HDFS-3723. Add support -h, -help to all the commands. Contributed by Jing Zhao.

git-svn-id: https://svn.apache.org/repos/asf/hadoop/common/trunk@1373170 13f79535-47bb-0310-9956-ffa450edef68
2012-08-15 00:03:19 +00:00 · 2012-08-15 00:03:19 +00:00 · f026d8bb1b
commit f026d8bb1b
parent f98d8eb291
13 changed files with 216 additions and 83 deletions
--- a/hadoop-hdfs-project/hadoop-hdfs/CHANGES.txt
+++ b/hadoop-hdfs-project/hadoop-hdfs/CHANGES.txt
@ -114,6 +114,9 @@ Trunk (unreleased changes)
    HDFS-3789. JournalManager#format() should be able to throw IOException
    (Ivan Kelly via todd)

+    HDFS-3723. Add support -h, -help to all the commands. (Jing Zhao via
+    suresh)
+
  OPTIMIZATIONS

  BUG FIXES
--- a/hadoop-hdfs-project/hadoop-hdfs/src/main/java/org/apache/hadoop/hdfs/DFSUtil.java
+++ b/hadoop-hdfs-project/hadoop-hdfs/src/main/java/org/apache/hadoop/hdfs/DFSUtil.java
@ -18,8 +18,21 @@

 package org.apache.hadoop.hdfs;

-import static org.apache.hadoop.hdfs.DFSConfigKeys.*;
+import static org.apache.hadoop.hdfs.DFSConfigKeys.DFS_HA_NAMENODES_KEY_PREFIX;
+import static org.apache.hadoop.hdfs.DFSConfigKeys.DFS_HA_NAMENODE_ID_KEY;
+import static org.apache.hadoop.hdfs.DFSConfigKeys.DFS_NAMENODE_BACKUP_ADDRESS_KEY;
+import static org.apache.hadoop.hdfs.DFSConfigKeys.DFS_NAMENODE_HTTPS_ADDRESS_DEFAULT;
+import static org.apache.hadoop.hdfs.DFSConfigKeys.DFS_NAMENODE_HTTPS_ADDRESS_KEY;
+import static org.apache.hadoop.hdfs.DFSConfigKeys.DFS_NAMENODE_HTTP_ADDRESS_DEFAULT;
+import static org.apache.hadoop.hdfs.DFSConfigKeys.DFS_NAMENODE_HTTP_ADDRESS_KEY;
+import static org.apache.hadoop.hdfs.DFSConfigKeys.DFS_NAMENODE_RPC_ADDRESS_KEY;
+import static org.apache.hadoop.hdfs.DFSConfigKeys.DFS_NAMENODE_SECONDARY_HTTP_ADDRESS_KEY;
+import static org.apache.hadoop.hdfs.DFSConfigKeys.DFS_NAMENODE_SERVICE_RPC_ADDRESS_KEY;
+import static org.apache.hadoop.hdfs.DFSConfigKeys.DFS_NAMESERVICES;
+import static org.apache.hadoop.hdfs.DFSConfigKeys.DFS_NAMESERVICE_ID;
+
 import java.io.IOException;
+import java.io.PrintStream;
 import java.io.UnsupportedEncodingException;
 import java.net.InetSocketAddress;
 import java.net.URI;
@ -33,10 +46,17 @@
 import java.util.Map;
 import java.util.Random;
 import java.util.Set;
-import java.util.StringTokenizer;

 import javax.net.SocketFactory;

+import org.apache.commons.cli.CommandLine;
+import org.apache.commons.cli.CommandLineParser;
+import org.apache.commons.cli.Option;
+import org.apache.commons.cli.Options;
+import org.apache.commons.cli.ParseException;
+import org.apache.commons.cli.PosixParser;
+import org.apache.commons.logging.Log;
+import org.apache.commons.logging.LogFactory;
 import org.apache.hadoop.HadoopIllegalArgumentException;
 import org.apache.hadoop.classification.InterfaceAudience;
 import org.apache.hadoop.conf.Configuration;
@ -57,8 +77,7 @@
 import org.apache.hadoop.net.NodeBase;
 import org.apache.hadoop.security.UserGroupInformation;
 import org.apache.hadoop.util.StringUtils;
-import org.apache.commons.logging.Log;
-import org.apache.commons.logging.LogFactory;
+import org.apache.hadoop.util.ToolRunner;

