HDFS-10959. Update DataNode to use DatasetVolumeChecker. Contributed by Xiaoyu Yao.

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

@@ -0,0 +1,110 @@
+/**
+ * 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
+ * <p>
+ * http://www.apache.org/licenses/LICENSE-2.0
+ * <p>
+ * 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.hadoop.classification.InterfaceAudience;
+import org.apache.hadoop.hdfs.server.datanode.fsdataset.DataNodeVolumeMetrics;
+import org.apache.hadoop.hdfs.server.datanode.fsdataset.FsVolumeSpi;
+import org.apache.hadoop.util.Time;
+
+import javax.annotation.Nullable;
+
+/**
+ * {@link FileIoEvents} that profiles the performance of the metadata and data
+ * related operations on datanode volumes.
+ */
+@InterfaceAudience.Private
+class ProfilingFileIoEvents implements FileIoEvents {
+
+  @Override
+  public long beforeMetadataOp(@Nullable FsVolumeSpi volume,
+      FileIoProvider.OPERATION op) {
+    DataNodeVolumeMetrics metrics = getVolumeMetrics(volume);
+    if (metrics != null) {
+      return Time.monotonicNow();
+    }
+    return 0;
+  }
+
+  @Override
+  public void afterMetadataOp(@Nullable FsVolumeSpi volume,
+      FileIoProvider.OPERATION op, long begin) {
+    DataNodeVolumeMetrics metrics = getVolumeMetrics(volume);
+    if (metrics != null) {
+      metrics.addMetadastaOperationLatency(Time.monotonicNow() - begin);
+    }
+  }
+
+  @Override
+  public long beforeFileIo(@Nullable FsVolumeSpi volume,
+      FileIoProvider.OPERATION op, long len) {
+    DataNodeVolumeMetrics metrics = getVolumeMetrics(volume);
+    if (metrics != null) {
+      return Time.monotonicNow();
+    }
+    return 0;
+  }
+
+  @Override
+  public void afterFileIo(@Nullable FsVolumeSpi volume,
+      FileIoProvider.OPERATION op, long begin, long len) {
+    DataNodeVolumeMetrics metrics = getVolumeMetrics(volume);
+    if (metrics != null) {
+      long latency = Time.monotonicNow() - begin;
+      metrics.addDataFileIoLatency(latency);
+      switch (op) {
+      case SYNC:
+        metrics.addSyncIoLatency(latency);
+        break;
+      case FLUSH:
+        metrics.addFlushIoLatency(latency);
+        break;
+      case READ:
+        metrics.addReadIoLatency(latency);
+        break;
+      case WRITE:
+        metrics.addWriteIoLatency(latency);
+        break;
+      default:
+      }
+    }
+  }
+
+  @Override
+  public void onFailure(@Nullable FsVolumeSpi volume,
+      FileIoProvider.OPERATION op, Exception e, long begin) {
+    DataNodeVolumeMetrics metrics = getVolumeMetrics(volume);
+    if (metrics != null) {
+      metrics.addFileIoError(Time.monotonicNow() - begin);
+    }
+  }
+
+  @Nullable
+  @Override
+  public String getStatistics() {
+    return null;
+  }
+
+  private DataNodeVolumeMetrics getVolumeMetrics(final FsVolumeSpi volume) {
+    if (volume != null) {
+      return volume.getMetrics();
+    }
+    return null;
+  }
+}

