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Posted to mapreduce-commits@hadoop.apache.org by sz...@apache.org on 2011/11/23 23:02:20 UTC
svn commit: r1205626 - in
/hadoop/common/trunk/hadoop-mapreduce-project/hadoop-yarn/hadoop-yarn-site/src/site/apt:
Federation.apt.vm WebHDFS.apt.vm
Author: szetszwo
Date: Wed Nov 23 22:02:19 2011
New Revision: 1205626
URL: http://svn.apache.org/viewvc?rev=1205626&view=rev
Log:
HDFS-2587. Add apt doc for WebHDFS REST API.
Added:
hadoop/common/trunk/hadoop-mapreduce-project/hadoop-yarn/hadoop-yarn-site/src/site/apt/WebHDFS.apt.vm
Modified:
hadoop/common/trunk/hadoop-mapreduce-project/hadoop-yarn/hadoop-yarn-site/src/site/apt/Federation.apt.vm
Modified: hadoop/common/trunk/hadoop-mapreduce-project/hadoop-yarn/hadoop-yarn-site/src/site/apt/Federation.apt.vm
URL: http://svn.apache.org/viewvc/hadoop/common/trunk/hadoop-mapreduce-project/hadoop-yarn/hadoop-yarn-site/src/site/apt/Federation.apt.vm?rev=1205626&r1=1205625&r2=1205626&view=diff
==============================================================================
--- hadoop/common/trunk/hadoop-mapreduce-project/hadoop-yarn/hadoop-yarn-site/src/site/apt/Federation.apt.vm (original)
+++ hadoop/common/trunk/hadoop-mapreduce-project/hadoop-yarn/hadoop-yarn-site/src/site/apt/Federation.apt.vm Wed Nov 23 22:02:19 2011
@@ -12,7 +12,7 @@
~~ limitations under the License. See accompanying LICENSE file.
---
- Hadoop Map Reduce Next Generation-${project.version} - Cluster Setup
+ Hadoop Distributed File System-${project.version} - Federation
---
---
${maven.build.timestamp}
@@ -57,12 +57,12 @@ HDFS Federation
* Storage - is provided by datanodes by storing blocks on the local file
system and allows read/write access.
- The current HDFS architecture allows only a single namespace for the
+ The prior HDFS architecture allows only a single namespace for the
entire cluster. A single Namenode manages this namespace. HDFS
- Federation addresses limitation of current architecture by adding
+ Federation addresses limitation of the prior architecture by adding
support multiple Namenodes/namespaces to HDFS file system.
-* {HDFS Federation}
+* {Multiple Namenodes/Namespaces}
In order to scale the name service horizontally, federation uses multiple
independent Namenodes/namespaces. The Namenodes are federated, that is, the
@@ -103,9 +103,9 @@ HDFS Federation
of small files benefit from scaling the namespace by adding more
Namenodes to the cluster
- * Performance - File system operation throughput is currently limited
- by a single Namenode. Adding more Namenodes to the cluster scales the
- file system read/write operations throughput.
+ * Performance - File system operation throughput is limited by a single
+ Namenode in the prior architecture. Adding more Namenodes to the cluster
+ scales the file system read/write operations throughput.
* Isolation - A single Namenode offers no isolation in multi user
environment. An experimental application can overload the Namenode
@@ -265,7 +265,7 @@ HDFS Federation
> $HADOOP_PREFIX_HOME/bin/start-dfs.sh
----
- To start the cluster run the following command:
+ To stop the cluster run the following command:
----
> $HADOOP_PREFIX_HOME/bin/stop-dfs.sh
@@ -300,7 +300,7 @@ HDFS Federation
** Decommissioning
Decommissioning is similar to prior releases. The nodes that need to be
- decommissioning are added to the exclude file at all the Namenode. Each
+ decomissioned are added to the exclude file at all the Namenode. Each
Namenode decommissions its Block Pool. When all the Namenodes finish
decommissioning a datanode, the datanode is considered to be decommissioned.
Added: hadoop/common/trunk/hadoop-mapreduce-project/hadoop-yarn/hadoop-yarn-site/src/site/apt/WebHDFS.apt.vm
URL: http://svn.apache.org/viewvc/hadoop/common/trunk/hadoop-mapreduce-project/hadoop-yarn/hadoop-yarn-site/src/site/apt/WebHDFS.apt.vm?rev=1205626&view=auto
==============================================================================
--- hadoop/common/trunk/hadoop-mapreduce-project/hadoop-yarn/hadoop-yarn-site/src/site/apt/WebHDFS.apt.vm (added)
+++ hadoop/common/trunk/hadoop-mapreduce-project/hadoop-yarn/hadoop-yarn-site/src/site/apt/WebHDFS.apt.vm Wed Nov 23 22:02:19 2011
@@ -0,0 +1,1626 @@
+~~ Licensed under the Apache License, Version 2.0 (the "License");
+~~ you may not use this file except in compliance with the License.
+~~ You may obtain a copy of the License at
+~~
+~~ http://www.apache.org/licenses/LICENSE-2.0
+~~
+~~ Unless required by applicable law or agreed to in writing, software
+~~ distributed under the License is distributed on an "AS IS" BASIS,
+~~ WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+~~ See the License for the specific language governing permissions and
+~~ limitations under the License. See accompanying LICENSE file.
+
+ ---
+ Hadoop Distributed File System-${project.version} - WebHDFS REST API
+ ---
+ ---
+ ${maven.build.timestamp}
+
+WebHDFS REST API
+
+ \[ {{{./index.html}Go Back}} \]
+
+%{toc|section=1|fromDepth=0}
+
+* {Document Conventions}
+
+*----------------------+-------------------------------------------------------------------------------+
+| <<<Monospaced>>> | Used for commands, HTTP request and responses and code blocks. |
+*----------------------+-------------------------------------------------------------------------------+
+| <<<\<Monospaced\>>>> | User entered values. |
+*----------------------+-------------------------------------------------------------------------------+
+| <<<[Monospaced]>>> | Optional values. When the value is not specified, the default value is used. |
+*----------------------+-------------------------------------------------------------------------------+
+| <Italics> | Important phrases and words. |
+*----------------------+-------------------------------------------------------------------------------+
+
+
+* {Introduction}
+
+ The HTTP REST API supports the complete
+ {{{../../api/org/apache/hadoop/fs/FileSystem.html}FileSystem}} interface for HDFS.
+ The operations and the corresponding FileSystem 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.