 import com.google.common.base.Joiner;
 import com.google.common.collect.Lists;
@ -424,7 +443,6 @@ private static Map<String, InetSocketAddress> getAddressesForNameserviceId(
   * 
   * @param conf configuration
   * @return list of InetSocketAddresses
-   * @throws IOException if no addresses are configured
   */
  public static Map<String, Map<String, InetSocketAddress>> getHaNnRpcAddresses(
      Configuration conf) {
@ -1073,4 +1091,44 @@ public static String getOnlyNameServiceIdOrNull(Configuration conf) {
      return null;
    }
  }
+  
+  public static Options helpOptions = new Options();
+  public static Option helpOpt = new Option("h", "help", false,
+      "get help information");
+
+  static {
+    helpOptions.addOption(helpOpt);
+  }
+
+  /**
+   * Parse the arguments for commands
+   * 
+   * @param args the argument to be parsed
+   * @param helpDescription help information to be printed out
+   * @param out Printer
+   * @param printGenericCommandUsage whether to print the 
+   *              generic command usage defined in ToolRunner
+   * @return true when the argument matches help option, false if not
+   */
+  public static boolean parseHelpArgument(String[] args,
+      String helpDescription, PrintStream out, boolean printGenericCommandUsage) {
+    if (args.length == 1) {
+      try {
+        CommandLineParser parser = new PosixParser();
+        CommandLine cmdLine = parser.parse(helpOptions, args);
+        if (cmdLine.hasOption(helpOpt.getOpt())
+            || cmdLine.hasOption(helpOpt.getLongOpt())) {
+          // should print out the help information
+          out.println(helpDescription + "\n");
+          if (printGenericCommandUsage) {
+            ToolRunner.printGenericCommandUsage(out);
+          }
+          return true;
+        }
+      } catch (ParseException pe) {
+        return false;
+      }
+    }
+    return false;
+  }
 }
--- a/hadoop-hdfs-project/hadoop-hdfs/src/main/java/org/apache/hadoop/hdfs/server/balancer/Balancer.java
+++ b/hadoop-hdfs-project/hadoop-hdfs/src/main/java/org/apache/hadoop/hdfs/server/balancer/Balancer.java
@ -17,6 +17,7 @@
 */
 package org.apache.hadoop.hdfs.server.balancer;

+import static com.google.common.base.Preconditions.checkArgument;
 import static org.apache.hadoop.hdfs.protocol.HdfsProtoUtil.vintPrefixed;

 import java.io.BufferedInputStream;
@ -26,6 +27,7 @@
 import java.io.IOException;
 import java.io.InputStream;
 import java.io.OutputStream;
+import java.io.PrintStream;
 import java.net.Socket;
 import java.net.URI;
 import java.text.DateFormat;
@ -68,7 +70,6 @@
 import org.apache.hadoop.hdfs.server.blockmanagement.BlockPlacementPolicy;
 import org.apache.hadoop.hdfs.server.blockmanagement.BlockPlacementPolicyDefault;
 import org.apache.hadoop.hdfs.server.common.HdfsServerConstants;
-import org.apache.hadoop.hdfs.server.common.Util;
 import org.apache.hadoop.hdfs.server.namenode.UnsupportedActionException;
 import org.apache.hadoop.hdfs.server.protocol.BlocksWithLocations.BlockWithLocations;
 import org.apache.hadoop.io.IOUtils;
@ -79,7 +80,6 @@
 import org.apache.hadoop.util.Time;
 import org.apache.hadoop.util.Tool;
 import org.apache.hadoop.util.ToolRunner;
-import static com.google.common.base.Preconditions.checkArgument;

 /** <p>The balancer is a tool that balances disk space usage on an HDFS cluster
 * when some datanodes become full or when new empty nodes join the cluster.
@ -189,6 +189,13 @@ public class Balancer {
   */
  public static final int MAX_NUM_CONCURRENT_MOVES = 5;
  
+  private static final String USAGE = "Usage: java "
+      + Balancer.class.getSimpleName()
+      + "\n\t[-policy <policy>]\tthe balancing policy: "
+      + BalancingPolicy.Node.INSTANCE.getName() + " or "
+      + BalancingPolicy.Pool.INSTANCE.getName()
+      + "\n\t[-threshold <threshold>]\tPercentage of disk capacity";
+  
  private final NameNodeConnector nnc;
  private final BalancingPolicy policy;
  private final double threshold;
@ -1550,7 +1557,7 @@ static Parameters parse(String[] args) {
            }
          }
        } catch(RuntimeException e) {
-          printUsage();
+          printUsage(System.err);
          throw e;
        }
      }
@ -1558,13 +1565,8 @@ static Parameters parse(String[] args) {
      return new Parameters(policy, threshold);
    }

