HDFS-2594. Support getDelegationTokens and createSymlink in WebHDFS.

git-svn-id: https://svn.apache.org/repos/asf/hadoop/common/trunk@1212299 13f79535-47bb-0310-9956-ffa450edef68

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

@@ -151,6 +151,9 @@ Release 0.23.1 - UNRELEASED
     HDFS-2316. [umbrella] WebHDFS: a complete FileSystem implementation for 
     accessing HDFS over HTTP (szetszwo)
 
+    HDFS-2594. Support getDelegationTokens and createSymlink in WebHDFS.
+    (szetszwo)
+
   IMPROVEMENTS
     HDFS-2560. Refactor BPOfferService to be a static inner class (todd)
 

hadoop-hdfs-project/hadoop-hdfs/src/main/java/org/apache/hadoop/hdfs/server/namenode/web/resources/NamenodeWebHdfsMethods.java

@@ -66,6 +66,7 @@
 import org.apache.hadoop.hdfs.web.resources.AccessTimeParam;
 import org.apache.hadoop.hdfs.web.resources.BlockSizeParam;
 import org.apache.hadoop.hdfs.web.resources.BufferSizeParam;
+import org.apache.hadoop.hdfs.web.resources.CreateParentParam;
 import org.apache.hadoop.hdfs.web.resources.DelegationParam;
 import org.apache.hadoop.hdfs.web.resources.DeleteOpParam;
 import org.apache.hadoop.hdfs.web.resources.DestinationParam;
@@ -245,12 +246,14 @@ public Response putRoot(
           final AccessTimeParam accessTime,
       @QueryParam(RenameOptionSetParam.NAME) @DefaultValue(RenameOptionSetParam.DEFAULT)
           final RenameOptionSetParam renameOptions,
+      @QueryParam(CreateParentParam.NAME) @DefaultValue(CreateParentParam.DEFAULT)
+          final CreateParentParam createParent,
       @QueryParam(TokenArgumentParam.NAME) @DefaultValue(TokenArgumentParam.DEFAULT)
           final TokenArgumentParam delegationTokenArgument
       ) throws IOException, InterruptedException {
     return put(ugi, delegation, username, doAsUser, ROOT, op, destination,
         owner, group, permission, overwrite, bufferSize, replication,
-        blockSize, modificationTime, accessTime, renameOptions,
+        blockSize, modificationTime, accessTime, renameOptions, createParent,
         delegationTokenArgument);
   }
 
@@ -292,6 +295,8 @@ public Response put(
           final AccessTimeParam accessTime,
       @QueryParam(RenameOptionSetParam.NAME) @DefaultValue(RenameOptionSetParam.DEFAULT)
           final RenameOptionSetParam renameOptions,
+      @QueryParam(CreateParentParam.NAME) @DefaultValue(CreateParentParam.DEFAULT)
+          final CreateParentParam createParent,
       @QueryParam(TokenArgumentParam.NAME) @DefaultValue(TokenArgumentParam.DEFAULT)
           final TokenArgumentParam delegationTokenArgument
       ) throws IOException, InterruptedException {
@@ -325,6 +330,12 @@ public Response run() throws IOException, URISyntaxException {
       final String js = JsonUtil.toJsonString("boolean", b);
       return Response.ok(js).type(MediaType.APPLICATION_JSON).build();
     }
+    case CREATESYMLINK:
+    {
+      np.createSymlink(destination.getValue(), fullpath,
+          PermissionParam.getDefaultFsPermission(), createParent.getValue());
+      return Response.ok().type(MediaType.APPLICATION_JSON).build();
+    }
     case RENAME:
     {
       final EnumSet<Options.Rename> s = renameOptions.getValue();
@@ -578,6 +589,17 @@ public Response run() throws IOException, URISyntaxException {
       final String js = JsonUtil.toJsonString(token);
       return Response.ok(js).type(MediaType.APPLICATION_JSON).build();
     }
+    case GETDELEGATIONTOKENS:
+    {
+      if (delegation.getValue() != null) {
+        throw new IllegalArgumentException(delegation.getName()
+            + " parameter is not null.");
+      }
+      final Token<? extends TokenIdentifier>[] tokens = new Token<?>[1];
+      tokens[0] = generateDelegationToken(namenode, ugi, renewer.getValue());
+      final String js = JsonUtil.toJsonString(tokens);
+      return Response.ok(js).type(MediaType.APPLICATION_JSON).build();
+    }
     case GETHOMEDIRECTORY:
     {
       final String js = JsonUtil.toJsonString(

hadoop-hdfs-project/hadoop-hdfs/src/main/java/org/apache/hadoop/hdfs/web/JsonUtil.java