+
+** {Operations}
+
+ * HTTP GET
+
+ * {{{Open and Read a File}<<<OPEN>>>}}
+ (see {{{../../api/org/apache/hadoop/fs/FileSystem.html}FileSystem}}.open)
+
+ * {{{Status of a File/Directory}<<<GETFILESTATUS>>>}}
+ (see {{{../../api/org/apache/hadoop/fs/FileSystem.html}FileSystem}}.getFileStatus)
+
+ * {{<<<LISTSTATUS>>>}}
+ (see {{{../../api/org/apache/hadoop/fs/FileSystem.html}FileSystem}}.listStatus)
+
+ * {{{Get Content Summary of a Directory}<<<GETCONTENTSUMMARY>>>}}
+ (see {{{../../api/org/apache/hadoop/fs/FileSystem.html}FileSystem}}.getContentSummary)
+
+ * {{{Get File Checksum}<<<GETFILECHECKSUM>>>}}
+ (see {{{../../api/org/apache/hadoop/fs/FileSystem.html}FileSystem}}.getFileChecksum)
+
+ * {{{Get Home Directory}<<<GETHOMEDIRECTORY>>>}}
+ (see {{{../../api/org/apache/hadoop/fs/FileSystem.html}FileSystem}}.getHomeDirectory)
+
+ * {{{Get Delegation Token}<<<GETDELEGATIONTOKEN>>>}}
+ (see {{{../../api/org/apache/hadoop/fs/FileSystem.html}FileSystem}}.getDelegationToken)
+
+ * HTTP PUT
+
+ * {{{Create and Write to a File}<<<CREATE>>>}}
+ (see {{{../../api/org/apache/hadoop/fs/FileSystem.html}FileSystem}}.create)
+
+ * {{{Make a Directory}<<<MKDIRS>>>}}
+ (see {{{../../api/org/apache/hadoop/fs/FileSystem.html}FileSystem}}.mkdirs)
+
+ * {{{Rename a File/Directory}<<<RENAME>>>}}
+ (see {{{../../api/org/apache/hadoop/fs/FileSystem.html}FileSystem}}.rename)
+
+ * {{{Set Replication Factor}<<<SETREPLICATION>>>}}
+ (see {{{../../api/org/apache/hadoop/fs/FileSystem.html}FileSystem}}.setReplication)
+
+ * {{{Set Owner}<<<SETOWNER>>>}}
+ (see {{{../../api/org/apache/hadoop/fs/FileSystem.html}FileSystem}}.setOwner)
+
+ * {{{Set Permission}<<<SETPERMISSION>>>}}
+ (see {{{../../api/org/apache/hadoop/fs/FileSystem.html}FileSystem}}.setPermission)
+
+ * {{{Set Access or Modification Time}<<<SETTIMES>>>}}
+ (see {{{../../api/org/apache/hadoop/fs/FileSystem.html}FileSystem}}.setTimes)
+
+ * {{{Renew Delegation Token}<<<RENEWDELEGATIONTOKEN>>>}}
+ (see {{{../../api/org/apache/hadoop/fs/FileSystem.html}FileSystem}}.renewDelegationToken)
+
+ * {{{Cancel Delegation Token}<<<CANCELDELEGATIONTOKEN>>>}}
+ (see {{{../../api/org/apache/hadoop/fs/FileSystem.html}FileSystem}}.cancelDelegationToken)
+
+ * HTTP POST
+
+ * {{{Append to a File}<<<APPEND>>>}}
+ (see {{{../../api/org/apache/hadoop/fs/FileSystem.html}FileSystem}}.append)
+
+ * HTTP DELETE
+
+ * {{{Delete a File/Directory}<<<DELETE>>>}}
+ (see {{{../../api/org/apache/hadoop/fs/FileSystem.html}FileSystem}}.delete)
+
+** {FileSystem URIs vs HTTP URLs}
+
+ The FileSystem scheme of WebHDFS is "<<<webhdfs://>>>".
+ A WebHDFS FileSystem URI has the following format.
+
++---------------------------------
+ webhdfs://<HOST>:<HTTP_PORT>/<PATH>
++---------------------------------
+
+ The above WebHDFS URI corresponds to the below HDFS URI.
+
++---------------------------------
+ hdfs://<HOST>:<RPC_PORT>/<PATH>
++---------------------------------
+
+ In the REST API, the prefix "<<</webhdfs/v1>>>" is inserted in the path and a query is appended at the end.
+ Therefore, the corresponding HTTP URL has the following format.
+
++---------------------------------
+ http://<HOST>:<HTTP_PORT>/webhdfs/v1/<PATH>?op=...
++---------------------------------
+
+* {Authentication}
+
+ When security is <off>, the authenticated user is the username specified in the <<<user.name>>> query parameter.
+ If the <<<user.name>>> parameter is not set,
+ the server may either set the authenticated user to a default web user, if there is any, or return an error response.
+
+
+ When security is <on>, authentication is performed by either Hadoop delegation token or Kerberos SPNEGO.
+ If a token is set in the <<<delegation>>> query parameter, the authenticated user is the user encoded in the token.
+ If the <<<delegation>>> parameter is not set, the user is authenticated by Kerberos SPNEGO.
+
+
+ Below are examples using the <<<curl>>> command tool.
+
+ [[1]] Authentication when security is off:
+
++---------------------------------
+curl -i "http://<HOST>:<PORT>/webhdfs/v1/<PATH>?[user.name=<USER>&]op=..."
++---------------------------------
+
+ [[1]] Authentication using Kerberos SPNEGO when security is on:
+
++---------------------------------
+curl -i --negotiate -u : "http://<HOST>:<PORT>/webhdfs/v1/<PATH>?op=..."
++---------------------------------
+
+ [[1]] Authentication using Hadoop delegation token when security is on:
+
++---------------------------------
+curl -i "http://<HOST>:<PORT>/webhdfs/v1/<PATH>?delegation=<TOKEN>&op=..."
++---------------------------------
+
+* {Proxy Users}
+
+ When the proxy user feature is enabled, a proxy user <P> may submit a request on behalf of another user <U>.
+ The username of <U> must be specified in the <<<doas>>> query parameter unless a delegation token is presented in authentication.
+ In such case, the information of both users <P> and <U> must be encoded in the delegation token.
+
+ [[1]] A proxy request when security is off:
+
++---------------------------------
+curl -i "http://<HOST>:<PORT>/webhdfs/v1/<PATH>?[user.name=<USER>&]doas=<USER>&op=..."
++---------------------------------
+
+ [[1]] A proxy request using Kerberos SPNEGO when security is on:
+
++---------------------------------
+curl -i --negotiate -u : "http://<HOST>:<PORT>/webhdfs/v1/<PATH>?doas=<USER>&op=..."
++---------------------------------
+
+ [[1]] A proxy request using Hadoop delegation token when security is on:
+
++---------------------------------
+curl -i "http://<HOST>:<PORT>/webhdfs/v1/<PATH>?delegation=<TOKEN>&op=..."
++---------------------------------
+
+
+* {File and Directory Operations}
+
+** {Create and Write to a File}
+
+ * Step 1: Submit a HTTP PUT request without automatically following redirects and without sending the file data.
+
++---------------------------------
+curl -i -X PUT "http://<HOST>:<PORT>/webhdfs/v1/<PATH>?op=CREATE
+ [&overwrite=<true|false>][&blocksize=<LONG>][&replication=<SHORT>]
+ [&permission=<OCTAL>][&buffersize=<INT>]"
++---------------------------------
+
+ The request is redirected to a datanode where the file data is to be written:
+
++---------------------------------
+HTTP/1.1 307 TEMPORARY_REDIRECT
+Location: http://<DATANODE>:<PORT>/webhdfs/v1/<PATH>?op=CREATE...
