1. Remove the “apm-trace” module, isolate the trace structure between agent...

1. Remove the “apm-trace” module, isolate the trace structure between agent and collector for considering performance.
2. Change the head name.
3. Provide potienal mechanism for ignore trace with certain suffix.

apm-application-toolkit/apm-toolkit-log4j-1.x/src/main/java/org/skywalking/apm/toolkit/log/log4j/v1/x/TraceIdPatternConverter.java

@@ -5,7 +5,7 @@ import org.apache.log4j.spi.LoggingEvent;
 
 /**
  * Default implementation outputs "TID: N/A".
- * But, if in sky-walking agent active mode, output will become the real TraceId.
+ * But, if in sky-walking agent active mode, output will become the real ids.
  * <p>
  * Created by wusheng on 2016/12/7.
  */

apm-collector/apm-collector-commons/pom.xml

@@ -18,10 +18,5 @@
             <artifactId>apm-collector-cluster</artifactId>
             <version>${project.version}</version>
         </dependency>
-        <dependency>
-            <groupId>org.skywalking</groupId>
-            <artifactId>apm-trace</artifactId>
-            <version>${project.version}</version>
-        </dependency>
     </dependencies>
 </project>

apm-collector/apm-collector-worker/src/test/java/org/skywalking/apm/collector/worker/span/persistence/SpanSearchWithIdTestCase.java

@@ -18,8 +18,8 @@ import org.skywalking.apm.collector.worker.Const;
 import org.skywalking.apm.collector.worker.segment.SegmentIndex;
 import org.skywalking.apm.collector.worker.segment.mock.SegmentMock;
 import org.skywalking.apm.collector.worker.storage.GetResponseFromEs;
-import org.skywalking.apm.trace.Span;
-import org.skywalking.apm.trace.TraceSegment;
+import org.skywalking.apm.agent.core.context.trace.Span;
+import org.skywalking.apm.agent.core.context.trace.TraceSegment;
 
 import java.util.TimeZone;
 

apm-commons/apm-trace/pom.xml

-<?xml version="1.0" encoding="UTF-8"?>
-<project xmlns="http://maven.apache.org/POM/4.0.0"
-         xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
-         xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
-    <parent>
-        <artifactId>apm-commons</artifactId>
-        <groupId>org.skywalking</groupId>
-        <version>3.1-2017</version>
-    </parent>
-    <modelVersion>4.0.0</modelVersion>
-
-    <artifactId>apm-trace</artifactId>
-
-    <dependencies>
-        <dependency>
-            <groupId>org.skywalking</groupId>
-            <artifactId>apm-util</artifactId>
-            <version>${project.version}</version>
-        </dependency>
-    </dependencies>
-
-    <build>
-        <extensions>
-            <extension>
-                <groupId>kr.motd.maven</groupId>
-                <artifactId>os-maven-plugin</artifactId>
-                <version>1.5.0.Final</version>
-            </extension>
-        </extensions>
-        <plugins>
-            <plugin>
-                <groupId>org.xolstice.maven.plugins</groupId>
-                <artifactId>protobuf-maven-plugin</artifactId>
-                <version>0.5.0</version>
-                <configuration>
-                    <protocArtifact>com.google.protobuf:protoc:3.0.0:exe:${os.detected.classifier}
-                    </protocArtifact>
-                    <pluginId>grpc-java</pluginId>
-                    <pluginArtifact>io.grpc:protoc-gen-grpc-java:1.0.2:exe:${os.detected.classifier}
-                    </pluginArtifact>
-                </configuration>
-                <executions>
-                    <execution>
-                        <goals>
-                            <goal>compile</goal>
-                            <goal>compile-custom</goal>
-                        </goals>
-                    </execution>
-                </executions>
-            </plugin>
-        </plugins>
-    </build>
-</project>

apm-commons/apm-trace/src/test/java/org/skywalking/apm/trace/tag/BooleanTagReader.java

-package org.skywalking.apm.trace.tag;
-
-import java.lang.reflect.Field;
-import java.util.List;
-import org.skywalking.apm.trace.Span;
-
-/**
- * @author wusheng
- */
-public class BooleanTagReader {
-    public static Boolean get(Span span, BooleanTag tag) {
-        List<BooleanTagItem> tagsWithBoolList = null;
-        try {
-            Field tagsWithBool = Span.class.getDeclaredField("tagsWithBool");
-            tagsWithBool.setAccessible(true);
-            tagsWithBoolList = (List<BooleanTagItem>)tagsWithBool.get(span);
-        } catch (IllegalAccessException e) {
-            e.printStackTrace();
-        } catch (NoSuchFieldException e) {
-            e.printStackTrace();
-        }
-
-        if (tagsWithBoolList != null) {
-            for (BooleanTagItem item : tagsWithBoolList) {
-                if (tag.key().equals(item.getKey())) {
-                    return item.getValue();
-                }
-            }
-        }
-        return tag.defaultValue();
-    }
-
-}

apm-commons/apm-trace/src/test/java/org/skywalking/apm/trace/tag/IntTagReader.java

-package org.skywalking.apm.trace.tag;
-
-import java.lang.reflect.Field;
-import java.util.List;
-import org.skywalking.apm.trace.Span;
-
-/**
- * @author wusheng
- */
-public class IntTagReader {
-    public static Integer get(Span span, IntTag tag) {
-        List<IntTagItem> tagsWithIntList = null;
-        try {
-            Field tagsWithInt = Span.class.getDeclaredField("tagsWithInt");
-            tagsWithInt.setAccessible(true);
-            tagsWithIntList = (List<IntTagItem>)tagsWithInt.get(span);
-        } catch (IllegalAccessException e) {
-            e.printStackTrace();
-        } catch (NoSuchFieldException e) {
-            e.printStackTrace();
-        }
-
-        if (tagsWithIntList != null) {
-            for (IntTagItem item : tagsWithIntList) {
-                if (tag.key().equals(item.getKey())) {
-                    return item.getValue();
-                }
-            }
-        }
-        return null;
-    }
-
-}

apm-commons/apm-trace/src/test/java/org/skywalking/apm/trace/tag/StringTagReader.java

-package org.skywalking.apm.trace.tag;
-
-import java.lang.reflect.Field;
-import java.util.List;
-import org.skywalking.apm.trace.Span;
-
-/**
- * @author wusheng
- */
-public class StringTagReader {
-    public static String get(Span span, StringTag tag) {
-        List<StringTagItem> tagsWithStrList = null;
-        try {
-            Field tagsWithStr = Span.class.getDeclaredField("tagsWithStr");
-            tagsWithStr.setAccessible(true);
-            tagsWithStrList = (List<StringTagItem>)tagsWithStr.get(span);
-        } catch (IllegalAccessException e) {
-            e.printStackTrace();
-        } catch (NoSuchFieldException e) {
-            e.printStackTrace();
-        }
-
-        for (StringTagItem item : tagsWithStrList) {
-            if (tag.key().equals(item.getKey())) {
-                return item.getValue();
-            }
-        }
-        return null;
-    }
-
-}

apm-commons/apm-trace/src/test/java/org/skywalking/apm/trace/tag/TagsTest.java

-package org.skywalking.apm.trace.tag;
-
-import org.junit.Assert;
-import org.junit.Test;
-import org.skywalking.apm.trace.Span;
-
-/**
- * @author wusheng
- */
-public class TagsTest {
-    @Test
-    public void testLayer() {
-        Span span = new Span(1, "/test");
-        Tags.SPAN_LAYER.asDB(span);
-        Assert.assertEquals("db", StringTagReader.get(span, Tags.SPAN_LAYER.SPAN_LAYER_TAG));
-
-        span = new Span(1, "/test");
-        Tags.SPAN_LAYER.asRPCFramework(span);
-        Assert.assertEquals("rpc", StringTagReader.get(span, Tags.SPAN_LAYER.SPAN_LAYER_TAG));
-
-        span = new Span(1, "/test");
-        Tags.SPAN_LAYER.asHttp(span);
-        Assert.assertEquals("http", StringTagReader.get(span, Tags.SPAN_LAYER.SPAN_LAYER_TAG));
-    }
-
-    @Test
-    public void testBooleanTag() {
-        BooleanTag tag = new BooleanTag("test.key", false);
-        Span span = new Span(1, "/test");
-        Assert.assertFalse(BooleanTagReader.get(span, tag));
-
-        span = new Span(1, "/test");
-        tag.set(span, true);
-        Assert.assertTrue(BooleanTagReader.get(span, tag));
-    }
-
-    @Test
-    public void testIntTag() {
-        IntTag tag = new IntTag("test.key");
-        Span span = new Span(1, "/test");
-        Assert.assertNull(IntTagReader.get(span, tag));
-    }
-}

apm-commons/pom.xml

@@ -11,7 +11,6 @@
     <packaging>pom</packaging>
 
     <modules>
-        <module>apm-trace</module>
         <module>apm-util</module>
         <module>apm-logging-api</module>
         <module>apm-logging-log4j2</module>

apm-sniffer/apm-agent-core/pom.xml

@@ -29,11 +29,6 @@
     </properties>
 
     <dependencies>
-        <dependency>
-            <groupId>org.skywalking</groupId>
-            <artifactId>apm-trace</artifactId>
-            <version>${project.version}</version>
-        </dependency>
         <dependency>
             <groupId>org.skywalking</groupId>
             <artifactId>apm-logging-api</artifactId>

apm-sniffer/apm-agent-core/src/main/java/org/skywalking/apm/agent/core/client/CollectorClient.java

@@ -10,11 +10,11 @@ import org.apache.http.impl.client.CloseableHttpClient;
 import org.apache.http.impl.client.HttpClients;
 import org.skywalking.apm.agent.core.boot.ServiceManager;
 import org.skywalking.apm.agent.core.conf.Config;
+import org.skywalking.apm.agent.core.context.trace.SegmentsMessage;
+import org.skywalking.apm.agent.core.context.trace.TraceSegment;
 import org.skywalking.apm.agent.core.queue.TraceSegmentProcessQueue;
 import org.skywalking.apm.logging.ILog;
 import org.skywalking.apm.logging.LogManager;
-import org.skywalking.apm.trace.SegmentsMessage;
-import org.skywalking.apm.trace.TraceSegment;
 
 import java.io.IOException;
 import java.util.List;

apm-sniffer/apm-agent-core/src/main/java/org/skywalking/apm/agent/core/client/CollectorClientService.java

 package org.skywalking.apm.agent.core.client;
 
+import org.skywalking.apm.agent.core.context.trace.TraceSegment;
 import org.skywalking.apm.agent.core.queue.TraceSegmentProcessQueue;
 import org.skywalking.apm.agent.core.boot.StatusBootService;
-import org.skywalking.apm.trace.TraceSegment;
 
 /**
  * The <code>CollectorClientService</code> is responsible for start {@link CollectorClient}.

apm-sniffer/apm-agent-core/src/main/java/org/skywalking/apm/agent/core/conf/Config.java

@@ -2,6 +2,7 @@ package org.skywalking.apm.agent.core.conf;
 
 import java.util.LinkedList;
 import java.util.List;
+import org.skywalking.apm.agent.core.context.trace.TraceSegment;
 import org.skywalking.apm.agent.core.logging.LogLevel;
 import org.skywalking.apm.agent.core.logging.WriterFactory;
 
@@ -20,11 +21,16 @@ public class Config {
         public static String APPLICATION_CODE = "";
 
         /**
-         * One, means sampling OFF.
-         * Greater than one, select one trace in every N traces.
-         * Zero and negative number are illegal.
+         * Negative or zero means off, by default.
+         * {@link #SAMPLE_N_PER_10_SECS} means sampling N {@link TraceSegment} in 10 seconds tops.
          */
-        public static int SAMPLING_CYCLE = 1;
+        public static int SAMPLE_N_PER_10_SECS = -1;
+
+        /**
+         * If the operation name of the first span is included in this set,
+         * this segment should be ignored.
+         */
+        public static String IGNORE_SUFFIX = ".jpg,.jpeg,.js,.css,.png,.bmp,.gif,.ico,.mp3,.mp4,.html";
     }
 
     public static class Collector {
@@ -103,12 +109,12 @@ public class Config {
             public static boolean TRACE_PARAM = false;
         }
 
-        public static class Http {
+        public static class Propagation {
 
             /**
-             * The header name of context data.
+             * The header name of cross process propagation data.
              */
-            public static String HEADER_NAME_OF_CONTEXT_DATA = "SWTraceContext";
+            public static String HEADER_NAME = "sw3";
         }
     }
 }

apm-sniffer/apm-agent-core/src/main/java/org/skywalking/apm/agent/core/context/AbstractTracerContext.java

+package org.skywalking.apm.agent.core.context;
+
+import org.skywalking.apm.agent.core.context.trace.Span;
+
+/**
+ * The <code>AbstractTracerContext</code> represents the tracer context manager.
+ *
+ * @author wusheng
+ */
+public interface AbstractTracerContext {
+    void inject(ContextCarrier carrier);
+
+    void extract(ContextCarrier carrier);
+
+    String getGlobalTraceId();
+
+    Span createSpan(String operationName, boolean isLeaf);
+
+    Span createSpan(String operationName, long startTime, boolean isLeaf);
+
+    Span activeSpan();
+
+    void stopSpan(Span span);
+
+    void stopSpan(Span span, Long endTime);
+}

apm-sniffer/apm-agent-core/src/main/java/org/skywalking/apm/agent/core/context/ContextCarrier.java

 package org.skywalking.apm.agent.core.context;
 
-import org.skywalking.apm.util.StringUtil;
-import org.skywalking.apm.trace.Span;
-import org.skywalking.apm.trace.TraceId.DistributedTraceId;
-import org.skywalking.apm.trace.TraceId.PropagatedTraceId;
-import org.skywalking.apm.trace.TraceSegment;
-import org.skywalking.apm.trace.tag.Tags;
-
 import java.io.Serializable;
 import java.util.LinkedList;
 import java.util.List;
+import org.skywalking.apm.agent.core.context.ids.DistributedTraceId;
+import org.skywalking.apm.agent.core.context.ids.PropagatedTraceId;
+import org.skywalking.apm.agent.core.context.trace.Span;
+import org.skywalking.apm.agent.core.context.trace.TraceSegment;
+import org.skywalking.apm.util.StringUtil;
 