@@ -97,6 +97,59 @@ private static Token<BlockTokenIdentifier> toBlockToken(
     return (Token<BlockTokenIdentifier>)toToken(m);
   }
 
+  /** Convert a Token[] to a JSON array. */
+  private static Object[] toJsonArray(final Token<? extends TokenIdentifier>[] array
+      ) throws IOException {
+    if (array == null) {
+      return null;
+    } else if (array.length == 0) {
+      return EMPTY_OBJECT_ARRAY;
+    } else {
+      final Object[] a = new Object[array.length];
+      for(int i = 0; i < array.length; i++) {
+        a[i] = toJsonMap(array[i]);
+      }
+      return a;
+    }
+  }
+
+  /** Convert a token object to a JSON string. */
+  public static String toJsonString(final Token<? extends TokenIdentifier>[] tokens
+      ) throws IOException {
+    if (tokens == null) {
+      return null;
+    }
+
+    final Map<String, Object> m = new TreeMap<String, Object>();
+    m.put(Token.class.getSimpleName(), toJsonArray(tokens));
+    return toJsonString(Token.class.getSimpleName() + "s", m);
+  }
+
+  /** Convert an Object[] to a List<Token<?>>.  */
+  private static List<Token<?>> toTokenList(final Object[] objects) throws IOException {
+    if (objects == null) {
+      return null;
+    } else if (objects.length == 0) {
+      return Collections.emptyList();
+    } else {
+      final List<Token<?>> list = new ArrayList<Token<?>>(objects.length);
+      for(int i = 0; i < objects.length; i++) {
+        list.add(toToken((Map<?, ?>)objects[i]));
+      }
+      return list;
+    }
+  }
+
+  /** Convert a JSON map to a List<Token<?>>. */
+  public static List<Token<?>> toTokenList(final Map<?, ?> json) throws IOException {
+    if (json == null) {
+      return null;
+    }
+
+    final Map<?, ?> m = (Map<?, ?>)json.get(Token.class.getSimpleName() + "s");
+    return toTokenList((Object[])m.get(Token.class.getSimpleName()));
+  }
+
   /** Convert an exception object to a Json string. */
   public static String toJsonString(final Exception e) {
     final Map<String, Object> m = new TreeMap<String, Object>();

hadoop-hdfs-project/hadoop-hdfs/src/main/java/org/apache/hadoop/hdfs/web/WebHdfsFileSystem.java

@@ -29,7 +29,6 @@
 import java.net.URI;
 import java.net.URISyntaxException;
 import java.net.URL;
-import java.util.Arrays;
 import java.util.List;
 import java.util.Map;
 import java.util.StringTokenizer;
@@ -64,6 +63,7 @@
 import org.apache.hadoop.hdfs.web.resources.AccessTimeParam;
 import org.apache.hadoop.hdfs.web.resources.BlockSizeParam;
 import org.apache.hadoop.hdfs.web.resources.BufferSizeParam;
+import org.apache.hadoop.hdfs.web.resources.CreateParentParam;
 import org.apache.hadoop.hdfs.web.resources.DeleteOpParam;
 import org.apache.hadoop.hdfs.web.resources.DestinationParam;
 import org.apache.hadoop.hdfs.web.resources.GetOpParam;
@@ -318,8 +318,9 @@ URL toUrl(final HttpOpParam.Op op, final Path fspath,
         + '&' + new UserParam(ugi)
         + Param.toSortedString("&", parameters);
     final URL url;
-    if (op.equals(PutOpParam.Op.RENEWDELEGATIONTOKEN)
+    if (op == PutOpParam.Op.RENEWDELEGATIONTOKEN
-        || op.equals(GetOpParam.Op.GETDELEGATIONTOKEN)) {
+        || op == GetOpParam.Op.GETDELEGATIONTOKEN
+        || op == GetOpParam.Op.GETDELEGATIONTOKENS) {
       // Skip adding delegation token for getting or renewing delegation token,
       // because these operations require kerberos authentication.
       url = getNamenodeURL(path, query);
@@ -458,6 +459,18 @@ public boolean mkdirs(Path f, FsPermission permission) throws IOException {
     return (Boolean)json.get("boolean");
   }
 