+Content-Length: 0
++---------------------------------
+
+ * Step 2: Submit another HTTP PUT request using the URL in the <<<Location>>> header with the file data to be written.
+
++---------------------------------
+curl -i -X PUT -T <LOCAL_FILE> "http://<DATANODE>:<PORT>/webhdfs/v1/<PATH>?op=CREATE..."
++---------------------------------
+
+ The client receives a <<<201 Created>>> response with zero content length
+ and the WebHDFS URI of the file in the <<<Location>>> header:
+
++---------------------------------
+HTTP/1.1 201 Created
+Location: webhdfs://<HOST>:<PORT>/<PATH>
+Content-Length: 0
++---------------------------------
+
+ []
+
+ <<Note>> that the reason of having two-step create/append is
+ for preventing clients to send out data before the redirect.
+ This issue is addressed by the "<<<Expect: 100-continue>>>" header in HTTP/1.1;
+ see {{{http://www.w3.org/Protocols/rfc2616/rfc2616-sec8.html#sec8.2.3}RFC 2616, Section 8.2.3}}.
+ Unfortunately, there are software library bugs (e.g. Jetty 6 HTTP server and Java 6 HTTP client),
+ which do not correctly implement "<<<Expect: 100-continue>>>".
+ The two-step create/append is a temporary workaround for the software library bugs.
+
+ See also:
+ {{{Overwrite}<<<overwrite>>>}},
+ {{{Block Size}<<<blocksize>>>}},
+ {{{Replication}<<<replication>>>}},
+ {{{Permission}<<<permission>>>}},
+ {{{Buffer Size}<<<buffersize>>>}},
+ {{{../../api/org/apache/hadoop/fs/FileSystem.html}FileSystem}}.create
+
+
+** {Append to a File}
+
+ * Step 1: Submit a HTTP POST request without automatically following redirects and without sending the file data.
+
++---------------------------------
+curl -i -X POST "http://<HOST>:<PORT>/webhdfs/v1/<PATH>?op=APPEND[&buffersize=<INT>]"
++---------------------------------
+
+ The request is redirected to a datanode where the file data is to be appended:
+
++---------------------------------
+HTTP/1.1 307 TEMPORARY_REDIRECT
+Location: http://<DATANODE>:<PORT>/webhdfs/v1/<PATH>?op=APPEND...
+Content-Length: 0
++---------------------------------
+
+ * Step 2: Submit another HTTP POST request using the URL in the <<<Location>>> header with the file data to be appended.
+
++---------------------------------
+curl -i -X POST -T <LOCAL_FILE> "http://<DATANODE>:<PORT>/webhdfs/v1/<PATH>?op=APPEND..."
++---------------------------------
+
+ The client receives a response with zero content length:
+
++---------------------------------
+HTTP/1.1 200 OK
+Content-Length: 0
++---------------------------------
+
+ []
+
+ See the note in the previous section for the description of why this operation requires two steps.
+
+ See also:
+ {{{Buffer Size}<<<buffersize>>>}},
+ {{{../../api/org/apache/hadoop/fs/FileSystem.html}FileSystem}}.append
+
+
+** {Open and Read a File}
+
+ * Submit a HTTP GET request with automatically following redirects.
+
++---------------------------------
+curl -i -L "http://<HOST>:<PORT>/webhdfs/v1/<PATH>?op=OPEN
+ [&offset=<LONG>][&length=<LONG>][&buffersize=<INT>]"
++---------------------------------
+
+ The request is redirected to a datanode where the file data can be read:
+
++---------------------------------
+HTTP/1.1 307 TEMPORARY_REDIRECT
+Location: http://<DATANODE>:<PORT>/webhdfs/v1/<PATH>?op=OPEN...
+Content-Length: 0
++---------------------------------
+
+ The client follows the redirect to the datanode and receives the file data:
+
++---------------------------------
+HTTP/1.1 200 OK
+Content-Type: application/octet-stream
+Content-Length: 22
+
+Hello, webhdfs user!
++---------------------------------
+
+ []
+
+ See also:
+ {{{Offset}<<<offset>>>}},
+ {{{Length}<<<length>>>}},
+ {{{Buffer Size}<<<buffersize>>>}},
+ {{{../../api/org/apache/hadoop/fs/FileSystem.html}FileSystem}}.open
+
+
+** {Make a Directory}
+
+ * Submit a HTTP PUT request.
+
++---------------------------------
+curl -i -X PUT "http://<HOST>:<PORT>/<PATH>?op=MKDIRS[&permission=<OCTAL>]"
++---------------------------------
+
+ The client receives a response with a {{{Boolean JSON Schema}<<<boolean>>> JSON object}}:
+
++---------------------------------
+HTTP/1.1 200 OK
+Content-Type: application/json
+Transfer-Encoding: chunked
+
+{"boolean": true}
++---------------------------------
+
+ []
+
+ See also:
+ {{{Permission}<<<permission>>>}},
+ {{{../../api/org/apache/hadoop/fs/FileSystem.html}FileSystem}}.mkdirs
+
+
+** {Rename a File/Directory}
+
+ * Submit a HTTP PUT request.
+
++---------------------------------
+curl -i -X PUT "<HOST>:<PORT>/webhdfs/v1/<PATH>?op=RENAME&destination=<PATH>"
++---------------------------------
+
+ The client receives a response with a {{{Boolean JSON Schema}<<<boolean>>> JSON object}}:
+
++---------------------------------
+HTTP/1.1 200 OK
+Content-Type: application/json
+Transfer-Encoding: chunked
+
+{"boolean": true}
++---------------------------------
+
+ []
+
+ See also:
+ {{{Destination}<<<destination>>>}},
+ {{{../../api/org/apache/hadoop/fs/FileSystem.html}FileSystem}}.rename
+
+
+** {Delete a File/Directory}
+
+ * Submit a HTTP DELETE request.
+
++---------------------------------
+curl -i -X DELETE "http://<host>:<port>/webhdfs/v1/<path>?op=DELETE
+ [&recursive=<true|false>]"
++---------------------------------
+
+ The client receives a response with a {{{Boolean JSON Schema}<<<boolean>>> JSON object}}:
+
++---------------------------------
+HTTP/1.1 200 OK
+Content-Type: application/json
+Transfer-Encoding: chunked
+
+{"boolean": true}
++---------------------------------
+
+ []
+
+ See also:
+ {{{Recursive}<<<recursive>>>}},
+ {{{../../api/org/apache/hadoop/fs/FileSystem.html}FileSystem}}.delete
+
+
+** {Status of a File/Directory}
+
+ * Submit a HTTP GET request.
+
++---------------------------------
+curl -i "http://<HOST>:<PORT>/webhdfs/v1/<PATH>?op=GETFILESTATUS"
++---------------------------------
+
+ The client receives a response with a {{{FileStatus JSON Schema}<<<FileStatus>>> JSON object}}:
+
++---------------------------------
+HTTP/1.1 200 OK
+Content-Type: application/json
+Transfer-Encoding: chunked
+
+{
+ "FileStatus":
+ {
+ "accessTime" : 0,
+ "blockSize" : 0,
+ "group" : "supergroup",
+ "length" : 0, //in bytes, zero for directories
+ "modificationTime": 1320173277227,
+ "owner" : "webuser",
+ "pathSuffix" : "",
+ "permission" : "777",
+ "replication" : 0,
+ "type" : "DIRECTORY" //enum {FILE, DIRECTORY, SYMLINK}
+ }
+}
++---------------------------------
+
+ []
+
+ See also:
+ {{{../../api/org/apache/hadoop/fs/FileSystem.html}FileSystem}}.getFileStatus
+
+
+** {List a Directory}
+
+ * Submit a HTTP GET request.