 /**
  * {@link ContextCarrier} is a data carrier of {@link TracerContext}.
@@ -34,7 +32,8 @@ public class ContextCarrier implements Serializable {
     private String applicationCode;
 
     /**
-     * {@link Tags#PEER_HOST}
+     * Either {@link Span#peerHost} + {@link Span#port} or {@link Span#peers},
+     * depend on which one of them is valid.
      */
     private String peerHost;
 
@@ -43,11 +42,6 @@ public class ContextCarrier implements Serializable {
      */
     private List<DistributedTraceId> distributedTraceIds;
 
-    /**
-     * {@link TraceSegment#sampled}
-     */
-    private boolean sampled;
-
     /**
      * Serialize this {@link ContextCarrier} to a {@link String},
      * with '|' split.
@@ -60,8 +54,7 @@ public class ContextCarrier implements Serializable {
             this.getSpanId() + "",
             this.getApplicationCode(),
             this.getPeerHost(),
-            this.serializeDistributedTraceIds(),
-            this.isSampled() ? "1" : "0");
+            this.serializeDistributedTraceIds());
     }
 
     /**
@@ -72,14 +65,13 @@ public class ContextCarrier implements Serializable {
     public ContextCarrier deserialize(String text) {
         if (text != null) {
             String[] parts = text.split("\\|", 6);
-            if (parts.length == 6) {
+            if (parts.length == 5) {
                 try {
                     setSpanId(Integer.parseInt(parts[1]));
                     setTraceSegmentId(parts[0]);
                     setApplicationCode(parts[2]);
                     setPeerHost(parts[3]);
                     setDistributedTraceIds(deserializeDistributedTraceIds(parts[4]));
-                    setSampled("1".equals(parts[5]));
                 } catch (NumberFormatException e) {
 
                 }
@@ -137,14 +129,6 @@ public class ContextCarrier implements Serializable {
         return distributedTraceIds;
     }
 
-    public boolean isSampled() {
-        return sampled;
-    }
-
-    public void setSampled(boolean sampled) {
-        this.sampled = sampled;
-    }
-
     public void setDistributedTraceIds(List<DistributedTraceId> distributedTraceIds) {
         this.distributedTraceIds = distributedTraceIds;
     }

apm-sniffer/apm-agent-core/src/main/java/org/skywalking/apm/agent/core/context/ContextManager.java

 package org.skywalking.apm.agent.core.context;
 
 import org.skywalking.apm.agent.core.boot.BootService;
-import org.skywalking.apm.trace.Span;
-import org.skywalking.apm.trace.TraceSegment;
+import org.skywalking.apm.agent.core.context.trace.Span;
+import org.skywalking.apm.agent.core.context.trace.TraceSegment;
 
 /**
  * {@link TracerContext} controls the whole context of {@link TraceSegment}. Any {@link TraceSegment} relates to
  * single-thread, so this context use {@link ThreadLocal} to maintain the context, and make sure, since a {@link
  * TraceSegment} starts, all ChildOf spans are in the same context.
+ * <p> What is 'ChildOf'? {@see
+ * https://github.com/opentracing/specification/blob/master/specification.md#references-between-spans}
+ * <p> Also, {@link
+ * ContextManager} delegates to all {@link TracerContext}'s major methods: {@link TracerContext#createSpan(String,
+ * boolean)}, {@link TracerContext#activeSpan()}, {@link TracerContext#stopSpan(Span)}
  * <p>
- * What is 'ChildOf'? {@see https://github.com/opentracing/specification/blob/master/specification.md#references-between-spans}
- * <p>
- * Also, {@link ContextManager} delegates to all {@link TracerContext}'s major methods: {@link
- * TracerContext#createSpan(String)}, {@link TracerContext#activeSpan()}, {@link TracerContext#stopSpan(Span)}
- * <p>
- * Created by wusheng on 2017/2/17.
+ *
+ * @author wusheng
  */
 public class ContextManager implements TracerContextListener, BootService {
-    private static ThreadLocal<TracerContext> CONTEXT = new ThreadLocal<TracerContext>();
+    private static ThreadLocal<AbstractTracerContext> CONTEXT = new ThreadLocal<AbstractTracerContext>();
 
-    private static TracerContext get() {
-        TracerContext segment = CONTEXT.get();
+    private static AbstractTracerContext get() {
+        AbstractTracerContext segment = CONTEXT.get();
         if (segment == null) {
             segment = new TracerContext();
             CONTEXT.set(segment);
@@ -46,7 +47,7 @@ public class ContextManager implements TracerContextListener, BootService {
      * @return the first global trace id if exist. Otherwise, "N/A".
      */
     public static String getGlobalTraceId() {
-        TracerContext segment = CONTEXT.get();
+        AbstractTracerContext segment = CONTEXT.get();
         if (segment == null) {
             return "N/A";
         } else {
@@ -95,4 +96,15 @@ public class ContextManager implements TracerContextListener, BootService {
     public void afterFinished(TraceSegment traceSegment) {
         CONTEXT.remove();
     }
+
+    /**
+     * The <code>ContextSwitcher</code> gives the chance to switch {@link AbstractTracerContext} in {@link #CONTEXT}.
+     */
+    enum ContextSwitcher {
+        INSTANCE;
+
+        void toNew(AbstractTracerContext context) {
+            CONTEXT.set(context);
+        }
+    }
 }

apm-sniffer/apm-agent-core/src/main/java/org/skywalking/apm/agent/core/context/TracerContext.java

@@ -2,12 +2,11 @@ package org.skywalking.apm.agent.core.context;
 
 import java.util.LinkedList;
 import java.util.List;
-import org.skywalking.apm.agent.core.boot.ServiceManager;
 import org.skywalking.apm.agent.core.conf.Config;
-import org.skywalking.apm.agent.core.sampling.SamplingService;
-import org.skywalking.apm.trace.Span;
-import org.skywalking.apm.trace.TraceSegment;
-import org.skywalking.apm.trace.TraceSegmentRef;
+import org.skywalking.apm.agent.core.context.trace.LeafSpan;
+import org.skywalking.apm.agent.core.context.trace.Span;
+import org.skywalking.apm.agent.core.context.trace.TraceSegment;
+import org.skywalking.apm.agent.core.context.trace.TraceSegmentRef;
 
 /**
  * {@link TracerContext} maintains the context.
@@ -15,7 +14,7 @@ import org.skywalking.apm.trace.TraceSegmentRef;
  * <p>
  * Created by wusheng on 2017/2/17.
  */
-public final class TracerContext {
+public final class TracerContext implements AbstractTracerContext {
     private TraceSegment segment;
 
     /**
@@ -34,7 +33,6 @@ public final class TracerContext {
      */
     TracerContext() {
         this.segment = new TraceSegment(Config.Agent.APPLICATION_CODE);
-        ServiceManager.INSTANCE.findService(SamplingService.class).trySampling(this.segment);
         this.spanIdGenerator = 0;
     }
 
@@ -104,7 +102,7 @@ public final class TracerContext {
     /**
      * @return the current trace id.
      */
-    String getGlobalTraceId() {
+    public String getGlobalTraceId() {
         return segment.getRelatedGlobalTraces().get(0).get();
     }
 
@@ -154,7 +152,6 @@ public final class TracerContext {
             carrier.setPeerHost(span.getPeers());
         }
         carrier.setDistributedTraceIds(this.segment.getRelatedGlobalTraces());
-        carrier.setSampled(this.segment.isSampled());
     }
 
     /**
@@ -166,7 +163,6 @@ public final class TracerContext {
     public void extract(ContextCarrier carrier) {
         if (carrier.isValid()) {
             this.segment.ref(getRef(carrier));
-            ServiceManager.INSTANCE.findService(SamplingService.class).setSampleWhenExtract(this.segment, carrier);
             this.segment.relatedGlobalTraces(carrier.getDistributedTraceIds());
         }
     }

apm-sniffer/apm-agent-core/src/main/java/org/skywalking/apm/agent/core/context/TracerContextListener.java

 package org.skywalking.apm.agent.core.context;
 
-import org.skywalking.apm.trace.TraceSegment;
+import org.skywalking.apm.agent.core.context.trace.TraceSegment;
 
 /**
  * {@link TracerContextListener} is a status change listener of {@link TracerContext}.

apm-commons/apm-trace/src/main/java/org/skywalking/apm/trace/TraceId/DistributedTraceId.java → apm-sniffer/apm-agent-core/src/main/java/org/skywalking/apm/agent/core/context/ids/DistributedTraceId.java

-package org.skywalking.apm.trace.TraceId;
+package org.skywalking.apm.agent.core.context.ids;
 
 /**
  * The <code>DistributedTraceId</code> presents a distributed call chain.

apm-commons/apm-trace/src/main/java/org/skywalking/apm/trace/TraceId/DistributedTraceIds.java → apm-sniffer/apm-agent-core/src/main/java/org/skywalking/apm/agent/core/context/ids/DistributedTraceIds.java

-package org.skywalking.apm.trace.TraceId;
+package org.skywalking.apm.agent.core.context.ids;
 
 import com.google.gson.TypeAdapter;
 import com.google.gson.annotations.JsonAdapter;
 import com.google.gson.stream.JsonReader;
 import com.google.gson.stream.JsonWriter;
-
 import java.io.IOException;
 import java.util.Collections;
 import java.util.LinkedList;

apm-commons/apm-trace/src/main/java/org/skywalking/apm/trace/GlobalIdGenerator.java → apm-sniffer/apm-agent-core/src/main/java/org/skywalking/apm/agent/core/context/ids/GlobalIdGenerator.java

-package org.skywalking.apm.trace;
+package org.skywalking.apm.agent.core.context.ids;
 
+import java.util.UUID;
 import org.skywalking.apm.util.MachineInfo;
 import org.skywalking.apm.util.StringUtil;
 
-import java.util.UUID;
-
 public final class GlobalIdGenerator {
     private static final ThreadLocal<Integer> THREAD_ID_SEQUENCE = new ThreadLocal<Integer>() {
         @Override

apm-commons/apm-trace/src/main/java/org/skywalking/apm/trace/TraceId/NewDistributedTraceId.java → apm-sniffer/apm-agent-core/src/main/java/org/skywalking/apm/agent/core/context/ids/NewDistributedTraceId.java

-package org.skywalking.apm.trace.TraceId;
-
-import org.skywalking.apm.trace.GlobalIdGenerator;
+package org.skywalking.apm.agent.core.context.ids;
 
 /**
  * The <code>NewDistributedTraceId</code> is a {@link DistributedTraceId} with a new generated id.

apm-commons/apm-trace/src/main/java/org/skywalking/apm/trace/TraceId/PropagatedTraceId.java → apm-sniffer/apm-agent-core/src/main/java/org/skywalking/apm/agent/core/context/ids/PropagatedTraceId.java

-package org.skywalking.apm.trace.TraceId;
+package org.skywalking.apm.agent.core.context.ids;
 
 /**
  * The <code>PropagatedTraceId</code> represents a {@link DistributedTraceId}, which is propagated from the peer.

apm-commons/apm-trace/src/main/java/org/skywalking/apm/trace/tag/AbstractTag.java → apm-sniffer/apm-agent-core/src/main/java/org/skywalking/apm/agent/core/context/tag/AbstractTag.java

-package org.skywalking.apm.trace.tag;
+package org.skywalking.apm.agent.core.context.tag;
 
-import org.skywalking.apm.trace.Span;
+import org.skywalking.apm.agent.core.context.trace.Span;
 
 /**
  * This is the abstract tag.

apm-commons/apm-trace/src/main/java/org/skywalking/apm/trace/tag/BooleanTag.java → apm-sniffer/apm-agent-core/src/main/java/org/skywalking/apm/agent/core/context/tag/BooleanTag.java

-package org.skywalking.apm.trace.tag;
+package org.skywalking.apm.agent.core.context.tag;
 
-import org.skywalking.apm.trace.Span;
+import org.skywalking.apm.agent.core.context.trace.Span;
 
 /**
  * Do the same thing as {@link StringTag}, just with a {@link Boolean} value.

apm-commons/apm-trace/src/main/java/org/skywalking/apm/trace/tag/BooleanTagItem.java → apm-sniffer/apm-agent-core/src/main/java/org/skywalking/apm/agent/core/context/tag/BooleanTagItem.java

-package org.skywalking.apm.trace.tag;
+package org.skywalking.apm.agent.core.context.tag;
 
 /**
  * The tag item with String key and Boolean value.

apm-commons/apm-trace/src/main/java/org/skywalking/apm/trace/tag/IntTag.java → apm-sniffer/apm-agent-core/src/main/java/org/skywalking/apm/agent/core/context/tag/IntTag.java

-package org.skywalking.apm.trace.tag;
+package org.skywalking.apm.agent.core.context.tag;
 
-import org.skywalking.apm.trace.Span;
+import org.skywalking.apm.agent.core.context.trace.Span;
 
 /**
  * Do the same thing as {@link StringTag}, just with a {@link Integer} value.

apm-commons/apm-trace/src/main/java/org/skywalking/apm/trace/tag/IntTagItem.java → apm-sniffer/apm-agent-core/src/main/java/org/skywalking/apm/agent/core/context/tag/IntTagItem.java

-package org.skywalking.apm.trace.tag;
+package org.skywalking.apm.agent.core.context.tag;
 
 /**
  * The tag item with String key and Int value.

apm-commons/apm-trace/src/main/java/org/skywalking/apm/trace/tag/StringTag.java → apm-sniffer/apm-agent-core/src/main/java/org/skywalking/apm/agent/core/context/tag/StringTag.java

-package org.skywalking.apm.trace.tag;
+package org.skywalking.apm.agent.core.context.tag;
 
-import org.skywalking.apm.trace.Span;
+import org.skywalking.apm.agent.core.context.trace.Span;
 
 /**
  * A subclass of {@link AbstractTag},

apm-commons/apm-trace/src/main/java/org/skywalking/apm/trace/tag/StringTagItem.java → apm-sniffer/apm-agent-core/src/main/java/org/skywalking/apm/agent/core/context/tag/StringTagItem.java

-package org.skywalking.apm.trace.tag;
+package org.skywalking.apm.agent.core.context.tag;
 
 /**
  * The tag item with String key and String value.

apm-commons/apm-trace/src/main/java/org/skywalking/apm/trace/tag/Tags.java → apm-sniffer/apm-agent-core/src/main/java/org/skywalking/apm/agent/core/context/tag/Tags.java

-package org.skywalking.apm.trace.tag;
+package org.skywalking.apm.agent.core.context.tag;
 
