| 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. |
The HTTP REST API supports the complete FileSystem/FileContext 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.
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=...
Note that if WebHDFS is secured with SSL, then the scheme should be “swebhdfs://”.
swebhdfs://<HOST>:<HTTP_PORT>/<PATH>
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 SPNEGO specification. A value of “*” will use all HTTP principals found in the keytab. |
| 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. |
| dfs.webhdfs.socket.connect-timeout | How long to wait for a connection to be established before failing. Specified as a time duration, ie numerical value followed by a units symbol, eg 2m for two minutes. Defaults to 60s. |
| dfs.webhdfs.socket.read-timeout | How long to wait for data to arrive before failing. Defaults to 60s. |
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.
Authentication when security is off:
curl -i "http://<HOST>:<PORT>/webhdfs/v1/<PATH>?[user.name=<USER>&]op=..."
Authentication using Kerberos SPNEGO when security is on:
curl -i --negotiate -u : "http://<HOST>:<PORT>/webhdfs/v1/<PATH>?op=..."
Authentication using Hadoop delegation token when security is on:
curl -i "http://<HOST>:<PORT>/webhdfs/v1/<PATH>?delegation=<TOKEN>&op=..."
See also: Authentication for Hadoop HTTP web-consoles
Additionally, WebHDFS supports OAuth2 on the client side. The Namenode and Datanodes do not currently support clients using OAuth2 but other backends that implement the WebHDFS REST interface may.
WebHDFS supports two type of OAuth2 code grants (user-provided refresh and access token or user provided credential) by default and provides a pluggable mechanism for implementing other OAuth2 authentications per the OAuth2 RFC, or custom authentications. When using either of the provided code grant mechanisms, the WebHDFS client will refresh the access token as necessary.
OAuth2 should only be enabled for clients not running with Kerberos SPENGO.
| OAuth2 code grant mechanism | Description | Value of dfs.webhdfs.oauth2.access.token.provider that implements code grant |
|---|---|---|
| Authorization Code Grant | The user provides an initial access token and refresh token, which are then used to authenticate WebHDFS requests and obtain replacement access tokens, respectively. | org.apache.hadoop.hdfs.web.oauth2.ConfRefreshTokenBasedAccessTokenProvider |
| Client Credentials Grant | The user provides a credential which is used to obtain access tokens, which are then used to authenticate WebHDFS requests. | org.apache.hadoop.hdfs.web.oauth2.ConfCredentialBasedAccessTokenProvider |
The following properties control OAuth2 authentication.
| OAuth2 related property | Description |
|---|---|
| dfs.webhdfs.oauth2.enabled | Boolean to enable/disable OAuth2 authentication |
| dfs.webhdfs.oauth2.access.token.provider | Class name of an implementation of org.apache.hadoop.hdfs.web.oauth.AccessTokenProvider. Two are provided with the code, as described above, or the user may specify a user-provided implementation. The default value for this configuration key is the ConfCredentialBasedAccessTokenProvider implementation. |
| dfs.webhdfs.oauth2.client.id | Client id used to obtain access token with either credential or refresh token |
| dfs.webhdfs.oauth2.refresh.url | URL against which to post for obtaining bearer token with either credential or refresh token |
| dfs.webhdfs.oauth2.access.token | (required if using ConfRefreshTokenBasedAccessTokenProvider) Initial access token with which to authenticate |
| dfs.webhdfs.oauth2.refresh.token | (required if using ConfRefreshTokenBasedAccessTokenProvider) Initial refresh token to use to obtain new access tokens |
| dfs.webhdfs.oauth2.refresh.token.expires.ms.since.epoch | (required if using ConfRefreshTokenBasedAccessTokenProvider) Access token expiration measured in milliseconds since Jan 1, 1970. Note this is a different value than provided by OAuth providers and has been munged as described in interface to be suitable for a client application |
| dfs.webhdfs.oauth2.credential | (required if using ConfCredentialBasedAccessTokenProvider). Credential used to obtain initial and subsequent access tokens. |
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.
A proxy request when security is off:
curl -i "http://<HOST>:<PORT>/webhdfs/v1/<PATH>?[user.name=<USER>&]doas=<USER>&op=..."
A proxy request using Kerberos SPNEGO when security is on:
curl -i --negotiate -u : "http://<HOST>:<PORT>/webhdfs/v1/<PATH>?doas=<USER>&op=..."
A proxy request using Hadoop delegation token when security is on:
curl -i "http://<HOST>:<PORT>/webhdfs/v1/<PATH>?delegation=<TOKEN>&op=..."
WebHDFS supports an optional, configurable mechanism for cross-site request forgery (CSRF) prevention. When enabled, WebHDFS HTTP requests to the NameNode or DataNode must include a custom HTTP header. Configuration properties allow adjusting which specific HTTP methods are protected and the name of the HTTP header. The value sent in the header is not relevant. Only the presence of a header by that name is required.
Enabling CSRF prevention also sets up the WebHdfsFileSystem class to send the required header. This ensures that CLI commands like hdfs dfs and hadoop distcp continue to work correctly when used with webhdfs: URIs.
Enabling CSRF prevention also sets up the NameNode web UI to send the required header. After enabling CSRF prevention and restarting the NameNode, existing users of the NameNode web UI need to refresh the browser to reload the page and find the new configuration.