-    private static void printUsage() {
-      System.out.println("Usage: java " + Balancer.class.getSimpleName());
-      System.out.println("    [-policy <policy>]\tthe balancing policy: "
-          + BalancingPolicy.Node.INSTANCE.getName() + " or " 
-          + BalancingPolicy.Pool.INSTANCE.getName());
-      System.out.println(
-          "    [-threshold <threshold>]\tPercentage of disk capacity");
+    private static void printUsage(PrintStream out) {
+      out.println(USAGE + "\n");
    }
  }

@ -1573,6 +1575,10 @@ private static void printUsage() {
   * @param args Command line arguments
   */
  public static void main(String[] args) {
+    if (DFSUtil.parseHelpArgument(args, USAGE, System.out, true)) {
+      System.exit(0);
+    }
+
    try {
      System.exit(ToolRunner.run(new HdfsConfiguration(), new Cli(), args));
    } catch (Throwable e) {
--- a/hadoop-hdfs-project/hadoop-hdfs/src/main/java/org/apache/hadoop/hdfs/server/datanode/DataNode.java
+++ b/hadoop-hdfs-project/hadoop-hdfs/src/main/java/org/apache/hadoop/hdfs/server/datanode/DataNode.java
@ -46,6 +46,7 @@
 import static org.apache.hadoop.hdfs.DFSConfigKeys.DFS_DATANODE_STARTUP_KEY;
 import static org.apache.hadoop.hdfs.DFSConfigKeys.DFS_DATANODE_USER_NAME_KEY;
 import static org.apache.hadoop.hdfs.DFSConfigKeys.DFS_HTTPS_ENABLE_KEY;
+import static org.apache.hadoop.util.ExitUtil.terminate;

 import java.io.BufferedOutputStream;
 import java.io.ByteArrayInputStream;
@ -55,6 +56,7 @@
 import java.io.IOException;
 import java.io.InputStream;
 import java.io.OutputStream;
+import java.io.PrintStream;
 import java.net.InetSocketAddress;
 import java.net.ServerSocket;
 import java.net.Socket;
@ -98,8 +100,8 @@
 import org.apache.hadoop.hdfs.protocol.HdfsProtoUtil;
 import org.apache.hadoop.hdfs.protocol.RecoveryInProgressException;
 import org.apache.hadoop.hdfs.protocol.datatransfer.BlockConstructionStage;
-import org.apache.hadoop.hdfs.protocol.datatransfer.DataTransferProtocol;
 import org.apache.hadoop.hdfs.protocol.datatransfer.DataTransferEncryptor;
+import org.apache.hadoop.hdfs.protocol.datatransfer.DataTransferProtocol;
 import org.apache.hadoop.hdfs.protocol.datatransfer.IOStreamPair;
 import org.apache.hadoop.hdfs.protocol.datatransfer.Sender;
 import org.apache.hadoop.hdfs.protocol.proto.ClientDatanodeProtocolProtos.ClientDatanodeProtocolService;
@ -124,9 +126,6 @@
 import org.apache.hadoop.hdfs.server.common.JspHelper;
 import org.apache.hadoop.hdfs.server.common.StorageInfo;
 import org.apache.hadoop.hdfs.server.common.Util;
-
-import static org.apache.hadoop.util.ExitUtil.terminate;
-
 import org.apache.hadoop.hdfs.server.datanode.SecureDataNodeStarter.SecureResources;
 import org.apache.hadoop.hdfs.server.datanode.fsdataset.FsDatasetSpi;
 import org.apache.hadoop.hdfs.server.datanode.fsdataset.FsVolumeSpi;
@ -171,9 +170,9 @@
 import org.apache.hadoop.util.VersionInfo;
 import org.mortbay.util.ajax.JSON;

+import com.google.common.annotations.VisibleForTesting;
 import com.google.common.base.Joiner;
 import com.google.common.base.Preconditions;
-import com.google.common.annotations.VisibleForTesting;
 import com.google.protobuf.BlockingService;

 /**********************************************************
@ -230,6 +229,8 @@ public class DataNode extends Configured
        
  static final Log ClientTraceLog =
    LogFactory.getLog(DataNode.class.getName() + ".clienttrace");
+  
+  private static final String USAGE = "Usage: java DataNode [-rollback | -regular]";

  /**
   * Use {@link NetUtils#createSocketAddr(String)} instead.
@ -1541,7 +1542,7 @@ public static DataNode instantiateDataNode(String args [], Configuration conf,
    }
    
    if (!parseArguments(args, conf)) {
-      printUsage();
+      printUsage(System.err);
      return null;
    }
    Collection<URI> dataDirs = getStorageDirs(conf);
@ -1655,9 +1656,8 @@ public String toString() {
        + xmitsInProgress.get() + "}";
  }