-import org.skywalking.apm.trace.Span;
+import org.skywalking.apm.agent.core.context.trace.Span;
 
 /**
  * The span tags are supported by sky-walking engine.

apm-sniffer/apm-agent-core/src/main/java/org/skywalking/apm/agent/core/context/LeafSpan.java → apm-sniffer/apm-agent-core/src/main/java/org/skywalking/apm/agent/core/context/trace/LeafSpan.java

-package org.skywalking.apm.agent.core.context;
+package org.skywalking.apm.agent.core.context.trace;
 
-import org.skywalking.apm.trace.Span;
-import org.skywalking.apm.trace.TraceSegment;
 
 /**
  * LeafSpan is a special type of {@link Span}
@@ -41,15 +39,15 @@ public class LeafSpan extends Span {
         super(spanId, parentSpan.getSpanId(), operationName, startTime);
     }
 
-    void push() {
+    public void push() {
         stackDepth++;
     }
 
-    void pop() {
+    public void pop() {
         stackDepth--;
     }
 
-    boolean isFinished() {
+    public boolean isFinished() {
         return stackDepth == 0;
     }
 

apm-commons/apm-trace/src/main/java/org/skywalking/apm/trace/LogData.java → apm-sniffer/apm-agent-core/src/main/java/org/skywalking/apm/agent/core/context/trace/LogData.java

-package org.skywalking.apm.trace;
+package org.skywalking.apm.agent.core.context.trace;
 
 import com.google.gson.annotations.Expose;
 import com.google.gson.annotations.SerializedName;
-
 import java.util.Collections;
 import java.util.Map;
 

apm-commons/apm-trace/src/main/java/org/skywalking/apm/trace/SegmentsMessage.java → apm-sniffer/apm-agent-core/src/main/java/org/skywalking/apm/agent/core/context/trace/SegmentsMessage.java

-package org.skywalking.apm.trace;
+package org.skywalking.apm.agent.core.context.trace;
 
 import com.google.gson.Gson;
 import java.util.Collections;

apm-commons/apm-trace/src/main/java/org/skywalking/apm/trace/Span.java → apm-sniffer/apm-agent-core/src/main/java/org/skywalking/apm/agent/core/context/trace/Span.java

-package org.skywalking.apm.trace;
+package org.skywalking.apm.agent.core.context.trace;
 
 import com.google.gson.Gson;
 import com.google.gson.GsonBuilder;
@@ -13,10 +13,11 @@ import java.util.HashMap;
 import java.util.LinkedList;
 import java.util.List;
 import java.util.Map;
-import org.skywalking.apm.trace.tag.BooleanTagItem;
-import org.skywalking.apm.trace.tag.IntTagItem;
-import org.skywalking.apm.trace.tag.StringTagItem;
-import org.skywalking.apm.trace.util.ThrowableTransformer;
+import org.skywalking.apm.agent.core.conf.Config;
+import org.skywalking.apm.agent.core.context.tag.BooleanTagItem;
+import org.skywalking.apm.agent.core.context.tag.IntTagItem;
+import org.skywalking.apm.agent.core.context.tag.StringTagItem;
+import org.skywalking.apm.agent.core.context.util.ThrowableTransformer;
 import org.skywalking.apm.util.StringUtil;
 
 /**
@@ -194,6 +195,14 @@ public class Span {
      */
     public Span setOperationName(String operationName) {
         this.operationName = operationName;
+        if (this.spanId == 0) {
+            if (operationName != null) {
+                int suffixIdx = operationName.lastIndexOf(".");
+                if (suffixIdx > -1 && Config.Agent.IGNORE_SUFFIX.contains(operationName.substring(suffixIdx))) {
+
+                }
+            }
+        }
         return this;
     }
 

apm-commons/apm-trace/src/main/java/org/skywalking/apm/trace/TraceSegment.java → apm-sniffer/apm-agent-core/src/main/java/org/skywalking/apm/agent/core/context/trace/TraceSegment.java

-package org.skywalking.apm.trace;
+package org.skywalking.apm.agent.core.context.trace;
 
 import com.google.gson.annotations.Expose;
 import com.google.gson.annotations.SerializedName;
-import org.skywalking.apm.trace.TraceId.DistributedTraceId;
-import org.skywalking.apm.trace.TraceId.DistributedTraceIds;
-import org.skywalking.apm.trace.TraceId.NewDistributedTraceId;
-
 import java.util.Collections;
 import java.util.LinkedList;
 import java.util.List;
+import org.skywalking.apm.agent.core.context.ids.GlobalIdGenerator;
+import org.skywalking.apm.agent.core.context.ids.DistributedTraceId;
+import org.skywalking.apm.agent.core.context.ids.DistributedTraceIds;
+import org.skywalking.apm.agent.core.context.ids.NewDistributedTraceId;
 
 /**
  * {@link TraceSegment} is a segment or fragment of the distributed trace.
@@ -90,16 +90,6 @@ public class TraceSegment {
     @SerializedName(value = "gt")
     private DistributedTraceIds relatedGlobalTraces;
 
-    /**
-     * The <code>sampled</code> is a flag, which represent, when this {@link TraceSegment} finished, it need to be send
-     * to Collector.
-     * <p>
-     * Its value depends on SamplingService. True, by default.
-     * <p>
-     * This value is not serialized.
-     */
-    private boolean sampled;
-
     /**
      * Create a trace segment, by the given applicationCode.
      */
@@ -119,7 +109,6 @@ public class TraceSegment {
         this.spans = new LinkedList<Span>();
         this.relatedGlobalTraces = new DistributedTraceIds();
         this.relatedGlobalTraces.append(new NewDistributedTraceId());
-        this.sampled = true;
     }
 
     /**
@@ -201,14 +190,6 @@ public class TraceSegment {
         return applicationCode;
     }
 
-    public boolean isSampled() {
-        return sampled;
-    }
-
-    public void setSampled(boolean sampled) {
-        this.sampled = sampled;
-    }
-
     @Override
     public String toString() {
         return "TraceSegment{" +

apm-commons/apm-trace/src/main/java/org/skywalking/apm/trace/TraceSegmentRef.java → apm-sniffer/apm-agent-core/src/main/java/org/skywalking/apm/agent/core/context/trace/TraceSegmentRef.java

-package org.skywalking.apm.trace;
+package org.skywalking.apm.agent.core.context.trace;
 
 import com.google.gson.annotations.Expose;
 import com.google.gson.annotations.SerializedName;
-import org.skywalking.apm.trace.tag.Tags;
+import org.skywalking.apm.agent.core.context.tag.Tags;
 
 /**
  * {@link TraceSegmentRef} is like a pointer, which ref to another {@link TraceSegment},

apm-commons/apm-trace/src/main/java/org/skywalking/apm/trace/util/ThrowableTransformer.java → apm-sniffer/apm-agent-core/src/main/java/org/skywalking/apm/agent/core/context/util/ThrowableTransformer.java

-package org.skywalking.apm.trace.util;
+package org.skywalking.apm.agent.core.context.util;
 
 /**
  * {@link ThrowableTransformer} is responsible for transferring stack trace of throwable.

apm-sniffer/apm-agent-core/src/main/java/org/skywalking/apm/agent/core/queue/TraceSegmentHolder.java

 package org.skywalking.apm.agent.core.queue;
 
 import com.lmax.disruptor.EventFactory;
-import org.skywalking.apm.trace.TraceSegment;
+import org.skywalking.apm.agent.core.context.trace.TraceSegment;
 
 /**
  * Just a holder of {@link TraceSegment} instance.

apm-sniffer/apm-agent-core/src/main/java/org/skywalking/apm/agent/core/queue/TraceSegmentProcessQueue.java

@@ -4,16 +4,16 @@ import com.lmax.disruptor.EventHandler;
 import com.lmax.disruptor.RingBuffer;
 import com.lmax.disruptor.dsl.Disruptor;
 import com.lmax.disruptor.util.DaemonThreadFactory;
+import java.util.LinkedList;
+import java.util.List;
 import org.skywalking.apm.agent.core.conf.Config;
 import org.skywalking.apm.agent.core.boot.StatusBootService;
 import org.skywalking.apm.agent.core.context.TracerContext;
 import org.skywalking.apm.agent.core.context.TracerContextListener;
+import org.skywalking.apm.agent.core.context.trace.TraceSegment;
 import org.skywalking.apm.logging.ILog;
 import org.skywalking.apm.logging.LogManager;
-import org.skywalking.apm.trace.TraceSegment;
 
-import java.util.LinkedList;
-import java.util.List;
 
 /**
  * {@link TraceSegmentProcessQueue} is a proxy of {@link Disruptor}, High Performance Inter-Thread MQ.
@@ -51,7 +51,7 @@ public class TraceSegmentProcessQueue extends StatusBootService implements Trace
      */
     @Override
     public void afterFinished(TraceSegment traceSegment) {
-        if (isStarted() && traceSegment.isSampled()) {
+        if (isStarted()) {
             long sequence = this.buffer.next();  // Grab the next sequence
             try {
                 TraceSegmentHolder data = this.buffer.get(sequence);

apm-sniffer/apm-agent-core/src/main/java/org/skywalking/apm/agent/core/sampling/SamplingService.java

@@ -3,16 +3,16 @@ package org.skywalking.apm.agent.core.sampling;
 import org.skywalking.apm.agent.core.boot.BootService;
 import org.skywalking.apm.agent.core.conf.Config;
 import org.skywalking.apm.agent.core.context.ContextCarrier;
+import org.skywalking.apm.agent.core.context.trace.TraceSegment;
 import org.skywalking.apm.logging.ILog;
 import org.skywalking.apm.logging.LogManager;
-import org.skywalking.apm.trace.TraceSegment;
 
 /**
  * The <code>SamplingService</code> take charge of how to sample the {@link TraceSegment}. Every {@link TraceSegment}s
  * have been traced, but, considering CPU cost of serialization/deserialization, and network bandwidth, the agent do NOT
  * send all of them to collector, if SAMPLING is on.
  * <p>
- * By default, SAMPLING is off, and {@link Config.Agent#SAMPLING_CYCLE} == 1.
+ * By default, SAMPLING is on, and {@see {@link Config.Agent#SAMPLE_N_PER_10_SECS}}
  *
  * @author wusheng
  */
@@ -24,27 +24,12 @@ public class SamplingService implements BootService {
 
     @Override
     public void bootUp() throws Throwable {
-        if (Config.Agent.SAMPLING_CYCLE == 1) {
-            this.on = false;
-            return;
+        if (Config.Agent.SAMPLE_N_PER_10_SECS > 0) {
+            on = true;
         }
-        if (Config.Agent.SAMPLING_CYCLE < 1) {
-            throw new IllegalSamplingRateException("sampling cycle must greater than 0.");
-        }
-        this.on = true;
-
-        logger.debug("The trace sampling is on, and the sampling cycle is: {}", Config.Agent.SAMPLING_CYCLE);
     }
 
     public void trySampling(TraceSegment segment) {
-        if (on) {
-            if (rollingSeed % Config.Agent.SAMPLING_CYCLE != 0) {
-                segment.setSampled(false);
-                rollingSeed++;
-            } else {
-                this.rollingSeed = 1;
-            }
-        }
     }
 
     /**
@@ -58,12 +43,6 @@ public class SamplingService implements BootService {
      * @param carrier
      */
     public void setSampleWhenExtract(TraceSegment segment, ContextCarrier carrier) {
-        if (on) {
-            if (!segment.isSampled() && carrier.isSampled()) {
-                segment.setSampled(true);
-                this.rollingSeed = 1;
-            }
-        }
     }
 
 }

apm-sniffer/apm-agent-core/src/test/java/org/skywalking/apm/agent/core/context/ContextCarrierTestCase.java

@@ -2,8 +2,8 @@ package org.skywalking.apm.agent.core.context;
 
 import org.junit.Assert;
 import org.junit.Test;
-import org.skywalking.apm.trace.TraceId.DistributedTraceId;
-import org.skywalking.apm.trace.TraceId.PropagatedTraceId;
+import org.skywalking.apm.agent.core.context.ids.DistributedTraceId;
+import org.skywalking.apm.agent.core.context.ids.PropagatedTraceId;
 
 import java.util.LinkedList;
 import java.util.List;
@@ -19,18 +19,17 @@ public class ContextCarrierTestCase {
         carrier.setSpanId(100);
         carrier.setApplicationCode("REMOTE_APP");
         carrier.setPeerHost("10.2.3.16:8080");
-        carrier.setSampled(true);
         List<DistributedTraceId> ids = new LinkedList<DistributedTraceId>();
         ids.add(new PropagatedTraceId("Trace.global.id.123"));
         carrier.setDistributedTraceIds(ids);
 
-        Assert.assertEquals("trace_id_A|100|REMOTE_APP|10.2.3.16:8080|Trace.global.id.123|1", carrier.serialize());
+        Assert.assertEquals("trace_id_A|100|REMOTE_APP|10.2.3.16:8080|Trace.global.id.123", carrier.serialize());
     }
 
     @Test
     public void testDeserialize() {
         ContextCarrier carrier = new ContextCarrier();
-        carrier.deserialize("trace_id_A|100|REMOTE_APP|10.2.3.16:8080|Trace.global.id.123,Trace.global.id.222|1");
+        carrier.deserialize("trace_id_A|100|REMOTE_APP|10.2.3.16:8080|Trace.global.id.123,Trace.global.id.222");
 
         Assert.assertEquals("trace_id_A", carrier.getTraceSegmentId());
         Assert.assertEquals(100, carrier.getSpanId());
@@ -38,7 +37,6 @@ public class ContextCarrierTestCase {
         Assert.assertEquals("10.2.3.16:8080", carrier.getPeerHost());
         Assert.assertEquals("Trace.global.id.123", carrier.getDistributedTraceIds().get(0).get());
         Assert.assertEquals("Trace.global.id.222", carrier.getDistributedTraceIds().get(1).get());
-        Assert.assertEquals(true, carrier.isSampled());
     }
 