The following properties control CSRF prevention.
| Property | Description | Default Value |
|---|---|---|
| dfs.webhdfs.rest-csrf.enabled | If true, then enables WebHDFS protection against cross-site request forgery (CSRF). The WebHDFS client also uses this property to determine whether or not it needs to send the custom CSRF prevention header in its HTTP requests. | false |
| dfs.webhdfs.rest-csrf.custom-header | The name of a custom header that HTTP requests must send when protection against cross-site request forgery (CSRF) is enabled for WebHDFS by setting dfs.webhdfs.rest-csrf.enabled to true. The WebHDFS client also uses this property to determine whether or not it needs to send the custom CSRF prevention header in its HTTP requests. | X-XSRF-HEADER |
| dfs.webhdfs.rest-csrf.methods-to-ignore | A comma-separated list of HTTP methods that do not require HTTP requests to include a custom header when protection against cross-site request forgery (CSRF) is enabled for WebHDFS by setting dfs.webhdfs.rest-csrf.enabled to true. The WebHDFS client also uses this property to determine whether or not it needs to send the custom CSRF prevention header in its HTTP requests. | GET,OPTIONS,HEAD,TRACE |
| dfs.webhdfs.rest-csrf.browser-useragents-regex | A comma-separated list of regular expressions used to match against an HTTP request’s User-Agent header when protection against cross-site request forgery (CSRF) is enabled for WebHDFS by setting dfs.webhdfs.reset-csrf.enabled to true. If the incoming User-Agent matches any of these regular expressions, then the request is considered to be sent by a browser, and therefore CSRF prevention is enforced. If the request’s User-Agent does not match any of these regular expressions, then the request is considered to be sent by something other than a browser, such as scripted automation. In this case, CSRF is not a potential attack vector, so the prevention is not enforced. This helps achieve backwards-compatibility with existing automation that has not been updated to send the CSRF prevention header. | ^Mozilla.*,^Opera.* |
The following is an example curl call that uses the -H option to include the custom header in the request.
curl -i -L -X PUT -H 'X-XSRF-HEADER: ""' 'http://<HOST>:<PORT>/webhdfs/v1/<PATH>?op=CREATE'
WebHDFS supports an optional, configurable retry policy for resilient copy of large files that could timeout, or copy file between HA clusters that could failover during the copy.
The following properties control WebHDFS retry and failover policy.
| Property | Description | Default Value |
|---|---|---|
| dfs.http.client.retry.policy.enabled | If “true”, enable the retry policy of WebHDFS client. If “false”, retry policy is turned off. | false |
| dfs.http.client.retry.policy.spec | Specify a policy of multiple linear random retry for WebHDFS client, e.g. given pairs of number of retries and sleep time (n0, t0), (n1, t1), …, the first n0 retries sleep t0 milliseconds on average, the following n1 retries sleep t1 milliseconds on average, and so on. | 10000,6,60000,10 |
| dfs.http.client.failover.max.attempts | Specify the max number of failover attempts for WebHDFS client in case of network exception. | 15 |
| dfs.http.client.retry.max.attempts | Specify the max number of retry attempts for WebHDFS client, if the difference between retried attempts and failovered attempts is larger than the max number of retry attempts, there will be no more retries. | 10 |
| dfs.http.client.failover.sleep.base.millis | Specify the base amount of time in milliseconds upon which the exponentially increased sleep time between retries or failovers is calculated for WebHDFS client. | 500 |
| dfs.http.client.failover.sleep.max.millis | Specify the upper bound of sleep time in milliseconds between retries or failovers for WebHDFS client. | 15000 |
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>][&noredirect=<true|false>]"
Usually 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
However, if you do not want to be automatically redirected, you can set the noredirect flag.
HTTP/1.1 200 OK
Content-Type: application/json
{"Location":"http://<DATANODE>:<PORT>/webhdfs/v1/<PATH>?op=CREATE..."}
Step 2: Submit another HTTP PUT request using the URL in the Location header (or the returned response in case you specified noredirect) 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
If no permissions are specified, the newly created file will be assigned with default 755 permission. This also applies for new directories. No umask mode will be applied from server side (so “fs.permissions.umask-mode” value configuration set on Namenode side will have no effect).
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 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, blocksize, replication, permission, buffersize, FileSystem.create
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>][&noredirect=<true|false>]"
Usually 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
However, if you do not want to be automatically redirected, you can set the noredirect flag.
HTTP/1.1 200 OK
Content-Type: application/json
{"Location":"http://<DATANODE>:<PORT>/webhdfs/v1/<PATH>?op=APPEND..."}
Step 2: Submit another HTTP POST request using the URL in the Location header (or the returned response in case you specified noredirect) 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: buffersize, FileSystem.append
Submit a HTTP POST request.
curl -i -X POST "http://<HOST>:<PORT>/webhdfs/v1/<PATH>?op=CONCAT&sources=<PATHS>"
The client receives a response with zero content length:
HTTP/1.1 200 OK Content-Length: 0
See also: sources, FileSystem.concat
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>][&noredirect=<true|false>]"
Usually 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
However if you do not want to be automatically redirected, you can set the noredirect flag.
HTTP/1.1 200 OK
Content-Type: application/json
{"Location":"http://<DATANODE>:<PORT>/webhdfs/v1/<PATH>?op=OPEN..."}
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, length, buffersize, FileSystem.open
Submit a HTTP PUT request.
curl -i -X PUT "http://<HOST>:<PORT>/webhdfs/v1/<PATH>?op=MKDIRS[&permission=<OCTAL>]"
The client receives a response with a boolean JSON object:
HTTP/1.1 200 OK
Content-Type: application/json
Transfer-Encoding: chunked
{"boolean": true}
If no permissions are specified, the newly created directory will be assigned with default 755 permission. This also applies to new files created. No umask mode will be applied from server side (so “fs.permissions.umask-mode” value configuration set on Namenode side will have no effect).
See also: permission, FileSystem.mkdirs
Submit a HTTP PUT request.
curl -i -X PUT "http://<HOST>:<PORT>/webhdfs/v1/<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, createParent, FileSystem.createSymlink
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 object:
HTTP/1.1 200 OK
Content-Type: application/json
Transfer-Encoding: chunked
{"boolean": true}
See also: destination, FileSystem.rename
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 object:
HTTP/1.1 200 OK
Content-Type: application/json
Transfer-Encoding: chunked
{"boolean": true}
See also: recursive, FileSystem.delete
Submit a HTTP POST request.
curl -i -X POST "http://<HOST>:<PORT>/webhdfs/v1/<PATH>?op=TRUNCATE&newlength=<LONG>"
The client receives a response with a boolean JSON object:
HTTP/1.1 200 OK
Content-Type: application/json
Transfer-Encoding: chunked
{"boolean": true}
See also: newlength, FileSystem.truncate
Submit a HTTP GET request.
curl -i "http://<HOST>:<PORT>/webhdfs/v1/<PATH>?op=GETFILESTATUS"
The client receives a response with a 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: FileSystem.getFileStatus
Submit a HTTP GET request.
curl -i "http://<HOST>:<PORT>/webhdfs/v1/<PATH>?op=LISTSTATUS"
The client receives a response with a 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" : "username",
"pathSuffix" : "bar",
"permission" : "711",
"replication" : 0,
"type" : "DIRECTORY"
},
...
