HDFS-12131. Add some of the FSNamesystem JMX values as metrics. Contributed by Erik Krogen.

(cherry picked from commit f4c6b00a9f48ae7667db4035b641769efc3bb7cf)

hadoop-common-project/hadoop-common/src/site/markdown/Metrics.md

@@ -230,7 +230,15 @@ Each metrics record contains tags such as HAState and Hostname as additional inf
 | `PendingDataNodeMessageCourt` | (HA-only) Current number of pending block-related messages for later processing in the standby NameNode |
 | `MillisSinceLastLoadedEdits` | (HA-only) Time in milliseconds since the last time standby NameNode load edit log. In active NameNode, set to 0 |
 | `BlockCapacity` | Current number of block capacity |
+| `NumLiveDataNodes` | Number of datanodes which are currently live |
+| `NumDeadDataNodes` | Number of datanodes which are currently dead |
+| `NumDecomLiveDataNodes` | Number of datanodes which have been decommissioned and are now live |
+| `NumDecomDeadDataNodes` | Number of datanodes which have been decommissioned and are now dead |
+| `NumDecommissioningDataNodes` | Number of datanodes in decommissioning state |
+| `VolumeFailuresTotal` | Total number of volume failures across all Datanodes |
+| `EstimatedCapacityLostTotal` | An estimate of the total capacity lost due to volume failures |
 | `StaleDataNodes` | Current number of DataNodes marked stale due to delayed heartbeat |
+| `NumStaleStorages` | Number of storages marked as content stale (after NameNode restart/failover before first block report is received) |
 | `TotalFiles` | Current number of files and directories (same as FilesTotal) |
 | `LockQueueLength` | Number of threads waiting to acquire FSNameSystem lock |
 

hadoop-hdfs-project/hadoop-hdfs/CHANGES.txt

@@ -12,6 +12,9 @@ Release 2.7.5 - UNRELEASED
 
     HDFS-8797. WebHdfsFileSystem creates too many connections for pread. (jing9)
 
+    HDFS-12131. Add some of the FSNamesystem JMX values as metrics.
+    (Erik Krogen via wang, shv)
+
   OPTIMIZATIONS
 
   BUG FIXES

hadoop-hdfs-project/hadoop-hdfs/src/main/java/org/apache/hadoop/hdfs/server/namenode/FSNamesystem.java

@@ -6030,16 +6030,20 @@ public class FSNamesystem implements Namesystem, FSNamesystemMBean,
   }
 
   @Override // FSNamesystemMBean
+  @Metric({"NumLiveDataNodes", "Number of datanodes which are currently live"})
   public int getNumLiveDataNodes() {
     return getBlockManager().getDatanodeManager().getNumLiveDataNodes();
   }
 
   @Override // FSNamesystemMBean
+  @Metric({"NumDeadDataNodes", "Number of datanodes which are currently dead"})
   public int getNumDeadDataNodes() {
     return getBlockManager().getDatanodeManager().getNumDeadDataNodes();
   }
   
   @Override // FSNamesystemMBean
+  @Metric({"NumDecomLiveDataNodes",
+      "Number of datanodes which have been decommissioned and are now live"})
   public int getNumDecomLiveDataNodes() {
     final List<DatanodeDescriptor> live = new ArrayList<DatanodeDescriptor>();
     getBlockManager().getDatanodeManager().fetchDatanodes(live, null, false);
@@ -6051,6 +6055,8 @@ public class FSNamesystem implements Namesystem, FSNamesystemMBean,
   }
 
   @Override // FSNamesystemMBean
+  @Metric({"NumDecomDeadDataNodes",
+      "Number of datanodes which have been decommissioned and are now dead"})
   public int getNumDecomDeadDataNodes() {
     final List<DatanodeDescriptor> dead = new ArrayList<DatanodeDescriptor>();
     getBlockManager().getDatanodeManager().fetchDatanodes(null, dead, false);
@@ -6062,6 +6068,8 @@ public class FSNamesystem implements Namesystem, FSNamesystemMBean,
   }
 
   @Override // FSNamesystemMBean
+  @Metric({"VolumeFailuresTotal",
+      "Total number of volume failures across all Datanodes"})
   public int getVolumeFailuresTotal() {
     List<DatanodeDescriptor> live = new ArrayList<DatanodeDescriptor>();
     getBlockManager().getDatanodeManager().fetchDatanodes(live, null, false);
@@ -6073,6 +6081,8 @@ public class FSNamesystem implements Namesystem, FSNamesystemMBean,
   }
 