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

@@ -0,0 +1,289 @@
+/**
+ * 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.fsdataset;
+
+import org.apache.hadoop.classification.InterfaceAudience;
+import org.apache.hadoop.classification.InterfaceStability;
+import org.apache.hadoop.conf.Configuration;
+import org.apache.hadoop.hdfs.DFSConfigKeys;
+import org.apache.hadoop.metrics2.MetricsSystem;
+import org.apache.hadoop.metrics2.annotation.Metric;
+import org.apache.hadoop.metrics2.annotation.Metrics;
+import org.apache.hadoop.metrics2.lib.DefaultMetricsSystem;
+import org.apache.hadoop.metrics2.lib.MetricsRegistry;
+import org.apache.hadoop.metrics2.lib.MutableCounterLong;
+import org.apache.hadoop.metrics2.lib.MutableQuantiles;
+import org.apache.hadoop.metrics2.lib.MutableRate;
+
+import java.util.concurrent.ThreadLocalRandom;
+
+/**
+ * This class is for maintaining Datanode Volume IO related statistics and
+ * publishing them through the metrics interfaces.
+ */
+@InterfaceAudience.Private
+@InterfaceStability.Evolving
+@Metrics(name = "DataNodeVolume", about = "DataNode Volume metrics",
+    context = "dfs")
+public class DataNodeVolumeMetrics {
+  private final MetricsRegistry registry = new MetricsRegistry("FsVolume");
+
+  @Metric("number of metadata operations")
+  private MutableCounterLong totalMetadataOperations;
+  @Metric("metadata operation rate")
+  private MutableRate metadataOperationRate;
+  private MutableQuantiles[] metadataOperationLatencyQuantiles;
+
+  @Metric("number of data file io operations")
+  private MutableCounterLong totalDataFileIos;
+  @Metric("data file io operation rate")
+  private MutableRate dataFileIoRate;
+  private MutableQuantiles[] dataFileIoLatencyQuantiles;
+
+  @Metric("file io flush rate")
+  private MutableRate flushIoRate;
+  private MutableQuantiles[] flushIoLatencyQuantiles;
+
+  @Metric("file io sync rate")
+  private MutableRate syncIoRate;
+  private MutableQuantiles[] syncIoLatencyQuantiles;
+
+  @Metric("file io read rate")
+  private MutableRate readIoRate;
+  private MutableQuantiles[] readIoLatencyQuantiles;
+
+  @Metric("file io write rate")
+  private MutableRate writeIoRate;
+  private MutableQuantiles[] writeIoLatencyQuantiles;
+
+  @Metric("number of file io errors")
+  private MutableCounterLong totalFileIoErrors;
+  @Metric("file io error rate")
+  private MutableRate fileIoErrorRate;
+
+  public long getTotalMetadataOperations() {
+    return totalMetadataOperations.value();
+  }
+
+  // Based on metadataOperationRate
+  public long getMetadataOperationSampleCount() {
+    return metadataOperationRate.lastStat().numSamples();
+  }
+
+  public double getMetadataOperationMean() {
+    return metadataOperationRate.lastStat().mean();
+  }
+
+  public double getMetadataOperationStdDev() {
+    return metadataOperationRate.lastStat().stddev();
+  }
+
+  public long getTotalDataFileIos() {
+    return totalDataFileIos.value();
+  }
+
+  // Based on dataFileIoRate
+  public long getDataFileIoSampleCount() {
+    return dataFileIoRate.lastStat().numSamples();
+  }
+
+  public double getDataFileIoMean() {
+    return dataFileIoRate.lastStat().mean();
+  }
+
+  public double getDataFileIoStdDev() {
+    return dataFileIoRate.lastStat().stddev();
+  }
+
+  // Based on flushIoRate
+  public long getFlushIoSampleCount() {
+    return flushIoRate.lastStat().numSamples();
+  }
+
+  public double getFlushIoMean() {
+    return flushIoRate.lastStat().mean();
+  }
+
+  public double getFlushIoStdDev() {
+    return flushIoRate.lastStat().stddev();
+  }
+
+  // Based on syncIoRate
+  public long getSyncIoSampleCount() {
+    return syncIoRate.lastStat().numSamples();
+  }
+
+  public double getSyncIoMean() {
+    return syncIoRate.lastStat().mean();
+  }
+
+  public double getSyncIoStdDev() {
+    return syncIoRate.lastStat().stddev();
+  }
+
+  // Based on readIoRate
+  public long getReadIoSampleCount() {
+    return readIoRate.lastStat().numSamples();
+  }
+
+  public double getReadIoMean() {
+    return readIoRate.lastStat().mean();
+  }
+
+  public double getReadIoStdDev() {
+    return readIoRate.lastStat().stddev();
+  }
+
+  // Based on writeIoRate
+  public long getWriteIoSampleCount() {
+    return syncIoRate.lastStat().numSamples();
+  }
+
+  public double getWriteIoMean() {
+    return syncIoRate.lastStat().mean();
+  }
