diff --git a/README.md b/README.md
index 2ab9f4090..3f649683f 100644
--- a/README.md
+++ b/README.md
@@ -8,7 +8,8 @@ SkyWalking-Distributed Application Tracing System, 是一个对JAVA应用程序
 * 张鑫   [亚信](http://www.asiainfo.com/) zhangxin10@asiainfo.com
 
 # 交流群
-QQ群：392443393，请注明“Sky Walking交流”
+* QQ群：392443393，请注明“Sky Walking交流”
+* 请各位使用者反馈下，都在哪些项目中使用。[点击进入](https://github.com/wu-sheng/sky-walking/issues/34)
 
 # 整体架构图
 ![整体架构图](http://wu-sheng.github.io/sky-walking/sample-code/images/skywalkingClusterDeploy.jpeg)
diff --git a/skywalking-api/src/main/java/com/ai/cloud/skywalking/buffer/ContextBuffer.java b/skywalking-api/src/main/java/com/ai/cloud/skywalking/buffer/ContextBuffer.java
index fd2321af6..a45317af2 100644
--- a/skywalking-api/src/main/java/com/ai/cloud/skywalking/buffer/ContextBuffer.java
+++ b/skywalking-api/src/main/java/com/ai/cloud/skywalking/buffer/ContextBuffer.java
@@ -4,9 +4,13 @@ import com.ai.cloud.skywalking.protocol.Span;
 
 import java.util.concurrent.ThreadLocalRandom;
 
+import org.apache.logging.log4j.LogManager;
+import org.apache.logging.log4j.Logger;
+
 import static com.ai.cloud.skywalking.conf.Config.Buffer.POOL_SIZE;
 
 public class ContextBuffer {
+	private static Logger logger = LogManager.getLogger(ContextBuffer.class);
 
     private static BufferPool pool = new BufferPool();
 
@@ -15,7 +19,11 @@ public class ContextBuffer {
     }
 
     public static void save(Span span) {
-        pool.save(span);
+    	try{
+    		pool.save(span);
+    	}catch(Throwable t){
+    		logger.error("save span error.", t);
+    	}
     }
 
 
diff --git a/skywalking-protocol/src/main/java/com/ai/cloud/skywalking/util/AtomicRangeInteger.java b/skywalking-protocol/src/main/java/com/ai/cloud/skywalking/util/AtomicRangeInteger.java
index bf1fe360d..ac69b97ce 100644
--- a/skywalking-protocol/src/main/java/com/ai/cloud/skywalking/util/AtomicRangeInteger.java
+++ b/skywalking-protocol/src/main/java/com/ai/cloud/skywalking/util/AtomicRangeInteger.java
@@ -21,11 +21,14 @@ public class AtomicRangeInteger extends Number implements java.io.Serializable {
 	 *
 	 * @param initialValue
 	 *            the initial value
+	 * @param endValue
+	 * 
+	 * AtomicRangeInteger在startValue和maxValue循环取值（ startValue <= value <  maxValue）
 	 */
-	public AtomicRangeInteger(int startValue, int endValue) {
+	public AtomicRangeInteger(int startValue, int maxValue) {
 		value = new AtomicInteger(startValue);
 		this.startValue = startValue;
-		this.endValue = endValue;
+		this.endValue = maxValue - 1;
 	}
 
 	/**
@@ -35,11 +38,8 @@ public class AtomicRangeInteger extends Number implements java.io.Serializable {
 	 */
 	public final int getAndIncrement() {
 		for (;;) {
-			int current = get();
-			int next = current + 1;
-			if (next >= this.endValue) {
-				next = this.startValue;
-			}
+			int current = value.get();
+			int next = current >= this.endValue ? this.startValue : current + 1;
 			if (value.compareAndSet(current, next))
 				return current;
 		}
diff --git a/skywalking-protocol/src/test/java/test/ai/cloud/skywalking/util/AtomicRangeIntegerTest.java b/skywalking-protocol/src/test/java/test/ai/cloud/skywalking/util/AtomicRangeIntegerTest.java
index c3e9330d2..bbaeeb392 100644
--- a/skywalking-protocol/src/test/java/test/ai/cloud/skywalking/util/AtomicRangeIntegerTest.java
+++ b/skywalking-protocol/src/test/java/test/ai/cloud/skywalking/util/AtomicRangeIntegerTest.java
@@ -9,6 +9,10 @@ import junit.framework.TestCase;
 import com.ai.cloud.skywalking.util.AtomicRangeInteger;
 
 public class AtomicRangeIntegerTest extends TestCase{
+	static String[] buffer = new String[5000];
+	
+	static AtomicRangeInteger ari = new AtomicRangeInteger(0, buffer.length);
+	
 	public void testGet(){
 		AtomicRangeInteger ari = new AtomicRangeInteger(0, 12);
 		for(int i = 0; i < 51; i++){
@@ -36,22 +40,20 @@ public class AtomicRangeIntegerTest extends TestCase{
 }
 
 class RangeIntegerThread extends Thread{
-	private static String[] buffer = new String[500000000];
-	
-	private static AtomicRangeInteger ari = new AtomicRangeInteger(0, buffer.length);
-	
 	@Override
 	public void run(){
 		while(true){
-			int i = ari.getAndIncrement();
+			int i = AtomicRangeIntegerTest.ari.getAndIncrement();
 			if(i % 10000000 == 0){
-				System.out.println(ari.get());
+				System.out.println(AtomicRangeIntegerTest.ari.get());
 			}
-			if(i >= buffer.length - 100000){
+			if(AtomicRangeIntegerTest.buffer[i] != null){
+				System.out.println("end at index:" + i + "," + AtomicRangeIntegerTest.buffer[i]);
 				break;
+			}else{
+				System.out.println("at index:" + i);
+				AtomicRangeIntegerTest.buffer[i] = "string";
 			}
-			Assert.assertNull(buffer[i]);
-			buffer[i] = "string";
 		}
 	}
 }