-  private static void printUsage() {
-    System.err.println("Usage: java DataNode");
-    System.err.println("           [-rollback]");
+  private static void printUsage(PrintStream out) {
+    out.println(USAGE + "\n");
  }

  /**
@ -1742,6 +1742,10 @@ public static void secureMain(String args[], SecureResources resources) {
  }
  
  public static void main(String args[]) {
+    if (DFSUtil.parseHelpArgument(args, DataNode.USAGE, System.out, true)) {
+      System.exit(0);
+    }
+
    secureMain(args, null);
  }

--- a/hadoop-hdfs-project/hadoop-hdfs/src/main/java/org/apache/hadoop/hdfs/server/namenode/NameNode.java
+++ b/hadoop-hdfs-project/hadoop-hdfs/src/main/java/org/apache/hadoop/hdfs/server/namenode/NameNode.java
@ -18,6 +18,7 @@
 package org.apache.hadoop.hdfs.server.namenode;

 import java.io.IOException;
+import java.io.PrintStream;
 import java.net.InetSocketAddress;
 import java.net.URI;
 import java.util.ArrayList;
@ -38,6 +39,8 @@
 import org.apache.hadoop.fs.FileSystem;
 import org.apache.hadoop.fs.Trash;
 import static org.apache.hadoop.hdfs.DFSConfigKeys.*;
+import static org.apache.hadoop.util.ExitUtil.terminate;
+import static org.apache.hadoop.util.ToolRunner.confirmPrompt;

 import org.apache.hadoop.hdfs.DFSConfigKeys;
 import org.apache.hadoop.hdfs.DFSUtil;
@ -69,12 +72,9 @@
 import org.apache.hadoop.security.UserGroupInformation;
 import org.apache.hadoop.security.authorize.RefreshAuthorizationPolicyProtocol;
 import org.apache.hadoop.tools.GetUserMappingsProtocol;
+import org.apache.hadoop.util.ExitUtil.ExitException;
 import org.apache.hadoop.util.ServicePlugin;
 import org.apache.hadoop.util.StringUtils;
-import org.apache.hadoop.util.ExitUtil.ExitException;
-
-import static org.apache.hadoop.util.ExitUtil.terminate;
-import static org.apache.hadoop.util.ToolRunner.confirmPrompt;

 import com.google.common.annotations.VisibleForTesting;
 import com.google.common.base.Preconditions;
@ -188,6 +188,22 @@ public static enum OperationCategory {
    DFS_HA_AUTO_FAILOVER_ENABLED_KEY
  };
  
+  private static final String USAGE = "Usage: java NameNode ["
+      + StartupOption.BACKUP.getName() + "] | ["
+      + StartupOption.CHECKPOINT.getName() + "] | ["
+      + StartupOption.FORMAT.getName() + " ["
+      + StartupOption.CLUSTERID.getName() + " cid ] ["
+      + StartupOption.FORCE.getName() + "] ["
+      + StartupOption.NONINTERACTIVE.getName() + "] ] | ["
+      + StartupOption.UPGRADE.getName() + "] | ["
+      + StartupOption.ROLLBACK.getName() + "] | ["
+      + StartupOption.FINALIZE.getName() + "] | ["
+      + StartupOption.IMPORT.getName() + "] | ["
+      + StartupOption.INITIALIZESHAREDEDITS.getName() + "] | ["
+      + StartupOption.BOOTSTRAPSTANDBY.getName() + "] | ["
+      + StartupOption.RECOVER.getName() + " [ " + StartupOption.FORCE.getName()
+      + " ] ]";
+  
  public long getProtocolVersion(String protocol, 
                                 long clientVersion) throws IOException {
    if (protocol.equals(ClientProtocol.class.getName())) {
@ -895,25 +911,8 @@ private static boolean finalize(Configuration conf,
    return false;
  }