     @Test
@@ -65,10 +63,10 @@ public class ContextCarrierTestCase {
 
         carrier = new ContextCarrier();
         carrier.deserialize("trace_id|100|REMOTE_APP|10.2.3.16:8080|Trace.global.id.123,Trace.global.id.222");
-        Assert.assertFalse(carrier.isValid());
+        Assert.assertTrue(carrier.isValid());
 
         carrier = new ContextCarrier();
         carrier.deserialize("trace_id|100|REMOTE_APP|10.2.3.16:8080|Trace.global.id.123,Trace.global.id.222|0");
-        Assert.assertTrue(carrier.isValid());
+        Assert.assertFalse(carrier.isValid());
     }
 }

apm-sniffer/apm-agent-core/src/test/java/org/skywalking/apm/agent/core/context/ContextManagerTestCase.java

@@ -5,9 +5,9 @@ import org.junit.Assert;
 import org.junit.BeforeClass;
 import org.junit.Test;
 import org.skywalking.apm.agent.core.boot.ServiceManager;
-import org.skywalking.apm.trace.Span;
-import org.skywalking.apm.trace.TraceSegment;
-import org.skywalking.apm.trace.tag.Tags;
+import org.skywalking.apm.agent.core.context.trace.Span;
+import org.skywalking.apm.agent.core.context.trace.TraceSegment;
+import org.skywalking.apm.agent.core.context.tag.Tags;
 
 /**
  * Created by wusheng on 2017/2/19.

apm-sniffer/apm-agent-core/src/test/java/org/skywalking/apm/agent/core/context/TestTracerContextListener.java

 package org.skywalking.apm.agent.core.context;
 
-import org.skywalking.apm.trace.TraceSegment;
+import org.skywalking.apm.agent.core.context.trace.TraceSegment;
 
 /**
  * Created by wusheng on 2017/2/19.

apm-sniffer/apm-agent-core/src/test/java/org/skywalking/apm/agent/core/context/TracerContextTestCase.java

@@ -3,11 +3,10 @@ package org.skywalking.apm.agent.core.context;
 import org.junit.After;
 import org.junit.Assert;
 import org.junit.Test;
-import org.skywalking.apm.trace.Span;
-import org.skywalking.apm.trace.TraceId.DistributedTraceId;
-import org.skywalking.apm.trace.TraceId.PropagatedTraceId;
-import org.skywalking.apm.trace.TraceSegment;
-import org.skywalking.apm.trace.tag.Tags;
+import org.skywalking.apm.agent.core.context.trace.Span;
+import org.skywalking.apm.agent.core.context.ids.DistributedTraceId;
+import org.skywalking.apm.agent.core.context.ids.PropagatedTraceId;
+import org.skywalking.apm.agent.core.context.trace.TraceSegment;
 
 import java.util.LinkedList;
 import java.util.List;

apm-sniffer/apm-agent-core/src/test/java/org/skywalking/apm/agent/core/context/LeafSpanTestCase.java → apm-sniffer/apm-agent-core/src/test/java/org/skywalking/apm/agent/core/context/trace/LeafSpanTestCase.java

-package org.skywalking.apm.agent.core.context;
+package org.skywalking.apm.agent.core.context.trace;
 
 import org.junit.Assert;
 import org.junit.Test;
+import org.skywalking.apm.agent.core.context.trace.LeafSpan;
 import org.skywalking.apm.agent.core.tags.BooleanTagReader;
 import org.skywalking.apm.agent.core.tags.IntTagReader;
 import org.skywalking.apm.agent.core.tags.StringTagReader;
-import org.skywalking.apm.trace.tag.BooleanTag;
-import org.skywalking.apm.trace.tag.IntTag;
-import org.skywalking.apm.trace.tag.StringTag;
+import org.skywalking.apm.agent.core.context.tag.BooleanTag;
+import org.skywalking.apm.agent.core.context.tag.IntTag;
+import org.skywalking.apm.agent.core.context.tag.StringTag;
 
 /**
  * @author wusheng

apm-commons/apm-trace/src/test/java/org/skywalking/apm/trace/LogDataTestCase.java → apm-sniffer/apm-agent-core/src/test/java/org/skywalking/apm/agent/core/context/trace/LogDataTestCase.java

-package org.skywalking.apm.trace;
-
-import org.junit.Assert;
-import org.junit.Test;
+package org.skywalking.apm.agent.core.context.trace;
 
 import java.util.HashMap;
 import java.util.Map;
+import org.junit.Assert;
+import org.junit.Test;
 
 /**
  * Created by wusheng on 2017/2/18.

apm-commons/apm-trace/src/test/java/org/skywalking/apm/trace/SpanTestCase.java → apm-sniffer/apm-agent-core/src/test/java/org/skywalking/apm/agent/core/context/trace/SpanTestCase.java

-package org.skywalking.apm.trace;
+package org.skywalking.apm.agent.core.context.trace;
 
 import java.lang.reflect.Field;
+import java.util.List;
 import org.junit.Assert;
 import org.junit.Test;
-import org.skywalking.apm.trace.tag.BooleanTagReader;
-import org.skywalking.apm.trace.tag.StringTagReader;
-import org.skywalking.apm.trace.tag.Tags;
-
-import java.util.List;
+import org.skywalking.apm.agent.core.tags.BooleanTagReader;
+import org.skywalking.apm.agent.core.tags.StringTagReader;
+import org.skywalking.apm.agent.core.context.trace.LogData;
+import org.skywalking.apm.agent.core.context.trace.Span;
+import org.skywalking.apm.agent.core.context.trace.TraceSegment;
+import org.skywalking.apm.agent.core.context.tag.Tags;
 
 /**
  * Created by wusheng on 2017/2/18.

apm-commons/apm-trace/src/test/java/org/skywalking/apm/trace/TraceSegmentTestCase.java → apm-sniffer/apm-agent-core/src/test/java/org/skywalking/apm/agent/core/context/trace/TraceSegmentTestCase.java

-package org.skywalking.apm.trace;
+package org.skywalking.apm.agent.core.context.trace;
 
 import com.google.gson.Gson;
 import com.google.gson.GsonBuilder;
 import com.google.gson.JsonObject;
 import org.junit.Assert;
 import org.junit.Test;
-import org.skywalking.apm.trace.tag.StringTagReader;
-import org.skywalking.apm.trace.tag.Tags;
+import org.skywalking.apm.agent.core.context.tag.Tags;
+import org.skywalking.apm.agent.core.tags.StringTagReader;
 
 /**
  * Created by wusheng on 2017/2/18.

apm-sniffer/apm-agent-core/src/test/java/org/skywalking/apm/agent/core/sampling/SamplingServiceTest.java

-package org.skywalking.apm.agent.core.sampling;
-
-import org.junit.AfterClass;
-import org.junit.Assert;
-import org.junit.Test;
-import org.skywalking.apm.agent.core.conf.Config;
-import org.skywalking.apm.agent.core.boot.ServiceManager;
-import org.skywalking.apm.trace.TraceSegment;
-
-/**
- * @author wusheng
- */
-public class SamplingServiceTest {
-    @Test
-    public void test50Percent() {
-        Config.Agent.SAMPLING_CYCLE = 2;
-        ServiceManager.INSTANCE.boot();
-
-        TraceSegment segment = new TraceSegment();
-        Assert.assertTrue(segment.isSampled());
-
-        SamplingService service = ServiceManager.INSTANCE.findService(SamplingService.class);
-        service.trySampling(segment);
-        Assert.assertFalse(segment.isSampled());
-
-        segment = new TraceSegment();
-        service.trySampling(segment);
-        Assert.assertTrue(segment.isSampled());
-
-        segment = new TraceSegment();
-        service.trySampling(segment);
-        Assert.assertFalse(segment.isSampled());
-    }
-
-    @AfterClass
-    public static void clear() {
-        Config.Agent.SAMPLING_CYCLE = 1;
-        ServiceManager.INSTANCE.boot();
-    }
-}

apm-sniffer/apm-agent-core/src/test/java/org/skywalking/apm/agent/core/tags/BooleanTagReader.java

@@ -2,9 +2,9 @@ package org.skywalking.apm.agent.core.tags;
 
 import java.lang.reflect.Field;
 import java.util.List;
-import org.skywalking.apm.trace.Span;
-import org.skywalking.apm.trace.tag.BooleanTag;
-import org.skywalking.apm.trace.tag.BooleanTagItem;
+import org.skywalking.apm.agent.core.context.trace.Span;
+import org.skywalking.apm.agent.core.context.tag.BooleanTag;
+import org.skywalking.apm.agent.core.context.tag.BooleanTagItem;
 
 /**
  * @author wusheng

apm-sniffer/apm-agent-core/src/test/java/org/skywalking/apm/agent/core/tags/IntTagReader.java

@@ -2,9 +2,9 @@ package org.skywalking.apm.agent.core.tags;
 
 import java.lang.reflect.Field;
 import java.util.List;
-import org.skywalking.apm.trace.Span;
-import org.skywalking.apm.trace.tag.IntTag;
-import org.skywalking.apm.trace.tag.IntTagItem;
+import org.skywalking.apm.agent.core.context.trace.Span;
+import org.skywalking.apm.agent.core.context.tag.IntTag;
+import org.skywalking.apm.agent.core.context.tag.IntTagItem;
 
 /**
  * @author wusheng

apm-sniffer/apm-agent-core/src/test/java/org/skywalking/apm/agent/core/tags/StringTagReader.java

@@ -2,9 +2,9 @@ package org.skywalking.apm.agent.core.tags;
 
 import java.lang.reflect.Field;
 import java.util.List;
-import org.skywalking.apm.trace.Span;
-import org.skywalking.apm.trace.tag.StringTag;
-import org.skywalking.apm.trace.tag.StringTagItem;
+import org.skywalking.apm.agent.core.context.trace.Span;
+import org.skywalking.apm.agent.core.context.tag.StringTag;
+import org.skywalking.apm.agent.core.context.tag.StringTagItem;
 
 /**
  * @author wusheng

apm-sniffer/apm-sdk-plugin/dubbo-plugin/src/main/java/org/skywalking/apm/plugin/dubbo/DubboInterceptor.java

@@ -5,6 +5,7 @@ import com.alibaba.dubbo.rpc.Invocation;
 import com.alibaba.dubbo.rpc.Invoker;
 import com.alibaba.dubbo.rpc.Result;
 import com.alibaba.dubbo.rpc.RpcContext;
+import org.skywalking.apm.agent.core.conf.Config;
 import org.skywalking.apm.agent.core.context.ContextCarrier;
 import org.skywalking.apm.agent.core.context.ContextManager;
 import org.skywalking.apm.agent.core.plugin.interceptor.EnhancedClassInstanceContext;
@@ -13,8 +14,8 @@ import org.skywalking.apm.agent.core.plugin.interceptor.enhance.InstanceMethodsA
 import org.skywalking.apm.agent.core.plugin.interceptor.enhance.MethodInterceptResult;
 import org.skywalking.apm.plugin.dubbox.BugFixActive;
 import org.skywalking.apm.plugin.dubbox.SWBaseBean;
-import org.skywalking.apm.trace.Span;
-import org.skywalking.apm.trace.tag.Tags;
+import org.skywalking.apm.agent.core.context.trace.Span;
+import org.skywalking.apm.agent.core.context.tag.Tags;
 
 /**
  * {@link DubboInterceptor} define how to enhance class {@link com.alibaba.dubbo.monitor.support.MonitorFilter#invoke(Invoker,
@@ -28,7 +29,6 @@ import org.skywalking.apm.trace.tag.Tags;
  */
 public class DubboInterceptor implements InstanceMethodsAroundInterceptor {
 
-    public static final String ATTACHMENT_NAME_OF_CONTEXT_DATA = "SWTraceContext";
     public static final String DUBBO_COMPONENT = "Dubbo";
 
     /**
@@ -64,7 +64,7 @@ public class DubboInterceptor implements InstanceMethodsAroundInterceptor {
             if (!BugFixActive.isActive()) {
                 //invocation.getAttachments().put("contextData", contextDataStr);
                 //@see https://github.com/alibaba/dubbo/blob/dubbo-2.5.3/dubbo-rpc/dubbo-rpc-api/src/main/java/com/alibaba/dubbo/rpc/RpcInvocation.java#L154-L161
-                rpcContext.getAttachments().put(ATTACHMENT_NAME_OF_CONTEXT_DATA, contextCarrier.serialize());
+                rpcContext.getAttachments().put(Config.Plugin.Propagation.HEADER_NAME, contextCarrier.serialize());
             } else {
                 fix283SendNoAttachmentIssue(invocation, contextCarrier);
             }
@@ -73,7 +73,7 @@ public class DubboInterceptor implements InstanceMethodsAroundInterceptor {
 
             ContextCarrier contextCarrier;
             if (!BugFixActive.isActive()) {
-                contextCarrier = new ContextCarrier().deserialize(rpcContext.getAttachment(ATTACHMENT_NAME_OF_CONTEXT_DATA));
+                contextCarrier = new ContextCarrier().deserialize(rpcContext.getAttachment(Config.Plugin.Propagation.HEADER_NAME));
             } else {
                 contextCarrier = fix283RecvNoAttachmentIssue(invocation);
             }

apm-sniffer/apm-sdk-plugin/dubbo-plugin/src/test/java/org/skywalking/apm/plugin/dubbo/DubboInterceptorTest.java

@@ -5,8 +5,6 @@ import com.alibaba.dubbo.rpc.Invocation;
 import com.alibaba.dubbo.rpc.Invoker;
 import com.alibaba.dubbo.rpc.Result;
 import com.alibaba.dubbo.rpc.RpcContext;
-import java.lang.reflect.Field;
-import java.util.List;
 import org.hamcrest.CoreMatchers;
 import org.junit.After;
 import org.junit.Assert;
@@ -29,11 +27,11 @@ import org.skywalking.apm.sniffer.mock.context.MockTracerContextListener;
 import org.skywalking.apm.sniffer.mock.context.SegmentAssert;
 import org.skywalking.apm.sniffer.mock.trace.SpanLogReader;
 import org.skywalking.apm.sniffer.mock.trace.tags.StringTagReader;
-import org.skywalking.apm.trace.LogData;
-import org.skywalking.apm.trace.Span;
-import org.skywalking.apm.trace.TraceSegment;
-import org.skywalking.apm.trace.TraceSegmentRef;
-import org.skywalking.apm.trace.tag.Tags;
+import org.skywalking.apm.agent.core.context.trace.LogData;
+import org.skywalking.apm.agent.core.context.trace.Span;
+import org.skywalking.apm.agent.core.context.trace.TraceSegment;
+import org.skywalking.apm.agent.core.context.trace.TraceSegmentRef;
+import org.skywalking.apm.agent.core.context.tag.Tags;
 
 import static org.hamcrest.CoreMatchers.is;
 import static org.hamcrest.MatcherAssert.assertThat;
@@ -156,7 +154,7 @@ public class DubboInterceptorTest {
     @Test
     public void testProviderWithAttachment() {
         when(rpcContext.isConsumerSide()).thenReturn(false);
-        when(rpcContext.getAttachment(DubboInterceptor.ATTACHMENT_NAME_OF_CONTEXT_DATA)).thenReturn("302017.1487666919810.624424584.17332.1.1|1|REMOTE_APP|127.0.0.1|Trace.globalId.123|1");
+        when(rpcContext.getAttachment(Config.Plugin.Propagation.HEADER_NAME)).thenReturn("302017.1487666919810.624424584.17332.1.1|1|REMOTE_APP|127.0.0.1|Trace.globalId.123");
 
         dubboInterceptor.beforeMethod(classInstanceContext, methodInvokeContext, methodInterceptResult);
         dubboInterceptor.afterMethod(classInstanceContext, methodInvokeContext, result);
@@ -168,7 +166,7 @@ public class DubboInterceptorTest {
         when(rpcContext.isConsumerSide()).thenReturn(false);
         when(BugFixActive.isActive()).thenReturn(true);
 
