HDFS-8449. Add tasks count metrics to datanode for ECWorker. Contributed by Bo Li.

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

@@ -179,11 +179,11 @@ class StripedReconstructor implements Runnable {
       // block replication.
     } catch (Throwable e) {
       LOG.warn("Failed to reconstruct striped block: {}", blockGroup, e);
+      datanode.getMetrics().incrECFailedReconstructionTasks();
     } finally {
       datanode.decrementXmitsInProgress();
-
+      datanode.getMetrics().incrECReconstructionTasks();
       stripedReader.close();
-
       stripedWriter.close();
     }
   }

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

@@ -126,6 +126,11 @@ public class DataNodeMetrics {
   @Metric MutableRate sendDataPacketTransferNanos;
   final MutableQuantiles[] sendDataPacketTransferNanosQuantiles;
 
+  @Metric("Count of erasure coding reconstruction tasks")
+  MutableCounterLong ecReconstructionTasks;
+  @Metric("Count of erasure coding failed reconstruction tasks")
+  MutableCounterLong ecFailedReconstructionTasks;
+
   final MetricsRegistry registry = new MetricsRegistry("datanode");
   final String name;
   JvmMetrics jvmMetrics = null;
@@ -415,4 +420,13 @@ public class DataNodeMetrics {
       q.add(latencyMs);
     }
   }
+
+  public void incrECReconstructionTasks() {
+    ecReconstructionTasks.incr();
+  }
+
+  public void incrECFailedReconstructionTasks() {
+    ecFailedReconstructionTasks.incr();
+  }
+
 }

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

@@ -74,7 +74,7 @@ public class StripedFileTestUtil {
   static int numDNs = NUM_DATA_BLOCKS + NUM_PARITY_BLOCKS + 2;
   static int BLOCK_GROUP_SIZE = blockSize * NUM_DATA_BLOCKS;
 
-  static byte[] generateBytes(int cnt) {
+  public static byte[] generateBytes(int cnt) {
     byte[] bytes = new byte[cnt];
     for (int i = 0; i < cnt; i++) {
       bytes[i] = getByte(i);
@@ -502,4 +502,34 @@ public class StripedFileTestUtil {
       }
     }
   }
+
+  /**
+   * Wait for the reconstruction to be finished when the file has
+   * corrupted blocks.
+   */
+  public static LocatedBlocks waitForReconstructionFinished(Path file,
+                                  DistributedFileSystem fs, int groupSize)
+      throws Exception {
+    final int attempts = 60;
+    for (int i = 0; i < attempts; i++) {
+      LocatedBlocks locatedBlocks = getLocatedBlocks(file, fs);
+      LocatedStripedBlock lastBlock =
+          (LocatedStripedBlock)locatedBlocks.getLastLocatedBlock();
+      DatanodeInfo[] storageInfos = lastBlock.getLocations();
+      if (storageInfos.length >= groupSize) {
+        return locatedBlocks;
+      }
+      Thread.sleep(1000);
+    }
+    throw new IOException("Time out waiting for EC block reconstruction.");
+  }
+
+  /**
+   * Get the located blocks of a file.
+   */
+  public static LocatedBlocks getLocatedBlocks(Path file,
+                                               DistributedFileSystem fs)
+      throws IOException {
+    return fs.getClient().getLocatedBlocks(file.toString(), 0, Long.MAX_VALUE);
+  }
 }

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

@@ -269,7 +269,8 @@ public class TestReconstructStripedFile {
     DFSTestUtil.writeFile(fs, file, data);
     StripedFileTestUtil.waitBlockGroupsReported(fs, fileName);
 
-    LocatedBlocks locatedBlocks = getLocatedBlocks(file);
+    LocatedBlocks locatedBlocks =
+        StripedFileTestUtil.getLocatedBlocks(file, fs);
     assertEquals(locatedBlocks.getFileLength(), fileLen);
 
     LocatedStripedBlock lastBlock =
@@ -325,7 +326,7 @@ public class TestReconstructStripedFile {
     int stoppedDN = generateErrors(errorMap, type);
 
     // Check the locatedBlocks of the file again
-    locatedBlocks = getLocatedBlocks(file);
+    locatedBlocks = StripedFileTestUtil.getLocatedBlocks(file, fs);
     lastBlock = (LocatedStripedBlock)locatedBlocks.getLastLocatedBlock();
     storageInfos = lastBlock.getLocations();
     assertEquals(storageInfos.length, groupSize - stoppedDN);
@@ -338,7 +339,7 @@ public class TestReconstructStripedFile {
       }
     }
 