]
}
}
See also: FileSystem.listStatus
Submit a HTTP GET request.
curl -i "http://<HOST>:<PORT>/webhdfs/v1/<PATH>?op=LISTSTATUS_BATCH&startAfter=<CHILD>"
The client receives a response with a DirectoryListing JSON object, which contains a FileStatuses JSON object, as well as iteration information:
HTTP/1.1 200 OK
Cache-Control: no-cache
Expires: Thu, 08 Sep 2016 03:40:38 GMT
Date: Thu, 08 Sep 2016 03:40:38 GMT
Pragma: no-cache
Expires: Thu, 08 Sep 2016 03:40:38 GMT
Date: Thu, 08 Sep 2016 03:40:38 GMT
Pragma: no-cache
Content-Type: application/json
X-FRAME-OPTIONS: SAMEORIGIN
Transfer-Encoding: chunked
Server: Jetty(6.1.26)
{
"DirectoryListing": {
"partialListing": {
"FileStatuses": {
"FileStatus": [
{
"accessTime": 0,
"blockSize": 0,
"childrenNum": 0,
"fileId": 16387,
"group": "supergroup",
"length": 0,
"modificationTime": 1473305882563,
"owner": "andrew",
"pathSuffix": "bardir",
"permission": "755",
"replication": 0,
"storagePolicy": 0,
"type": "DIRECTORY"
},
{
"accessTime": 1473305896945,
"blockSize": 1024,
"childrenNum": 0,
"fileId": 16388,
"group": "supergroup",
"length": 0,
"modificationTime": 1473305896965,
"owner": "andrew",
"pathSuffix": "bazfile",
"permission": "644",
"replication": 3,
"storagePolicy": 0,
"type": "FILE"
}
]
}
},
"remainingEntries": 2
}
}
If remainingEntries is non-zero, there are additional entries in the directory. To query the next batch, set the startAfter parameter to the pathSuffix of the last item returned in the current batch. For example:
curl -i "http://<HOST>:<PORT>/webhdfs/v1/<PATH>?op=LISTSTATUS_BATCH&startAfter=bazfile"
Which will return the next batch of directory entries:
HTTP/1.1 200 OK
Cache-Control: no-cache
Expires: Thu, 08 Sep 2016 03:43:20 GMT
Date: Thu, 08 Sep 2016 03:43:20 GMT
Pragma: no-cache
Expires: Thu, 08 Sep 2016 03:43:20 GMT
Date: Thu, 08 Sep 2016 03:43:20 GMT
Pragma: no-cache
Content-Type: application/json
X-FRAME-OPTIONS: SAMEORIGIN
Transfer-Encoding: chunked
Server: Jetty(6.1.26)
{
"DirectoryListing": {
"partialListing": {
"FileStatuses": {
"FileStatus": [
{
"accessTime": 0,
"blockSize": 0,
"childrenNum": 0,
"fileId": 16386,
"group": "supergroup",
"length": 0,
"modificationTime": 1473305878951,
"owner": "andrew",
"pathSuffix": "foodir",
"permission": "755",
"replication": 0,
"storagePolicy": 0,
"type": "DIRECTORY"
},
{
"accessTime": 1473305902864,
"blockSize": 1024,
"childrenNum": 0,
"fileId": 16389,
"group": "supergroup",
"length": 0,
"modificationTime": 1473305902878,
"owner": "andrew",
"pathSuffix": "quxfile",
"permission": "644",
"replication": 3,
"storagePolicy": 0,
"type": "FILE"
}
]
}
},
"remainingEntries": 0
}
}
Batch size is controlled by the dfs.ls.limit option on the NameNode.
See also: FileSystem.listStatusIterator
Submit a HTTP GET request.
curl -i "http://<HOST>:<PORT>/webhdfs/v1/<PATH>?op=GETCONTENTSUMMARY"
The client receives a response with a 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,
"typeQuota":
{
"ARCHIVE":
{
"consumed": 500,
"quota": 10000
},
"DISK":
{
"consumed": 500,
"quota": 10000
},
"SSD":
{
"consumed": 500,
"quota": 10000
}
}
}
}
See also: FileSystem.getContentSummary
Submit a HTTP GET request.
curl -i "http://<HOST>:<PORT>/webhdfs/v1/<PATH>?op=GETQUOTAUSAGE"
The client receives a response with a QuotaUsage JSON object:
HTTP/1.1 200 OK
Content-Type: application/json
Transfer-Encoding: chunked
{
"QuotaUsage":
{
"fileAndDirectoryCount": 1,
"quota" : 100,
"spaceConsumed" : 24930,
"spaceQuota" : 100000,
"typeQuota":
{
"ARCHIVE":
{
"consumed": 500,
"quota": 10000
},
"DISK":
{
"consumed": 500,
"quota": 10000
},
"SSD":
{
"consumed": 500,
"quota": 10000
}
}
}
}
See also: FileSystem.getQuotaUsage
Submit a HTTP GET request.
curl -i "http://<HOST>:<PORT>/webhdfs/v1/<PATH>?op=GETFILECHECKSUM"
Usually 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
However, if you do not want to be automatically redirected, you can set the noredirect flag.