   @Override // FSNamesystemMBean
+  @Metric({"EstimatedCapacityLostTotal",
+      "An estimate of the total capacity lost due to volume failures"})
   public long getEstimatedCapacityLostTotal() {
     List<DatanodeDescriptor> live = new ArrayList<DatanodeDescriptor>();
     getBlockManager().getDatanodeManager().fetchDatanodes(live, null, false);
@@ -6088,6 +6098,8 @@ public class FSNamesystem implements Namesystem, FSNamesystemMBean,
   }
 
   @Override // FSNamesystemMBean
+  @Metric({"NumDecommissioningDataNodes",
+      "Number of datanodes in decommissioning state"})
   public int getNumDecommissioningDataNodes() {
     return getBlockManager().getDatanodeManager().getDecommissioningNodes()
         .size();
@@ -6105,6 +6117,8 @@ public class FSNamesystem implements Namesystem, FSNamesystemMBean,
    * before NN receives the first Heartbeat followed by the first Blockreport.
    */
   @Override // FSNamesystemMBean
+  @Metric({"NumStaleStorages",
+      "Number of storages marked as content stale"})
   public int getNumStaleStorages() {
     return getBlockManager().getDatanodeManager().getNumStaleStorages();
   }

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

@@ -142,6 +142,8 @@ public class MiniDFSCluster {
   public static final String HDFS_MINIDFS_BASEDIR = "hdfs.minidfs.basedir";
   public static final String  DFS_NAMENODE_SAFEMODE_EXTENSION_TESTING_KEY
       = DFS_NAMENODE_SAFEMODE_EXTENSION_KEY + ".testing";
+  public static final String  DFS_NAMENODE_DECOMMISSION_INTERVAL_TESTING_KEY
+      = DFS_NAMENODE_DECOMMISSION_INTERVAL_KEY + ".testing";
 
   // Changing this default may break some tests that assume it is 2.
   private static final int DEFAULT_STORAGES_PER_DATANODE = 2;
@@ -788,7 +790,9 @@ public class MiniDFSCluster {
       int safemodeExtension = conf.getInt(
           DFS_NAMENODE_SAFEMODE_EXTENSION_TESTING_KEY, 0);
       conf.setInt(DFS_NAMENODE_SAFEMODE_EXTENSION_KEY, safemodeExtension);
-      conf.setInt(DFS_NAMENODE_DECOMMISSION_INTERVAL_KEY, 3); // 3 second
+      int decommissionInterval = conf.getInt(
+          DFS_NAMENODE_DECOMMISSION_INTERVAL_TESTING_KEY, 3);
+      conf.setInt(DFS_NAMENODE_DECOMMISSION_INTERVAL_KEY, decommissionInterval);
       conf.setClass(NET_TOPOLOGY_NODE_SWITCH_MAPPING_IMPL_KEY, 
                      StaticMapping.class, DNSToSwitchMapping.class);
     

hadoop-hdfs-project/hadoop-hdfs/src/test/java/org/apache/hadoop/hdfs/server/namenode/metrics/TestNameNodeMetrics.java

@@ -24,10 +24,15 @@ import static org.apache.hadoop.test.MetricsAsserts.assertQuantileGauges;
 import static org.apache.hadoop.test.MetricsAsserts.getMetrics;
 import static org.junit.Assert.assertTrue;
 
+import com.google.common.base.Joiner;
 import java.io.DataInputStream;
+import java.io.File;
 import java.io.IOException;
+import java.util.ArrayList;
+import java.util.List;
 import java.util.Random;
 