-    waitForReconstructionFinished(file, groupSize);
+    StripedFileTestUtil.waitForReconstructionFinished(file, fs, groupSize);
 
     targetDNs = sortTargetsByReplicas(blocks, targetDNs);
 
@@ -381,26 +382,6 @@ public class TestReconstructStripedFile {
     return result;
   }
 
-  private LocatedBlocks waitForReconstructionFinished(Path file, int groupSize)
-      throws Exception {
-    final int ATTEMPTS = 60;
-    for (int i = 0; i < ATTEMPTS; i++) {
-      LocatedBlocks locatedBlocks = getLocatedBlocks(file);
-      LocatedStripedBlock lastBlock =
-          (LocatedStripedBlock)locatedBlocks.getLastLocatedBlock();
-      DatanodeInfo[] storageInfos = lastBlock.getLocations();
-      if (storageInfos.length >= groupSize) {
-        return locatedBlocks;
-      }
-      Thread.sleep(1000);
-    }
-    throw new IOException ("Time out waiting for EC block reconstruction.");
-  }
-
-  private LocatedBlocks getLocatedBlocks(Path file) throws IOException {
-    return fs.getClient().getLocatedBlocks(file.toString(), 0, Long.MAX_VALUE);
-  }
-
   /*
    * Tests that processErasureCodingTasks should not throw exceptions out due to
    * invalid ECTask submission.

hadoop-hdfs-project/hadoop-hdfs/src/test/java/org/apache/hadoop/hdfs/server/datanode/TestDataNodeErasureCodingMetrics.java