+  /**
+   * Create a symlink pointing to the destination path.
+   * @see org.apache.hadoop.fs.Hdfs#createSymlink(Path, Path, boolean) 
+   */
+  public void createSymlink(Path destination, Path f, boolean createParent
+      ) throws IOException {
+    statistics.incrementWriteOps(1);
+    final HttpOpParam.Op op = PutOpParam.Op.CREATESYMLINK;
+    run(op, f, new DestinationParam(makeQualified(destination).toUri().getPath()),
+        new CreateParentParam(createParent));
+  }
+
   @Override
   public boolean rename(final Path src, final Path dst) throws IOException {
     statistics.incrementWriteOps(1);
@@ -703,8 +716,13 @@ public Token<DelegationTokenIdentifier> getDelegationToken(final String renewer
   @Override
   public List<Token<?>> getDelegationTokens(final String renewer
       ) throws IOException {
-    final Token<?>[] t = {getDelegationToken(renewer)};
+    final HttpOpParam.Op op = GetOpParam.Op.GETDELEGATIONTOKENS;
-    return Arrays.asList(t);
+    final Map<?, ?> m = run(op, null, new RenewerParam(renewer));
+    final List<Token<?>> tokens = JsonUtil.toTokenList(m);
+    for(Token<?> t : tokens) {
+      SecurityUtil.setTokenService(t, nnAddr);
+    }
+    return tokens;
   }
 
   @Override

hadoop-hdfs-project/hadoop-hdfs/src/main/java/org/apache/hadoop/hdfs/web/resources/CreateParentParam.java

@@ -0,0 +1,49 @@
+/**
+ * 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.web.resources;
+
+/** Create Parent parameter. */
+public class CreateParentParam extends BooleanParam {
+  /** Parameter name. */
+  public static final String NAME = "createparent";
+  /** Default parameter value. */
+  public static final String DEFAULT = FALSE;
+
+  private static final Domain DOMAIN = new Domain(NAME);
+
+  /**
+   * Constructor.
+   * @param value the parameter value.
+   */
+  public CreateParentParam(final Boolean value) {
+    super(DOMAIN, value);
+  }
+
+  /**
+   * Constructor.
+   * @param str a string representation of the parameter value.
+   */
+  public CreateParentParam(final String str) {
+    this(DOMAIN.parse(str));
+  }
+
+  @Override
+  public String getName() {
+    return NAME;
+  }
+}

hadoop-hdfs-project/hadoop-hdfs/src/main/java/org/apache/hadoop/hdfs/web/resources/GetOpParam.java

@@ -32,6 +32,7 @@ public static enum Op implements HttpOpParam.Op {
 
     GETHOMEDIRECTORY(HttpURLConnection.HTTP_OK),
     GETDELEGATIONTOKEN(HttpURLConnection.HTTP_OK),
+    GETDELEGATIONTOKENS(HttpURLConnection.HTTP_OK),
 
     /** GET_BLOCK_LOCATIONS is a private unstable op. */
     GET_BLOCK_LOCATIONS(HttpURLConnection.HTTP_OK),

hadoop-hdfs-project/hadoop-hdfs/src/main/java/org/apache/hadoop/hdfs/web/resources/PermissionParam.java

@@ -29,6 +29,11 @@ public class PermissionParam extends ShortParam {
   private static final Domain DOMAIN = new Domain(NAME, 8);
 
   private static final short DEFAULT_PERMISSION = 0755;
+
+  /** @return the default FsPermission. */
+  public static FsPermission getDefaultFsPermission() {
+    return new FsPermission(DEFAULT_PERMISSION);
+  }
   
   /**
    * Constructor.

hadoop-hdfs-project/hadoop-hdfs/src/main/java/org/apache/hadoop/hdfs/web/resources/PutOpParam.java

@@ -26,6 +26,7 @@ public static enum Op implements HttpOpParam.Op {
     CREATE(true, HttpURLConnection.HTTP_CREATED),
 
