HDFS-6572. Add an option to the NameNode that prints the software and on-disk image versions. Contributed by Charles Lamb.

git-svn-id: https://svn.apache.org/repos/asf/hadoop/common/trunk@1605928 13f79535-47bb-0310-9956-ffa450edef68

Author: cnauroth

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

@@ -479,6 +479,9 @@ Release 2.5.0 - UNRELEASED
     HDFS-6595. Allow the maximum threads for balancing on datanodes to be
     configurable. (Benoy Antony via szetszwo)
 
+    HDFS-6572. Add an option to the NameNode that prints the software and
+    on-disk image versions. (Charles Lamb via cnauroth)
+
   OPTIMIZATIONS
 
     HDFS-6214. Webhdfs has poor throughput for files >2GB (daryn)

hadoop-hdfs-project/hadoop-hdfs/src/main/java/org/apache/hadoop/hdfs/server/common/HdfsServerConstants.java

@@ -92,7 +92,8 @@ static public enum StartupOption{
     RECOVER  ("-recover"),
     FORCE("-force"),
     NONINTERACTIVE("-nonInteractive"),
-    RENAMERESERVED("-renameReserved");
+    RENAMERESERVED("-renameReserved"),
+    METADATAVERSION("-metadataVersion");
 
     private static final Pattern ENUM_WITH_ROLLING_UPGRADE_OPTION = Pattern.compile(
         "(\\w+)\\((\\w+)\\)");

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

@@ -214,6 +214,13 @@ boolean recoverTransitionRead(StartupOption startOpt, FSNamesystem target,
 
 
     int layoutVersion = storage.getLayoutVersion();
+    if (startOpt == StartupOption.METADATAVERSION) {
+      System.out.println("HDFS Image Version: " + layoutVersion);
+      System.out.println("Software format version: " +
+        HdfsConstants.NAMENODE_LAYOUT_VERSION);
+      return false;
+    }
+
     if (layoutVersion < Storage.LAST_PRE_UPGRADE_LAYOUT_VERSION) {
       NNStorage.checkVersionUpgradable(storage.getLayoutVersion());
     }
@@ -289,6 +296,12 @@ private boolean recoverStorageDirs(StartupOption startOpt,
                       storage.dirIterator(); it.hasNext();) {
       StorageDirectory sd = it.next();
       StorageState curState;
+      if (startOpt == StartupOption.METADATAVERSION) {
+        /* All we need is the layout version. */
+        storage.readProperties(sd);
+        return true;
+      }
+
       try {
         curState = sd.analyzeStorage(startOpt, storage);
         // sd is locked but not opened

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

@@ -201,25 +201,28 @@ public static enum OperationCategory {
   };
 
   private static final String USAGE = "Usage: java NameNode ["
-      + StartupOption.BACKUP.getName() + "] | ["
-      + StartupOption.CHECKPOINT.getName() + "] | ["
+      + StartupOption.BACKUP.getName() + "] | \n\t["
+      + StartupOption.CHECKPOINT.getName() + "] | \n\t["
       + StartupOption.FORMAT.getName() + " ["
       + StartupOption.CLUSTERID.getName() + " cid ] ["
       + StartupOption.FORCE.getName() + "] ["
-      + StartupOption.NONINTERACTIVE.getName() + "] ] | ["
+      + StartupOption.NONINTERACTIVE.getName() + "] ] | \n\t["
       + StartupOption.UPGRADE.getName() + 
         " [" + StartupOption.CLUSTERID.getName() + " cid]" +
-        " [" + StartupOption.RENAMERESERVED.getName() + "<k-v pairs>] ] | ["
-      + StartupOption.ROLLBACK.getName() + "] | ["
+        " [" + StartupOption.RENAMERESERVED.getName() + "<k-v pairs>] ] | \n\t["
+      + StartupOption.ROLLBACK.getName() + "] | \n\t["
       + StartupOption.ROLLINGUPGRADE.getName() + " <"
       + RollingUpgradeStartupOption.DOWNGRADE.name().toLowerCase() + "|"
-      + RollingUpgradeStartupOption.ROLLBACK.name().toLowerCase() + "> ] | ["
-      + StartupOption.FINALIZE.getName() + "] | ["
-      + StartupOption.IMPORT.getName() + "] | ["
-      + StartupOption.INITIALIZESHAREDEDITS.getName() + "] | ["
-      + StartupOption.BOOTSTRAPSTANDBY.getName() + "] | ["
-      + StartupOption.RECOVER.getName() + " [ " + StartupOption.FORCE.getName()
-      + " ] ]";
+      + RollingUpgradeStartupOption.ROLLBACK.name().toLowerCase() + "> ] | \n\t["
+      + StartupOption.FINALIZE.getName() + "] | \n\t["
+      + StartupOption.IMPORT.getName() + "] | \n\t["
+      + StartupOption.INITIALIZESHAREDEDITS.getName() + "] | \n\t["
+      + StartupOption.BOOTSTRAPSTANDBY.getName() + "] | \n\t["
+      + StartupOption.RECOVER.getName() + " [ "
+      + StartupOption.FORCE.getName() + "] ] | \n\t["
+      + StartupOption.METADATAVERSION.getName() + " ] "
+      + " ]";
+
 
