.java
@@ -39,7 +39,7 @@ public class CallbackInstrumentation extends ClassInstanceMethodsEnhancePluginDe
 
     public static final String ENHANCE_CLASS = "org.apache.kafka.clients.producer.Callback";
     public static final String ENHANCE_METHOD = "onCompletion";
-    public static final String INTERCEPTOR_CLASS = "org.apache.skywalking.apm.plugin.kafka.v11.CallbackInterceptor";
+    public static final String INTERCEPTOR_CLASS = "org.apache.skywalking.apm.plugin.kafka.v1.CallbackInterceptor";
 
     @Override protected ConstructorInterceptPoint[] getConstructorsInterceptPoints() {
         return new ConstructorInterceptPoint[0];
diff --git a/apm-sniffer/apm-sdk-plugin/kafka-v1-plugin/src/main/java/org/apache/skywalking/apm/plugin/kafka/v1/define/KafkaConsumerInstrumentation.java b/apm-sniffer/apm-sdk-plugin/kafka-v1-plugin/src/main/java/org/apache/skywalking/apm/plugin/kafka/v1/define/KafkaConsumerInstrumentation.java
index e4e1445f6..878a8302c 100644
--- a/apm-sniffer/apm-sdk-plugin/kafka-v1-plugin/src/main/java/org/apache/skywalking/apm/plugin/kafka/v1/define/KafkaConsumerInstrumentation.java
+++ b/apm-sniffer/apm-sdk-plugin/kafka-v1-plugin/src/main/java/org/apache/skywalking/apm/plugin/kafka/v1/define/KafkaConsumerInstrumentation.java
@@ -48,12 +48,13 @@ import static org.apache.skywalking.apm.agent.core.plugin.match.NameMatch.byName
 public class KafkaConsumerInstrumentation extends ClassInstanceMethodsEnhancePluginDefine {
 
     public static final String CONSTRUCTOR_INTERCEPT_TYPE = "org.apache.kafka.clients.consumer.ConsumerConfig";
-    public static final String CONSTRUCTOR_INTERCEPTOR_CLASS = "org.apache.skywalking.apm.plugin.kafka.v11.ConsumerConstructorInterceptor";
-    public static final String INTERCEPTOR_CLASS = "org.apache.skywalking.apm.plugin.kafka.v11.KafkaConsumerInterceptor";
+    public static final String CONSTRUCTOR_INTERCEPTOR_CLASS = "org.apache.skywalking.apm.plugin.kafka.v1.ConsumerConstructorInterceptor";
+    public static final String INTERCEPTOR_CLASS = "org.apache.skywalking.apm.plugin.kafka.v1.KafkaConsumerInterceptor";
     public static final String ENHANCE_METHOD = "pollOnce";
     public static final String ENHANCE_CLASS = "org.apache.kafka.clients.consumer.KafkaConsumer";
     public static final String SUBSCRIBE_METHOD = "subscribe";
     public static final String SUBSCRIBE_INTERCEPT_TYPE = "org.apache.kafka.clients.consumer.ConsumerRebalanceListener";
+    public static final String SUBSCRIBE_INTERCEPT_CLASS = "org.apache.skywalking.apm.plugin.kafka.v1.SubscribeMethodInterceptor";
 
     @Override protected ConstructorInterceptPoint[] getConstructorsInterceptPoints() {
         return new ConstructorInterceptPoint[] {
@@ -90,7 +91,7 @@ public class KafkaConsumerInstrumentation extends ClassInstanceMethodsEnhancePlu
                 }
 
                 @Override public String getMethodsInterceptor() {
-                    return "org.apache.skywalking.apm.plugin.kafka.v11.SubscribeMethodInterceptor";
+                    return SUBSCRIBE_INTERCEPT_CLASS;
                 }
 