HTTP/1.1 200 OK
Content-Type: application/json
{"Location":"http://<DATANODE>:<PORT>/webhdfs/v1/<PATH>?op=GETFILECHECKSUM..."}
The client follows the redirect to the datanode and receives a [`FileChecksum` JSON object](#FileChecksum_JSON_Schema):
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: FileSystem.getFileChecksum
Submit a HTTP GET request.
curl -i "http://<HOST>:<PORT>/webhdfs/v1/?op=GETHOMEDIRECTORY"
The client receives a response with a Path JSON object:
HTTP/1.1 200 OK
Content-Type: application/json
Transfer-Encoding: chunked
{"Path": "/user/username"}
See also: FileSystem.getHomeDirectory
Submit a HTTP GET request.
curl -i "http://<HOST>:<PORT>/webhdfs/v1/<PATH>?op=GETTRASHROOT"
The client receives a response with a Path JSON object:
HTTP/1.1 200 OK
Content-Type: application/json
Transfer-Encoding: chunked
{"Path": "/user/username/.Trash"}
if the path is an encrypted zone path and user has permission of the path, the client receives a response like this:
HTTP/1.1 200 OK
Content-Type: application/json
Transfer-Encoding: chunked
{"Path": "/PATH/.Trash/username"}
See also: FileSystem.getTrashRoot
For more details about trash root in an encrypted zone, please refer to Transparent Encryption Guide.
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, FileSystem.setPermission
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, group, FileSystem.setOwner
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 object:
HTTP/1.1 200 OK
Content-Type: application/json
Transfer-Encoding: chunked
{"boolean": true}
See also: replication, FileSystem.setReplication
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: modificationtime, accesstime, FileSystem.setTimes
Submit a HTTP PUT request.
curl -i -X PUT "http://<HOST>:<PORT>/webhdfs/v1/<PATH>?op=MODIFYACLENTRIES
&aclspec=<ACLSPEC>"
The client receives a response with zero content length:
HTTP/1.1 200 OK Content-Length: 0
See also: FileSystem.modifyAclEntries
Submit a HTTP PUT request.
curl -i -X PUT "http://<HOST>:<PORT>/webhdfs/v1/<PATH>?op=REMOVEACLENTRIES
&aclspec=<ACLSPEC>"
The client receives a response with zero content length:
HTTP/1.1 200 OK Content-Length: 0
See also: FileSystem.removeAclEntries
Submit a HTTP PUT request.
curl -i -X PUT "http://<HOST>:<PORT>/webhdfs/v1/<PATH>?op=REMOVEDEFAULTACL"
The client receives a response with zero content length:
HTTP/1.1 200 OK Content-Length: 0
See also: FileSystem.removeDefaultAcl
Submit a HTTP PUT request.
curl -i -X PUT "http://<HOST>:<PORT>/webhdfs/v1/<PATH>?op=REMOVEACL"
The client receives a response with zero content length:
HTTP/1.1 200 OK Content-Length: 0
See also: FileSystem.removeAcl
Submit a HTTP PUT request.
curl -i -X PUT "http://<HOST>:<PORT>/webhdfs/v1/<PATH>?op=SETACL
&aclspec=<ACLSPEC>"
The client receives a response with zero content length:
HTTP/1.1 200 OK Content-Length: 0
See also: FileSystem.setAcl
Submit a HTTP GET request.
curl -i "http://<HOST>:<PORT>/webhdfs/v1/<PATH>?op=GETACLSTATUS"
The client receives a response with a AclStatus JSON object:
HTTP/1.1 200 OK
Content-Type: application/json
Transfer-Encoding: chunked
{
"AclStatus": {
"entries": [
"user:carla:rw-",
"group::r-x"
],
"group": "supergroup",
"owner": "hadoop",
"permission":"775",
"stickyBit": false
}
}
See also: FileSystem.getAclStatus
Submit a HTTP GET request.
curl -i "http://<HOST>:<PORT>/webhdfs/v1/<PATH>?op=CHECKACCESS
&fsaction=<FSACTION>
The client receives a response with zero content length:
HTTP/1.1 200 OK Content-Length: 0
See also: FileSystem.access
Submit a HTTP GET request.
curl -i "http://<HOST>:<PORT>/webhdfs/v1?op=GETALLSTORAGEPOLICY"
The client receives a response with a BlockStoragePolicies JSON object:
HTTP/1.1 200 OK
Content-Type: application/json
Transfer-Encoding: chunked
{
"BlockStoragePolicies": {
"BlockStoragePolicy": [
{
"copyOnCreateFile": false,
"creationFallbacks": [],
"id": 2,
"name": "COLD",
"replicationFallbacks": [],
"storageTypes": ["ARCHIVE"]
},
{
"copyOnCreateFile": false,
"creationFallbacks": ["DISK","ARCHIVE"],
"id": 5,
"name": "WARM",
"replicationFallbacks": ["DISK","ARCHIVE"],
"storageTypes": ["DISK","ARCHIVE"]
},
{
"copyOnCreateFile": false,
"creationFallbacks": [],
"id": 7,
"name": "HOT",
"replicationFallbacks": ["ARCHIVE"],
"storageTypes": ["DISK"]
},
{
"copyOnCreateFile": false,
"creationFallbacks": ["SSD","DISK"],
"id": 10,"name": "ONE_SSD",
"replicationFallbacks": ["SSD","DISK"],
"storageTypes": ["SSD","DISK"]
},
{
"copyOnCreateFile": false,
"creationFallbacks": ["DISK"],
"id": 12,
"name": "ALL_SSD",
"replicationFallbacks": ["DISK"],
"storageTypes": ["SSD"]
},
{
"copyOnCreateFile": true,
"creationFallbacks": ["DISK"],
"id": 15,
"name": "LAZY_PERSIST",
"replicationFallbacks": ["DISK"],
"storageTypes": ["RAM_DISK","DISK"]
}
]
}
}
See also: FileSystem.getAllStoragePolicies
Submit a HTTP PUT request.