+import org.apache.commons.io.FileUtils;
 import org.apache.commons.logging.LogFactory;
 import org.apache.commons.logging.impl.Log4JLogger;
 import org.apache.hadoop.conf.Configuration;
@@ -46,6 +51,8 @@ import org.apache.hadoop.hdfs.server.blockmanagement.BlockManagerTestUtil;
 import org.apache.hadoop.hdfs.server.blockmanagement.DatanodeDescriptor;
 import org.apache.hadoop.hdfs.server.datanode.DataNode;
 import org.apache.hadoop.hdfs.server.datanode.DataNodeTestUtils;
+import org.apache.hadoop.hdfs.server.datanode.fsdataset.FsVolumeSpi;
+import org.apache.hadoop.hdfs.server.datanode.fsdataset.impl.FsVolumeImpl;
 import org.apache.hadoop.hdfs.server.namenode.FSNamesystem;
 import org.apache.hadoop.hdfs.server.namenode.NameNodeAdapter;
 import org.apache.hadoop.hdfs.server.namenode.top.TopAuditLogger;
@@ -84,6 +91,13 @@ public class TestNameNodeMetrics {
         DFS_REPLICATION_INTERVAL);
     CONF.setInt(DFSConfigKeys.DFS_NAMENODE_REPLICATION_INTERVAL_KEY, 
         DFS_REPLICATION_INTERVAL);
+    // Set it long enough to essentially disable unless we manually call it
+    // Used for decommissioning DataNode metrics
+    CONF.setInt(MiniDFSCluster.DFS_NAMENODE_DECOMMISSION_INTERVAL_TESTING_KEY,
+        9999999);
+    // For checking failed volume metrics
+    CONF.setInt(DFSConfigKeys.DFS_DF_INTERVAL_KEY, 1000);
+    CONF.setInt(DFSConfigKeys.DFS_DATANODE_FAILED_VOLUMES_TOLERATED_KEY, 1);
     CONF.set(DFSConfigKeys.DFS_METRICS_PERCENTILES_INTERVALS_KEY, 
         "" + PERCENTILES_INTERVAL);
     // Enable stale DataNodes checking
@@ -97,6 +111,8 @@ public class TestNameNodeMetrics {
   private final Random rand = new Random();
   private FSNamesystem namesystem;
   private BlockManager bm;
+  // List of temporary files on local FileSystem to be cleaned up
+  private List<Path> tempFiles;
 
   private static Path getTestPath(String fileName) {
     return new Path(TEST_ROOT_DIR_PATH, fileName);
@@ -109,6 +125,7 @@ public class TestNameNodeMetrics {
     namesystem = cluster.getNamesystem();
     bm = namesystem.getBlockManager();
     fs = cluster.getFileSystem();
+    tempFiles = new ArrayList<>();
   }
   
   @After
@@ -120,6 +137,9 @@ public class TestNameNodeMetrics {
       assertQuantileGauges("GetGroups1s", rb);
     }
     cluster.shutdown();
+    for (Path p : tempFiles) {
+      FileUtils.deleteQuietly(new File(p.toUri().getPath()));
+    }
   }
   