+
+  public double getWriteIoStdDev() {
+    return syncIoRate.lastStat().stddev();
+  }
+
+  public long getTotalFileIoErrors() {
+    return totalFileIoErrors.value();
+  }
+
+  // Based on fileIoErrorRate
+  public long getFileIoErrorSampleCount() {
+    return fileIoErrorRate.lastStat().numSamples();
+  }
+
+  public double getFileIoErrorMean() {
+    return fileIoErrorRate.lastStat().mean();
+  }
+
+  public double getFileIoErrorStdDev() {
+    return fileIoErrorRate.lastStat().stddev();
+  }
+
+  private final String name;
+  private final MetricsSystem ms;
+
+  public DataNodeVolumeMetrics(final MetricsSystem metricsSystem,
+      final String volumeName, final int[] intervals) {
+    this.ms = metricsSystem;
+    this.name = volumeName;
+    final int len = intervals.length;
+    metadataOperationLatencyQuantiles = new MutableQuantiles[len];
+    dataFileIoLatencyQuantiles = new MutableQuantiles[len];
+    flushIoLatencyQuantiles = new MutableQuantiles[len];
+    syncIoLatencyQuantiles = new MutableQuantiles[len];
+    readIoLatencyQuantiles = new MutableQuantiles[len];
+    writeIoLatencyQuantiles = new MutableQuantiles[len];
+    for (int i = 0; i < len; i++) {
+      int interval = intervals[i];
+      metadataOperationLatencyQuantiles[i] = registry.newQuantiles(
+          "metadataOperationLatency" + interval + "s",
+          "Meatadata Operation Latency in ms", "ops", "latency", interval);
+      dataFileIoLatencyQuantiles[i] = registry.newQuantiles(
+          "dataFileIoLatency" + interval + "s",
+          "Data File Io Latency in ms", "ops", "latency", interval);
+      flushIoLatencyQuantiles[i] = registry.newQuantiles(
+          "flushIoLatency" + interval + "s",
+          "Data flush Io Latency in ms", "ops", "latency", interval);
+      syncIoLatencyQuantiles[i] = registry.newQuantiles(
+          "syncIoLatency" + interval + "s",
+          "Data sync Io Latency in ms", "ops", "latency", interval);
+      readIoLatencyQuantiles[i] = registry.newQuantiles(
+          "readIoLatency" + interval + "s",
+          "Data read Io Latency in ms", "ops", "latency", interval);
+      writeIoLatencyQuantiles[i] = registry.newQuantiles(
+          "writeIoLatency" + interval + "s",
+          "Data write Io Latency in ms", "ops", "latency", interval);
+    }
+  }
+
+  public static DataNodeVolumeMetrics create(final Configuration conf,
+      final String volumeName) {
+    MetricsSystem ms = DefaultMetricsSystem.instance();
+    String name = "DataNodeVolume-"+ (volumeName.isEmpty()
+        ? "UndefinedDataNodeVolume"+ ThreadLocalRandom.current().nextInt()
+        : volumeName.replace(':', '-'));
+
+    // Percentile measurement is off by default, by watching no intervals
+    int[] intervals =
+        conf.getInts(DFSConfigKeys.DFS_METRICS_PERCENTILES_INTERVALS_KEY);
+    return ms.register(name, null, new DataNodeVolumeMetrics(ms, name,
+        intervals));
+  }
+
+  public String name() {
+    return name;
+  }
+
+  public void unRegister() {
+    ms.unregisterSource(name);
+  }
+
+  public void addMetadastaOperationLatency(final long latency) {
+    totalMetadataOperations.incr();
+    metadataOperationRate.add(latency);
+    for (MutableQuantiles q : metadataOperationLatencyQuantiles) {
+      q.add(latency);
+    }
+  }
+
+  public void addDataFileIoLatency(final long latency) {
+    totalDataFileIos.incr();
+    dataFileIoRate.add(latency);
+    for (MutableQuantiles q : dataFileIoLatencyQuantiles) {
+      q.add(latency);
+    }
+  }
+
+  public void addSyncIoLatency(final long latency) {
+    syncIoRate.add(latency);
+    for (MutableQuantiles q : syncIoLatencyQuantiles) {
+      q.add(latency);
+    }
+  }
+
+  public void addFlushIoLatency(final long latency) {
+    flushIoRate.add(latency);
+    for (MutableQuantiles q : flushIoLatencyQuantiles) {
+      q.add(latency);
+    }
+  }
+
+  public void addReadIoLatency(final long latency) {
+    readIoRate.add(latency);
+    for (MutableQuantiles q : readIoLatencyQuantiles) {
+      q.add(latency);
+    }
+  }
+
+  public void addWriteIoLatency(final long latency) {
+    writeIoRate.add(latency);
+    for (MutableQuantiles q: writeIoLatencyQuantiles) {
+      q.add(latency);
+    }
+  }
+
+  public void addFileIoError(final long latency) {
+    totalFileIoErrors.incr();
+    metadataOperationRate.add(latency);
+  }
+}

