1. 移除在static的时候获取初始化sender

2. 修复ParentLevel为null判断

skywalking-api/src/main/java/com/ai/cloud/skywalking/model/ContextData.java

@@ -54,7 +54,7 @@ public class ContextData {
         StringBuilder stringBuilder = new StringBuilder();
         stringBuilder.append(traceId);
         stringBuilder.append("-");
-        if (parentLevel != null && parentLevel.length() > 0) {
+        if (parentLevel == null || parentLevel.length() == 0) {
             stringBuilder.append(" ");
         } else {
             stringBuilder.append(parentLevel);

skywalking-api/src/main/java/com/ai/cloud/skywalking/sender/DataSenderFactoryWithBalance.java

@@ -62,23 +62,6 @@ public class DataSenderFactoryWithBalance {
                     * Config.Buffer.POOL_SIZE;
         }
 
-		// 初始化的发送程序
-		int index = 0;
-		while (usingDataSender.size() < maxKeepConnectingSenderSize) {
-			index = ThreadLocalRandom.current().nextInt(0,
-					unusedServerAddresses.size());
-			try {
-				usingDataSender.add(new DataSender(unusedServerAddresses
-						.get(index)));
-				unusedServerAddresses.remove(index);
-			} catch (IOException e) {
-				// 服务器连接不上
-				logger.log(Level.SEVERE, "Failed to connect server["
-						+ unusedServerAddresses.get(index).getHostName() + "]");
-				continue;
-			}
-		}
-
         new DataSenderChecker().start();
     }
 
@@ -87,26 +70,20 @@ public class DataSenderFactoryWithBalance {
         DataSenderWithCopies readySender = new DataSenderWithCopies(maxKeepConnectingSenderSize);
         while (true) {
             try {
-				if (usingDataSender.size() == 0) {
-					try {
-						Thread.sleep(RETRY_GET_SENDER_WAIT_INTERVAL);
-					} catch (InterruptedException e) {
-						logger.log(Level.ALL, "Sleep failed");
-					}
-				}
-
+                if (usingDataSender.size() > 0) {
                     int index = ThreadLocalRandom.current().nextInt(0,
                             usingDataSender.size());
                     if (usingDataSender.get(index).getStatus() == DataSender.SenderStatus.READY) {
-					while(readySender.append(usingDataSender.get(index))){
-						if(++index == usingDataSender.size()){
+                        while (readySender.append(usingDataSender.get(index))) {
+                            if (++index == usingDataSender.size()) {
                                 index = 0;
                             }
                         }
                         break;
                     }
+                }
 
-				if (readySender == null) {
+                if (!readySender.isReady()) {
                     try {
                         Thread.sleep(RETRY_GET_SENDER_WAIT_INTERVAL);
                     } catch (InterruptedException e) {
@@ -209,10 +186,19 @@ public class DataSenderFactoryWithBalance {
     }
 
     private static DataSender findReadySender() {
+
         DataSender result = null;
-		for (InetSocketAddress serverAddress : unusedServerAddresses) {
+        int index = ThreadLocalRandom.current().nextInt(0,
+                unusedServerAddresses.size());
+        for (int i = 0; i < unusedServerAddresses.size();i++, index++) {
+
+            if(index == unusedServerAddresses.size()){
+                index = 0;
+            }
+
             try {
-				result = new DataSender(serverAddress);
+                result = new DataSender(unusedServerAddresses.get(index));
+                unusedServerAddresses.remove(index);
                 break;
             } catch (IOException e) {
                 if (result != null) {
@@ -221,6 +207,7 @@ public class DataSenderFactoryWithBalance {
                 continue;
             }
         }
+
         return result;
     }
 

skywalking-api/src/main/java/com/ai/cloud/skywalking/sender/DataSenderWithCopies.java

@@ -37,6 +37,11 @@ public class DataSenderWithCopies implements IDataSender {
 		return senders.size() < maxCopyNum;
 	}
 
+	boolean isReady(){
+		return senders.size() > 0 ;
+	}
+
+
 	/**
 	 * 尝试向所有副本发送
 	 */