-  private static void printUsage() {
-    System.err.println(
-      "Usage: java NameNode [" +
-      StartupOption.BACKUP.getName() + "] | [" +
-      StartupOption.CHECKPOINT.getName() + "] | [" +
-      StartupOption.FORMAT.getName() + " [" + StartupOption.CLUSTERID.getName() +  
-      " cid ] [" + StartupOption.FORCE.getName() + "] [" +
-      StartupOption.NONINTERACTIVE.getName() + "] ] | [" +
-      StartupOption.UPGRADE.getName() + "] | [" +
-      StartupOption.ROLLBACK.getName() + "] | [" +
-      StartupOption.FINALIZE.getName() + "] | [" +
-      StartupOption.IMPORT.getName() + "] | [" +
-      StartupOption.INITIALIZESHAREDEDITS.getName() + 
-        " [" + StartupOption.FORCE.getName() + "] [" +
-             StartupOption.NONINTERACTIVE.getName() + "]" +
-      "] | [" +
-      StartupOption.BOOTSTRAPSTANDBY.getName() + "] | [" + 
-      StartupOption.RECOVER.getName() + " [ " +
-        StartupOption.FORCE.getName() + " ] ]");
+  private static void printUsage(PrintStream out) {
+    out.println(USAGE + "\n");
  }

  private static StartupOption parseArguments(String args[]) {
@ -1061,7 +1060,7 @@ public static NameNode createNameNode(String argv[], Configuration conf)
      conf = new HdfsConfiguration();
    StartupOption startOpt = parseArguments(argv);
    if (startOpt == null) {
-      printUsage();
+      printUsage(System.err);
      return null;
    }
    setStartupOption(conf, startOpt);
@ -1175,6 +1174,10 @@ protected String getNameServiceId(Configuration conf) {
  /**
   */
  public static void main(String argv[]) throws Exception {
+    if (DFSUtil.parseHelpArgument(argv, NameNode.USAGE, System.out, true)) {
+      System.exit(0);
+    }
+
    try {
      StringUtils.startupShutdownMessage(NameNode.class, argv, LOG);
      NameNode namenode = createNameNode(argv, null);
--- a/hadoop-hdfs-project/hadoop-hdfs/src/main/java/org/apache/hadoop/hdfs/server/namenode/SecondaryNameNode.java
+++ b/hadoop-hdfs-project/hadoop-hdfs/src/main/java/org/apache/hadoop/hdfs/server/namenode/SecondaryNameNode.java
@ -562,6 +562,9 @@ public static void main(String[] argv) throws Exception {
    if (opts == null) {
      LOG.fatal("Failed to parse options");
      terminate(1);
+    } else if (opts.shouldPrintHelp()) {
+      opts.usage();
+      System.exit(0);
    }
    
    StringUtils.startupShutdownMessage(SecondaryNameNode.class, argv, LOG);
@ -595,6 +598,7 @@ static class CommandLineOpts {
    private final Option geteditsizeOpt;
    private final Option checkpointOpt;
    private final Option formatOpt;
+    private final Option helpOpt;


    Command cmd;
@ -605,6 +609,7 @@ enum Command {
    
    private boolean shouldForce;
    private boolean shouldFormat;
+    private boolean shouldPrintHelp;

    CommandLineOpts() {
      geteditsizeOpt = new Option("geteditsize",
@ -612,20 +617,32 @@ enum Command {
      checkpointOpt = OptionBuilder.withArgName("force")
        .hasOptionalArg().withDescription("checkpoint on startup").create("checkpoint");;
      formatOpt = new Option("format", "format the local storage during startup");
+      helpOpt = new Option("h", "help", false, "get help information");
      
      options.addOption(geteditsizeOpt);
      options.addOption(checkpointOpt);
      options.addOption(formatOpt);
+      options.addOption(helpOpt);
    }
    
    public boolean shouldFormat() {
      return shouldFormat;
    }

+    public boolean shouldPrintHelp() {
+      return shouldPrintHelp;
+    }
+    
    public void parse(String ... argv) throws ParseException {
      CommandLineParser parser = new PosixParser();
      CommandLine cmdLine = parser.parse(options, argv);
      
+      if (cmdLine.hasOption(helpOpt.getOpt())
+          || cmdLine.hasOption(helpOpt.getLongOpt())) {
+        shouldPrintHelp = true;
+        return;
+      }
+      
      boolean hasGetEdit = cmdLine.hasOption(geteditsizeOpt.getOpt());
      boolean hasCheckpoint = cmdLine.hasOption(checkpointOpt.getOpt()); 
      if (hasGetEdit && hasCheckpoint) {
@ -662,8 +679,13 @@ public boolean shouldForceCheckpoint() {
    }
    
    void usage() {
+      String header = "The Secondary NameNode is a helper "
+          + "to the primary NameNode. The Secondary is responsible "
+          + "for supporting periodic checkpoints of the HDFS metadata. "
+          + "The current design allows only one Secondary NameNode "
+          + "per HDFS cluster.";
      HelpFormatter formatter = new HelpFormatter();
-      formatter.printHelp("secondarynamenode", options);
+      formatter.printHelp("secondarynamenode", header, options, "", false);
    }
  }