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

@@ -210,4 +210,6 @@ class VolumeCheckContext {
   }
 
   FileIoProvider getFileIoProvider();
+
+  DataNodeVolumeMetrics getMetrics();
 }

hadoop-hdfs-project/hadoop-hdfs/src/main/java/org/apache/hadoop/hdfs/server/datanode/fsdataset/impl/FsVolumeImpl.java

@@ -47,6 +47,7 @@
 import org.apache.hadoop.hdfs.server.datanode.FileIoProvider;
 import org.apache.hadoop.hdfs.server.datanode.BlockMetadataHeader;
 import org.apache.hadoop.hdfs.server.datanode.checker.VolumeCheckResult;
+import org.apache.hadoop.hdfs.server.datanode.fsdataset.DataNodeVolumeMetrics;
 import org.apache.hadoop.hdfs.server.datanode.fsdataset.FsDatasetSpi;
 import org.apache.hadoop.util.AutoCloseableLock;
 import org.apache.hadoop.hdfs.DFSConfigKeys;
@@ -110,6 +111,7 @@ public class FsVolumeImpl implements FsVolumeSpi {
   // query from the filesystem.
   protected volatile long configuredCapacity;
   private final FileIoProvider fileIoProvider;
+  private final DataNodeVolumeMetrics metrics;
 
   /**
    * Per-volume worker pool that processes new blocks to cache.
@@ -137,6 +139,7 @@ public class FsVolumeImpl implements FsVolumeSpi {
     this.fileIoProvider = dataset.datanode != null ?
         dataset.datanode.getFileIoProvider() : new FileIoProvider(conf);
     cacheExecutor = initializeCacheExecutor(parent);
+    this.metrics = DataNodeVolumeMetrics.create(conf, parent.getAbsolutePath());
   }
 
   protected ThreadPoolExecutor initializeCacheExecutor(File parent) {
@@ -950,6 +953,9 @@ void shutdown() {
     for (Entry<String, BlockPoolSlice> entry : set) {
       entry.getValue().shutdown(null);
     }
+    if (metrics != null) {
+      metrics.unRegister();
+    }
   }
 
   void addBlockPool(String bpid, Configuration conf) throws IOException {
@@ -1105,4 +1111,10 @@ public byte[] loadLastPartialChunkChecksum(
   public FileIoProvider getFileIoProvider() {
     return fileIoProvider;
   }
+
+
+  @Override
+  public DataNodeVolumeMetrics getMetrics() {
+    return metrics;
+  }
 }

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

@@ -22,7 +22,11 @@
 import java.io.File;
 import java.io.IOException;
 
+import org.apache.commons.logging.Log;
+import org.apache.commons.logging.LogFactory;
 import org.apache.hadoop.conf.Configuration;
+import org.apache.hadoop.conf.ReconfigurationException;
+import org.apache.hadoop.hdfs.DFSConfigKeys;
 import org.apache.hadoop.hdfs.MiniDFSCluster;
 import org.apache.hadoop.hdfs.protocol.DatanodeID;
 import org.apache.hadoop.hdfs.server.datanode.fsdataset.FsDatasetSpi;
@@ -30,12 +34,17 @@
 import org.apache.hadoop.hdfs.server.protocol.DatanodeRegistration;
 import org.apache.hadoop.hdfs.server.protocol.InterDatanodeProtocol;
 
+import static org.hamcrest.core.Is.is;
+import static org.junit.Assert.assertThat;
+
 /**
  * Utility class for accessing package-private DataNode information during tests.
  * Must not contain usage of classes that are not explicitly listed as
  * dependencies to {@link MiniDFSCluster}.
  */
 public class DataNodeTestUtils {
+  private static final Log LOG =
+      LogFactory.getLog(DataNodeTestUtils.class);
   private static final String DIR_FAILURE_SUFFIX = ".origin";
 
   public final static String TEST_CLUSTER_ID = "testClusterID";
@@ -175,4 +184,34 @@ public static void runDirectoryScanner(DataNode dn) throws IOException {
       dn.getDirectoryScanner().reconcile();
     }
   }
+
+  /**
+   * Reconfigure a DataNode by setting a new list of volumes.
+   *
+   * @param dn DataNode to reconfigure
+   * @param newVols new volumes to configure
+   * @throws Exception if there is any failure
+   */
+  public static void reconfigureDataNode(DataNode dn, File... newVols)
+      throws Exception {
+    StringBuilder dnNewDataDirs = new StringBuilder();
+    for (File newVol: newVols) {
+      if (dnNewDataDirs.length() > 0) {
+        dnNewDataDirs.append(',');
+      }
+      dnNewDataDirs.append(newVol.getAbsolutePath());
+    }
+    try {
+      assertThat(
+          dn.reconfigurePropertyImpl(
+              DFSConfigKeys.DFS_DATANODE_DATA_DIR_KEY,
+              dnNewDataDirs.toString()),
+          is(dn.getConf().get(DFSConfigKeys.DFS_DATANODE_DATA_DIR_KEY)));
+    } catch (ReconfigurationException e) {
+      // This can be thrown if reconfiguration tries to use a failed volume.
+      // We need to swallow the exception, because some of our tests want to
+      // cover this case.
+      LOG.warn("Could not reconfigure DataNode.", e);
+    }
+  }
 }