     MKDIRS(false, HttpURLConnection.HTTP_OK),
+    CREATESYMLINK(false, HttpURLConnection.HTTP_OK),
     RENAME(false, HttpURLConnection.HTTP_OK),
     SETREPLICATION(false, HttpURLConnection.HTTP_OK),
 

hadoop-hdfs-project/hadoop-hdfs/src/test/java/org/apache/hadoop/fs/TestFcHdfsSymlink.java

@@ -17,29 +17,28 @@
  */
 package org.apache.hadoop.fs;
 
-import java.io.*;
+import static org.apache.hadoop.fs.FileContextTestHelper.getAbsoluteTestRootDir;
+import static org.junit.Assert.assertEquals;
+import static org.junit.Assert.fail;
+
+import java.io.IOException;
 import java.net.URI;
 
 import org.apache.commons.logging.impl.Log4JLogger;
-import org.apache.log4j.Level;
-
 import org.apache.hadoop.conf.Configuration;
-import org.apache.hadoop.fs.FileStatus;
-import org.apache.hadoop.fs.FileContext;
-import org.apache.hadoop.fs.Path;
 import org.apache.hadoop.fs.permission.FsPermission;
 import org.apache.hadoop.hdfs.DFSConfigKeys;
 import org.apache.hadoop.hdfs.HdfsConfiguration;
 import org.apache.hadoop.hdfs.MiniDFSCluster;
-import org.apache.hadoop.hdfs.server.namenode.NameNode;
 import org.apache.hadoop.hdfs.protocol.HdfsConstants;
-import static org.apache.hadoop.fs.FileContextTestHelper.*;
+import org.apache.hadoop.hdfs.server.namenode.NameNode;
+import org.apache.hadoop.hdfs.web.WebHdfsFileSystem;
+import org.apache.hadoop.hdfs.web.WebHdfsTestUtil;
 import org.apache.hadoop.ipc.RemoteException;
-
+import org.apache.log4j.Level;
-import static org.junit.Assert.*;
-import org.junit.Test;
-import org.junit.BeforeClass;
 import org.junit.AfterClass;
+import org.junit.BeforeClass;
+import org.junit.Test;
 
 /**
  * Test symbolic links using FileContext and Hdfs.
@@ -51,6 +50,8 @@ public class TestFcHdfsSymlink extends FileContextSymlinkBaseTest {
   }
 
   private static MiniDFSCluster cluster;
+  private static WebHdfsFileSystem webhdfs;
+
   
   protected String getScheme() {
     return "hdfs";
@@ -79,10 +80,11 @@ protected IOException unwrapException(IOException e) {
   @BeforeClass
   public static void testSetUp() throws Exception {
     Configuration conf = new HdfsConfiguration();
-    conf.setBoolean(DFSConfigKeys.DFS_PERMISSIONS_ENABLED_KEY, true);
+    conf.setBoolean(DFSConfigKeys.DFS_WEBHDFS_ENABLED_KEY, true);
     conf.set(FsPermission.UMASK_LABEL, "000");
     cluster = new MiniDFSCluster.Builder(conf).build();
     fc = FileContext.getFileContext(cluster.getURI(0));
+    webhdfs = WebHdfsTestUtil.getWebHdfsFileSystem(conf);
   }
   
   @AfterClass
@@ -263,4 +265,17 @@ public void testLinkOwner() throws IOException {
     FileStatus statLink = fc.getFileStatus(link);
     assertEquals(statLink.getOwner(), statFile.getOwner());
   }
+
+  @Test
+  /** Test WebHdfsFileSystem.craeteSymlink(..). */  
+  public void testWebHDFS() throws IOException {
+    Path file = new Path(testBaseDir1(), "file");
+    Path link = new Path(testBaseDir1(), "linkToFile");
+    createAndWriteFile(file);
+    webhdfs.createSymlink(file, link, false);
+    fc.setReplication(link, (short)2);
+    assertEquals(0, fc.getFileLinkStatus(link).getReplication());
+    assertEquals(2, fc.getFileStatus(link).getReplication());      
+    assertEquals(2, fc.getFileStatus(file).getReplication());
+  }
 }

hadoop-hdfs-project/hadoop-hdfs/src/test/java/org/apache/hadoop/hdfs/security/TestDelegationToken.java