@@ -0,0 +1,153 @@
+/**
+ * Licensed to the Apache Software Foundation (ASF) under one
+ * or more contributor license agreements.  See the NOTICE file
+ * distributed with this work for additional information
+ * regarding copyright ownership.  The ASF licenses this file
+ * to you under the Apache License, Version 2.0 (the
+ * "License"); you may not use this file except in compliance
+ * with the License.  You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package org.apache.hadoop.hdfs.server.datanode;
+
+import org.apache.commons.logging.Log;
+import org.apache.commons.logging.LogFactory;
+import org.apache.hadoop.conf.Configuration;
+import org.apache.hadoop.fs.Path;
+import org.apache.hadoop.hdfs.DFSConfigKeys;
+import org.apache.hadoop.hdfs.DFSTestUtil;
+import org.apache.hadoop.hdfs.DistributedFileSystem;
+import org.apache.hadoop.hdfs.MiniDFSCluster;
+import org.apache.hadoop.hdfs.StripedFileTestUtil;
+import org.apache.hadoop.hdfs.protocol.DatanodeID;
+import org.apache.hadoop.hdfs.protocol.DatanodeInfo;
+import org.apache.hadoop.hdfs.protocol.LocatedBlocks;
+import org.apache.hadoop.hdfs.protocol.LocatedStripedBlock;
+import org.apache.hadoop.hdfs.server.blockmanagement.BlockManager;
+import org.apache.hadoop.hdfs.server.blockmanagement.BlockManagerTestUtil;
+import org.apache.hadoop.hdfs.server.blockmanagement.DatanodeDescriptor;
+import org.apache.hadoop.hdfs.server.namenode.NameNodeAdapter;
+import org.apache.hadoop.metrics2.MetricsRecordBuilder;
+import static org.apache.hadoop.test.MetricsAsserts.assertCounter;
+import static org.apache.hadoop.test.MetricsAsserts.getMetrics;
+import static org.junit.Assert.assertEquals;
+
+import org.junit.After;
+import org.junit.Before;
+import org.junit.Test;
+
+import java.io.IOException;
+
+
+/**
+ * This file tests the erasure coding metrics in DataNode.
+ */
+public class TestDataNodeErasureCodingMetrics {
+  public static final Log LOG = LogFactory.
+      getLog(TestDataNodeErasureCodingMetrics.class);
+
+  private static final int DATA_BLK_NUM = StripedFileTestUtil.NUM_DATA_BLOCKS;
+  private static final int PARITY_BLK_NUM =
+      StripedFileTestUtil.NUM_PARITY_BLOCKS;
+  private static final int CELLSIZE =
+      StripedFileTestUtil.BLOCK_STRIPED_CELL_SIZE;
+  private static final int BLOCKSIZE = CELLSIZE;
+  private static final int GROUPSIZE = DATA_BLK_NUM + PARITY_BLK_NUM;
+  private static final int DN_NUM = GROUPSIZE + 1;
+
+  private MiniDFSCluster cluster;
+  private Configuration conf;
+  private DistributedFileSystem fs;
+
+  @Before
+  public void setup() throws IOException {
+    conf = new Configuration();
+
+    conf.setLong(DFSConfigKeys.DFS_BLOCK_SIZE_KEY, BLOCKSIZE);
+    conf.setInt(DFSConfigKeys.DFS_NAMENODE_REPLICATION_INTERVAL_KEY, 1);
+    cluster = new MiniDFSCluster.Builder(conf).numDataNodes(DN_NUM).build();
+    cluster.waitActive();
+    cluster.getFileSystem().getClient().setErasureCodingPolicy("/", null);
+    fs = cluster.getFileSystem();
+  }
+
+  @After
+  public void tearDown() {
+    if (cluster != null) {
+      cluster.shutdown();
+    }
+  }
+
+  @Test(timeout = 120000)
+  public void testEcTasks() throws Exception {
+    DataNode workerDn = doTest("/testEcTasks");
+    MetricsRecordBuilder rb = getMetrics(workerDn.getMetrics().name());
+    assertCounter("EcReconstructionTasks", (long) 1, rb);
+    assertCounter("EcFailedReconstructionTasks", (long) 0, rb);
+  }
+
+  private DataNode doTest(String fileName) throws Exception {
+
+    Path file = new Path(fileName);
+    long fileLen = DATA_BLK_NUM * BLOCKSIZE;
+    final byte[] data = StripedFileTestUtil.generateBytes((int) fileLen);
+    DFSTestUtil.writeFile(fs, file, data);
+    StripedFileTestUtil.waitBlockGroupsReported(fs, fileName);
+
+    LocatedBlocks locatedBlocks =
+        StripedFileTestUtil.getLocatedBlocks(file, fs);
+    //only one block group
+    LocatedStripedBlock lastBlock =
+        (LocatedStripedBlock)locatedBlocks.getLastLocatedBlock();
+    DataNode workerDn = null;
+    DatanodeInfo[] locations = lastBlock.getLocations();
+    assertEquals(locations.length, GROUPSIZE);
+    // we have ONE extra datanode in addition to the GROUPSIZE datanodes, here
+    // is to find the extra datanode that the reconstruction task will run on,
+    // according to the current block placement logic for striped files.
+    // This can be improved later to be flexible regardless wherever the task
+    // runs.
+    for (DataNode dn: cluster.getDataNodes()) {
+      boolean appear = false;
+      for (DatanodeInfo info: locations) {
+        if (dn.getDatanodeUuid().equals(info.getDatanodeUuid())) {
+          appear = true;
+          break;
+        }
+      }
+      if(!appear) {
+        workerDn = dn;
+        break;
+      }
+    }
+    byte[] indices = lastBlock.getBlockIndices();
+    //corrupt the first block
+    DataNode toCorruptDn = cluster.getDataNodes().get(indices[0]);
+    toCorruptDn.shutdown();
+    setDataNodeDead(toCorruptDn.getDatanodeId());
+    DFSTestUtil.waitForDatanodeState(cluster, toCorruptDn.getDatanodeUuid(),
+        false, 10000 );
+    final BlockManager bm = cluster.getNamesystem().getBlockManager();
+    BlockManagerTestUtil.getComputedDatanodeWork(bm);
+    cluster.triggerHeartbeats();
+    StripedFileTestUtil.waitForReconstructionFinished(file, fs, GROUPSIZE);
+
+    return workerDn;
+  }
+
+  private void setDataNodeDead(DatanodeID dnID) throws IOException {
+    DatanodeDescriptor dnd =
+        NameNodeAdapter.getDatanode(cluster.getNamesystem(), dnID);
+    DFSTestUtil.setDatanodeDead(dnd);
+    BlockManagerTestUtil.checkHeartbeat(
+        cluster.getNamesystem().getBlockManager());
+  }
+
+}