+
++---------------------------------
+curl -i "http://<HOST>:<PORT>/webhdfs/v1/<PATH>?op=LISTSTATUS"
++---------------------------------
+
+ The client receives a response with a {{{FileStatuses JSON Schema}<<<FileStatuses>>> JSON object}}:
+
++---------------------------------
+HTTP/1.1 200 OK
+Content-Type: application/json
+Content-Length: 427
+
+{
+ "FileStatuses":
+ {
+ "FileStatus":
+ [
+ {
+ "accessTime" : 1320171722771,
+ "blockSize" : 33554432,
+ "group" : "supergroup",
+ "length" : 24930,
+ "modificationTime": 1320171722771,
+ "owner" : "webuser",
+ "pathSuffix" : "a.patch",
+ "permission" : "644",
+ "replication" : 1,
+ "type" : "FILE"
+ },
+ {
+ "accessTime" : 0,
+ "blockSize" : 0,
+ "group" : "supergroup",
+ "length" : 0,
+ "modificationTime": 1320895981256,
+ "owner" : "szetszwo",
+ "pathSuffix" : "bar",
+ "permission" : "711",
+ "replication" : 0,
+ "type" : "DIRECTORY"
+ },
+ ...
+ ]
+ }
+}
++---------------------------------
+
+ []
+
+ See also:
+ {{{../../api/org/apache/hadoop/fs/FileSystem.html}FileSystem}}.listStatus
+
+
+* {Other File System Operations}
+
+** {Get Content Summary of a Directory}
+
+ * Submit a HTTP GET request.
+
++---------------------------------
+curl -i "http://<HOST>:<PORT>/webhdfs/v1/<PATH>?op=GETCONTENTSUMMARY"
++---------------------------------
+
+ The client receives a response with a {{{ContentSummary JSON Schema}<<<ContentSummary>>> JSON object}}:
+
++---------------------------------
+HTTP/1.1 200 OK
+Content-Type: application/json
+Transfer-Encoding: chunked
+
+{
+ "ContentSummary":
+ {
+ "directoryCount": 2,
+ "fileCount" : 1,
+ "length" : 24930,
+ "quota" : -1,
+ "spaceConsumed" : 24930,
+ "spaceQuota" : -1
+ }
+}
++---------------------------------
+
+ []
+
+ See also:
+ {{{../../api/org/apache/hadoop/fs/FileSystem.html}FileSystem}}.getContentSummary
+
+
+** {Get File Checksum}
+
+ * Submit a HTTP GET request.
+
++---------------------------------
+curl -i "http://<HOST>:<PORT>/webhdfs/v1/<PATH>?op=GETFILECHECKSUM"
++---------------------------------
+
+ The request is redirected to a datanode:
+
++---------------------------------
+HTTP/1.1 307 TEMPORARY_REDIRECT
+Location: http://<DATANODE>:<PORT>/webhdfs/v1/<PATH>?op=GETFILECHECKSUM...
+Content-Length: 0
++---------------------------------
+
+ The client follows the redirect to the datanode and receives a {{{FileChecksum JSON Schema}<<<FileChecksum>>> JSON object}}:
+
++---------------------------------
+HTTP/1.1 200 OK
+Content-Type: application/json
+Transfer-Encoding: chunked
+
+{
+ "FileChecksum":
+ {
+ "algorithm": "MD5-of-1MD5-of-512CRC32",
+ "bytes" : "eadb10de24aa315748930df6e185c0d ...",
+ "length" : 28
+ }
+}
++---------------------------------
+
+ []
+
+ See also:
+ {{{../../api/org/apache/hadoop/fs/FileSystem.html}FileSystem}}.getFileChecksum
+
+
+** {Get Home Directory}
+
+ * Submit a HTTP GET request.
+
++---------------------------------
+curl -i "http://<HOST>:<PORT>/webhdfs/v1/?op=GETHOMEDIRECTORY"
++---------------------------------
+
+ The client receives a response with a {{{Path JSON Schema}<<<Path>>> JSON object}}:
+
++---------------------------------
+HTTP/1.1 200 OK
+Content-Type: application/json
+Transfer-Encoding: chunked
+
+{"Path": "/user/szetszwo"}
++---------------------------------
+
+ []
+
+ See also:
+ {{{../../api/org/apache/hadoop/fs/FileSystem.html}FileSystem}}.getHomeDirectory
+
+
+** {Set Permission}
+
+ * Submit a HTTP PUT request.
+
++---------------------------------
+curl -i -X PUT "http://<HOST>:<PORT>/webhdfs/v1/<PATH>?op=SETPERMISSION
+ [&permission=<OCTAL>]"
++---------------------------------
+
+ The client receives a response with zero content length:
+
++---------------------------------
+HTTP/1.1 200 OK
+Content-Length: 0
++---------------------------------
+
+ []
+
+ See also:
+ {{{Permission}<<<permission>>>}},
+ {{{../../api/org/apache/hadoop/fs/FileSystem.html}FileSystem}}.setPermission
+
+
+** {Set Owner}
+
+ * Submit a HTTP PUT request.
+
++---------------------------------
+curl -i -X PUT "http://<HOST>:<PORT>/webhdfs/v1/<PATH>?op=SETOWNER
+ [&owner=<USER>][&group=<GROUP>]"
++---------------------------------
+
+ The client receives a response with zero content length:
+
++---------------------------------
+HTTP/1.1 200 OK
+Content-Length: 0
++---------------------------------
+
+ []
+
+ See also:
+ {{{Owner}<<<owner>>>}},
+ {{{Group}<<<group>>>}},
+ {{{../../api/org/apache/hadoop/fs/FileSystem.html}FileSystem}}.setOwner
+
+
+** {Set Replication Factor}
+
+ * Submit a HTTP PUT request.
+
++---------------------------------
+curl -i -X PUT "http://<HOST>:<PORT>/webhdfs/v1/<PATH>?op=SETREPLICATION
+ [&replication=<SHORT>]"
++---------------------------------
+
+ The client receives a response with a {{{Boolean JSON Schema}<<<boolean>>> JSON object}}:
+
++---------------------------------
+HTTP/1.1 200 OK
+Content-Type: application/json
+Transfer-Encoding: chunked
+
+{"boolean": true}
++---------------------------------
+
+ []
+
+ See also:
+ {{{Replication}<<<replication>>>}},
+ {{{../../api/org/apache/hadoop/fs/FileSystem.html}FileSystem}}.setReplication
+
+
+** {Set Access or Modification Time}
+
+ * Submit a HTTP PUT request.