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

@@ -45,6 +45,7 @@
 import org.apache.hadoop.hdfs.protocol.ExtendedBlock;
 import org.apache.hadoop.hdfs.protocol.HdfsBlocksMetadata;
 import org.apache.hadoop.hdfs.server.common.HdfsServerConstants.ReplicaState;
+import org.apache.hadoop.hdfs.server.datanode.fsdataset.DataNodeVolumeMetrics;
 import org.apache.hadoop.hdfs.server.datanode.fsdataset.FsDatasetSpi;
 import org.apache.hadoop.hdfs.server.datanode.fsdataset.FsVolumeReference;
 import org.apache.hadoop.hdfs.server.datanode.fsdataset.FsVolumeSpi;
@@ -449,11 +450,14 @@ false, getCapacity(), getUsed(), getFree(),
   static class SimulatedVolume implements FsVolumeSpi {
     private final SimulatedStorage storage;
     private final FileIoProvider fileIoProvider;
+    private final DataNodeVolumeMetrics metrics;
 
     SimulatedVolume(final SimulatedStorage storage,
-                    final FileIoProvider fileIoProvider) {
+                    final FileIoProvider fileIoProvider,
+                    final DataNodeVolumeMetrics metrics) {
       this.storage = storage;
       this.fileIoProvider = fileIoProvider;
+      this.metrics = metrics;
     }
 
     @Override
@@ -540,6 +544,11 @@ public FileIoProvider getFileIoProvider() {
       return fileIoProvider;
     }
 
+    @Override
+    public DataNodeVolumeMetrics getMetrics() {
+      return metrics;
+    }
+
     @Override
     public VolumeCheckResult check(VolumeCheckContext context)
         throws Exception {
@@ -575,7 +584,12 @@ public SimulatedFSDataset(DataNode datanode, DataStorage storage, Configuration
     this.storage = new SimulatedStorage(
         conf.getLong(CONFIG_PROPERTY_CAPACITY, DEFAULT_CAPACITY),
         conf.getEnum(CONFIG_PROPERTY_STATE, DEFAULT_STATE));
-    this.volume = new SimulatedVolume(this.storage, this.fileIoProvider);
+
+    // TODO: per volume id or path
+    DataNodeVolumeMetrics volumeMetrics = DataNodeVolumeMetrics.create(conf,
+        datanodeUuid);
+    this.volume = new SimulatedVolume(this.storage, this.fileIoProvider,
+        volumeMetrics);
     this.datasetLock = new AutoCloseableLock();
   }
 
@@ -1393,4 +1407,3 @@ public AutoCloseableLock acquireDatasetLock() {
     return datasetLock.acquire();
   }
 }
-

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

@@ -24,7 +24,6 @@
 import static org.junit.Assert.assertEquals;
 import static org.junit.Assert.assertFalse;
 import static org.junit.Assert.assertNull;
-import static org.junit.Assert.assertThat;
 import static org.junit.Assert.assertTrue;
 import static org.junit.Assume.assumeTrue;
 
@@ -34,7 +33,6 @@
 import org.apache.commons.logging.Log;
 import org.apache.commons.logging.LogFactory;
 import org.apache.hadoop.conf.Configuration;
-import org.apache.hadoop.conf.ReconfigurationException;
 import org.apache.hadoop.fs.FileSystem;
 import org.apache.hadoop.fs.Path;
 import org.apache.hadoop.hdfs.DFSConfigKeys;
@@ -59,7 +57,8 @@
  */
 public class TestDataNodeVolumeFailureReporting {
 
-  private static final Log LOG = LogFactory.getLog(TestDataNodeVolumeFailureReporting.class);
+  private static final Log LOG =
+      LogFactory.getLog(TestDataNodeVolumeFailureReporting.class);
   {
     GenericTestUtils.setLogLevel(TestDataNodeVolumeFailureReporting.LOG,
         Level.ALL);
@@ -387,8 +386,8 @@ public void testDataNodeReconfigureWithVolumeFailures() throws Exception {
     checkFailuresAtNameNode(dm, dns.get(1), true, dn2Vol1.getAbsolutePath());
 
     // Reconfigure again to try to add back the failed volumes.
-    reconfigureDataNode(dns.get(0), dn1Vol1, dn1Vol2);
-    reconfigureDataNode(dns.get(1), dn2Vol1, dn2Vol2);
+    DataNodeTestUtils.reconfigureDataNode(dns.get(0), dn1Vol1, dn1Vol2);
+    DataNodeTestUtils.reconfigureDataNode(dns.get(1), dn2Vol1, dn2Vol2);
 