@@ -25,6 +25,7 @@
 import java.io.IOException;
 import java.net.URI;
 import java.security.PrivilegedExceptionAction;
+import java.util.List;
 
 import org.apache.commons.logging.Log;
 import org.apache.commons.logging.LogFactory;
@@ -183,23 +184,44 @@ public WebHdfsFileSystem run() throws Exception {
       }
     });
 
-    final Token<DelegationTokenIdentifier> token = webhdfs
+    { //test getDelegationToken(..)
-        .getDelegationToken("JobTracker");
+      final Token<DelegationTokenIdentifier> token = webhdfs
-    DelegationTokenIdentifier identifier = new DelegationTokenIdentifier();
+          .getDelegationToken("JobTracker");
-    byte[] tokenId = token.getIdentifier();
+      DelegationTokenIdentifier identifier = new DelegationTokenIdentifier();
-    identifier
+      byte[] tokenId = token.getIdentifier();
-        .readFields(new DataInputStream(new ByteArrayInputStream(tokenId)));
+      identifier.readFields(new DataInputStream(new ByteArrayInputStream(tokenId)));
-    LOG.info("A valid token should have non-null password, and should be renewed successfully");
+      LOG.info("A valid token should have non-null password, and should be renewed successfully");
-    Assert.assertTrue(null != dtSecretManager.retrievePassword(identifier));
+      Assert.assertTrue(null != dtSecretManager.retrievePassword(identifier));
-    dtSecretManager.renewToken(token, "JobTracker");
+      dtSecretManager.renewToken(token, "JobTracker");
-    ugi.doAs(new PrivilegedExceptionAction<Object>() {
+      ugi.doAs(new PrivilegedExceptionAction<Void>() {
-      @Override
+        @Override
-      public Object run() throws Exception {
+        public Void run() throws Exception {
-        token.renew(config);
+          token.renew(config);
-        token.cancel(config);
+          token.cancel(config);
-        return null;
+          return null;
-      }
+        }
-    });
+      });
+    }
+
+    { //test getDelegationTokens(..)
+      final List<Token<?>> tokenlist = webhdfs.getDelegationTokens("JobTracker");
+      DelegationTokenIdentifier identifier = new DelegationTokenIdentifier();
+      @SuppressWarnings("unchecked")
+      final Token<DelegationTokenIdentifier> token = (Token<DelegationTokenIdentifier>)tokenlist.get(0);
+      byte[] tokenId = token.getIdentifier();
+      identifier.readFields(new DataInputStream(new ByteArrayInputStream(tokenId)));
+      LOG.info("A valid token should have non-null password, and should be renewed successfully");
+      Assert.assertTrue(null != dtSecretManager.retrievePassword(identifier));
+      dtSecretManager.renewToken(token, "JobTracker");
+      ugi.doAs(new PrivilegedExceptionAction<Void>() {
+        @Override
+        public Void run() throws Exception {
+          token.renew(config);
+          token.cancel(config);
+          return null;
+        }
+      });
+    }
   }
 
   @SuppressWarnings("deprecation")

hadoop-mapreduce-project/hadoop-yarn/hadoop-yarn-site/src/site/apt/WebHDFS.apt.vm

@@ -38,8 +38,9 @@ WebHDFS REST API
 * {Introduction}
 
   The HTTP REST API supports the complete
-  {{{../../api/org/apache/hadoop/fs/FileSystem.html}FileSystem}} interface for HDFS.
+  {{{../../api/org/apache/hadoop/fs/FileSystem.html}FileSystem}}/{{{../../api/org/apache/hadoop/fs/FileContext.html}FileContext}}
-  The operations and the corresponding FileSystem methods are shown in the next section.
+  interface for HDFS.
+  The operations and the corresponding FileSystem/FileContext methods are shown in the next section.
   The Section {{HTTP Query Parameter Dictionary}} specifies the parameter details
   such as the defaults and the valid values.
 