+
++---------------------------------
+curl -i -X PUT "http://<HOST>:<PORT>/webhdfs/v1/<PATH>?op=SETTIMES
+ [&modificationtime=<TIME>][&accesstime=<TIME>]"
++---------------------------------
+
+ The client receives a response with zero content length:
+
++---------------------------------
+HTTP/1.1 200 OK
+Content-Length: 0
++---------------------------------
+
+ []
+
+ See also:
+ {{{Modification Time}<<<modificationtime>>>}},
+ {{{Access Time}<<<accesstime>>>}},
+ {{{../../api/org/apache/hadoop/fs/FileSystem.html}FileSystem}}.setTimes
+
+
+* {Delegation Token Operations}
+
+** {Get Delegation Token}
+
+ * Submit a HTTP GET request.
+
++---------------------------------
+curl -i "http://<HOST>:<PORT>/webhdfs/v1/?op=GETDELEGATIONTOKEN&renewer=<USER>"
++---------------------------------
+
+ The client receives a response with a {{{Token JSON Schema}<<<Token>>> JSON object}}:
+
++---------------------------------
+HTTP/1.1 200 OK
+Content-Type: application/json
+Transfer-Encoding: chunked
+
+{
+ "Token":
+ {
+ "urlString": "JQAIaG9y..."
+ }
+}
++---------------------------------
+
+ []
+
+ See also:
+ {{{Renewer}<<<renewer>>>}},
+ {{{../../api/org/apache/hadoop/fs/FileSystem.html}FileSystem}}.getDelegationToken
+
+
+** {Renew Delegation Token}
+
+ * Submit a HTTP PUT request.
+
++---------------------------------
+curl -i -X PUT "http://<HOST>:<PORT>/webhdfs/v1/?op=RENEWDELEGATIONTOKEN&token=<TOKEN>"
++---------------------------------
+
+ The client receives a response with a {{{Long JSON Schema}<<<long>>> JSON object}}:
+
++---------------------------------
+HTTP/1.1 200 OK
+Content-Type: application/json
+Transfer-Encoding: chunked
+
+{"long": 1320962673997} //the new expiration time
++---------------------------------
+
+ []
+
+ See also:
+ {{{Token}<<<token>>>}},
+ {{{../../api/org/apache/hadoop/fs/FileSystem.html}FileSystem}}.renewDelegationToken
+
+
+** {Cancel Delegation Token}
+
+ * Submit a HTTP PUT request.
+
++---------------------------------
+curl -i -X PUT "http://<HOST>:<PORT>/webhdfs/v1/?op=CANCELDELEGATIONTOKEN&token=<TOKEN>"
++---------------------------------
+
+ The client receives a response with zero content length:
+
++---------------------------------
+HTTP/1.1 200 OK
+Content-Length: 0
++---------------------------------
+
+ []
+
+ See also:
+ {{{Token}<<<token>>>}},
+ {{{../../api/org/apache/hadoop/fs/FileSystem.html}FileSystem}}.cancelDelegationToken
+
+
+* {Error Responses}
+
+ When an operation fails, the server may throw an exception.
+ The JSON schema of error responses is defined in {{<<<RemoteException>>> JSON schema}}.
+ The table below shows the mapping from exceptions to HTTP response codes.
+
+** {HTTP Response Codes}
+
+*-------------------------------------+---------------------------------+
+|| Exceptions || HTTP Response Codes |
+*-------------------------------------+---------------------------------+
+| <<<IllegalArgumentException >>> | <<<400 Bad Request >>> |
+*-------------------------------------+---------------------------------+
+| <<<UnsupportedOperationException>>> | <<<400 Bad Request >>> |
+*-------------------------------------+---------------------------------+
+| <<<SecurityException >>> | <<<401 Unauthorized >>> |
+*-------------------------------------+---------------------------------+
+| <<<IOException >>> | <<<403 Forbidden >>> |
+*-------------------------------------+---------------------------------+
+| <<<FileNotFoundException >>> | <<<404 Not Found >>> |
+*-------------------------------------+---------------------------------+
+| <<<RumtimeException >>> | <<<500 Internal Server Error>>> |
+*-------------------------------------+---------------------------------+
+
+ Below are examples of exception responses.
+
+*** {Illegal Argument Exception}
+
++---------------------------------
+HTTP/1.1 400 Bad Request
+Content-Type: application/json
+Transfer-Encoding: chunked
+
+{
+ "RemoteException":
+ {
+ "exception" : "IllegalArgumentException",
+ "javaClassName": "java.lang.IllegalArgumentException",
+ "message" : "Invalid value for webhdfs parameter \"permission\": ..."
+ }
+}
++---------------------------------
+
+
+*** {Security Exception}
+
++---------------------------------
+HTTP/1.1 401 Unauthorized
+Content-Type: application/json
+Transfer-Encoding: chunked
+
+{
+ "RemoteException":
+ {
+ "exception" : "SecurityException",
+ "javaClassName": "java.lang.SecurityException",
+ "message" : "Failed to obtain user group information: ..."
+ }
+}
++---------------------------------
+
+
+*** {Access Control Exception}
+
++---------------------------------
+HTTP/1.1 403 Forbidden
+Content-Type: application/json
+Transfer-Encoding: chunked
+
+{
+ "RemoteException":
+ {
+ "exception" : "AccessControlException",
+ "javaClassName": "org.apache.hadoop.security.AccessControlException",
+ "message" : "Permission denied: ..."
+ }
+}
++---------------------------------
+
+
+*** {File Not Found Exception}
+
++---------------------------------
+HTTP/1.1 404 Not Found
+Content-Type: application/json
+Transfer-Encoding: chunked
+
+{
+ "RemoteException":
+ {
+ "exception" : "FileNotFoundException",
+ "javaClassName": "java.io.FileNotFoundException",
+ "message" : "File does not exist: /foo/a.patch"
+ }
+}
++---------------------------------
+
+
+* {JSON Schemas}
+
+ All operations, except for {{{Open and Read a File}<<<OPEN>>>}},
+ either return a zero-length response or a JSON response.
+ For {{{Open and Read a File}<<<OPEN>>>}}, the response is an octet-stream.
+ The JSON schemas are shown below.
+ See {{{http://tools.ietf.org/id/draft-zyp-json-schema-03.html}draft-zyp-json-schema-03}}
+ for the syntax definitions of the JSON schemas.