curl -i -X PUT "http://<HOST>:<PORT>/webhdfs/v1/<PATH>?op=SETSTORAGEPOLICY
&storagepolicy=<policy>"
The client receives a response with zero content length:
HTTP/1.1 200 OK Content-Length: 0
See also: FileSystem.setStoragePolicy
Submit a HTTP POT request.
curl -i -X POST "http://<HOST>:<PORT>/webhdfs/v1/<PATH>?op=UNSETSTORAGEPOLICY"
The client receives a response with zero content length:
HTTP/1.1 200 OK Content-Length: 0
See also: FileSystem.unsetStoragePolicy
Submit a HTTP GET request.
curl -i "http://<HOST>:<PORT>/webhdfs/v1/<PATH>?op=GETSTORAGEPOLICY"
The client receives a response with a BlockStoragePolicy JSON object:
HTTP/1.1 200 OK
Content-Type: application/json
Transfer-Encoding: chunked
{
"BlockStoragePolicy": {
"copyOnCreateFile": false,
"creationFallbacks": [],
"id":7,
"name":"HOT",
"replicationFallbacks":["ARCHIVE"],
"storageTypes":["DISK"]
}
}
See also: FileSystem.getStoragePolicy
Submit a HTTP GET request.
curl -i "http://<HOST>:<PORT>/webhdfs/v1/<PATH>?op=GETFILEBLOCKLOCATIONS
The client receives a response with a BlockLocations JSON Object:
HTTP/1.1 200 OK
Content-Type: application/json
Transfer-Encoding: chunked
{
"BlockLocations" :
{
"BlockLocation":
[
{
"cachedHosts" : [],
"corrupt" : false,
"hosts" : ["host"],
"length" : 134217728, // length of this block
"names" : ["host:ip"],
"offset" : 0, // offset of the block in the file
"storageIds" : ["storageid"],
"storageTypes" : ["DISK"], // enum {RAM_DISK, SSD, DISK, ARCHIVE}
"topologyPaths" : ["/default-rack/hostname:ip"]
}, {
"cachedHosts" : [],
"corrupt" : false,
"hosts" : ["host"],
"length" : 62599364,
"names" : ["host:ip"],
"offset" : 134217728,
"storageIds" : ["storageid"],
"storageTypes" : ["DISK"],
"topologyPaths" : ["/default-rack/hostname:ip"]
},
...
]
}
}
See also: offset, length, FileSystem.getFileBlockLocations
Submit a HTTP PUT request.
curl -i -X PUT "http://<HOST>:<PORT>/webhdfs/v1/<PATH>?op=SETXATTR
&xattr.name=<XATTRNAME>&xattr.value=<XATTRVALUE>
&flag=<FLAG>"
The client receives a response with zero content length:
HTTP/1.1 200 OK Content-Length: 0
See also: FileSystem.setXAttr
Submit a HTTP PUT request.
curl -i -X PUT "http://<HOST>:<PORT>/webhdfs/v1/<PATH>?op=REMOVEXATTR
&xattr.name=<XATTRNAME>"
The client receives a response with zero content length:
HTTP/1.1 200 OK Content-Length: 0
See also: FileSystem.removeXAttr
Submit a HTTP GET request.
curl -i "http://<HOST>:<PORT>/webhdfs/v1/<PATH>?op=GETXATTRS
&xattr.name=<XATTRNAME>&encoding=<ENCODING>"
The client receives a response with a XAttrs JSON object:
HTTP/1.1 200 OK
Content-Type: application/json
Transfer-Encoding: chunked
{
"XAttrs": [
{
"name":"XATTRNAME",
"value":"XATTRVALUE"
}
]
}
See also: FileSystem.getXAttr
Submit a HTTP GET request.
curl -i "http://<HOST>:<PORT>/webhdfs/v1/<PATH>?op=GETXATTRS
&xattr.name=<XATTRNAME1>&xattr.name=<XATTRNAME2>
&encoding=<ENCODING>"
The client receives a response with a XAttrs JSON object:
HTTP/1.1 200 OK
Content-Type: application/json
Transfer-Encoding: chunked
{
"XAttrs": [
{
"name":"XATTRNAME1",
"value":"XATTRVALUE1"
},
{
"name":"XATTRNAME2",
"value":"XATTRVALUE2"
}
]
}
See also: FileSystem.getXAttrs
Submit a HTTP GET request.
curl -i "http://<HOST>:<PORT>/webhdfs/v1/<PATH>?op=GETXATTRS
&encoding=<ENCODING>"
The client receives a response with a XAttrs JSON object:
HTTP/1.1 200 OK
Content-Type: application/json
Transfer-Encoding: chunked
{
"XAttrs": [
{
"name":"XATTRNAME1",
"value":"XATTRVALUE1"
},
{
"name":"XATTRNAME2",
"value":"XATTRVALUE2"
},
{
"name":"XATTRNAME3",
"value":"XATTRVALUE3"
}
]
}
See also: FileSystem.getXAttrs
Submit a HTTP GET request.
curl -i "http://<HOST>:<PORT>/webhdfs/v1/<PATH>?op=LISTXATTRS"
The client receives a response with a XAttrNames JSON object:
HTTP/1.1 200 OK
Content-Type: application/json
Transfer-Encoding: chunked
{
"XAttrNames":"[\"XATTRNAME1\",\"XATTRNAME2\",\"XATTRNAME3\"]"
}
See also: FileSystem.listXAttrs
Submit a HTTP PUT request.
curl -i -X PUT "http://<HOST>:<PORT>/webhdfs/v1/<PATH>?op=ALLOWSNAPSHOT"
The client receives a response with zero content length on success:
HTTP/1.1 200 OK Content-Length: 0
Submit a HTTP PUT request.
curl -i -X PUT "http://<HOST>:<PORT>/webhdfs/v1/<PATH>?op=DISALLOWSNAPSHOT"
The client receives a response with zero content length on success:
HTTP/1.1 200 OK Content-Length: 0
Submit a HTTP PUT request.