     DataNodeTestUtils.triggerHeartbeat(dns.get(0));
     DataNodeTestUtils.triggerHeartbeat(dns.get(1));
@@ -408,8 +407,8 @@ public void testDataNodeReconfigureWithVolumeFailures() throws Exception {
 
     // Reconfigure a third time with the failed volumes.  Afterwards, we expect
     // the same volume failures to be reported.  (No double-counting.)
-    reconfigureDataNode(dns.get(0), dn1Vol1, dn1Vol2);
-    reconfigureDataNode(dns.get(1), dn2Vol1, dn2Vol2);
+    DataNodeTestUtils.reconfigureDataNode(dns.get(0), dn1Vol1, dn1Vol2);
+    DataNodeTestUtils.reconfigureDataNode(dns.get(1), dn2Vol1, dn2Vol2);
 
     DataNodeTestUtils.triggerHeartbeat(dns.get(0));
     DataNodeTestUtils.triggerHeartbeat(dns.get(1));
@@ -430,8 +429,8 @@ public void testDataNodeReconfigureWithVolumeFailures() throws Exception {
     // Replace failed volume with healthy volume and run reconfigure DataNode.
     // The failed volume information should be cleared.
     DataNodeTestUtils.restoreDataDirFromFailure(dn1Vol1, dn2Vol1);
-    reconfigureDataNode(dns.get(0), dn1Vol1, dn1Vol2);
-    reconfigureDataNode(dns.get(1), dn2Vol1, dn2Vol2);
+    DataNodeTestUtils.reconfigureDataNode(dns.get(0), dn1Vol1, dn1Vol2);
+    DataNodeTestUtils.reconfigureDataNode(dns.get(1), dn2Vol1, dn2Vol2);
 
     DataNodeTestUtils.triggerHeartbeat(dns.get(0));
     DataNodeTestUtils.triggerHeartbeat(dns.get(1));
@@ -631,34 +630,4 @@ private void initCluster(int numDataNodes, int storagesPerDatanode,
         cluster.getNamesystem().getBlockManager().getDatanodeManager(), 0);
     volumeCapacity = dnCapacity / cluster.getStoragesPerDatanode();
   }
-
-  /**
-   * Reconfigure a DataNode by setting a new list of volumes.
-   *
-   * @param dn DataNode to reconfigure
-   * @param newVols new volumes to configure
-   * @throws Exception if there is any failure
-   */
-  private static void reconfigureDataNode(DataNode dn, File... newVols)
-      throws Exception {
-    StringBuilder dnNewDataDirs = new StringBuilder();
-    for (File newVol: newVols) {
-      if (dnNewDataDirs.length() > 0) {
-        dnNewDataDirs.append(',');
-      }
-      dnNewDataDirs.append(newVol.getAbsolutePath());
-    }
-    try {
-      assertThat(
-          dn.reconfigurePropertyImpl(
-              DFSConfigKeys.DFS_DATANODE_DATA_DIR_KEY,
-              dnNewDataDirs.toString()),
-          is(dn.getConf().get(DFSConfigKeys.DFS_DATANODE_DATA_DIR_KEY)));
-    } catch (ReconfigurationException e) {
-      // This can be thrown if reconfiguration tries to use a failed volume.
-      // We need to swallow the exception, because some of our tests want to
-      // cover this case.
-      LOG.warn("Could not reconfigure DataNode.", e);
-    }
-  }
 }