+
+
+** {Boolean JSON Schema}
+
++---------------------------------
+{
+ "name" : "boolean",
+ "properties":
+ {
+ "boolean":
+ {
+ "description": "A boolean value",
+ "type" : "boolean",
+ "required" : true
+ }
+ }
+}
++---------------------------------
+
+ See also:
+ {{{Make a Directory}<<<MKDIRS>>>}},
+ {{{Rename a File/Directory}<<<RENAME>>>}},
+ {{{Delete a File/Directory}<<<DELETE>>>}},
+ {{{Set Replication Factor}<<<SETREPLICATION>>>}}
+
+
+** {ContentSummary JSON Schema}
+
++---------------------------------
+{
+ "name" : "ContentSummary",
+ "properties":
+ {
+ "ContentSummary":
+ {
+ "type" : "object",
+ "properties":
+ {
+ "directoryCount":
+ {
+ "description": "The number of directories.",
+ "type" : "integer",
+ "required" : true
+ },
+ "fileCount":
+ {
+ "description": "The number of files.",
+ "type" : "integer",
+ "required" : true
+ },
+ "length":
+ {
+ "description": "The number of bytes used by the content.",
+ "type" : "integer",
+ "required" : true
+ },
+ "quota":
+ {
+ "description": "The namespace quota of this directory.",
+ "type" : "integer",
+ "required" : true
+ },
+ "spaceConsumed":
+ {
+ "description": "The disk space consumed by the content.",
+ "type" : "integer",
+ "required" : true
+ },
+ "spaceQuota":
+ {
+ "description": "The disk space quota.",
+ "type" : "integer",
+ "required" : true
+ }
+ }
+ }
+ }
+}
++---------------------------------
+
+ See also:
+ {{{Get Content Summary of a Directory}<<<GETCONTENTSUMMARY>>>}}
+
+
+** {FileChecksum JSON Schema}
+
++---------------------------------
+{
+ "name" : "FileChecksum",
+ "properties":
+ {
+ "FileChecksum":
+ {
+ "type" : "object",
+ "properties":
+ {
+ "algorithm":
+ {
+ "description": "The name of the checksum algorithm.",
+ "type" : "string",
+ "required" : true
+ },
+ "bytes":
+ {
+ "description": "The byte sequence of the checksum in hexadecimal.",
+ "type" : "string",
+ "required" : true
+ },
+ "length":
+ {
+ "description": "The length of the bytes (not the length of the string).",
+ "type" : "integer",
+ "required" : true
+ }
+ }
+ }
+ }
+}
++---------------------------------
+
+ See also:
+ {{{Get File Checksum}<<<GETFILECHECKSUM>>>}}
+
+
+** {FileStatus JSON Schema}
+
++---------------------------------
+{
+ "name" : "FileStatus",
+ "properties":
+ {
+ "FileStatus": fileStatusProperties //See FileStatus Properties
+ }
+}
++---------------------------------
+
+ See also:
+ {{{FileStatus Properties}<<<FileStatus>>> Properties}},
+ {{{Status of a File/Directory}<<<GETFILESTATUS>>>}},
+ {{{../../api/org/apache/hadoop/fs/FileStatus}FileStatus}}
+
+
+*** {FileStatus Properties}
+
+ JavaScript syntax is used to define <<<fileStatusProperties>>>
+ so that it can be referred in both <<<FileStatus>>> and <<<FileStatuses>>> JSON schemas.
+
++---------------------------------
+var fileStatusProperties =
+{
+ "type" : "object",
+ "properties":
+ {
+ "accessTime":
+ {
+ "description": "The access time.",
+ "type" : "integer",
+ "required" : true
+ },
+ "blockSize":
+ {
+ "description": "The block size of a file.",
+ "type" : "integer",
+ "required" : true
+ },
+ "group":
+ {
+ "description": "The group owner.",
+ "type" : "string",
+ "required" : true
+ },
+ "length":
+ {
+ "description": "The number of bytes in a file.",
+ "type" : "integer",
+ "required" : true
+ },
+ "modificationTime":
+ {
+ "description": "The modification time.",
+ "type" : "integer",
+ "required" : true
+ },
+ "owner":
+ {
+ "description": "The user who is the owner.",
+ "type" : "string",
+ "required" : true
+ },
+ "pathSuffix":
+ {
+ "description": "The path suffix.",
+ "type" : "string",
+ "required" : true
+ },
+ "permission":
+ {
+ "description": "The permission represented as a octal string.",
+ "type" : "string",
+ "required" : true
+ },
+ "replication":
+ {
+ "description": "The number of replication of a file.",
+ "type" : "integer",
+ "required" : true
+ },
+ "symlink": //an optional property
+ {
+ "description": "The link target of a symlink.",
+ "type" : "string"
+ },
+ "type":
+ {
+ "description": "The type of the path object.",
+ "enum" : ["FILE", "DIRECTORY", "SYMLINK"],
+ "required" : true
+ }
+ }
+};
++---------------------------------
+
+
+** {FileStatuses JSON Schema}
+
+ A <<<FileStatuses>>> JSON object represents an array of <<<FileStatus>>> JSON objects.
+
++---------------------------------
+{
+ "name" : "FileStatuses",
+ "properties":
+ {
+ "FileStatuses":
+ {
+ "type" : "object",
+ "properties":
+ {
+ "FileStatus":
+ {
+ "description": "An array of FileStatus",
+ "type" : "array",
+ "items" : fileStatusProperties //See FileStatus Properties
+ }
+ }
+ }
+ }
+}
++---------------------------------
+
+ See also:
+ {{{FileStatus Properties}<<<FileStatus>>> Properties}},
+ {{{List a Directory}<<<LISTSTATUS>>>}},
+ {{{../../api/org/apache/hadoop/fs/FileStatus}FileStatus}}
+
+
+** {Long JSON Schema}
+
++---------------------------------
+{
+ "name" : "long",
+ "properties":
+ {
+ "long":
+ {
+ "description": "A long integer value",
+ "type" : "integer",
+ "required" : true
+ }
+ }
+}
++---------------------------------
+
+ See also:
+ {{{Renew Delegation Token}<<<RENEWDELEGATIONTOKEN>>>}},
+
+
+** {Path JSON Schema}
+
++---------------------------------
+{
+ "name" : "Path",
+ "properties":
+ {
+ "Path":
+ {
+ "description": "The string representation a Path.",
+ "type" : "string",
+ "required" : true
+ }
+ }
+}
++---------------------------------
+
+ See also:
+ {{{Get Home Directory}<<<GETHOMEDIRECTORY>>>}},
+ {{{../../api/org/apache/hadoop/fs/Path}Path}}
+
+
+** {RemoteException JSON Schema}
+
++---------------------------------
+{
+ "name" : "RemoteException",
+ "properties":
+ {
+ "RemoteException":
+ {
+ "type" : "object",
+ "properties":
+ {
+ "exception":
+ {
+ "description": "Name of the exception",
+ "type" : "string",
+ "required" : true
+ },
+ "message":
+ {
+ "description": "Exception message",
+ "type" : "string",
+ "required" : true
+ },
+ "javaClassName": //an optional property
+ {
+ "description": "Java class name of the exception",
+ "type" : "string",
+ }
+ }
+ }
+ }
+}
++---------------------------------
+
+ See also:
+ {{Error Responses}}
+
+
+** {Token JSON Schema}
+
++---------------------------------
+{
+ "name" : "Token",
+ "properties":
+ {
+ "Token":
+ {
+ "type" : "object",
+ "properties":
+ {
+ "urlString":
+ {
+ "description": "A delegation token encoded as a URL safe string.",
+ "type" : "string",
+ "required" : true
+ }
+ }
+ }
+ }
+}
++---------------------------------
+
+ See also:
+ {{{Get Delegation Token}<<<GETDELEGATIONTOKEN>>>}},
+ the note in {{Delegation}}.