   /** create a file with a length of <code>fileLen</code> */
@@ -196,7 +216,113 @@ public class TestNameNodeMetrics {
         .getBlockManager());
     assertGauge("StaleDataNodes", 0, getMetrics(NS_METRICS));
   }
-  
+
+  /**
+   * Test metrics associated with volume failures.
+   */
+  @Test
+  public void testVolumeFailures() throws Exception {
+    assertGauge("VolumeFailuresTotal", 0, getMetrics(NS_METRICS));
+    assertGauge("EstimatedCapacityLostTotal", 0L, getMetrics(NS_METRICS));
+    DataNode dn = cluster.getDataNodes().get(0);
+    FsVolumeSpi fsVolume =
+        DataNodeTestUtils.getFSDataset(dn).getVolumes().get(0);
+    File dataDir = new File(fsVolume.getBasePath());
+    long capacity = ((FsVolumeImpl) fsVolume).getCapacity();
+    DataNodeTestUtils.injectDataDirFailure(dataDir);
+    long lastDiskErrorCheck = dn.getLastDiskErrorCheck();
+    dn.checkDiskErrorAsync();
+    while (dn.getLastDiskErrorCheck() == lastDiskErrorCheck) {
+      Thread.sleep(100);
+    }
+    DataNodeTestUtils.triggerHeartbeat(dn);
+    BlockManagerTestUtil.checkHeartbeat(bm);
+    assertGauge("VolumeFailuresTotal", 1, getMetrics(NS_METRICS));
+    assertGauge("EstimatedCapacityLostTotal", capacity, getMetrics(NS_METRICS));
+  }
+
+  /**
+   * Test metrics associated with liveness and decommission status of DataNodes.
+   */
+  @Test
+  public void testDataNodeLivenessAndDecom() throws Exception {
+    Path hostFileDir = new Path(MiniDFSCluster.getBaseDirectory(), "hosts");
+    FileSystem localFs = FileSystem.getLocal(CONF);
+    localFs.mkdirs(hostFileDir);
+    Path includeFile = new Path(hostFileDir, "include");
+    Path excludeFile = new Path(hostFileDir, "exclude");
+    tempFiles.add(includeFile);
+    tempFiles.add(excludeFile);
+    CONF.set(DFSConfigKeys.DFS_HOSTS, includeFile.toUri().getPath());
+    CONF.set(DFSConfigKeys.DFS_HOSTS_EXCLUDE, excludeFile.toUri().getPath());
+
+    List<DataNode> dataNodes = cluster.getDataNodes();
+    DatanodeDescriptor[] dnDescriptors = new DatanodeDescriptor[DATANODE_COUNT];
+    String[] dnAddresses = new String[DATANODE_COUNT];
+    for (int i = 0; i < DATANODE_COUNT; i++) {
+      dnDescriptors[i] = bm.getDatanodeManager()
+          .getDatanode(dataNodes.get(i).getDatanodeId());
+      dnAddresses[i] = dnDescriptors[i].getXferAddr();
+    }
+    // First put all DNs into include
+    DFSTestUtil.writeFile(localFs, includeFile,
+        Joiner.on("\n").join(dnAddresses));
+    DFSTestUtil.writeFile(localFs, excludeFile, "");
+    bm.getDatanodeManager().refreshNodes(CONF);
+    assertGauge("NumDecomLiveDataNodes", 0, getMetrics(NS_METRICS));
+    assertGauge("NumLiveDataNodes", DATANODE_COUNT, getMetrics(NS_METRICS));
+
+    // Now decommission one DN
+    DFSTestUtil.writeFile(localFs, excludeFile, dnAddresses[0]);
+    bm.getDatanodeManager().refreshNodes(CONF);
+    assertGauge("NumDecommissioningDataNodes", 1, getMetrics(NS_METRICS));
+    BlockManagerTestUtil.recheckDecommissionState(bm.getDatanodeManager());
+    assertGauge("NumDecommissioningDataNodes", 0, getMetrics(NS_METRICS));
+    assertGauge("NumDecomLiveDataNodes", 1, getMetrics(NS_METRICS));
+    assertGauge("NumLiveDataNodes", DATANODE_COUNT, getMetrics(NS_METRICS));
+
+    // Now kill all DNs by expiring their heartbeats
+    for (int i = 0; i < DATANODE_COUNT; i++) {
+      DataNodeTestUtils.setHeartbeatsDisabledForTests(dataNodes.get(i), true);
+      long expireInterval = CONF.getLong(
+          DFSConfigKeys.DFS_NAMENODE_HEARTBEAT_RECHECK_INTERVAL_KEY,
+          DFSConfigKeys.DFS_NAMENODE_HEARTBEAT_RECHECK_INTERVAL_DEFAULT) * 2L
+          + CONF.getLong(DFSConfigKeys.DFS_HEARTBEAT_INTERVAL_KEY,
+          DFSConfigKeys.DFS_HEARTBEAT_INTERVAL_DEFAULT) * 10 * 1000L;
+      DFSTestUtil.resetLastUpdatesWithOffset(dnDescriptors[i],
+          -(expireInterval + 1));
+    }
+    BlockManagerTestUtil.checkHeartbeat(bm);
+    assertGauge("NumDecomLiveDataNodes", 0, getMetrics(NS_METRICS));
+    assertGauge("NumDecomDeadDataNodes", 1, getMetrics(NS_METRICS));
+    assertGauge("NumLiveDataNodes", 0, getMetrics(NS_METRICS));
+    assertGauge("NumDeadDataNodes", DATANODE_COUNT, getMetrics(NS_METRICS));
+
+    // Now remove the decommissioned DN altogether
+    String[] includeHosts = new String[dnAddresses.length - 1];
+    for (int i = 0; i < includeHosts.length; i++) {
+      includeHosts[i] = dnAddresses[i + 1];
+    }
+    DFSTestUtil.writeFile(localFs, includeFile,
+        Joiner.on("\n").join(includeHosts));
+    // Just init to a nonexistent host to clear out the previous exclusion
+    DFSTestUtil.writeFile(localFs, excludeFile, "");
+    bm.getDatanodeManager().refreshNodes(CONF);
+    assertGauge("NumDecomLiveDataNodes", 0, getMetrics(NS_METRICS));
+    assertGauge("NumDecomDeadDataNodes", 0, getMetrics(NS_METRICS));
+    assertGauge("NumLiveDataNodes", 0, getMetrics(NS_METRICS));
+    assertGauge("NumDeadDataNodes", DATANODE_COUNT - 1, getMetrics(NS_METRICS));
+
+    // Finally mark the remaining DNs as live again
+    for (int i = 1; i < dataNodes.size(); i++) {
+      DataNodeTestUtils.setHeartbeatsDisabledForTests(dataNodes.get(i), false);
+      DFSTestUtil.resetLastUpdatesWithOffset(dnDescriptors[i], 0);
+    }
+    BlockManagerTestUtil.checkHeartbeat(bm);
+    assertGauge("NumLiveDataNodes", DATANODE_COUNT - 1, getMetrics(NS_METRICS));
+    assertGauge("NumDeadDataNodes", 0, getMetrics(NS_METRICS));
+  }
+
   /** Test metrics associated with addition of a file */
   @Test
   public void testFileAdd() throws Exception {