-        testParam.setTraceContext("302017.1487666919810.624424584.17332.1.1|1|REMOTE_APP|127.0.0.1|Trace.globalId.123|1");
+        testParam.setTraceContext("302017.1487666919810.624424584.17332.1.1|1|REMOTE_APP|127.0.0.1|Trace.globalId.123");
 
         dubboInterceptor.beforeMethod(classInstanceContext, methodInvokeContext, methodInterceptResult);
         dubboInterceptor.afterMethod(classInstanceContext, methodInvokeContext, result);

apm-sniffer/apm-sdk-plugin/feign-default-http-9.x-plugin/src/main/java/org/skywalking/apm/plugin/feign/http/v9/DefaultHttpClientInterceptor.java

@@ -18,8 +18,8 @@ import org.skywalking.apm.agent.core.plugin.interceptor.EnhancedClassInstanceCon
 import org.skywalking.apm.agent.core.plugin.interceptor.enhance.InstanceMethodInvokeContext;
 import org.skywalking.apm.agent.core.plugin.interceptor.enhance.InstanceMethodsAroundInterceptor;
 import org.skywalking.apm.agent.core.plugin.interceptor.enhance.MethodInterceptResult;
-import org.skywalking.apm.trace.Span;
-import org.skywalking.apm.trace.tag.Tags;
+import org.skywalking.apm.agent.core.context.trace.Span;
+import org.skywalking.apm.agent.core.context.tag.Tags;
 
 /**
  * {@link DefaultHttpClientInterceptor} intercept the default implementation of http calls by the Feign.
@@ -68,7 +68,7 @@ public class DefaultHttpClientInterceptor implements InstanceMethodsAroundInterc
 
         headersField.setAccessible(true);
         Map<String, Collection<String>> headers = new LinkedHashMap<String, Collection<String>>();
-        headers.put(Config.Plugin.Http.HEADER_NAME_OF_CONTEXT_DATA, contextCollection);
+        headers.put(Config.Plugin.Propagation.HEADER_NAME, contextCollection);
         headers.putAll(request.headers());
 
         headersField.set(request, Collections.unmodifiableMap(headers));

apm-sniffer/apm-sdk-plugin/feign-default-http-9.x-plugin/src/test/java/org/skywalking/apm/plugin/feign/http/v9/DefaultHttpClientInterceptorTest.java

@@ -22,9 +22,9 @@ import org.skywalking.apm.sniffer.mock.context.SegmentAssert;
 import org.skywalking.apm.sniffer.mock.trace.SpanLogReader;
 import org.skywalking.apm.sniffer.mock.trace.tags.BooleanTagReader;
 import org.skywalking.apm.sniffer.mock.trace.tags.StringTagReader;
-import org.skywalking.apm.trace.Span;
-import org.skywalking.apm.trace.TraceSegment;
-import org.skywalking.apm.trace.tag.Tags;
+import org.skywalking.apm.agent.core.context.trace.Span;
+import org.skywalking.apm.agent.core.context.trace.TraceSegment;
+import org.skywalking.apm.agent.core.context.tag.Tags;
 
 import static org.mockito.Mockito.mock;
 import static org.mockito.Mockito.when;

apm-sniffer/apm-sdk-plugin/httpClient-4.x-plugin/src/main/java/org/skywalking/apm/plugin/httpClient/v4/HttpClientExecuteInterceptor.java

 package org.skywalking.apm.plugin.httpClient.v4;
 
 import org.apache.http.*;
+import org.skywalking.apm.agent.core.conf.Config;
 import org.skywalking.apm.agent.core.context.ContextCarrier;
 import org.skywalking.apm.agent.core.context.ContextManager;
 import org.skywalking.apm.agent.core.plugin.interceptor.EnhancedClassInstanceContext;
 import org.skywalking.apm.agent.core.plugin.interceptor.enhance.InstanceMethodInvokeContext;
 import org.skywalking.apm.agent.core.plugin.interceptor.enhance.InstanceMethodsAroundInterceptor;
 import org.skywalking.apm.agent.core.plugin.interceptor.enhance.MethodInterceptResult;
-import org.skywalking.apm.trace.Span;
-import org.skywalking.apm.trace.tag.Tags;
+import org.skywalking.apm.agent.core.context.trace.Span;
+import org.skywalking.apm.agent.core.context.tag.Tags;
 
 import java.net.MalformedURLException;
 import java.net.URL;
@@ -20,19 +21,18 @@ import java.net.URL;
  * @author zhangxin
  */
 public class HttpClientExecuteInterceptor implements InstanceMethodsAroundInterceptor {
-    public static final String HEADER_NAME_OF_CONTEXT_DATA = "SWTraceContext";
     private static final String COMPONENT_NAME = "HttpClient";
 
     @Override
     public void beforeMethod(EnhancedClassInstanceContext context,
-                             InstanceMethodInvokeContext interceptorContext, MethodInterceptResult result) {
+        InstanceMethodInvokeContext interceptorContext, MethodInterceptResult result) {
         Object[] allArguments = interceptorContext.allArguments();
         if (allArguments[0] == null || allArguments[1] == null) {
             // illegal args, can't trace. ignore.
             return;
         }
-        HttpHost httpHost = (HttpHost) allArguments[0];
-        HttpRequest httpRequest = (HttpRequest) allArguments[1];
+        HttpHost httpHost = (HttpHost)allArguments[0];
+        HttpRequest httpRequest = (HttpRequest)allArguments[1];
         Span span = createSpan(httpRequest);
         span.setPeerHost(httpHost.getHostName());
         span.setPort(httpHost.getPort());
@@ -43,7 +43,7 @@ public class HttpClientExecuteInterceptor implements InstanceMethodsAroundInterc
 
         ContextCarrier contextCarrier = new ContextCarrier();
         ContextManager.inject(contextCarrier);
-        httpRequest.setHeader(HEADER_NAME_OF_CONTEXT_DATA, contextCarrier.serialize());
+        httpRequest.setHeader(Config.Plugin.Propagation.HEADER_NAME, contextCarrier.serialize());
     }
 
     /**
@@ -71,13 +71,13 @@ public class HttpClientExecuteInterceptor implements InstanceMethodsAroundInterc
 
     @Override
     public Object afterMethod(EnhancedClassInstanceContext context,
-                              InstanceMethodInvokeContext interceptorContext, Object ret) {
+        InstanceMethodInvokeContext interceptorContext, Object ret) {
         Object[] allArguments = interceptorContext.allArguments();
         if (allArguments[0] == null || allArguments[1] == null) {
             return ret;
         }
 
-        HttpResponse response = (HttpResponse) ret;
+        HttpResponse response = (HttpResponse)ret;
         int statusCode = response.getStatusLine().getStatusCode();
         Span span = ContextManager.activeSpan();
         if (statusCode != 200) {
@@ -91,7 +91,7 @@ public class HttpClientExecuteInterceptor implements InstanceMethodsAroundInterc
 
     @Override
     public void handleMethodException(Throwable t, EnhancedClassInstanceContext context,
-                                      InstanceMethodInvokeContext interceptorContext) {
+        InstanceMethodInvokeContext interceptorContext) {
         Tags.ERROR.set(ContextManager.activeSpan(), true);
         ContextManager.activeSpan().log(t);
     }

apm-sniffer/apm-sdk-plugin/httpClient-4.x-plugin/src/test/java/org/skywalking/apm/plugin/httpClient/v4/HttpClientExecuteInterceptorTest.java

@@ -18,10 +18,10 @@ import org.skywalking.apm.sniffer.mock.context.MockTracerContextListener;
 import org.skywalking.apm.sniffer.mock.context.SegmentAssert;
 import org.skywalking.apm.sniffer.mock.trace.tags.BooleanTagReader;
 import org.skywalking.apm.sniffer.mock.trace.tags.StringTagReader;
-import org.skywalking.apm.trace.LogData;
-import org.skywalking.apm.trace.Span;
-import org.skywalking.apm.trace.TraceSegment;
-import org.skywalking.apm.trace.tag.Tags;
+import org.skywalking.apm.agent.core.context.trace.LogData;
+import org.skywalking.apm.agent.core.context.trace.Span;
+import org.skywalking.apm.agent.core.context.trace.TraceSegment;
+import org.skywalking.apm.agent.core.context.tag.Tags;
 
 import java.util.List;
 

apm-sniffer/apm-sdk-plugin/jdbc-plugin/src/main/java/org/skywalking/apm/plugin/jdbc/CallableStatementTracing.java

@@ -2,8 +2,8 @@ package org.skywalking.apm.plugin.jdbc;
 
 import org.skywalking.apm.agent.core.context.ContextManager;
 import org.skywalking.apm.util.StringUtil;
-import org.skywalking.apm.trace.Span;
-import org.skywalking.apm.trace.tag.Tags;
+import org.skywalking.apm.agent.core.context.trace.Span;
+import org.skywalking.apm.agent.core.context.tag.Tags;
 
 import java.sql.SQLException;
 

apm-sniffer/apm-sdk-plugin/jdbc-plugin/src/main/java/org/skywalking/apm/plugin/jdbc/ConnectionTracing.java

@@ -2,8 +2,8 @@ package org.skywalking.apm.plugin.jdbc;
 
 import org.skywalking.apm.agent.core.context.ContextManager;
 import org.skywalking.apm.util.StringUtil;
-import org.skywalking.apm.trace.Span;
-import org.skywalking.apm.trace.tag.Tags;
+import org.skywalking.apm.agent.core.context.trace.Span;
+import org.skywalking.apm.agent.core.context.tag.Tags;
 
 import java.sql.SQLException;
 

apm-sniffer/apm-sdk-plugin/jdbc-plugin/src/main/java/org/skywalking/apm/plugin/jdbc/PreparedStatementTracing.java

@@ -2,8 +2,8 @@ package org.skywalking.apm.plugin.jdbc;
 
 import org.skywalking.apm.agent.core.context.ContextManager;
 import org.skywalking.apm.util.StringUtil;
-import org.skywalking.apm.trace.Span;
-import org.skywalking.apm.trace.tag.Tags;
+import org.skywalking.apm.agent.core.context.trace.Span;
+import org.skywalking.apm.agent.core.context.tag.Tags;
 
 import java.sql.SQLException;
 

apm-sniffer/apm-sdk-plugin/jdbc-plugin/src/main/java/org/skywalking/apm/plugin/jdbc/StatementTracing.java

@@ -2,8 +2,8 @@ package org.skywalking.apm.plugin.jdbc;
 
 import org.skywalking.apm.agent.core.context.ContextManager;
 import org.skywalking.apm.util.StringUtil;
-import org.skywalking.apm.trace.Span;
-import org.skywalking.apm.trace.tag.Tags;
+import org.skywalking.apm.agent.core.context.trace.Span;
+import org.skywalking.apm.agent.core.context.tag.Tags;
 
 import java.sql.SQLException;
 

apm-sniffer/apm-sdk-plugin/jdbc-plugin/src/test/java/org/skywalking/apm/plugin/jdbc/AbstractStatementTest.java

@@ -5,9 +5,9 @@ import java.util.List;
 import org.hamcrest.CoreMatchers;
 import org.skywalking.apm.sniffer.mock.context.MockTracerContextListener;
 import org.skywalking.apm.sniffer.mock.trace.tags.StringTagReader;
-import org.skywalking.apm.trace.LogData;
-import org.skywalking.apm.trace.Span;
-import org.skywalking.apm.trace.tag.Tags;
+import org.skywalking.apm.agent.core.context.trace.LogData;
+import org.skywalking.apm.agent.core.context.trace.Span;
+import org.skywalking.apm.agent.core.context.tag.Tags;
 
 import java.sql.SQLException;
 

apm-sniffer/apm-sdk-plugin/jdbc-plugin/src/test/java/org/skywalking/apm/plugin/jdbc/SWCallableStatementTest.java

@@ -16,9 +16,9 @@ import org.skywalking.apm.agent.core.boot.ServiceManager;
 import org.skywalking.apm.agent.core.context.TracerContext;
 import org.skywalking.apm.sniffer.mock.context.MockTracerContextListener;
 import org.skywalking.apm.sniffer.mock.context.SegmentAssert;
-import org.skywalking.apm.trace.LogData;
-import org.skywalking.apm.trace.Span;
-import org.skywalking.apm.trace.TraceSegment;
+import org.skywalking.apm.agent.core.context.trace.LogData;
+import org.skywalking.apm.agent.core.context.trace.Span;
+import org.skywalking.apm.agent.core.context.trace.TraceSegment;
 
 import java.io.InputStream;
 import java.io.Reader;

apm-sniffer/apm-sdk-plugin/jdbc-plugin/src/test/java/org/skywalking/apm/plugin/jdbc/SWConnectionTest.java

@@ -11,7 +11,7 @@ import org.skywalking.apm.agent.core.boot.ServiceManager;
 import org.skywalking.apm.agent.core.context.TracerContext;
 import org.skywalking.apm.sniffer.mock.context.MockTracerContextListener;
 import org.skywalking.apm.sniffer.mock.context.SegmentAssert;
-import org.skywalking.apm.trace.TraceSegment;
+import org.skywalking.apm.agent.core.context.trace.TraceSegment;
 
 import java.sql.PreparedStatement;
 import java.sql.SQLException;

apm-sniffer/apm-sdk-plugin/jdbc-plugin/src/test/java/org/skywalking/apm/plugin/jdbc/SWStatementTest.java