+
+
+* {HTTP Query Parameter Dictionary}
+
+** {Access Time}
+
+*----------------+-------------------------------------------------------------------+
+|| Name | <<<accesstime>>> |
+*----------------+-------------------------------------------------------------------+
+|| Description | The access time of a file/directory. |
+*----------------+-------------------------------------------------------------------+
+|| Type | long |
+*----------------+-------------------------------------------------------------------+
+|| Default Value | -1 (means keeping it unchanged) |
+*----------------+-------------------------------------------------------------------+
+|| Valid Values | -1 or a timestamp |
+*----------------+-------------------------------------------------------------------+
+|| Syntax | Any integer. |
+*----------------+-------------------------------------------------------------------+
+
+ See also:
+ {{{Set Access or Modification Time}<<<SETTIMES>>>}}
+
+
+** {Block Size}
+
+*----------------+-------------------------------------------------------------------+
+|| Name | <<<blocksize>>> |
+*----------------+-------------------------------------------------------------------+
+|| Description | The block size of a file. |
+*----------------+-------------------------------------------------------------------+
+|| Type | long |
+*----------------+-------------------------------------------------------------------+
+|| Default Value | Specified in the configuration. |
+*----------------+-------------------------------------------------------------------+
+|| Valid Values | \> 0 |
+*----------------+-------------------------------------------------------------------+
+|| Syntax | Any integer. |
+*----------------+-------------------------------------------------------------------+
+
+ See also:
+ {{{Create and Write to a File}<<<CREATE>>>}}
+
+
+** {Buffer Size}
+
+*----------------+-------------------------------------------------------------------+
+|| Name | <<<buffersize>>> |
+*----------------+-------------------------------------------------------------------+
+|| Description | The size of the buffer used in transferring data. |
+*----------------+-------------------------------------------------------------------+
+|| Type | int |
+*----------------+-------------------------------------------------------------------+
+|| Default Value | Specified in the configuration. |
+*----------------+-------------------------------------------------------------------+
+|| Valid Values | \> 0 |
+*----------------+-------------------------------------------------------------------+
+|| Syntax | Any integer. |
+*----------------+-------------------------------------------------------------------+
+
+ See also:
+ {{{Create and Write to a File}<<<CREATE>>>}},
+ {{{Append to a File}<<<APPEND>>>}},
+ {{{Open and Read a File}<<<OPEN>>>}}
+
+
+** {Delegation}
+
+*----------------+-------------------------------------------------------------------+
+|| Name | <<<delegation>>> |
+*----------------+-------------------------------------------------------------------+
+|| Description | The delegation token used for authentication. |
+*----------------+-------------------------------------------------------------------+
+|| Type | String |
+*----------------+-------------------------------------------------------------------+
+|| Default Value | \<empty\> |
+*----------------+-------------------------------------------------------------------+
+|| Valid Values | An encoded token. |
+*----------------+-------------------------------------------------------------------+
+|| Syntax | See the note below. |
+*----------------+-------------------------------------------------------------------+
+
+ <<Note>> that delegation tokens are encoded as a URL safe string;
+ see <<<encodeToUrlString()>>>
+ and <<<decodeFromUrlString(String)>>>
+ in <<<org.apache.hadoop.security.token.Token>>> for the details of the encoding.
+
+
+ See also:
+ {{Authentication}}
+
+
+** {Destination}
+
+*----------------+-------------------------------------------------------------------+
+|| Name | <<<destination>>> |
+*----------------+-------------------------------------------------------------------+
+|| Description | The destination path used in {{{Rename a File/Directory}<<<RENAME>>>}}. |
+*----------------+-------------------------------------------------------------------+
+|| Type | Path |
+*----------------+-------------------------------------------------------------------+
+|| Default Value | \<empty\> (an invalid path) |
+*----------------+-------------------------------------------------------------------+
+|| Valid Values | An absolute FileSystem path without scheme and authority. |
+*----------------+-------------------------------------------------------------------+
+|| Syntax | Any path. |
+*----------------+-------------------------------------------------------------------+
+
+ See also:
+ {{{Rename a File/Directory}<<<RENAME>>>}}
+
+
+** {Do As}
+
+*----------------+-------------------------------------------------------------------+
+|| Name | <<<doas>>> |
+*----------------+-------------------------------------------------------------------+
+|| Description | Allowing a proxy user to do as another user. |
+*----------------+-------------------------------------------------------------------+
+|| Type | String |
+*----------------+-------------------------------------------------------------------+
+|| Default Value | null |
+*----------------+-------------------------------------------------------------------+
+|| Valid Values | Any valid username. |
+*----------------+-------------------------------------------------------------------+
+|| Syntax | Any string. |
+*----------------+-------------------------------------------------------------------+
+
+ See also:
+ {{Proxy Users}}
+
+
+** {Group}
+
+*----------------+-------------------------------------------------------------------+
+|| Name | <<<group>>> |
+*----------------+-------------------------------------------------------------------+
+|| Description | The name of a group. |
+*----------------+-------------------------------------------------------------------+
+|| Type | String |
+*----------------+-------------------------------------------------------------------+
+|| Default Value | \<empty\> (means keeping it unchanged) |
+*----------------+-------------------------------------------------------------------+
+|| Valid Values | Any valid group name. |
+*----------------+-------------------------------------------------------------------+
+|| Syntax | Any string. |
+*----------------+-------------------------------------------------------------------+
+
+ See also:
+ {{{Set Owner}<<<SETOWNER>>>}}
+
+
+** {Length}
+
+*----------------+-------------------------------------------------------------------+
+|| Name | <<<length>>> |
+*----------------+-------------------------------------------------------------------+
+|| Description | The number of bytes to be processed. |
+*----------------+-------------------------------------------------------------------+
+|| Type | long |
+*----------------+-------------------------------------------------------------------+
+|| Default Value | null (means the entire file) |
+*----------------+-------------------------------------------------------------------+
+|| Valid Values | \>= 0 or null |
+*----------------+-------------------------------------------------------------------+
+|| Syntax | Any integer. |
+*----------------+-------------------------------------------------------------------+
+
+ See also:
+ {{{Open and Read a File}<<<OPEN>>>}}
+
+
+** {Modification Time}
+
+*----------------+-------------------------------------------------------------------+
+|| Name | <<<modificationtime>>> |
+*----------------+-------------------------------------------------------------------+
+|| Description | The modification time of a file/directory. |
+*----------------+-------------------------------------------------------------------+
+|| Type | long |
+*----------------+-------------------------------------------------------------------+
+|| Default Value | -1 (means keeping it unchanged) |
+*----------------+-------------------------------------------------------------------+
+|| Valid Values | -1 or a timestamp |
+*----------------+-------------------------------------------------------------------+
+|| Syntax | Any integer. |
+*----------------+-------------------------------------------------------------------+
+
+ See also:
+ {{{Set Access or Modification Time}<<<SETTIMES>>>}}
+
+
+** {Offset}
+
+*----------------+-------------------------------------------------------------------+
+|| Name | <<<offset>>> |
+*----------------+-------------------------------------------------------------------+
+|| Description | The starting byte position. |
+*----------------+-------------------------------------------------------------------+