                 @Override public boolean isOverrideArgs() {
diff --git a/apm-sniffer/apm-sdk-plugin/kafka-v1-plugin/src/main/java/org/apache/skywalking/apm/plugin/kafka/v1/define/KafkaProducerInstrumentation.java b/apm-sniffer/apm-sdk-plugin/kafka-v1-plugin/src/main/java/org/apache/skywalking/apm/plugin/kafka/v1/define/KafkaProducerInstrumentation.java
index 54932a8af..f93e936c6 100644
--- a/apm-sniffer/apm-sdk-plugin/kafka-v1-plugin/src/main/java/org/apache/skywalking/apm/plugin/kafka/v1/define/KafkaProducerInstrumentation.java
+++ b/apm-sniffer/apm-sdk-plugin/kafka-v1-plugin/src/main/java/org/apache/skywalking/apm/plugin/kafka/v1/define/KafkaProducerInstrumentation.java
@@ -48,9 +48,9 @@ import static org.apache.skywalking.apm.agent.core.plugin.match.NameMatch.byName
  */
 public class KafkaProducerInstrumentation extends ClassInstanceMethodsEnhancePluginDefine {
 
-    public static final String INTERCEPTOR_CLASS = "org.apache.skywalking.apm.plugin.kafka.v11.KafkaProducerInterceptor";
+    public static final String INTERCEPTOR_CLASS = "org.apache.skywalking.apm.plugin.kafka.v1.KafkaProducerInterceptor";
     public static final String ENHANCE_CLASS = "org.apache.kafka.clients.producer.KafkaProducer";
-    public static final String CONSTRUCTOR_INTERCEPTOR_CLASS = "org.apache.skywalking.apm.plugin.kafka.v11.ProducerConstructorInterceptor";
+    public static final String CONSTRUCTOR_INTERCEPTOR_CLASS = "org.apache.skywalking.apm.plugin.kafka.v1.ProducerConstructorInterceptor";
     public static final String CONSTRUCTOR_INTERCEPTOR_FLAG = "org.apache.kafka.clients.producer.ProducerConfig";
 
     @Override protected ConstructorInterceptPoint[] getConstructorsInterceptPoints() {
diff --git a/apm-sniffer/apm-sdk-plugin/kafka-v1-plugin/src/main/java/org/apache/skywalking/apm/plugin/kafka/v1/define/ProducerRecordInstrumentation.java b/apm-sniffer/apm-sdk-plugin/kafka-v1-plugin/src/main/java/org/apache/skywalking/apm/plugin/kafka/v1/define/ProducerRecordInstrumentation.java
index fe4d8b203..e2035b29f 100644
--- a/apm-sniffer/apm-sdk-plugin/kafka-v1-plugin/src/main/java/org/apache/skywalking/apm/plugin/kafka/v1/define/ProducerRecordInstrumentation.java
+++ b/apm-sniffer/apm-sdk-plugin/kafka-v1-plugin/src/main/java/org/apache/skywalking/apm/plugin/kafka/v1/define/ProducerRecordInstrumentation.java
@@ -39,7 +39,7 @@ import static org.apache.skywalking.apm.agent.core.plugin.match.NameMatch.byName
  */
 public class ProducerRecordInstrumentation extends ClassInstanceMethodsEnhancePluginDefine {
 
-    public static final String CONSTRUCTOR_INTERCEPTOR_CLASS = "org.apache.skywalking.apm.plugin.kafka.v11.ProducerRecordConstructorInterceptor";
+    public static final String CONSTRUCTOR_INTERCEPTOR_CLASS = "org.apache.skywalking.apm.plugin.kafka.v1.ProducerRecordConstructorInterceptor";
     public static final String ENHANCE_CLASS = "org.apache.kafka.clients.producer.ProducerRecord";
 
     @Override protected ConstructorInterceptPoint[] getConstructorsInterceptPoints() {
diff --git a/docs/Supported-list.md b/docs/Supported-list.md
index b1187e394..85dc2fcdf 100644
--- a/docs/Supported-list.md
+++ b/docs/Supported-list.md
@@ -27,7 +27,7 @@
   * [Dubbo](https://github.com/alibaba/dubbo) 2.5.4 -> 2.6.0
   * [Dubbox](https://github.com/dangdangdotcom/dubbox) 2.8.4
   * [Motan](https://github.com/weibocom/motan) 0.2.x -> 1.1.0
-  * [gRPC](https://github.com/grpc/grpc-java) 1.6+
+  * [gRPC](https://github.com/grpc/grpc-java) 1.x
 * MQ
   * [RocketMQ](https://github.com/apache/rocketmq) 4.x
   * [Kafka](http://kafka.apache.org) 0.11.0.0 -> 1.0