@@ -13,9 +13,9 @@ import org.skywalking.apm.agent.core.boot.ServiceManager;
 import org.skywalking.apm.agent.core.context.TracerContext;
 import org.skywalking.apm.sniffer.mock.context.MockTracerContextListener;
 import org.skywalking.apm.sniffer.mock.context.SegmentAssert;
-import org.skywalking.apm.trace.LogData;
-import org.skywalking.apm.trace.Span;
-import org.skywalking.apm.trace.TraceSegment;
+import org.skywalking.apm.agent.core.context.trace.LogData;
+import org.skywalking.apm.agent.core.context.trace.Span;
+import org.skywalking.apm.agent.core.context.trace.TraceSegment;
 
 import java.net.MalformedURLException;
 import java.sql.Connection;

apm-sniffer/apm-sdk-plugin/jdbc-plugin/src/test/java/org/skywalking/apm/plugin/jdbc/SwPreparedStatementTest.java

@@ -16,9 +16,9 @@ import org.skywalking.apm.agent.core.boot.ServiceManager;
 import org.skywalking.apm.agent.core.context.TracerContext;
 import org.skywalking.apm.sniffer.mock.context.MockTracerContextListener;
 import org.skywalking.apm.sniffer.mock.context.SegmentAssert;
-import org.skywalking.apm.trace.LogData;
-import org.skywalking.apm.trace.Span;
-import org.skywalking.apm.trace.TraceSegment;
+import org.skywalking.apm.agent.core.context.trace.LogData;
+import org.skywalking.apm.agent.core.context.trace.Span;
+import org.skywalking.apm.agent.core.context.trace.TraceSegment;
 
 import java.io.InputStream;
 import java.io.Reader;

apm-sniffer/apm-sdk-plugin/jedis-2.x-plugin/src/main/java/org/skywalking/apm/plugin/jedis/v2/JedisMethodInterceptor.java

@@ -6,8 +6,8 @@ import org.skywalking.apm.agent.core.plugin.interceptor.assist.NoConcurrencyAcce
 import org.skywalking.apm.agent.core.plugin.interceptor.enhance.InstanceMethodInvokeContext;
 import org.skywalking.apm.agent.core.plugin.interceptor.enhance.InstanceMethodsAroundInterceptor;
 import org.skywalking.apm.agent.core.plugin.interceptor.enhance.MethodInterceptResult;
-import org.skywalking.apm.trace.Span;
-import org.skywalking.apm.trace.tag.Tags;
+import org.skywalking.apm.agent.core.context.trace.Span;
+import org.skywalking.apm.agent.core.context.tag.Tags;
 import org.skywalking.apm.util.StringUtil;
 
 /**

apm-sniffer/apm-sdk-plugin/jedis-2.x-plugin/src/test/java/org/skywalking/apm/plugin/jedis/v2/JedisMethodInterceptorTest.java

@@ -18,10 +18,10 @@ import org.skywalking.apm.sniffer.mock.context.MockTracerContextListener;
 import org.skywalking.apm.sniffer.mock.context.SegmentAssert;
 import org.skywalking.apm.sniffer.mock.trace.tags.BooleanTagReader;
 import org.skywalking.apm.sniffer.mock.trace.tags.StringTagReader;
-import org.skywalking.apm.trace.LogData;
-import org.skywalking.apm.trace.Span;
-import org.skywalking.apm.trace.TraceSegment;
-import org.skywalking.apm.trace.tag.Tags;
+import org.skywalking.apm.agent.core.context.trace.LogData;
+import org.skywalking.apm.agent.core.context.trace.Span;
+import org.skywalking.apm.agent.core.context.trace.TraceSegment;
+import org.skywalking.apm.agent.core.context.tag.Tags;
 
 import static org.hamcrest.CoreMatchers.is;
 import static org.junit.Assert.*;

apm-sniffer/apm-sdk-plugin/mongodb-3.x-plugin/src/main/java/org/skywalking/apm/plugin/mongodb/v3/MongoDBMethodInterceptor.java

@@ -13,8 +13,8 @@ import org.skywalking.apm.agent.core.plugin.interceptor.EnhancedClassInstanceCon
 import org.skywalking.apm.agent.core.plugin.interceptor.enhance.InstanceMethodInvokeContext;
 import org.skywalking.apm.agent.core.plugin.interceptor.enhance.InstanceMethodsAroundInterceptor;
 import org.skywalking.apm.agent.core.plugin.interceptor.enhance.MethodInterceptResult;
-import org.skywalking.apm.trace.Span;
-import org.skywalking.apm.trace.tag.Tags;
+import org.skywalking.apm.agent.core.context.trace.Span;
+import org.skywalking.apm.agent.core.context.tag.Tags;
 
 import java.util.List;
 

apm-sniffer/apm-sdk-plugin/mongodb-3.x-plugin/src/test/java/org/skywalking/apm/plugin/mongodb/v3/MongoDBMethodInterceptorTest.java

@@ -23,10 +23,10 @@ import org.skywalking.apm.sniffer.mock.context.MockTracerContextListener;
 import org.skywalking.apm.sniffer.mock.context.SegmentAssert;
 import org.skywalking.apm.sniffer.mock.trace.SpanLogReader;
 import org.skywalking.apm.sniffer.mock.trace.tags.StringTagReader;
-import org.skywalking.apm.trace.LogData;
-import org.skywalking.apm.trace.Span;
-import org.skywalking.apm.trace.TraceSegment;
-import org.skywalking.apm.trace.tag.Tags;
+import org.skywalking.apm.agent.core.context.trace.LogData;
+import org.skywalking.apm.agent.core.context.trace.Span;
+import org.skywalking.apm.agent.core.context.trace.TraceSegment;
+import org.skywalking.apm.agent.core.context.tag.Tags;
 
 import static org.hamcrest.CoreMatchers.is;
 import static org.junit.Assert.*;

apm-sniffer/apm-sdk-plugin/mongodb-3.x-plugin/src/test/java/org/skywalking/apm/plugin/mongodb/v3/MongoDBWriteMethodInterceptorTest.java

@@ -24,10 +24,10 @@ import org.skywalking.apm.sniffer.mock.context.MockTracerContextListener;
 import org.skywalking.apm.sniffer.mock.context.SegmentAssert;
 import org.skywalking.apm.sniffer.mock.trace.SpanLogReader;
 import org.skywalking.apm.sniffer.mock.trace.tags.StringTagReader;
-import org.skywalking.apm.trace.LogData;
-import org.skywalking.apm.trace.Span;
-import org.skywalking.apm.trace.TraceSegment;
-import org.skywalking.apm.trace.tag.Tags;
+import org.skywalking.apm.agent.core.context.trace.LogData;
+import org.skywalking.apm.agent.core.context.trace.Span;
+import org.skywalking.apm.agent.core.context.trace.TraceSegment;
+import org.skywalking.apm.agent.core.context.tag.Tags;
 
 import java.util.ArrayList;
 import java.util.List;

apm-sniffer/apm-sdk-plugin/motan-plugin/src/main/java/org/skywalking/apm/plugin/motan/MotanConsumerInterceptor.java

@@ -3,6 +3,7 @@ package org.skywalking.apm.plugin.motan;
 import com.weibo.api.motan.rpc.Request;
 import com.weibo.api.motan.rpc.Response;
 import com.weibo.api.motan.rpc.URL;
+import org.skywalking.apm.agent.core.conf.Config;
 import org.skywalking.apm.agent.core.context.ContextCarrier;
 import org.skywalking.apm.agent.core.context.ContextManager;
 import org.skywalking.apm.agent.core.plugin.interceptor.EnhancedClassInstanceContext;
@@ -11,8 +12,8 @@ import org.skywalking.apm.agent.core.plugin.interceptor.enhance.InstanceConstruc
 import org.skywalking.apm.agent.core.plugin.interceptor.enhance.InstanceMethodInvokeContext;
 import org.skywalking.apm.agent.core.plugin.interceptor.enhance.InstanceMethodsAroundInterceptor;
 import org.skywalking.apm.agent.core.plugin.interceptor.enhance.MethodInterceptResult;
-import org.skywalking.apm.trace.Span;
-import org.skywalking.apm.trace.tag.Tags;
+import org.skywalking.apm.agent.core.context.trace.Span;
+import org.skywalking.apm.agent.core.context.tag.Tags;
 
 /**
  * {@link MotanProviderInterceptor} create span by fetch request url from
@@ -28,10 +29,6 @@ public class MotanConsumerInterceptor implements InstanceConstructorInterceptor,
      */
     private static final String KEY_NAME_OF_REQUEST_URL = "REQUEST_URL";
 
-    /**
-     * The {@link Request#getAttachments()} key. It maps to the serialized {@link ContextCarrier}.
-     */
-    private static final String ATTACHMENT_KEY_OF_CONTEXT_DATA = "SWTraceContext";
     /**
      * Motan component
      */
@@ -58,7 +55,7 @@ public class MotanConsumerInterceptor implements InstanceConstructorInterceptor,
 
             ContextCarrier contextCarrier = new ContextCarrier();
             ContextManager.inject(contextCarrier);
-            request.setAttachment(ATTACHMENT_KEY_OF_CONTEXT_DATA, contextCarrier.serialize());
+            request.setAttachment(Config.Plugin.Propagation.HEADER_NAME, contextCarrier.serialize());
         }
     }
 

apm-sniffer/apm-sdk-plugin/motan-plugin/src/main/java/org/skywalking/apm/plugin/motan/MotanProviderInterceptor.java

@@ -2,6 +2,7 @@ package org.skywalking.apm.plugin.motan;
 
 import com.weibo.api.motan.rpc.Request;
 import com.weibo.api.motan.rpc.Response;
+import org.skywalking.apm.agent.core.conf.Config;
 import org.skywalking.apm.agent.core.context.ContextCarrier;
 import org.skywalking.apm.agent.core.context.ContextManager;
 import org.skywalking.apm.agent.core.plugin.interceptor.EnhancedClassInstanceContext;
@@ -9,8 +10,8 @@ import org.skywalking.apm.agent.core.plugin.interceptor.enhance.InstanceMethodIn
 import org.skywalking.apm.agent.core.plugin.interceptor.enhance.InstanceMethodsAroundInterceptor;
 import org.skywalking.apm.agent.core.plugin.interceptor.enhance.MethodInterceptResult;
 import org.skywalking.apm.util.StringUtil;
-import org.skywalking.apm.trace.Span;
-import org.skywalking.apm.trace.tag.Tags;
+import org.skywalking.apm.agent.core.context.trace.Span;
+import org.skywalking.apm.agent.core.context.tag.Tags;
 
 /**
  * Current trace segment will ref the trace segment if the serialized trace context that fetch from {@link
@@ -22,12 +23,6 @@ import org.skywalking.apm.trace.tag.Tags;
  * @author zhangxin
  */
 public class MotanProviderInterceptor implements InstanceMethodsAroundInterceptor {
-
-    /**
-     * Attachment key of the serialized context data.
-     */
-    private static final String ATTACHMENT_KEY_OF_CONTEXT_DATA = "SWTraceContext";
-
     /**
      * Motan component
      */
@@ -42,7 +37,7 @@ public class MotanProviderInterceptor implements InstanceMethodsAroundIntercepto
         Tags.SPAN_KIND.set(span, Tags.SPAN_KIND_SERVER);
         Tags.SPAN_LAYER.asRPCFramework(span);
 
-        String serializedContextData = request.getAttachments().get(ATTACHMENT_KEY_OF_CONTEXT_DATA);
+        String serializedContextData = request.getAttachments().get(Config.Plugin.Propagation.HEADER_NAME);
         if (!StringUtil.isEmpty(serializedContextData)) {
             ContextManager.extract(new ContextCarrier().deserialize(serializedContextData));
         }

apm-sniffer/apm-sdk-plugin/motan-plugin/src/test/java/org/skywalking/apm/plugin/motan/MotanConsumerInterceptorTest.java

@@ -19,10 +19,10 @@ import org.skywalking.apm.sniffer.mock.context.MockTracerContextListener;
 import org.skywalking.apm.sniffer.mock.context.SegmentAssert;
 import org.skywalking.apm.sniffer.mock.trace.SpanLogReader;
 import org.skywalking.apm.sniffer.mock.trace.tags.StringTagReader;
-import org.skywalking.apm.trace.LogData;
-import org.skywalking.apm.trace.Span;
-import org.skywalking.apm.trace.TraceSegment;
-import org.skywalking.apm.trace.tag.Tags;
+import org.skywalking.apm.agent.core.context.trace.LogData;
+import org.skywalking.apm.agent.core.context.trace.Span;
+import org.skywalking.apm.agent.core.context.trace.TraceSegment;
+import org.skywalking.apm.agent.core.context.tag.Tags;
 
 import static org.hamcrest.CoreMatchers.is;
 import static org.junit.Assert.*;

apm-sniffer/apm-sdk-plugin/motan-plugin/src/test/java/org/skywalking/apm/plugin/motan/MotanProviderInterceptorTest.java

@@ -12,6 +12,7 @@ import org.junit.runner.RunWith;
 import org.mockito.Mock;
 import org.mockito.runners.MockitoJUnitRunner;
 import org.skywalking.apm.agent.core.boot.ServiceManager;
+import org.skywalking.apm.agent.core.conf.Config;
 import org.skywalking.apm.agent.core.context.TracerContext;
 import org.skywalking.apm.agent.core.plugin.interceptor.EnhancedClassInstanceContext;
 import org.skywalking.apm.agent.core.plugin.interceptor.enhance.ConstructorInvokeContext;
@@ -20,11 +21,11 @@ import org.skywalking.apm.sniffer.mock.context.MockTracerContextListener;
 import org.skywalking.apm.sniffer.mock.context.SegmentAssert;
 import org.skywalking.apm.sniffer.mock.trace.SpanLogReader;
 import org.skywalking.apm.sniffer.mock.trace.tags.StringTagReader;
-import org.skywalking.apm.trace.LogData;
-import org.skywalking.apm.trace.Span;
-import org.skywalking.apm.trace.TraceSegment;
-import org.skywalking.apm.trace.TraceSegmentRef;
-import org.skywalking.apm.trace.tag.Tags;
+import org.skywalking.apm.agent.core.context.trace.LogData;
+import org.skywalking.apm.agent.core.context.trace.Span;
+import org.skywalking.apm.agent.core.context.trace.TraceSegment;
+import org.skywalking.apm.agent.core.context.trace.TraceSegmentRef;
+import org.skywalking.apm.agent.core.context.tag.Tags;
 
 import java.util.HashMap;
 