+|| Type | long |
+*----------------+-------------------------------------------------------------------+
+|| Default Value | 0 |
+*----------------+-------------------------------------------------------------------+
+|| Valid Values | \>= 0 |
+*----------------+-------------------------------------------------------------------+
+|| Syntax | Any integer. |
+*----------------+-------------------------------------------------------------------+
+
+ See also:
+ {{{Open and Read a File}<<<OPEN>>>}}
+
+
+** {Op}
+
+*----------------+-------------------------------------------------------------------+
+|| Name | <<<op>>> |
+*----------------+-------------------------------------------------------------------+
+|| Description | The name of the operation to be executed. |
+*----------------+-------------------------------------------------------------------+
+|| Type | enum |
+*----------------+-------------------------------------------------------------------+
+|| Default Value | null (an invalid value) |
+*----------------+-------------------------------------------------------------------+
+|| Valid Values | Any valid operation name. |
+*----------------+-------------------------------------------------------------------+
+|| Syntax | Any string. |
+*----------------+-------------------------------------------------------------------+
+
+ See also:
+ {{Operations}}
+
+
+** {Overwrite}
+
+*----------------+-------------------------------------------------------------------+
+|| Name | <<<overwrite>>> |
+*----------------+-------------------------------------------------------------------+
+|| Description | If a file already exists, should it be overwritten? |
+*----------------+-------------------------------------------------------------------+
+|| Type | boolean |
+*----------------+-------------------------------------------------------------------+
+|| Default Value | false |
+*----------------+-------------------------------------------------------------------+
+|| Valid Values | true | false |
+*----------------+-------------------------------------------------------------------+
+|| Syntax | true | false |
+*----------------+-------------------------------------------------------------------+
+
+ See also:
+ {{{Create and Write to a File}<<<CREATE>>>}}
+
+
+** {Owner}
+
+*----------------+-------------------------------------------------------------------+
+|| Name | <<<owner>>> |
+*----------------+-------------------------------------------------------------------+
+|| Description | The username who is the owner of a file/directory. |
+*----------------+-------------------------------------------------------------------+
+|| Type | String |
+*----------------+-------------------------------------------------------------------+
+|| Default Value | \<empty\> (means keeping it unchanged) |
+*----------------+-------------------------------------------------------------------+
+|| Valid Values | Any valid username. |
+*----------------+-------------------------------------------------------------------+
+|| Syntax | Any string. |
+*----------------+-------------------------------------------------------------------+
+
+ See also:
+ {{{Set Owner}<<<SETOWNER>>>}}
+
+
+** {Permission}
+
+*----------------+-------------------------------------------------------------------+
+|| Name | <<<permission>>> |
+*----------------+-------------------------------------------------------------------+
+|| Description | The permission of a file/directory. |
+*----------------+-------------------------------------------------------------------+
+|| Type | Octal |
+*----------------+-------------------------------------------------------------------+
+|| Default Value | 755 |
+*----------------+-------------------------------------------------------------------+
+|| Valid Values | 0 - 1777 |
+*----------------+-------------------------------------------------------------------+
+|| Syntax | Any radix-8 integer (leading zeros may be omitted.) |
+*----------------+-------------------------------------------------------------------+
+
+ See also:
+ {{{Create and Write to a File}<<<CREATE>>>}},
+ {{{Make a Directory}<<<MKDIRS>>>}},
+ {{{Set Permission}<<<SETPERMISSION>>>}}
+
+
+** {Recursive}
+
+*----------------+-------------------------------------------------------------------+
+|| Name | <<<recursive>>> |
+*----------------+-------------------------------------------------------------------+
+|| Description | Should the operation act on the content in the subdirectories? |
+*----------------+-------------------------------------------------------------------+
+|| Type | boolean |
+*----------------+-------------------------------------------------------------------+
+|| Default Value | false |
+*----------------+-------------------------------------------------------------------+
+|| Valid Values | true | false |
+*----------------+-------------------------------------------------------------------+
+|| Syntax | true | false |
+*----------------+-------------------------------------------------------------------+
+
+ See also:
+ {{{Rename a File/Directory}<<<RENAME>>>}}
+
+
+** {Renewer}
+
+*----------------+-------------------------------------------------------------------+
+|| Name | <<<renewer>>> |
+*----------------+-------------------------------------------------------------------+
+|| Description | The username of the renewer of a delegation token. |
+*----------------+-------------------------------------------------------------------+
+|| Type | String |
+*----------------+-------------------------------------------------------------------+
+|| Default Value | \<empty\> (means the current user) |
+*----------------+-------------------------------------------------------------------+
+|| Valid Values | Any valid username. |
+*----------------+-------------------------------------------------------------------+
+|| Syntax | Any string. |
+*----------------+-------------------------------------------------------------------+
+
+ See also:
+ {{{Get Delegation Token}<<<GETDELEGATIONTOKEN>>>}}
+
+
+** {Replication}
+
+*----------------+-------------------------------------------------------------------+
+|| Name | <<<replication>>> |
+*----------------+-------------------------------------------------------------------+
+|| Description | The number of replications of a file. |
+*----------------+-------------------------------------------------------------------+
+|| Type | short |
+*----------------+-------------------------------------------------------------------+
+|| Default Value | Specified in the configuration. |
+*----------------+-------------------------------------------------------------------+
+|| Valid Values | \> 0 |
+*----------------+-------------------------------------------------------------------+
+|| Syntax | Any integer. |
+*----------------+-------------------------------------------------------------------+
+
+ See also:
+ {{{Create and Write to a File}<<<CREATE>>>}},
+ {{{Set Replication Factor}<<<SETREPLICATION>>>}}
+
+
+** {Token}
+
+*----------------+-------------------------------------------------------------------+
+|| Name | <<<token>>> |
+*----------------+-------------------------------------------------------------------+
+|| Description | The delegation token used for the operation. |
+*----------------+-------------------------------------------------------------------+
+|| Type | String |
+*----------------+-------------------------------------------------------------------+
+|| Default Value | \<empty\> |
+*----------------+-------------------------------------------------------------------+
+|| Valid Values | An encoded token. |
+*----------------+-------------------------------------------------------------------+
+|| Syntax | See the note in {{Delegation}}. |
+*----------------+-------------------------------------------------------------------+
+
+ See also:
+ {{{Renew Delegation Token}<<<RENEWDELEGATIONTOKEN>>>}},
+ {{{Cancel Delegation Token}<<<CANCELDELEGATIONTOKEN>>>}}
+
+
+** {Username}
+
+*----------------+-------------------------------------------------------------------+
+|| Name | <<<user.name>>> |
+*----------------+-------------------------------------------------------------------+
+|| Description | The authenticated user; see {{Authentication}}. |
+*----------------+-------------------------------------------------------------------+
+|| Type | String |
+*----------------+-------------------------------------------------------------------+
+|| Default Value | null |
+*----------------+-------------------------------------------------------------------+
+|| Valid Values | Any valid username. |
+*----------------+-------------------------------------------------------------------+
+|| Syntax | Any string. |
+*----------------+-------------------------------------------------------------------+
+
+ See also:
+ {{Authentication}}
+