curl -i -X PUT "http://<HOST>:<PORT>/webhdfs/v1/<PATH>?op=CREATESNAPSHOT[&snapshotname=<SNAPSHOTNAME>]"
The client receives a response with a Path JSON object:
HTTP/1.1 200 OK
Content-Type: application/json
Transfer-Encoding: chunked
{"Path": "/user/username/.snapshot/s1"}
See also: FileSystem.createSnapshot
Submit a HTTP DELETE request.
curl -i -X DELETE "http://<HOST>:<PORT>/webhdfs/v1/<PATH>?op=DELETESNAPSHOT&snapshotname=<SNAPSHOTNAME>"
The client receives a response with zero content length:
HTTP/1.1 200 OK Content-Length: 0
See also: FileSystem.deleteSnapshot
Submit a HTTP PUT request.
curl -i -X PUT "http://<HOST>:<PORT>/webhdfs/v1/<PATH>?op=RENAMESNAPSHOT
&oldsnapshotname=<SNAPSHOTNAME>&snapshotname=<SNAPSHOTNAME>"
The client receives a response with zero content length:
HTTP/1.1 200 OK Content-Length: 0
See also: FileSystem.renameSnapshot
Submit a HTTP GET request.
curl -i "http://<HOST>:<PORT>/webhdfs/v1/?op=GETDELEGATIONTOKEN&renewer=<USER>&service=<SERVICE>&kind=<KIND>"
The client receives a response with a Token JSON object:
HTTP/1.1 200 OK
Content-Type: application/json
Transfer-Encoding: chunked
{
"Token":
{
"urlString": "JQAIaG9y..."
}
}
See also: renewer, FileSystem.getDelegationToken, kind, service
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 object:
HTTP/1.1 200 OK
Content-Type: application/json
Transfer-Encoding: chunked
{"long": 1320962673997} //the new expiration time
See also: token, DelegationTokenAuthenticator.renewDelegationToken
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, DelegationTokenAuthenticator.cancelDelegationToken
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.
| Exceptions | HTTP Response Codes |
|---|---|
| IllegalArgumentException | 400 Bad Request |
| UnsupportedOperationException | 400 Bad Request |
| SecurityException | 401 Unauthorized |
| IOException | 403 Forbidden |
| FileNotFoundException | 404 Not Found |
| RuntimeException | 500 Internal Server Error |
Below are examples of exception responses.
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\": ..."
}
}
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: ..."
}
}
All operations, except for OPEN, either return a zero-length response or a JSON response. For OPEN, the response is an octet-stream. The JSON schemas are shown below. See draft-zyp-json-schema-03 for the syntax definitions of the JSON schemas.
Note that the default value of additionalProperties is an empty schema which allows any value for additional properties. Therefore, all WebHDFS JSON responses allow any additional property. However, if additional properties are included in the responses, they are considered as optional properties in order to maintain compatibility.
{
"name" : "AclStatus",
"properties":
{
"AclStatus":
{
"type" : "object",
"properties":
{
"entries":
{
"type": "array",
"items":
{
"description": "ACL entry.",
"type": "string"
}
},
"group":
{
"description": "The group owner.",
"type" : "string",
"required" : true
},
"owner":
{
"description": "The user who is the owner.",
"type" : "string",
"required" : true
},
"stickyBit":
{
"description": "True if the sticky bit is on.",
"type" : "boolean",
"required" : true
}
}
}
}
}
{
"name" : "XAttrs",
"properties":
{
"XAttrs":
{
"type" : "array",
"items":
{
"type" : "object",
"properties":
{
"name":
{
"description": "XAttr name.",
"type" : "string",
"required" : true
},
"value":
{
"description": "XAttr value.",
"type" : "string"
}
}
}
}
}
}
{
"name" : "XAttrNames",
"properties":
{
"XAttrNames":
{
"description": "XAttr names.",
"type" : "string",
"required" : true
}
}
}
{
"name" : "boolean",
"properties":
{
"boolean":
{
"description": "A boolean value",
"type" : "boolean",
"required" : true
}
}
}
See also: MKDIRS, RENAME, DELETE, SETREPLICATION
{
"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
},
"typeQuota":
{
"type" : "object",
"properties":
{
"ARCHIVE":
{
"type" : "object",
"properties":
{
"consumed":
{
"description": "The storage type space consumed.",
"type" : "integer",
"required" : true
},
"quota":
{
"description": "The storage type quota.",
"type" : "integer",
"required" : true
}
}
},
"DISK":
{
"type" : "object",
"properties":
{
"consumed":
{
"description": "The storage type space consumed.",
"type" : "integer",
"required" : true
},
"quota":
{
"description": "The storage type quota.",
"type" : "integer",
"required" : true
}
}
},
"SSD":
{
"type" : "object",
"properties":
{
"consumed":
{
"description": "The storage type space consumed.",
"type" : "integer",
"required" : true
},
"quota":
{
"description": "The storage type quota.",
"type" : "integer",
"required" : true
}
}
}
}
}
}
}
}
}
See also: GETCONTENTSUMMARY
{
"name" : "QuotaUsage",
"properties":
{
"QuotaUsage":
{
"type" : "object",
"properties":
{
"fileAndDirectoryCount":
{
"description": "The number of files and directories.",
"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
},
"typeQuota":
{
"type" : "object",
"properties":
{
"ARCHIVE":
{
"type" : "object",
"properties":
{
"consumed":
{
"description": "The storage type space consumed.",
"type" : "integer",
"required" : true
},
"quota":
{
"description": "The storage type quota.",
"type" : "integer",
"required" : true
}
}
},
"DISK":
{
"type" : "object",
"properties":
{
"consumed":
{
"description": "The storage type space consumed.",
"type" : "integer",
"required" : true
},
"quota":
{
"description": "The storage type quota.",
"type" : "integer",
"required" : true
}
}
},
"SSD":
{
"type" : "object",
"properties":
{
"consumed":
{
"description": "The storage type space consumed.",
"type" : "integer",
"required" : true
},
"quota":
{
"description": "The storage type quota.",
"type" : "integer",
"required" : true
}
}
}
}
}
}
}
}
}
See also: GETQUOTAUSAGE
{
"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
}
}
}
}
}
{
"name" : "FileStatus",
"properties":
{
"FileStatus": fileStatusProperties //See FileStatus Properties
}
}
See also: FileStatus Properties, GETFILESTATUS, FileStatus
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
}
}
};
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, LISTSTATUS, FileStatus
A DirectoryListing JSON object represents a batch of directory entries while iteratively listing a directory. It contains a FileStatuses JSON object as well as iteration information.