@@ -89,7 +90,7 @@ public class MotanProviderInterceptorTest {
     @Test
     public void testInvokerWithRefSegment() {
         HashMap attachments = new HashMap();
-        attachments.put("SWTraceContext", "302017.1487666919810.624424584.17332.1.1|1|REMOTE_APP|127.0.0.1|Trace.globalId.123|1");
+        attachments.put(Config.Plugin.Propagation.HEADER_NAME, "302017.1487666919810.624424584.17332.1.1|1|REMOTE_APP|127.0.0.1|Trace.globalId.123");
         when(request.getAttachments()).thenReturn(attachments);
 
         invokeInterceptor.beforeMethod(instanceContext, interceptorContext, null);

apm-sniffer/apm-sdk-plugin/okhttp-3.x-plugin/src/main/java/org/skywalking/apm/plugin/okhttp/v3/RealCallInterceptor.java

@@ -15,8 +15,8 @@ import org.skywalking.apm.agent.core.plugin.interceptor.enhance.InstanceConstruc
 import org.skywalking.apm.agent.core.plugin.interceptor.enhance.InstanceMethodInvokeContext;
 import org.skywalking.apm.agent.core.plugin.interceptor.enhance.InstanceMethodsAroundInterceptor;
 import org.skywalking.apm.agent.core.plugin.interceptor.enhance.MethodInterceptResult;
-import org.skywalking.apm.trace.Span;
-import org.skywalking.apm.trace.tag.Tags;
+import org.skywalking.apm.agent.core.context.trace.Span;
+import org.skywalking.apm.agent.core.context.tag.Tags;
 
 /**
  * {@link RealCallInterceptor} intercept the synchronous http calls by the client of okhttp.
@@ -75,7 +75,7 @@ public class RealCallInterceptor implements InstanceMethodsAroundInterceptor, In
         modifiersField.setInt(headersField, headersField.getModifiers() & ~Modifier.FINAL);
 
         headersField.setAccessible(true);
-        Headers headers = request.headers().newBuilder().add(Config.Plugin.Http.HEADER_NAME_OF_CONTEXT_DATA, contextCarrier.serialize()).build();
+        Headers headers = request.headers().newBuilder().add(Config.Plugin.Propagation.HEADER_NAME, contextCarrier.serialize()).build();
         headersField.set(request, headers);
     }
 

apm-sniffer/apm-sdk-plugin/okhttp-3.x-plugin/src/test/java/org/skywalking/apm/plugin/okhttp/v3/RealCallInterceptorTest.java

@@ -20,9 +20,9 @@ import org.skywalking.apm.sniffer.mock.context.SegmentAssert;
 import org.skywalking.apm.sniffer.mock.trace.SpanLogReader;
 import org.skywalking.apm.sniffer.mock.trace.tags.BooleanTagReader;
 import org.skywalking.apm.sniffer.mock.trace.tags.StringTagReader;
-import org.skywalking.apm.trace.Span;
-import org.skywalking.apm.trace.TraceSegment;
-import org.skywalking.apm.trace.tag.Tags;
+import org.skywalking.apm.agent.core.context.trace.Span;
+import org.skywalking.apm.agent.core.context.trace.TraceSegment;
+import org.skywalking.apm.agent.core.context.tag.Tags;
 
 import static org.mockito.Mockito.mock;
 import static org.mockito.Mockito.when;

apm-sniffer/apm-sdk-plugin/resin-3.x-plugin/src/main/java/org/skywalking/apm/plugin/resin/v3/ResinV3Interceptor.java

 package org.skywalking.apm.plugin.resin.v3;
 
 import com.caucho.server.connection.CauchoRequest;
-import com.caucho.server.http.HttpRequest;
 import com.caucho.server.http.HttpResponse;
+import org.skywalking.apm.agent.core.conf.Config;
 import org.skywalking.apm.agent.core.context.ContextCarrier;
 import org.skywalking.apm.agent.core.context.ContextManager;
 import org.skywalking.apm.agent.core.plugin.interceptor.EnhancedClassInstanceContext;
 import org.skywalking.apm.agent.core.plugin.interceptor.enhance.InstanceMethodInvokeContext;
 import org.skywalking.apm.agent.core.plugin.interceptor.enhance.InstanceMethodsAroundInterceptor;
 import org.skywalking.apm.agent.core.plugin.interceptor.enhance.MethodInterceptResult;
-import org.skywalking.apm.trace.Span;
-import org.skywalking.apm.trace.tag.Tags;
+import org.skywalking.apm.agent.core.context.trace.Span;
+import org.skywalking.apm.agent.core.context.tag.Tags;
 import org.skywalking.apm.util.StringUtil;
 
 /**
@@ -20,11 +20,6 @@ import org.skywalking.apm.util.StringUtil;
  * @author baiyang
  */
 public class ResinV3Interceptor implements InstanceMethodsAroundInterceptor {
-    /**
-     * Header name that the serialized context data stored in
-     * {@link HttpRequest#getHeader(String)}.
-     */
-    public static final String HEADER_NAME_OF_CONTEXT_DATA = "SWTraceContext";
     /**
      * Resin component.
      */
@@ -43,7 +38,7 @@ public class ResinV3Interceptor implements InstanceMethodsAroundInterceptor {
         Tags.URL.set(span, appendRequestURL(request));
         Tags.SPAN_LAYER.asHttp(span);
 
-        String tracingHeaderValue = request.getHeader(HEADER_NAME_OF_CONTEXT_DATA);
+        String tracingHeaderValue = request.getHeader(Config.Plugin.Propagation.HEADER_NAME);
         if (!StringUtil.isEmpty(tracingHeaderValue)) {
             ContextManager.extract(new ContextCarrier().deserialize(tracingHeaderValue));
         }

apm-sniffer/apm-sdk-plugin/resin-3.x-plugin/src/test/java/org/skywalking/apm/plugin/resin/v3/ResinV3InterceptorTest.java

@@ -10,6 +10,7 @@ import org.junit.runner.RunWith;
 import org.mockito.Mock;
 import org.mockito.runners.MockitoJUnitRunner;
 import org.skywalking.apm.agent.core.boot.ServiceManager;
+import org.skywalking.apm.agent.core.conf.Config;
 import org.skywalking.apm.agent.core.context.TracerContext;
 import org.skywalking.apm.agent.core.plugin.interceptor.EnhancedClassInstanceContext;
 import org.skywalking.apm.agent.core.plugin.interceptor.enhance.InstanceMethodInvokeContext;
@@ -19,11 +20,11 @@ import org.skywalking.apm.sniffer.mock.context.SegmentAssert;
 import org.skywalking.apm.sniffer.mock.trace.SpanLogReader;
 import org.skywalking.apm.sniffer.mock.trace.tags.IntTagReader;
 import org.skywalking.apm.sniffer.mock.trace.tags.StringTagReader;
-import org.skywalking.apm.trace.LogData;
-import org.skywalking.apm.trace.Span;
-import org.skywalking.apm.trace.TraceSegment;
-import org.skywalking.apm.trace.TraceSegmentRef;
-import org.skywalking.apm.trace.tag.Tags;
+import org.skywalking.apm.agent.core.context.trace.LogData;
+import org.skywalking.apm.agent.core.context.trace.Span;
+import org.skywalking.apm.agent.core.context.trace.TraceSegment;
+import org.skywalking.apm.agent.core.context.trace.TraceSegmentRef;
+import org.skywalking.apm.agent.core.context.tag.Tags;
 
 import static org.hamcrest.CoreMatchers.is;
 import static org.hamcrest.MatcherAssert.assertThat;
@@ -89,7 +90,7 @@ public class ResinV3InterceptorTest {
 
     @Test
     public void testWithSerializedContextData() {
-        when(request.getHeader(ResinV3Interceptor.HEADER_NAME_OF_CONTEXT_DATA)).thenReturn("302017.1487666919810.624424584.17332.1.1|1|REMOTE_APP|127.0.0.1|Trace.globalId.123|1");
+        when(request.getHeader(Config.Plugin.Propagation.HEADER_NAME)).thenReturn("302017.1487666919810.624424584.17332.1.1|1|REMOTE_APP|127.0.0.1|Trace.globalId.123");
 
         interceptor.beforeMethod(classInstanceContext, methodInvokeContext, methodInterceptResult);
         interceptor.afterMethod(classInstanceContext, methodInvokeContext, null);

apm-sniffer/apm-sdk-plugin/resin-4.x-plugin/src/main/java/org/skywalking/apm/plugin/resin/v4/ResinV4Interceptor.java

 package org.skywalking.apm.plugin.resin.v4;
 
 import com.caucho.server.http.CauchoRequest;
-import com.caucho.server.http.HttpRequest;
 import javax.servlet.http.HttpServletResponse;
+import org.skywalking.apm.agent.core.conf.Config;
 import org.skywalking.apm.agent.core.context.ContextCarrier;
 import org.skywalking.apm.agent.core.context.ContextManager;
 import org.skywalking.apm.agent.core.plugin.interceptor.EnhancedClassInstanceContext;
 import org.skywalking.apm.agent.core.plugin.interceptor.enhance.InstanceMethodInvokeContext;
 import org.skywalking.apm.agent.core.plugin.interceptor.enhance.InstanceMethodsAroundInterceptor;
 import org.skywalking.apm.agent.core.plugin.interceptor.enhance.MethodInterceptResult;
-import org.skywalking.apm.trace.Span;
-import org.skywalking.apm.trace.tag.Tags;
+import org.skywalking.apm.agent.core.context.trace.Span;
+import org.skywalking.apm.agent.core.context.tag.Tags;
 import org.skywalking.apm.util.StringUtil;
 
 /**
  * Created by Baiyang on 2017/5/2.
  */
 public class ResinV4Interceptor implements InstanceMethodsAroundInterceptor {
-    /**
-     * Header name that the serialized context data stored in
-     * {@link HttpRequest#getHeader(String)}.
-     */
-    public static final String HEADER_NAME_OF_CONTEXT_DATA = "SWTraceContext";
     /**
      * Resin component.
      */
@@ -40,7 +35,7 @@ public class ResinV4Interceptor implements InstanceMethodsAroundInterceptor {
         Tags.URL.set(span, appendRequestURL(request));
         Tags.SPAN_LAYER.asHttp(span);
 
-        String tracingHeaderValue = request.getHeader(HEADER_NAME_OF_CONTEXT_DATA);
+        String tracingHeaderValue = request.getHeader(Config.Plugin.Propagation.HEADER_NAME);
         if (!StringUtil.isEmpty(tracingHeaderValue)) {
             ContextManager.extract(new ContextCarrier().deserialize(tracingHeaderValue));
         }

apm-sniffer/apm-sdk-plugin/resin-4.x-plugin/src/test/java/org/skywalking/apm/plugin/resin/v4/ResinV4InterceptorTest.java

@@ -10,6 +10,7 @@ import org.junit.runner.RunWith;
 import org.mockito.Mock;
 import org.mockito.runners.MockitoJUnitRunner;
 import org.skywalking.apm.agent.core.boot.ServiceManager;
+import org.skywalking.apm.agent.core.conf.Config;
 import org.skywalking.apm.agent.core.context.TracerContext;
 import org.skywalking.apm.agent.core.plugin.interceptor.EnhancedClassInstanceContext;
 import org.skywalking.apm.agent.core.plugin.interceptor.enhance.InstanceMethodInvokeContext;
@@ -19,11 +20,11 @@ import org.skywalking.apm.sniffer.mock.context.SegmentAssert;
 import org.skywalking.apm.sniffer.mock.trace.SpanLogReader;
 import org.skywalking.apm.sniffer.mock.trace.tags.IntTagReader;
 import org.skywalking.apm.sniffer.mock.trace.tags.StringTagReader;
-import org.skywalking.apm.trace.LogData;
-import org.skywalking.apm.trace.Span;
-import org.skywalking.apm.trace.TraceSegment;
-import org.skywalking.apm.trace.TraceSegmentRef;
-import org.skywalking.apm.trace.tag.Tags;
+import org.skywalking.apm.agent.core.context.trace.LogData;
+import org.skywalking.apm.agent.core.context.trace.Span;
+import org.skywalking.apm.agent.core.context.trace.TraceSegment;
+import org.skywalking.apm.agent.core.context.trace.TraceSegmentRef;
+import org.skywalking.apm.agent.core.context.tag.Tags;
 
 import static org.hamcrest.CoreMatchers.is;
 import static org.hamcrest.MatcherAssert.assertThat;
@@ -88,7 +89,7 @@ public class ResinV4InterceptorTest {
 
     @Test
     public void testWithSerializedContextData() {
-        when(request.getHeader(ResinV4Interceptor.HEADER_NAME_OF_CONTEXT_DATA)).thenReturn("302017.1487666919810.624424584.17332.1.1|1|REMOTE_APP|127.0.0.1|Trace.globalId.123|1");
+        when(request.getHeader(Config.Plugin.Propagation.HEADER_NAME)).thenReturn("302017.1487666919810.624424584.17332.1.1|1|REMOTE_APP|127.0.0.1|Trace.globalId.123");
 
         interceptor.beforeMethod(classInstanceContext, methodInvokeContext, methodInterceptResult);
         interceptor.afterMethod(classInstanceContext, methodInvokeContext, null);

apm-sniffer/apm-sdk-plugin/tomcat-7.x-8.x-plugin/src/main/java/org/skywalking/apm/plugin/tomcat78x/TomcatInterceptor.java

 package org.skywalking.apm.plugin.tomcat78x;
 