--- a/hadoop-hdfs-project/hadoop-hdfs/src/main/java/org/apache/hadoop/hdfs/tools/DFSHAAdmin.java
+++ b/hadoop-hdfs-project/hadoop-hdfs/src/main/java/org/apache/hadoop/hdfs/tools/DFSHAAdmin.java
@ -42,6 +42,10 @@ public class DFSHAAdmin extends HAAdmin {
  protected void setErrOut(PrintStream errOut) {
    this.errOut = errOut;
  }
+  
+  protected void setOut(PrintStream out) {
+    this.out = out;
+  }

  @Override
  public void setConf(Configuration conf) {
--- a/hadoop-hdfs-project/hadoop-hdfs/src/main/java/org/apache/hadoop/hdfs/tools/DFSZKFailoverController.java
+++ b/hadoop-hdfs-project/hadoop-hdfs/src/main/java/org/apache/hadoop/hdfs/tools/DFSZKFailoverController.java
@ -162,6 +162,10 @@ protected String getScopeInsideParentNode() {

  public static void main(String args[])
      throws Exception {
+    if (DFSUtil.parseHelpArgument(args, 
+        ZKFailoverController.USAGE, System.out, true)) {
+      System.exit(0);
+    }
    
    GenericOptionsParser parser = new GenericOptionsParser(
        new HdfsConfiguration(), args);
--- a/hadoop-hdfs-project/hadoop-hdfs/src/main/java/org/apache/hadoop/hdfs/tools/DFSck.java
+++ b/hadoop-hdfs-project/hadoop-hdfs/src/main/java/org/apache/hadoop/hdfs/tools/DFSck.java
@ -73,6 +73,25 @@ public class DFSck extends Configured implements Tool {
    HdfsConfiguration.init();
  }

+  private static final String USAGE = "Usage: DFSck <path> "
+      + "[-list-corruptfileblocks | "
+      + "[-move | -delete | -openforwrite] "
+      + "[-files [-blocks [-locations | -racks]]]]\n"
+      + "\t<path>\tstart checking from this path\n"
+      + "\t-move\tmove corrupted files to /lost+found\n"
+      + "\t-delete\tdelete corrupted files\n"
+      + "\t-files\tprint out files being checked\n"
+      + "\t-openforwrite\tprint out files opened for write\n"
+      + "\t-list-corruptfileblocks\tprint out list of missing "
+      + "blocks and files they belong to\n"
+      + "\t-blocks\tprint out block report\n"
+      + "\t-locations\tprint out locations for every block\n"
+      + "\t-racks\tprint out network topology for data-node locations\n"
+      + "\t\tBy default fsck ignores files opened for write, "
+      + "use -openforwrite to report such files. They are usually "
+      + " tagged CORRUPT or HEALTHY depending on their block "
+      + "allocation status";
+  
  private final UserGroupInformation ugi;
  private final PrintStream out;

@ -93,25 +112,9 @@ public DFSck(Configuration conf, PrintStream out) throws IOException {
  /**
   * Print fsck usage information
   */
-  static void printUsage() {
-    System.err.println("Usage: DFSck <path> [-list-corruptfileblocks | " +
-        "[-move | -delete | -openforwrite] " +
-        "[-files [-blocks [-locations | -racks]]]]");
-    System.err.println("\t<path>\tstart checking from this path");
-    System.err.println("\t-move\tmove corrupted files to /lost+found");
-    System.err.println("\t-delete\tdelete corrupted files");
-    System.err.println("\t-files\tprint out files being checked");
-    System.err.println("\t-openforwrite\tprint out files opened for write");
-    System.err.println("\t-list-corruptfileblocks\tprint out list of missing "
-        + "blocks and files they belong to");
-    System.err.println("\t-blocks\tprint out block report");
-    System.err.println("\t-locations\tprint out locations for every block");
-    System.err.println("\t-racks\tprint out network topology for data-node locations");
-    System.err.println("\t\tBy default fsck ignores files opened for write, " +
-                       "use -openforwrite to report such files. They are usually " +
-                       " tagged CORRUPT or HEALTHY depending on their block " +
-                        "allocation status");
-    ToolRunner.printGenericCommandUsage(System.err);
+  static void printUsage(PrintStream out) {
+    out.println(USAGE + "\n");
+    ToolRunner.printGenericCommandUsage(out);
  }
  /**
   * @param args
@ -119,7 +122,7 @@ static void printUsage() {
  @Override
  public int run(final String[] args) throws IOException {
    if (args.length == 0) {
-      printUsage();
+      printUsage(System.err);
      return -1;
    }