{
"name" : "DirectoryListing",
"properties":
{
"DirectoryListing":
{
"type" : "object",
"properties":
{
"partialListing":
{
"description": "A partial directory listing",
"type" : "object", // A FileStatuses object
"required" : true
},
"remainingEntries":
{
"description": "Number of remaining entries",
"type" : "integer",
"required" : true
}
}
}
}
}
See also: FileStatuses JSON Schema, LISTSTATUS_BATCH, FileStatus
{
"name" : "long",
"properties":
{
"long":
{
"description": "A long integer value",
"type" : "integer",
"required" : true
}
}
}
See also: RENEWDELEGATIONTOKEN,
{
"name" : "Path",
"properties":
{
"Path":
{
"description": "The string representation a Path.",
"type" : "string",
"required" : true
}
}
}
See also: GETHOMEDIRECTORY, Path
{
"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
{
"name" : "Token",
"properties":
{
"Token": tokenProperties //See Token Properties
}
}
See also: Token Properties, GETDELEGATIONTOKEN, the note in Delegation.
JavaScript syntax is used to define tokenProperties so that it can be referred in Token JSON schema.
var tokenProperties =
{
"type" : "object",
"properties":
{
"urlString":
{
"description": "A delegation token encoded as a URL safe string.",
"type" : "string",
"required" : true
}
}
}
See also: Token Properties, the note in Delegation.
{
"name" : "BlockStoragePolicy",
"properties":
{
"BlockStoragePolicy": blockStoragePolicyProperties //See BlockStoragePolicy Properties
}
}
See also: BlockStoragePolicy Properties, GETSTORAGEPOLICY
JavaScript syntax is used to define blockStoragePolicyProperties so that it can be referred in both BlockStoragePolicy and BlockStoragePolicies JSON schemas.
var blockStoragePolicyProperties =
{
"type" : "object",
"properties":
{
"id":
{
"description": "Policy ID.",
"type" : "integer",
"required" : true
},
"name":
{
"description": "Policy name.",
"type" : "string",
"required" : true
},
"storageTypes":
{
"description": "An array of storage types for block placement.",
"type" : "array",
"required" : true
"items" :
{
"type": "string"
}
},
"replicationFallbacks":
{
"description": "An array of fallback storage types for replication.",
"type" : "array",
"required" : true
"items" :
{
"type": "string"
}
},
"creationFallbacks":
{
"description": "An array of fallback storage types for file creation.",
"type" : "array",
"required" : true
"items" :
{
"type": "string"
}
},
"copyOnCreateFile":
{
"description": "If set then the policy cannot be changed after file creation.",
"type" : "boolean",
"required" : true
}
}
};
A BlockStoragePolicies JSON object represents an array of BlockStoragePolicy JSON objects.
{
"name" : "BlockStoragePolicies",
"properties":
{
"BlockStoragePolicies":
{
"type" : "object",
"properties":
{
"BlockStoragePolicy":
{
"description": "An array of BlockStoragePolicy",
"type" : "array",
"items" : blockStoragePolicyProperties //See BlockStoragePolicy Properties
}
}
}
}
}
A BlockLocations JSON object represents an array of BlockLocation JSON objects.
{
"name" : "BlockLocations",
"properties":
{
"BlockLocations":
{
"type" : "object",
"properties":
{
"BlockLocation":
{
"description": "An array of BlockLocation",
"type" : "array",
"items" : blockLocationProperties //See BlockLocation Properties
}
}
}
}
}
See also BlockLocation Properties, GETFILEBLOCKLOCATIONS, BlockLocation
{
"name" : "BlockLocation",
"properties":
{
"BlockLocation": blockLocationProperties //See BlockLocation Properties
}
}
See also BlockLocation Properties, GETFILEBLOCKLOCATIONS, BlockLocation
JavaScript syntax is used to define blockLocationProperties so that it can be referred in both BlockLocation and BlockLocations JSON schemas.