+import org.skywalking.apm.agent.core.conf.Config;
 import org.skywalking.apm.agent.core.context.ContextCarrier;
 import org.skywalking.apm.agent.core.context.ContextManager;
 import org.skywalking.apm.agent.core.plugin.interceptor.EnhancedClassInstanceContext;
@@ -7,9 +8,9 @@ import org.skywalking.apm.agent.core.plugin.interceptor.enhance.InstanceMethodIn
 import org.skywalking.apm.agent.core.plugin.interceptor.enhance.InstanceMethodsAroundInterceptor;
 import org.skywalking.apm.agent.core.plugin.interceptor.enhance.MethodInterceptResult;
 import org.skywalking.apm.util.StringUtil;
-import org.skywalking.apm.trace.Span;
-import org.skywalking.apm.trace.TraceSegment;
-import org.skywalking.apm.trace.tag.Tags;
+import org.skywalking.apm.agent.core.context.trace.Span;
+import org.skywalking.apm.agent.core.context.trace.TraceSegment;
+import org.skywalking.apm.agent.core.context.tag.Tags;
 
 import javax.servlet.http.HttpServletRequest;
 import javax.servlet.http.HttpServletResponse;
@@ -20,10 +21,6 @@ import javax.servlet.http.HttpServletResponse;
  * segment id of the previous level if the serialized context is not null.
  */
 public class TomcatInterceptor implements InstanceMethodsAroundInterceptor {
-    /**
-     * Header name that the serialized context data stored in {@link HttpServletRequest#getHeader(String)}.
-     */
-    public static final String HEADER_NAME_OF_CONTEXT_DATA = "SWTraceContext";
     /**
      * Tomcat component.
      */
@@ -51,7 +48,7 @@ public class TomcatInterceptor implements InstanceMethodsAroundInterceptor {
         Tags.URL.set(span, request.getRequestURL().toString());
         Tags.SPAN_LAYER.asHttp(span);
 
-        String tracingHeaderValue = request.getHeader(HEADER_NAME_OF_CONTEXT_DATA);
+        String tracingHeaderValue = request.getHeader(Config.Plugin.Propagation.HEADER_NAME);
         if (!StringUtil.isEmpty(tracingHeaderValue)) {
             ContextManager.extract(new ContextCarrier().deserialize(tracingHeaderValue));
         }

apm-sniffer/apm-sdk-plugin/tomcat-7.x-8.x-plugin/src/test/java/org/skywalking/apm/plugin/tomcat78x/TomcatInterceptorTest.java

@@ -10,6 +10,7 @@ import org.junit.runner.RunWith;
 import org.mockito.Mock;
 import org.mockito.runners.MockitoJUnitRunner;
 import org.skywalking.apm.agent.core.boot.ServiceManager;
+import org.skywalking.apm.agent.core.conf.Config;
 import org.skywalking.apm.agent.core.context.TracerContext;
 import org.skywalking.apm.agent.core.plugin.interceptor.EnhancedClassInstanceContext;
 import org.skywalking.apm.agent.core.plugin.interceptor.enhance.InstanceMethodInvokeContext;
@@ -19,11 +20,11 @@ import org.skywalking.apm.sniffer.mock.context.SegmentAssert;
 import org.skywalking.apm.sniffer.mock.trace.SpanLogReader;
 import org.skywalking.apm.sniffer.mock.trace.tags.IntTagReader;
 import org.skywalking.apm.sniffer.mock.trace.tags.StringTagReader;
-import org.skywalking.apm.trace.LogData;
-import org.skywalking.apm.trace.Span;
-import org.skywalking.apm.trace.TraceSegment;
-import org.skywalking.apm.trace.TraceSegmentRef;
-import org.skywalking.apm.trace.tag.Tags;
+import org.skywalking.apm.agent.core.context.trace.LogData;
+import org.skywalking.apm.agent.core.context.trace.Span;
+import org.skywalking.apm.agent.core.context.trace.TraceSegment;
+import org.skywalking.apm.agent.core.context.trace.TraceSegmentRef;
+import org.skywalking.apm.agent.core.context.tag.Tags;
 
 import static org.hamcrest.CoreMatchers.is;
 import static org.hamcrest.MatcherAssert.assertThat;
@@ -81,7 +82,7 @@ public class TomcatInterceptorTest {
 
     @Test
     public void testWithSerializedContextData() {
-        when(request.getHeader(TomcatInterceptor.HEADER_NAME_OF_CONTEXT_DATA)).thenReturn("302017.1487666919810.624424584.17332.1.1|1|REMOTE_APP|127.0.0.1|Trace.globalId.123|1");
+        when(request.getHeader(Config.Plugin.Propagation.HEADER_NAME)).thenReturn("302017.1487666919810.624424584.17332.1.1|1|REMOTE_APP|127.0.0.1|Trace.globalId.123");
 
         tomcatInterceptor.beforeMethod(classInstanceContext, methodInvokeContext, methodInterceptResult);
         tomcatInterceptor.afterMethod(classInstanceContext, methodInvokeContext, null);

apm-sniffer/apm-sniffer-mock/src/main/java/org/skywalking/apm/sniffer/mock/context/MockTracerContextListener.java

@@ -3,7 +3,7 @@ package org.skywalking.apm.sniffer.mock.context;
 import org.junit.Assert;
 import org.skywalking.apm.agent.core.context.TracerContext;
 import org.skywalking.apm.agent.core.context.TracerContextListener;
-import org.skywalking.apm.trace.TraceSegment;
+import org.skywalking.apm.agent.core.context.trace.TraceSegment;
 
 import java.util.ArrayList;
 import java.util.Collections;

apm-sniffer/apm-sniffer-mock/src/main/java/org/skywalking/apm/sniffer/mock/context/SegmentAssert.java

 package org.skywalking.apm.sniffer.mock.context;
 
-import org.skywalking.apm.trace.TraceSegment;
+import org.skywalking.apm.agent.core.context.trace.TraceSegment;
 
 /**
  * The <code>SegmentAssert</code> interface should be implemented by any

apm-sniffer/apm-sniffer-mock/src/main/java/org/skywalking/apm/sniffer/mock/trace/SpanLogReader.java

@@ -2,8 +2,8 @@ package org.skywalking.apm.sniffer.mock.trace;
 
 import java.lang.reflect.Field;
 import java.util.List;
-import org.skywalking.apm.trace.LogData;
-import org.skywalking.apm.trace.Span;
+import org.skywalking.apm.agent.core.context.trace.LogData;
+import org.skywalking.apm.agent.core.context.trace.Span;
 
 /**
  * @author wusheng

apm-sniffer/apm-sniffer-mock/src/main/java/org/skywalking/apm/sniffer/mock/trace/TraceSegmentBuilder.java

 package org.skywalking.apm.sniffer.mock.trace;
 
 import org.skywalking.apm.sniffer.mock.context.MockTracerContextListener;
-import org.skywalking.apm.trace.TraceSegment;
+import org.skywalking.apm.agent.core.context.trace.TraceSegment;
 
 /**
  * Created by wusheng on 2017/2/20.

apm-sniffer/apm-sniffer-mock/src/main/java/org/skywalking/apm/sniffer/mock/trace/TraceSegmentBuilderFactory.java

@@ -3,7 +3,7 @@ package org.skywalking.apm.sniffer.mock.trace;
 import org.skywalking.apm.agent.core.context.TracerContext;
 import org.skywalking.apm.sniffer.mock.context.MockTracerContextListener;
 import org.skywalking.apm.sniffer.mock.trace.builders.trace.*;
-import org.skywalking.apm.trace.TraceSegment;
+import org.skywalking.apm.agent.core.context.trace.TraceSegment;
 
 /**
  * The <code>TraceSegmentBuilderFactory</code> contains all {@link TraceSegmentBuilder} implementations. All the

apm-sniffer/apm-sniffer-mock/src/main/java/org/skywalking/apm/sniffer/mock/trace/builders/span/DubboSpanGenerator.java

 package org.skywalking.apm.sniffer.mock.trace.builders.span;
 
 import org.skywalking.apm.agent.core.context.ContextManager;
-import org.skywalking.apm.trace.Span;
-import org.skywalking.apm.trace.tag.Tags;
+import org.skywalking.apm.agent.core.context.trace.Span;
+import org.skywalking.apm.agent.core.context.tag.Tags;
 
 /**
  * The <code>DubboSpanGenerator</code> generates all possible spans, by tracing Dubbo rpc.

apm-sniffer/apm-sniffer-mock/src/main/java/org/skywalking/apm/sniffer/mock/trace/builders/span/MySQLGenerator.java

 package org.skywalking.apm.sniffer.mock.trace.builders.span;
 
 import org.skywalking.apm.agent.core.context.ContextManager;
-import org.skywalking.apm.trace.Span;
-import org.skywalking.apm.trace.tag.Tags;
+import org.skywalking.apm.agent.core.context.trace.Span;
+import org.skywalking.apm.agent.core.context.tag.Tags;
 
 /**
  * The <code>MySQLGenerator</code> generates all possible spans, by tracing mysql client access.

apm-sniffer/apm-sniffer-mock/src/main/java/org/skywalking/apm/sniffer/mock/trace/builders/span/TomcatSpanGenerator.java

 package org.skywalking.apm.sniffer.mock.trace.builders.span;
 
 import org.skywalking.apm.agent.core.context.ContextManager;
-import org.skywalking.apm.trace.Span;
-import org.skywalking.apm.trace.tag.Tags;
+import org.skywalking.apm.agent.core.context.trace.Span;
+import org.skywalking.apm.agent.core.context.tag.Tags;
 
 /**
  * The <code>TomcatSpanGenerator</code> generate all possible spans, by tracing Tomcat.

apm-sniffer/apm-sniffer-mock/src/main/java/org/skywalking/apm/sniffer/mock/trace/builders/trace/DubboServerMysqlTraceBuilder.java

@@ -4,7 +4,7 @@ import org.skywalking.apm.sniffer.mock.context.MockTracerContextListener;
 import org.skywalking.apm.sniffer.mock.trace.TraceSegmentBuilder;
 import org.skywalking.apm.sniffer.mock.trace.builders.span.DubboSpanGenerator;
 import org.skywalking.apm.sniffer.mock.trace.builders.span.MySQLGenerator;
-import org.skywalking.apm.trace.TraceSegment;
+import org.skywalking.apm.agent.core.context.trace.TraceSegment;
 
 /**
  * @author wusheng

apm-sniffer/apm-sniffer-mock/src/main/java/org/skywalking/apm/sniffer/mock/trace/builders/trace/SingleTomcat200TraceBuilder.java

@@ -3,7 +3,7 @@ package org.skywalking.apm.sniffer.mock.trace.builders.trace;
 import org.skywalking.apm.sniffer.mock.context.MockTracerContextListener;
 import org.skywalking.apm.sniffer.mock.trace.TraceSegmentBuilder;
 import org.skywalking.apm.sniffer.mock.trace.builders.span.TomcatSpanGenerator;
-import org.skywalking.apm.trace.TraceSegment;
+import org.skywalking.apm.agent.core.context.trace.TraceSegment;
 
 /**
  * A Trace contains only one span, which represent a tomcat server side span.

apm-sniffer/apm-sniffer-mock/src/main/java/org/skywalking/apm/sniffer/mock/trace/builders/trace/SingleTomcat404TraceBuilder.java

@@ -3,7 +3,7 @@ package org.skywalking.apm.sniffer.mock.trace.builders.trace;
 import org.skywalking.apm.sniffer.mock.context.MockTracerContextListener;
 import org.skywalking.apm.sniffer.mock.trace.TraceSegmentBuilder;
 import org.skywalking.apm.sniffer.mock.trace.builders.span.TomcatSpanGenerator;
-import org.skywalking.apm.trace.TraceSegment;
+import org.skywalking.apm.agent.core.context.trace.TraceSegment;
 
 /**
  * A Trace contains only one span, which represent a tomcat server side span.

apm-sniffer/apm-sniffer-mock/src/main/java/org/skywalking/apm/sniffer/mock/trace/builders/trace/SingleTomcat500TraceBuilder.java

@@ -3,7 +3,7 @@ package org.skywalking.apm.sniffer.mock.trace.builders.trace;
 import org.skywalking.apm.sniffer.mock.context.MockTracerContextListener;
 import org.skywalking.apm.sniffer.mock.trace.TraceSegmentBuilder;
 import org.skywalking.apm.sniffer.mock.trace.builders.span.TomcatSpanGenerator;
-import org.skywalking.apm.trace.TraceSegment;
+import org.skywalking.apm.agent.core.context.trace.TraceSegment;
 
 /**
  * A Trace contains only one span, which represent a tomcat server side span.

apm-sniffer/apm-sniffer-mock/src/main/java/org/skywalking/apm/sniffer/mock/trace/builders/trace/TomcatDubboClientTraceBuilder.java

@@ -4,7 +4,7 @@ import org.skywalking.apm.sniffer.mock.context.MockTracerContextListener;
 import org.skywalking.apm.sniffer.mock.trace.TraceSegmentBuilder;
 import org.skywalking.apm.sniffer.mock.trace.builders.span.DubboSpanGenerator;
 import org.skywalking.apm.sniffer.mock.trace.builders.span.TomcatSpanGenerator;
-import org.skywalking.apm.trace.TraceSegment;
+import org.skywalking.apm.agent.core.context.trace.TraceSegment;
 
 /**
  * A Trace segment contains two spans with ChildOf relations,

apm-sniffer/apm-sniffer-mock/src/main/java/org/skywalking/apm/sniffer/mock/trace/tags/BooleanTagReader.java

@@ -2,9 +2,9 @@ package org.skywalking.apm.sniffer.mock.trace.tags;
 
 import java.lang.reflect.Field;
 import java.util.List;
-import org.skywalking.apm.trace.Span;
-import org.skywalking.apm.trace.tag.BooleanTag;
-import org.skywalking.apm.trace.tag.BooleanTagItem;
+import org.skywalking.apm.agent.core.context.trace.Span;
+import org.skywalking.apm.agent.core.context.tag.BooleanTag;
+import org.skywalking.apm.agent.core.context.tag.BooleanTagItem;
 
 /**
  * @author wusheng

apm-sniffer/apm-sniffer-mock/src/main/java/org/skywalking/apm/sniffer/mock/trace/tags/IntTagReader.java

@@ -2,9 +2,9 @@ package org.skywalking.apm.sniffer.mock.trace.tags;
 
 import java.lang.reflect.Field;
 import java.util.List;
-import org.skywalking.apm.trace.Span;
-import org.skywalking.apm.trace.tag.IntTag;
-import org.skywalking.apm.trace.tag.IntTagItem;
+import org.skywalking.apm.agent.core.context.trace.Span;
+import org.skywalking.apm.agent.core.context.tag.IntTag;
+import org.skywalking.apm.agent.core.context.tag.IntTagItem;
 
 /**
  * @author wusheng