diff --git a/README.md b/README.md
index 625d210bc..bcdb0036a 100644
--- a/README.md
+++ b/README.md
@@ -11,7 +11,7 @@ Sky Walking | [中文](README_ZH.md)
 [![OpenTracing-1.x Badge](https://img.shields.io/badge/OpenTracing--1.x-enabled-blue.svg)](http://opentracing.io)
 
 * Provide Java agent, **no need to CHANGE any application source code**.
-  * High performance agent. Only increase extra **10%** cpu cost in 5000+ tps application, even **When collect all traces**, [check test reports](#test-reports).
+  * High performance agent. Only increase extra **10%** cpu cost in 5000+ tps application, even **when collect all traces**.
   * [Supported middlewares, frameworks and libraries](https://github.com/OpenSkywalking/sky-walking/wiki/3.2-supported-list).
 * Manual instrumentation
   * As an [OpenTracing supported tracer](http://opentracing.io/documentation/pages/supported-tracers)
diff --git a/apm-collector/apm-collector-core/src/main/java/org/skywalking/apm/collector/core/graph/Graph.java b/apm-collector/apm-collector-core/src/main/java/org/skywalking/apm/collector/core/graph/Graph.java
index 8c1f88251..d570cd48b 100644
--- a/apm-collector/apm-collector-core/src/main/java/org/skywalking/apm/collector/core/graph/Graph.java
+++ b/apm-collector/apm-collector-core/src/main/java/org/skywalking/apm/collector/core/graph/Graph.java
@@ -23,7 +23,7 @@ import java.util.concurrent.ConcurrentHashMap;
 /**
  * @author peng-yongsheng, wu-sheng
  */
-public final class Graph<Input> {
+public final class Graph<INPUT> {
     private int id;
     private Node startNode;
     private ConcurrentHashMap<Integer, Node> nodeIndex = new ConcurrentHashMap<>();
@@ -32,11 +32,11 @@ public final class Graph<Input> {
         this.id = id;
     }
 
-    public void start(Input input) {
-        startNode.execute(input);
+    public void start(INPUT INPUT) {
+        startNode.execute(INPUT);
     }
 
-    public <Output> Node<Input, Output> addNode(NodeHandler<Input, Output> nodeHandler) {
+    public <OUTPUT> Node<INPUT, OUTPUT> addNode(NodeHandler<INPUT, OUTPUT> nodeHandler) {
         synchronized (this) {
             startNode = new Node(this, nodeHandler);
             return startNode;
diff --git a/apm-collector/apm-collector-core/src/main/java/org/skywalking/apm/collector/core/graph/Next.java b/apm-collector/apm-collector-core/src/main/java/org/skywalking/apm/collector/core/graph/Next.java
index a7f636a4f..ba8e6c049 100644
--- a/apm-collector/apm-collector-core/src/main/java/org/skywalking/apm/collector/core/graph/Next.java
+++ b/apm-collector/apm-collector-core/src/main/java/org/skywalking/apm/collector/core/graph/Next.java
@@ -27,7 +27,7 @@ import org.skywalking.apm.collector.core.framework.Executor;
  *
  * @author peng-yongsheng, wu-sheng
  */
-public class Next<Input> implements Executor<Input> {
+public class Next<INPUT> implements Executor<INPUT> {
 
     private final List<Node> nextNodes;
 
@@ -42,9 +42,9 @@ public class Next<Input> implements Executor<Input> {
     /**
      * Drive to the next nodes
      *
-     * @param input
+     * @param INPUT
      */
-    @Override public void execute(Input input) {
-        nextNodes.forEach(node -> node.execute(input));
+    @Override public void execute(INPUT INPUT) {
+        nextNodes.forEach(node -> node.execute(INPUT));
     }
 }
diff --git a/apm-collector/apm-collector-core/src/main/java/org/skywalking/apm/collector/core/graph/Node.java b/apm-collector/apm-collector-core/src/main/java/org/skywalking/apm/collector/core/graph/Node.java
index 8a947bb34..87ea56cb0 100644
--- a/apm-collector/apm-collector-core/src/main/java/org/skywalking/apm/collector/core/graph/Node.java
+++ b/apm-collector/apm-collector-core/src/main/java/org/skywalking/apm/collector/core/graph/Node.java
@@ -19,39 +19,39 @@
 package org.skywalking.apm.collector.core.graph;
 
 /**
- * The <code>Node</code> in the graph with explicit Input and Output types.
+ * The <code>Node</code> in the graph with explicit INPUT and OUTPUT types.
  *
  * @author peng-yongsheng, wu-sheng
  */
-public final class Node<Input, Output> {
+public final class Node<INPUT, OUTPUT> {
     private final NodeHandler nodeHandler;
-    private final Next<Output> next;
+    private final Next<OUTPUT> next;
     private final Graph graph;
 