   public long getProtocolVersion(String protocol, 
                                  long clientVersion) throws IOException {
@@ -1266,6 +1269,8 @@ static StartupOption parseArguments(String args[]) {
               "can't understand option \"" + args[i] + "\"");
           }
         }
+      } else if (StartupOption.METADATAVERSION.getName().equalsIgnoreCase(cmd)) {
+        startOpt = StartupOption.METADATAVERSION;
       } else {
         return null;
       }
@@ -1318,6 +1323,21 @@ private static void doRecovery(StartupOption startOpt, Configuration conf)
     }
   }
 
+  /**
+   * Verify that configured directories exist, then print the metadata versions
+   * of the software and the image.
+   *
+   * @param conf configuration to use
+   * @throws IOException
+   */
+  private static boolean printMetadataVersion(Configuration conf)
+    throws IOException {
+    final FSImage fsImage = new FSImage(conf);
+    final FSNamesystem fs = new FSNamesystem(conf, fsImage, false);
+    return fsImage.recoverTransitionRead(
+      StartupOption.METADATAVERSION, fs, null);
+  }
+
   public static NameNode createNameNode(String argv[], Configuration conf)
       throws IOException {
     LOG.info("createNameNode " + Arrays.asList(argv));
@@ -1382,6 +1402,11 @@ public static NameNode createNameNode(String argv[], Configuration conf)
         NameNode.doRecovery(startOpt, conf);
         return null;
       }
+      case METADATAVERSION: {
+        printMetadataVersion(conf);
+        terminate(0);
+        return null; // avoid javac warning
+      }
       default: {
         DefaultMetricsSystem.initialize("NameNode");
         return new NameNode(conf);

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

@@ -0,0 +1,77 @@
+/**
+ * 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.namenode;
+
+import static org.apache.hadoop.test.GenericTestUtils.assertExceptionContains;
+import static org.junit.Assert.assertTrue;
+
+import org.apache.hadoop.conf.Configuration;
+import org.apache.hadoop.hdfs.MiniDFSCluster;
+import org.apache.hadoop.hdfs.protocol.HdfsConstants;
+
+import org.junit.After;
+import org.junit.Before;
+import org.junit.Test;
+
+import java.io.ByteArrayOutputStream;
+import java.io.IOException;
+import java.io.PrintStream;
+
+public class TestMetadataVersionOutput {
+
+  private MiniDFSCluster dfsCluster = null;
+  private final Configuration conf = new Configuration();
+
+  @Before
+  public void setUp() throws Exception {
+    dfsCluster = new MiniDFSCluster.Builder(conf).
+            numDataNodes(1).
+            checkExitOnShutdown(false).
+            build();
+    dfsCluster.waitClusterUp();
+  }
+
+  @After
+  public void tearDown() throws Exception {
+    if (dfsCluster != null) {
+      dfsCluster.shutdown();
+    }
+    Thread.sleep(2000);
+  }
+
+  @Test(timeout = 30000)
+  public void testMetadataVersionOutput() throws IOException {
+
+    final PrintStream origOut = System.out;
+    final ByteArrayOutputStream baos = new ByteArrayOutputStream();
+    final PrintStream stdOut = new PrintStream(baos);
+    System.setOut(stdOut);
+    try {
+      NameNode.createNameNode(new String[] { "-metadataVersion" }, conf);
+    } catch (Exception e) {
+      assertExceptionContains("ExitException", e);
+    }
+    /* Check if meta data version is printed correctly. */
+    final String verNumStr = HdfsConstants.NAMENODE_LAYOUT_VERSION + "";
+    assertTrue(baos.toString("UTF-8").
+      contains("HDFS Image Version: " + verNumStr));
+    assertTrue(baos.toString("UTF-8").
+      contains("Software format version: " + verNumStr));
+    System.setOut(origOut);
+  }
+}