@ -258,12 +261,12 @@ else if (args[idx].equals("-list-corruptfileblocks")) {
        } else {
          System.err.println("fsck: can only operate on one path at a time '"
              + args[idx] + "'");
-          printUsage();
+          printUsage(System.err);
          return -1;
        }
      } else {
        System.err.println("fsck: Illegal option '" + args[idx] + "'");
-        printUsage();
+        printUsage(System.err);
        return -1;
      }
    }
@ -304,10 +307,14 @@ public static void main(String[] args) throws Exception {
    // -files option is also used by GenericOptionsParser
    // Make sure that is not the first argument for fsck
    int res = -1;
-    if ((args.length == 0 ) || ("-files".equals(args[0]))) 
-      printUsage();
-    else
+    if ((args.length == 0) || ("-files".equals(args[0]))) {
+      printUsage(System.err);
+      ToolRunner.printGenericCommandUsage(System.err);
+    } else if (DFSUtil.parseHelpArgument(args, USAGE, System.out, true)) {
+      res = 0;
+    } else {
      res = ToolRunner.run(new DFSck(new HdfsConfiguration()), args);
+    }
    System.exit(res);
  }
 }
--- a/hadoop-hdfs-project/hadoop-hdfs/src/main/java/org/apache/hadoop/hdfs/tools/DelegationTokenFetcher.java
+++ b/hadoop-hdfs-project/hadoop-hdfs/src/main/java/org/apache/hadoop/hdfs/tools/DelegationTokenFetcher.java
@ -40,7 +40,6 @@
 import org.apache.hadoop.conf.Configuration;
 import org.apache.hadoop.fs.FileSystem;
 import org.apache.hadoop.fs.Path;
-import org.apache.hadoop.hdfs.DFSConfigKeys;
 import org.apache.hadoop.hdfs.HdfsConfiguration;
 import org.apache.hadoop.hdfs.HftpFileSystem;
 import org.apache.hadoop.hdfs.security.token.delegation.DelegationTokenIdentifier;
@ -48,9 +47,7 @@
 import org.apache.hadoop.hdfs.server.namenode.CancelDelegationTokenServlet;
 import org.apache.hadoop.hdfs.server.namenode.GetDelegationTokenServlet;
 import org.apache.hadoop.hdfs.server.namenode.RenewDelegationTokenServlet;
-import org.apache.hadoop.hdfs.web.URLUtils;
 import org.apache.hadoop.io.IOUtils;
-import org.apache.hadoop.io.Text;
 import org.apache.hadoop.net.NetUtils;
 import org.apache.hadoop.security.Credentials;
 import org.apache.hadoop.security.SecurityUtil;
@ -71,8 +68,10 @@ public class DelegationTokenFetcher {
  private static final String CANCEL = "cancel";
  private static final String RENEW = "renew";
  private static final String PRINT = "print";
+  private static final String HELP = "help";
+  private static final String HELP_SHORT = "h";

-  private static void printUsage(PrintStream err) throws IOException {
+  private static void printUsage(PrintStream err) {
    err.println("fetchdt retrieves delegation tokens from the NameNode");
    err.println();
    err.println("fetchdt <opts> <token file>");
@ -107,6 +106,7 @@ public static void main(final String[] args) throws Exception {
    fetcherOptions.addOption(CANCEL, false, "cancel the token");
    fetcherOptions.addOption(RENEW, false, "renew the token");
    fetcherOptions.addOption(PRINT, false, "print the token");
+    fetcherOptions.addOption(HELP_SHORT, HELP, false, "print out help information");
    GenericOptionsParser parser = new GenericOptionsParser(conf,
        fetcherOptions, args);
    CommandLine cmd = parser.getCommandLine();
@ -119,9 +119,14 @@ public static void main(final String[] args) throws Exception {
    final boolean cancel = cmd.hasOption(CANCEL);
    final boolean renew = cmd.hasOption(RENEW);
    final boolean print = cmd.hasOption(PRINT);
+    final boolean help = cmd.hasOption(HELP);
    String[] remaining = parser.getRemainingArgs();