@@ -68,6 +69,9 @@ WebHDFS REST API
     * {{{Get Delegation Token}<<<GETDELEGATIONTOKEN>>>}}
         (see  {{{../../api/org/apache/hadoop/fs/FileSystem.html}FileSystem}}.getDelegationToken)
 
+    * {{{Get Delegation Tokens}<<<GETDELEGATIONTOKENS>>>}}
+        (see  {{{../../api/org/apache/hadoop/fs/FileSystem.html}FileSystem}}.getDelegationTokens)
+
   * HTTP PUT
 
     * {{{Create and Write to a File}<<<CREATE>>>}}
@@ -76,6 +80,9 @@ WebHDFS REST API
     * {{{Make a Directory}<<<MKDIRS>>>}}
         (see  {{{../../api/org/apache/hadoop/fs/FileSystem.html}FileSystem}}.mkdirs)
 
+    * {{{Create a Symbolic Link}<<<CREATESYMLINK>>>}}
+        (see  {{{../../api/org/apache/hadoop/fs/FileContext.html}FileContext}}.createSymlink)
+
     * {{{Rename a File/Directory}<<<RENAME>>>}}
         (see  {{{../../api/org/apache/hadoop/fs/FileSystem.html}FileSystem}}.rename)
 
@@ -129,6 +136,20 @@ WebHDFS REST API
   http://<HOST>:<HTTP_PORT>/webhdfs/v1/<PATH>?op=...
 +---------------------------------
 
+** {HDFS Configuration Options}
+
+  Below are the HDFS configuration options for WebHDFS.
+
+*-------------------------------------------------+---------------------------------------------------+
+|| Property Name	                          || Description                                      |
+*-------------------------------------------------+---------------------------------------------------+
+| <<<dfs.webhdfs.enabled                      >>> | Enable/disable WebHDFS in Namenodes and Datanodes |
+*-------------------------------------------------+---------------------------------------------------+
+| <<<dfs.web.authentication.kerberos.principal>>> | The HTTP Kerberos principal used by Hadoop-Auth in the HTTP endpoint. The HTTP Kerberos principal MUST start with 'HTTP/' per Kerberos HTTP SPENGO specification. |
+*-------------------------------------------------+---------------------------------------------------+
+| <<<dfs.web.authentication.kerberos.keytab   >>> | The Kerberos keytab file with the credentials for the HTTP Kerberos principal used by Hadoop-Auth in the HTTP endpoint. |
+*-------------------------------------------------+---------------------------------------------------+
+
 * {Authentication}
 
   When security is <off>, the authenticated user is the username specified in the <<<user.name>>> query parameter.
@@ -339,6 +360,30 @@ Transfer-Encoding: chunked
    {{{../../api/org/apache/hadoop/fs/FileSystem.html}FileSystem}}.mkdirs
 
 
+** {Create a Symbolic Link}
+
+  * Submit a HTTP PUT request.
+
++---------------------------------
+curl -i -X PUT "http://<HOST>:<PORT>/<PATH>?op=CREATESYMLINK
+                              &destination=<PATH>[&createParent=<true|false>]"
++---------------------------------
+
+  The client receives a response with zero content length:
+
++---------------------------------
+HTTP/1.1 200 OK
+Content-Length: 0
++---------------------------------
+
+  []
+
+  See also:
+  {{{Destination}<<<destination>>>}},
+  {{{Create Parent}<<<createParent>>>}},
+   {{{../../api/org/apache/hadoop/fs/FileSystem.html}FileSystem}}.createSymlink
+
+
 ** {Rename a File/Directory}
 
   * Submit a HTTP PUT request.
@@ -712,6 +757,41 @@ Transfer-Encoding: chunked
    {{{../../api/org/apache/hadoop/fs/FileSystem.html}FileSystem}}.getDelegationToken
 
 
+** {Get Delegation Tokens}
+
+  * Submit a HTTP GET request.
+
++---------------------------------
+curl -i "http://<HOST>:<PORT>/webhdfs/v1/?op=GETDELEGATIONTOKENS&renewer=<USER>"
++---------------------------------
+
+  The client receives a response with a {{{Tokens JSON Schema}<<<Tokens>>> JSON object}}:
+
++---------------------------------
+HTTP/1.1 200 OK
+Content-Type: application/json
+Transfer-Encoding: chunked
+
+{
+  "Tokens":
+  {
+    "Token":
+    [
+      {
+        "urlString":"KAAKSm9i ..."
+      }
+    ]
+  }
+}
++---------------------------------
+
+  []
+
+  See also:
+  {{{Renewer}<<<renewer>>>}},
+   {{{../../api/org/apache/hadoop/fs/FileSystem.html}FileSystem}}.getDelegationTokens
+
+
 ** {Renew Delegation Token}
 