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

@@ -0,0 +1,182 @@
+/**
+ * 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 static org.apache.hadoop.test.MetricsAsserts.assertCounter;
+import static org.apache.hadoop.test.MetricsAsserts.getMetrics;
+import static org.junit.Assert.assertTrue;
+
+import java.io.File;
+import java.io.IOException;
+import java.util.ArrayList;
+import java.util.List;
+
+import org.apache.commons.logging.Log;
+import org.apache.commons.logging.LogFactory;
+import org.apache.hadoop.conf.Configuration;
+import org.apache.hadoop.fs.FSDataOutputStream;
+import org.apache.hadoop.fs.FileSystem;
+import org.apache.hadoop.fs.Path;
+import org.apache.hadoop.fs.StorageType;
+import org.apache.hadoop.hdfs.DFSConfigKeys;
+import org.apache.hadoop.hdfs.DFSOutputStream;
+import org.apache.hadoop.hdfs.DFSTestUtil;
+import org.apache.hadoop.hdfs.HdfsConfiguration;
+import org.apache.hadoop.hdfs.MiniDFSCluster;
+import org.apache.hadoop.hdfs.protocol.ExtendedBlock;
+import org.apache.hadoop.hdfs.server.datanode.fsdataset.DataNodeVolumeMetrics;
+import org.apache.hadoop.hdfs.server.datanode.fsdataset.FsVolumeSpi;
+import org.apache.hadoop.metrics2.MetricsRecordBuilder;
+import org.junit.Rule;
+import org.junit.Test;
+import org.junit.rules.Timeout;
+
+/**
+ * Test class for DataNodeVolumeMetrics.
+ */
+public class TestDataNodeVolumeMetrics {
+  private static final Log LOG =
+      LogFactory.getLog(TestDataNodeVolumeMetrics.class);
+
+  private static final int BLOCK_SIZE = 1024;
+  private static final short REPL = 1;
+  private static final int NUM_DATANODES = 1;
+
+  @Rule
+  public Timeout timeout = new Timeout(300000);
+
+  @Test
+  public void testVolumeMetrics() throws Exception {
+    MiniDFSCluster cluster = setupClusterForVolumeMetrics();
+    try {
+      FileSystem fs = cluster.getFileSystem();
+      final Path fileName = new Path("/test.dat");
+      final long fileLen = Integer.MAX_VALUE + 1L;
+      DFSTestUtil.createFile(fs, fileName, false, BLOCK_SIZE, fileLen,
+          fs.getDefaultBlockSize(fileName),
+          REPL, 1L, true);
+
+      try (FSDataOutputStream out = fs.append(fileName)) {
+        out.writeBytes("hello world");
+        ((DFSOutputStream) out.getWrappedStream()).hsync();
+      }
+
+      verifyDataNodeVolumeMetrics(fs, cluster, fileName);
+    } finally {
+      if (cluster != null) {
+        cluster.shutdown();
+      }
+    }
+  }
+
+  @Test
+  public void testVolumeMetricsWithVolumeDepartureArrival() throws Exception {
+    MiniDFSCluster cluster = setupClusterForVolumeMetrics();
+    try {
+      FileSystem fs = cluster.getFileSystem();
+      final Path fileName = new Path("/test.dat");
+      final long fileLen = Integer.MAX_VALUE + 1L;
+      DFSTestUtil.createFile(fs, fileName, false, BLOCK_SIZE, fileLen,
+          fs.getDefaultBlockSize(fileName),
+          REPL, 1L, true);
+
+      try (FSDataOutputStream out = fs.append(fileName)) {
+        out.writeBytes("hello world");
+        ((DFSOutputStream) out.getWrappedStream()).hsync();
+      }
+
+      ArrayList<DataNode> dns = cluster.getDataNodes();
+      assertTrue("DN1 should be up", dns.get(0).isDatanodeUp());
+
+      final String dataDir = cluster.getDataDirectory();
+      final File dn1Vol2 = new File(dataDir, "data2");
+
+      DataNodeTestUtils.injectDataDirFailure(dn1Vol2);
+      verifyDataNodeVolumeMetrics(fs, cluster, fileName);
+
+      DataNodeTestUtils.restoreDataDirFromFailure(dn1Vol2);
+      DataNodeTestUtils.reconfigureDataNode(dns.get(0), dn1Vol2);
+      verifyDataNodeVolumeMetrics(fs, cluster, fileName);
+    } finally {
+      if (cluster != null) {
+        cluster.shutdown();
+      }
+    }
+  }
+
+  private MiniDFSCluster setupClusterForVolumeMetrics() throws IOException {
+    Configuration conf = new HdfsConfiguration();
+    conf.set(DFSConfigKeys.DFS_DATANODE_FILE_IO_EVENTS_CLASS_KEY,
+        "org.apache.hadoop.hdfs.server.datanode.ProfilingFileIoEvents");
+    SimulatedFSDataset.setFactory(conf);
+    return new MiniDFSCluster.Builder(conf)
+        .numDataNodes(NUM_DATANODES)
+        .storageTypes(new StorageType[]{StorageType.RAM_DISK, StorageType.DISK})
+        .storagesPerDatanode(2)
+        .build();
+  }
+
+  private void verifyDataNodeVolumeMetrics(final FileSystem fs,
+      final MiniDFSCluster cluster, final Path fileName) throws IOException {
+    List<DataNode> datanodes = cluster.getDataNodes();
+    DataNode datanode = datanodes.get(0);
+
+    final ExtendedBlock block = DFSTestUtil.getFirstBlock(fs, fileName);
+    final FsVolumeSpi volume = datanode.getFSDataset().getVolume(block);
+    DataNodeVolumeMetrics metrics = volume.getMetrics();
+
+    MetricsRecordBuilder rb = getMetrics(volume.getMetrics().name());
+    assertCounter("TotalDataFileIos", metrics.getTotalDataFileIos(), rb);
+
+    LOG.info("TotalMetadataOperations : " +
+        metrics.getTotalMetadataOperations());
+    LOG.info("TotalDataFileIos : " + metrics.getTotalDataFileIos());
+    LOG.info("TotalFileIoErrors : " + metrics.getTotalFileIoErrors());
+
+    LOG.info("MetadataOperationSampleCount : " +
+        metrics.getMetadataOperationSampleCount());
+    LOG.info("MetadataOperationMean : " + metrics.getMetadataOperationMean());
+    LOG.info("MetadataFileIoStdDev : " +
+        metrics.getMetadataOperationStdDev());
+
+    LOG.info("DataFileIoSampleCount : " + metrics.getDataFileIoSampleCount());
+    LOG.info("DataFileIoMean : " + metrics.getDataFileIoMean());
+    LOG.info("DataFileIoStdDev : " + metrics.getDataFileIoStdDev());
+
+    LOG.info("flushIoSampleCount : " + metrics.getFlushIoSampleCount());
+    LOG.info("flushIoMean : " + metrics.getFlushIoMean());
+    LOG.info("flushIoStdDev : " + metrics.getFlushIoStdDev());
+
+    LOG.info("syncIoSampleCount : " + metrics.getSyncIoSampleCount());
+    LOG.info("syncIoMean : " + metrics.getSyncIoMean());
+    LOG.info("syncIoStdDev : " + metrics.getSyncIoStdDev());
+
+    LOG.info("readIoSampleCount : " + metrics.getReadIoMean());
+    LOG.info("readIoMean : " + metrics.getReadIoMean());
+    LOG.info("readIoStdDev : " + metrics.getReadIoStdDev());
+
+    LOG.info("writeIoSampleCount : " + metrics.getWriteIoSampleCount());
+    LOG.info("writeIoMean : " + metrics.getWriteIoMean());
+    LOG.info("writeIoStdDev : " + metrics.getWriteIoStdDev());
+
+    LOG.info("fileIoErrorSampleCount : "
+        + metrics.getFileIoErrorSampleCount());
+    LOG.info("fileIoErrorMean : " + metrics.getFileIoErrorMean());
+    LOG.info("fileIoErrorStdDev : " + metrics.getFileIoErrorStdDev());
+  }
+}

