HDFS-9185. Fix null tracer in ErasureCodingWorker. Contributed by Rakesh R.

hadoop-hdfs-project/hadoop-hdfs-client/src/main/java/org/apache/hadoop/hdfs/util/StripedBlockUtil.java

@@ -222,11 +222,14 @@ public class StripedBlockUtil {
       }
     } catch (ExecutionException e) {
       if (DFSClient.LOG.isDebugEnabled()) {
-        DFSClient.LOG.debug("ExecutionException " + e);
+        DFSClient.LOG.debug("Exception during striped read task", e);
       }
       return new StripingChunkReadResult(futures.remove(future),
           StripingChunkReadResult.FAILED);
     } catch (CancellationException e) {
+      if (DFSClient.LOG.isDebugEnabled()) {
+        DFSClient.LOG.debug("Exception during striped read task", e);
+      }
       return new StripingChunkReadResult(futures.remove(future),
           StripingChunkReadResult.CANCELLED);
     }

hadoop-hdfs-project/hadoop-hdfs/CHANGES-HDFS-EC-7285.txt

@@ -453,3 +453,5 @@
 
     HDFS-9040. Erasure coding: coordinate data streamers in
     DFSStripedOutputStream. (jing9 and Walter Su)
+
+    HDFS-9185. Fix null tracer in ErasureCodingWorker. (Rakesh R via jing9)

hadoop-hdfs-project/hadoop-hdfs/src/main/java/org/apache/hadoop/hdfs/server/datanode/BlockSender.java

@@ -707,7 +707,7 @@ class BlockSender implements java.io.Closeable {
    */
   long sendBlock(DataOutputStream out, OutputStream baseStream, 
                  DataTransferThrottler throttler) throws IOException {
-    TraceScope scope = datanode.tracer.
+    final TraceScope scope = datanode.getTracer().
         newScope("sendBlock_" + block.getBlockId());
     try {
       return doSendBlock(out, baseStream, throttler);

hadoop-hdfs-project/hadoop-hdfs/src/main/java/org/apache/hadoop/hdfs/server/datanode/DataNode.java

@@ -369,7 +369,7 @@ public class DataNode extends ReconfigurableBase
   private boolean isPermissionEnabled;
   private String dnUserName = null;
   private ErasureCodingWorker ecWorker;
-  final Tracer tracer;
+  private final Tracer tracer;
   private final TracerConfigurationManager tracerConfigurationManager;
   private static final int NUM_CORES = Runtime.getRuntime()
       .availableProcessors();
@@ -3395,4 +3395,8 @@ public class DataNode extends ReconfigurableBase
   ScheduledThreadPoolExecutor getMetricsLoggerTimer() {
     return metricsLoggerTimer;
   }
+
+  public Tracer getTracer() {
+    return tracer;
+  }
 }

hadoop-hdfs-project/hadoop-hdfs/src/main/java/org/apache/hadoop/hdfs/server/datanode/DataXceiver.java

@@ -126,7 +126,7 @@ class DataXceiver extends Receiver implements Runnable {
   
   private DataXceiver(Peer peer, DataNode datanode,
       DataXceiverServer dataXceiverServer) throws IOException {
-    super(datanode.tracer);
+    super(datanode.getTracer());
     this.peer = peer;
     this.dnConf = datanode.getDnConf();
     this.socketIn = peer.getInputStream();

hadoop-hdfs-project/hadoop-hdfs/src/main/java/org/apache/hadoop/hdfs/server/datanode/erasurecode/ErasureCodingWorker.java

@@ -50,11 +50,9 @@ import org.apache.hadoop.fs.StorageType;
 import org.apache.hadoop.hdfs.BlockReader;
 import org.apache.hadoop.hdfs.DFSConfigKeys;
 import org.apache.hadoop.hdfs.DFSPacket;
-import org.apache.hadoop.hdfs.DFSUtil;
 import org.apache.hadoop.hdfs.DFSUtilClient;
 import org.apache.hadoop.hdfs.RemoteBlockReader2;
 import org.apache.hadoop.hdfs.net.Peer;
-import org.apache.hadoop.hdfs.net.TcpPeerServer;
 import org.apache.hadoop.hdfs.protocol.DatanodeID;
 import org.apache.hadoop.hdfs.protocol.DatanodeInfo;
 import org.apache.hadoop.hdfs.protocol.ExtendedBlock;
@@ -818,7 +816,7 @@ public final class ErasureCodingWorker {
             "dummy", block, blockToken, offsetInBlock, 
             block.getNumBytes() - offsetInBlock, true,
             "", newConnectedPeer(block, dnAddr, blockToken, dnInfo), dnInfo,
-            null, cachingStrategy, null);
+            null, cachingStrategy, datanode.getTracer());
       } catch (IOException e) {
         return null;
       }

hadoop-hdfs-project/hadoop-hdfs/src/test/java/org/apache/hadoop/hdfs/TestRecoverStripedFile.java

@@ -38,7 +38,6 @@ import org.apache.hadoop.fs.Path;
 import org.apache.hadoop.hdfs.protocol.DatanodeID;
 import org.apache.hadoop.hdfs.protocol.DatanodeInfo;
 import org.apache.hadoop.hdfs.protocol.ExtendedBlock;
-import org.apache.hadoop.hdfs.protocol.HdfsConstants;
 import org.apache.hadoop.hdfs.protocol.LocatedBlocks;
 import org.apache.hadoop.hdfs.protocol.LocatedStripedBlock;
 import org.apache.hadoop.hdfs.server.blockmanagement.BlockManagerTestUtil;
@@ -50,6 +49,8 @@ import org.apache.hadoop.hdfs.server.namenode.NameNodeAdapter;
 import org.apache.hadoop.hdfs.server.protocol.DatanodeStorage;
 import org.apache.hadoop.hdfs.server.protocol.BlockECRecoveryCommand.BlockECRecoveryInfo;
 import org.apache.hadoop.hdfs.util.StripedBlockUtil;
+import org.apache.hadoop.test.GenericTestUtils;
+import org.apache.log4j.Level;
 import org.junit.After;
 import org.junit.Assert;
 import org.junit.Before;
@@ -64,7 +65,11 @@ public class TestRecoverStripedFile {
   private static final int blockSize = cellSize * 3;
   private static final int groupSize = dataBlkNum + parityBlkNum;
   private static final int dnNum = groupSize + parityBlkNum;
-  
+
+  static {
+    GenericTestUtils.setLogLevel(DFSClient.LOG, Level.ALL);
+  }
+
   private MiniDFSCluster cluster;
   private Configuration conf;
   private DistributedFileSystem fs;