var blockLocationProperties =
{
"type" : "object",
"properties":
{
"cachedHosts":
{
"description": "Datanode hostnames with a cached replica",
"type" : "array",
"required" : "true",
"items" :
{
"description": "A datanode hostname",
"type" : "string"
}
},
"corrupt":
{
"description": "True if the block is corrupted",
"type" : "boolean",
"required" : "true"
},
"hosts":
{
"description": "Datanode hostnames store the block",
"type" : "array",
"required" : "true",
"items" :
{
"description": "A datanode hostname",
"type" : "string"
}
},
"length":
{
"description": "Length of the block",
"type" : "integer",
"required" : "true"
},
"names":
{
"description": "Datanode IP:xferPort for accessing the block",
"type" : "array",
"required" : "true",
"items" :
{
"description": "DatanodeIP:xferPort",
"type" : "string"
}
},
"offset":
{
"description": "Offset of the block in the file",
"type" : "integer",
"required" : "true"
},
"storageIds":
{
"description": "Storage ID of each replica",
"type" : "array",
"required" : "true",
"items" :
{
"description": "Storage ID",
"type" : "string"
}
},
"storageTypes":
{
"description": "Storage type of each replica",
"type" : "array",
"required" : "true",
"items" :
{
"description": "Storage type",
"enum" : ["RAM_DISK", "SSD", "DISK", "ARCHIVE"]
}
},
"topologyPaths":
{
"description": "Datanode addresses in network topology",
"type" : "array",
"required" : "true",
"items" :
{
"description": "/rack/host:ip",
"type" : "string"
}
}
}
};
| Name | aclspec |
|---|---|
| Description | The ACL spec included in ACL modification operations. |
| Type | String |
| Default Value | <empty> |
| Valid Values | See Permissions and HDFS. |
| Syntax | See Permissions and HDFS. |
| Name | xattr.name |
|---|---|
| Description | The XAttr name of a file/directory. |
| Type | String |
| Default Value | <empty> |
| Valid Values | Any string prefixed with user./trusted./system./security.. |
| Syntax | Any string prefixed with user./trusted./system./security.. |
| Name | xattr.value |
|---|---|
| Description | The XAttr value of a file/directory. |
| Type | String |
| Default Value | <empty> |
| Valid Values | An encoded value. |
| Syntax | Enclosed in double quotes or prefixed with 0x or 0s. |
See also: Extended Attributes
| Name | flag |
|---|---|
| Description | The XAttr set flag. |
| Type | String |
| Default Value | <empty> |
| Valid Values | CREATE,REPLACE. |
| Syntax | CREATE,REPLACE. |
See also: Extended Attributes
| Name | encoding | ||
|---|---|---|---|
| Description | The XAttr value encoding. | ||
| Type | String | ||
| Default Value | <empty> | ||
| Valid Values | text | hex | base64 |
| Syntax | text | hex | base64 |
See also: Extended Attributes
| 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: SETTIMES
| 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
| 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. |
| Name | createflag |
|---|---|
| Description | Enum of possible flags to process while creating a file |
| Type | enumerated strings |
| Default Value | <empty> |
| Valid Values | Legal combinations of create, overwrite, append and sync_block |
| Syntax | See note below |
The following combinations are not valid: * append,create * create,append,overwrite
See also: CREATE
| Name | createparent |
|---|---|
| Description | If the parent directories do not exist, should they be created? |
| Type | boolean |
| Default Value | true |
| Valid Values | true, false |
| Syntax | true |
See also: CREATESYMLINK
| 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
| Name | destination |
|---|---|
| Description | The destination path. |
| Type | Path |
| Default Value | <empty> (an invalid path) |
| Valid Values | An absolute FileSystem path without scheme and authority. |
| Syntax | Any path. |
See also: CREATESYMLINK, RENAME
| 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
| Name | fsaction |
|---|---|
| Description | File system operation read/write/execute |
| Type | String |
| Default Value | null (an invalid value) |
| Valid Values | Strings matching regex pattern “[r-][w-][x-] ” |
| Syntax | “[r-][w-][x-] ” |
See also: CHECKACCESS,
| 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: SETOWNER
| 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
| 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: SETTIMES
| Name | newlength |
|---|---|
| Description | The size the file is to be truncated to. |
| Type | long |
| Valid Values | >= 0 |
| Syntax | Any long. |
| Name | offset |
|---|---|
| Description | The starting byte position. |
| Type | long |
| Default Value | 0 |
| Valid Values | >= 0 |
| Syntax | Any integer. |
See also: OPEN
| Name | oldsnapshotname |
|---|---|
| Description | The old name of the snapshot to be renamed. |
| Type | String |
| Default Value | null |
| Valid Values | An existing snapshot name. |
| Syntax | Any string. |
See also: RENAMESNAPSHOT
| 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
| Name | overwrite |
|---|---|
| Description | If a file already exists, should it be overwritten? |
| Type | boolean |
| Default Value | false |
| Valid Values | true |
| Syntax | true |
See also: CREATE
| 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: SETOWNER
| 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, MKDIRS, SETPERMISSION
| Name | recursive |
|---|---|
| Description | Should the operation act on the content in the subdirectories? |
| Type | boolean |
| Default Value | false |
| Valid Values | true |
| Syntax | true |
See also: RENAME
| 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: GETDELEGATIONTOKEN
| 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, SETREPLICATION
| Name | snapshotname |
|---|---|
| Description | The name of the snapshot to be created/deleted. Or the new name for snapshot rename. |
| Type | String |
| Default Value | null |
| Valid Values | Any valid snapshot name. |
| Syntax | Any string. |
See also: CREATESNAPSHOT, DELETESNAPSHOT, RENAMESNAPSHOT
| Name | sources |
|---|---|
| Description | A list of source paths. |
| Type | String |
| Default Value | <empty> |
| Valid Values | A list of comma seperated absolute FileSystem paths without scheme and authority. |
| Syntax | Any string. |
See also: CONCAT
| 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: RENEWDELEGATIONTOKEN, CANCELDELEGATIONTOKEN
| Name | kind |
|---|---|
| Description | The kind of the delegation token requested |
| Type | String |
| Default Value | <empty> (Server sets the default kind for the service) |
| Valid Values | A string that represents token kind e.g “HDFS_DELEGATION_TOKEN” or “WEBHDFS delegation” |
| Syntax | Any string. |
See also: GETDELEGATIONTOKEN
| Name | service |
|---|---|
| Description | The name of the service where the token is supposed to be used, e.g. ip:port of the namenode |
| Type | String |
| Default Value | <empty> |
| Valid Values | ip:port in string format or logical name of the service |
| Syntax | Any string. |
See also: GETDELEGATIONTOKEN
| 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
| Name | noredirect |
|---|---|
| Description | Whether the response should return an HTTP 307 redirect or HTTP 200 OK. See Create and Write to a File. |
| Type | boolean |
| Default Value | false |
| Valid Values | true |
| Syntax | true |
See also: Create and Write to a File
| Name | storagepolicy |
|---|---|
| Description | The name of the storage policy. |
| Type | String |
| Default Value | <empty> |
| Valid Values | Any valid storage policy name; see GETALLSTORAGEPOLICY. |
| Syntax | Any string. |
See also: SETSTORAGEPOLICY
| Name | startAfter |
|---|---|
| Description | The last item returned in the liststatus batch. |
| Type | String |
| Default Value | <empty> |
| Valid Values | Any valid file/directory name. |
| Syntax | Any string. |
See also: LISTSTATUS_BATCH