-    Node(Graph graph, NodeHandler<Input, Output> nodeHandler) {
+    Node(Graph graph, NodeHandler<INPUT, OUTPUT> nodeHandler) {
         this.graph = graph;
         this.nodeHandler = nodeHandler;
         this.next = new Next<>();
         this.graph.checkForNewNode(this);
     }
 
-    public final <NextOutput> Node<Output, NextOutput> addNext(NodeHandler<Output, NextOutput> nodeHandler) {
+    public final <NEXTOUTPUT> Node<OUTPUT, NEXTOUTPUT> addNext(NodeHandler<OUTPUT, NEXTOUTPUT> nodeHandler) {
         synchronized (graph) {
-            Node<Output, NextOutput> node = new Node<>(graph, nodeHandler);
+            Node<OUTPUT, NEXTOUTPUT> node = new Node<>(graph, nodeHandler);
             next.addNext(node);
             return node;
         }
     }
 
-    final void execute(Input input) {
-        nodeHandler.process(input, next);
+    final void execute(INPUT INPUT) {
+        nodeHandler.process(INPUT, next);
     }
 
     NodeHandler getHandler() {
         return nodeHandler;
     }
 
-    Next<Output> getNext() {
+    Next<OUTPUT> getNext() {
         return next;
     }
 }
diff --git a/apm-collector/apm-collector-core/src/main/java/org/skywalking/apm/collector/core/graph/NodeHandler.java b/apm-collector/apm-collector-core/src/main/java/org/skywalking/apm/collector/core/graph/NodeHandler.java
index 10b1d63fb..9a35100a6 100644
--- a/apm-collector/apm-collector-core/src/main/java/org/skywalking/apm/collector/core/graph/NodeHandler.java
+++ b/apm-collector/apm-collector-core/src/main/java/org/skywalking/apm/collector/core/graph/NodeHandler.java
@@ -21,7 +21,7 @@ package org.skywalking.apm.collector.core.graph;
 /**
  * @author peng-yongsheng, wu-sheng
  */
-public interface NodeHandler<Input, Output> {
+public interface NodeHandler<INPUT, OUTPUT> {
     /**
      * The unique id in the certain graph.
      *
@@ -29,5 +29,5 @@ public interface NodeHandler<Input, Output> {
      */
     int id();
 
-    void process(Input input, Next<Output> next);
+    void process(INPUT INPUT, Next<OUTPUT> next);
 }
diff --git a/apm-collector/apm-collector-core/src/test/java/org/skywalking/apm/collector/core/graph/GraphManagerTest.java b/apm-collector/apm-collector-core/src/test/java/org/skywalking/apm/collector/core/graph/GraphManagerTest.java
index 11a13490e..3e84ad091 100644
--- a/apm-collector/apm-collector-core/src/test/java/org/skywalking/apm/collector/core/graph/GraphManagerTest.java
+++ b/apm-collector/apm-collector-core/src/test/java/org/skywalking/apm/collector/core/graph/GraphManagerTest.java
@@ -31,6 +31,7 @@ import org.junit.Test;
 public class GraphManagerTest {
     private static PrintStream OUT_REF;
     private ByteArrayOutputStream outputStream;
+    private static String lineSeparator = System.lineSeparator();
 
     @Before
     public void initAndHoldOut() {
@@ -53,8 +54,8 @@ public class GraphManagerTest {
         testGraph.start("Input String");
 
         String output = outputStream.toString();
-        String expected = "Node1 process: s=Input String\n" +
-            "Node2 process: s=Input String\n";
+        String expected = "Node1 process: s=Input String" + lineSeparator +
+            "Node2 process: s=Input String" + lineSeparator;
 
         Assert.assertEquals(expected, output);
     }
@@ -67,9 +68,9 @@ public class GraphManagerTest {
         graph.start("Input String");
 
         String output = outputStream.toString();
-        String expected = "Node1 process: s=Input String\n" +
-            "Node2 process: s=Input String\n" +
-            "Node4 process: int=123\n";
+        String expected = "Node1 process: s=Input String" + lineSeparator +
+            "Node2 process: s=Input String" + lineSeparator +
+            "Node4 process: int=123" + lineSeparator;
 
         Assert.assertEquals(expected, output);
     }
@@ -91,7 +92,7 @@ public class GraphManagerTest {
         next.execute(123);
         String output = outputStream.toString();
         String expected =
-            "Node4 process: int=123\n";
+            "Node4 process: int=123" + lineSeparator;
 
         Assert.assertEquals(expected, output);
     }