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

@@ -53,6 +53,9 @@
 import org.apache.hadoop.hdfs.HdfsConfiguration;
 import org.apache.hadoop.hdfs.MiniDFSCluster;
 import org.apache.hadoop.hdfs.server.datanode.checker.VolumeCheckResult;
+import org.apache.hadoop.hdfs.server.datanode.fsdataset.DataNodeVolumeMetrics;
+import org.apache.hadoop.util.AutoCloseableLock;
+import org.apache.hadoop.util.AutoCloseableLock;
 import org.apache.hadoop.hdfs.protocol.Block;
 import org.apache.hadoop.hdfs.protocol.HdfsConstants;
 import org.apache.hadoop.hdfs.protocol.LocatedBlock;
@@ -891,6 +894,11 @@ public FileIoProvider getFileIoProvider() {
       return null;
     }
 
+    @Override
+    public DataNodeVolumeMetrics getMetrics() {
+      return null;
+    }
+
     @Override
     public VolumeCheckResult check(VolumeCheckContext context)
         throws Exception {

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

@@ -25,6 +25,7 @@
 import org.apache.hadoop.fs.StorageType;
 import org.apache.hadoop.hdfs.server.datanode.FileIoProvider;
 import org.apache.hadoop.hdfs.server.datanode.checker.VolumeCheckResult;
+import org.apache.hadoop.hdfs.server.datanode.fsdataset.DataNodeVolumeMetrics;
 import org.apache.hadoop.hdfs.server.datanode.fsdataset.FsDatasetSpi;
 import org.apache.hadoop.hdfs.server.datanode.fsdataset.FsVolumeReference;
 import org.apache.hadoop.hdfs.server.datanode.fsdataset.FsVolumeSpi;
@@ -115,6 +116,11 @@ public FileIoProvider getFileIoProvider() {
     return null;
   }
 
+  @Override
+  public DataNodeVolumeMetrics getMetrics() {
+    return null;
+  }
+
   @Override
   public VolumeCheckResult check(VolumeCheckContext context)
       throws Exception {