    // check option validity
+    if (help) {
+      printUsage(System.out);
+      System.exit(0);
+    }
    if (cancel && renew || cancel && print || renew && print || cancel && renew
        && print) {
      System.err.println("ERROR: Only specify cancel, renew or print.");
--- a/hadoop-hdfs-project/hadoop-hdfs/src/main/java/org/apache/hadoop/hdfs/tools/GetConf.java
+++ b/hadoop-hdfs-project/hadoop-hdfs/src/main/java/org/apache/hadoop/hdfs/tools/GetConf.java
@ -324,6 +324,10 @@ public Integer run() throws Exception {
  }

  public static void main(String[] args) throws Exception {
+    if (DFSUtil.parseHelpArgument(args, USAGE, System.out, true)) {
+      System.exit(0);
+    }
+    
    int res = ToolRunner.run(new GetConf(new HdfsConfiguration()), args);
    System.exit(res);
  }
--- a/hadoop-hdfs-project/hadoop-hdfs/src/main/java/org/apache/hadoop/hdfs/tools/GetGroups.java
+++ b/hadoop-hdfs-project/hadoop-hdfs/src/main/java/org/apache/hadoop/hdfs/tools/GetGroups.java
@ -28,6 +28,7 @@
 import org.apache.hadoop.fs.CommonConfigurationKeys;
 import org.apache.hadoop.fs.FileSystem;
 import org.apache.hadoop.hdfs.DFSConfigKeys;
+import org.apache.hadoop.hdfs.DFSUtil;
 import org.apache.hadoop.hdfs.HdfsConfiguration;
 import org.apache.hadoop.hdfs.NameNodeProxies;
 import org.apache.hadoop.hdfs.server.namenode.NameNode;
@ -43,6 +44,8 @@
 public class GetGroups extends GetGroupsBase {
  
  private static final Log LOG = LogFactory.getLog(GetGroups.class);
+  
+  static final String USAGE = "Usage: hdfs groups [username ...]";

  static{
    HdfsConfiguration.init();
@ -86,6 +89,10 @@ protected GetUserMappingsProtocol getUgmProtocol() throws IOException {
  }

  public static void main(String[] argv) throws Exception {
+    if (DFSUtil.parseHelpArgument(argv, USAGE, System.out, true)) {
+      System.exit(0);
+    }
+    
    int res = ToolRunner.run(new GetGroups(new HdfsConfiguration()), argv);
    System.exit(res);
  }
--- a/hadoop-hdfs-project/hadoop-hdfs/src/test/java/org/apache/hadoop/hdfs/tools/TestDFSHAAdmin.java
+++ b/hadoop-hdfs-project/hadoop-hdfs/src/test/java/org/apache/hadoop/hdfs/tools/TestDFSHAAdmin.java
@ -55,7 +55,9 @@ public class TestDFSHAAdmin {
  
  private DFSHAAdmin tool;
  private ByteArrayOutputStream errOutBytes = new ByteArrayOutputStream();
+  private ByteArrayOutputStream outBytes = new ByteArrayOutputStream();
  private String errOutput;
+  private String output;
  private HAServiceProtocol mockProtocol;
  private ZKFCProtocol mockZkfcProtocol;
  
@ -111,12 +113,14 @@ protected HAServiceTarget resolveTarget(String nnId) {
    };
    tool.setConf(getHAConf());
    tool.setErrOut(new PrintStream(errOutBytes));
+    tool.setOut(new PrintStream(outBytes));
  }

  private void assertOutputContains(String string) {
-    if (!errOutput.contains(string)) {
-      fail("Expected output to contain '" + string + "' but was:\n" +
-          errOutput);
+    if (!errOutput.contains(string) && !output.contains(string)) {
+      fail("Expected output to contain '" + string + 
+          "' but err_output was:\n" + errOutput + 
+          "\n and output was: \n" + output);
    }
  }
  
@ -143,7 +147,7 @@ public void testNamenodeResolution() throws Exception {

  @Test
  public void testHelp() throws Exception {
-    assertEquals(-1, runTool("-help"));
+    assertEquals(0, runTool("-help"));
    assertEquals(0, runTool("-help", "transitionToActive"));
    assertOutputContains("Transitions the service into Active");
  }
@ -378,10 +382,12 @@ public void testFencingConfigPerNameNode() throws Exception {
  
  private Object runTool(String ... args) throws Exception {
    errOutBytes.reset();
+    outBytes.reset();
    LOG.info("Running: DFSHAAdmin " + Joiner.on(" ").join(args));
    int ret = tool.run(args);
    errOutput = new String(errOutBytes.toByteArray(), Charsets.UTF_8);
-    LOG.info("Output:\n" + errOutput);
+    output = new String(outBytes.toByteArray(), Charsets.UTF_8);
+    LOG.info("Err_output:\n" + errOutput + "\nOutput:\n" + output);
    return ret;
  }