   * Submit a HTTP PUT request.
@@ -1209,16 +1289,56 @@ var fileStatusProperties =
   "name"      : "Token",
   "properties":
   {
-    "Token":
+    "Token": tokenProperties      //See Token Properties
+  }
+}
++---------------------------------
+
+  See also:
+  {{{Token Properties}<<<Token>>> Properties}},
+  {{{Get Delegation Token}<<<GETDELEGATIONTOKEN>>>}},
+  the note in {{Delegation}}.
+
+*** {Token Properties}
+
+  JavaScript syntax is used to define <<<tokenProperties>>>
+  so that it can be referred in both <<<Token>>> and <<<Tokens>>> JSON schemas.
+
++---------------------------------
+var tokenProperties =
+{
+  "type"      : "object",
+  "properties":
+  {
+    "urlString":
+    {
+      "description": "A delegation token encoded as a URL safe string.",
+      "type"       : "string",
+      "required"   : true
+    }
+  }
+}
++---------------------------------
+
+** {Tokens JSON Schema}
+
+  A <<<Tokens>>> JSON object represents an array of <<<Token>>> JSON objects.
+
++---------------------------------
+{
+  "name"      : "Tokens",
+  "properties":
+  {
+    "Tokens":
     {
       "type"      : "object",
       "properties":
       {
-        "urlString":
+        "Token":
         {
-          "description": "A delegation token encoded as a URL safe string.",
+          "description": "An array of Token",
-          "type"       : "string",
+          "type"       : "array",
-          "required"   : true
+          "items"      : "Token": tokenProperties      //See Token Properties
         }
       }
     }
@@ -1227,7 +1347,8 @@ var fileStatusProperties =
 +---------------------------------
 
   See also:
-  {{{Get Delegation Token}<<<GETDELEGATIONTOKEN>>>}},
+  {{{Token Properties}<<<Token>>> Properties}},
+  {{{Get Delegation Tokens}<<<GETDELEGATIONTOKENS>>>}},
   the note in {{Delegation}}.
 
 
@@ -1295,6 +1416,26 @@ var fileStatusProperties =
   {{{Open and Read a File}<<<OPEN>>>}}
 
 
+** {Create Parent}
+
+*----------------+-------------------------------------------------------------------+
+|| Name          | <<<createparent>>> |
+*----------------+-------------------------------------------------------------------+
+|| Description   | If the parent directories do not exist, should they be created?   |
+*----------------+-------------------------------------------------------------------+
+|| Type          | boolean |
+*----------------+-------------------------------------------------------------------+
+|| Default Value | false |
+*----------------+-------------------------------------------------------------------+
+|| Valid Values  | true | false |
+*----------------+-------------------------------------------------------------------+
+|| Syntax        | true | false |
+*----------------+-------------------------------------------------------------------+
+
+  See also:
+  {{{Create a Symbolic Link}<<<CREATESYMLINK>>>}}
+
+
 ** {Delegation}
 
 *----------------+-------------------------------------------------------------------+
@@ -1326,7 +1467,7 @@ var fileStatusProperties =
 *----------------+-------------------------------------------------------------------+
 || Name          | <<<destination>>> |
 *----------------+-------------------------------------------------------------------+
-|| Description   | The destination path used in {{{Rename a File/Directory}<<<RENAME>>>}}. |
+|| Description   | The destination path. |
 *----------------+-------------------------------------------------------------------+
 || Type          | Path |
 *----------------+-------------------------------------------------------------------+
@@ -1338,6 +1479,7 @@ var fileStatusProperties =
 *----------------+-------------------------------------------------------------------+
 
   See also:
+  {{{Create a Symbolic Link}<<<CREATESYMLINK>>>}},
   {{{Rename a File/Directory}<<<RENAME>>>}}
 
 
@@ -1560,7 +1702,8 @@ var fileStatusProperties =
 *----------------+-------------------------------------------------------------------+
 
   See also:
-  {{{Get Delegation Token}<<<GETDELEGATIONTOKEN>>>}}
+  {{{Get Delegation Token}<<<GETDELEGATIONTOKEN>>>}},
+  {{{Get Delegation Tokens}<<<GETDELEGATIONTOKENS>>>}}
 
 
 ** {Replication}