FME Transformers: 2025.2 BETA

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Web

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Workflows

Related Transformers
AzureBlobStorageConnector
AzureFileStorageConnector
BoxConnector
CesiumIonConnector
DropboxConnector
GoogleCloudStorageConnector
GoogleDriveConnector
OneDriveConnector
ProjectWiseWSGConnector
S3Connector
Categories
Integrations

Integrations

Web

Web

Workflows

Workflows

Related Transformers
AzureBlobStorageConnector
AzureFileStorageConnector
BoxConnector
CesiumIonConnector
DropboxConnector
GoogleCloudStorageConnector
GoogleDriveConnector
OneDriveConnector
ProjectWiseWSGConnector
S3Connector

HDFSConnector

Connects to an HDFS (Hadoop Distributed File System) to manage files and folders.

Jump to Configuration

Typical Uses

  • Managing datasets on an HDFS by uploading, downloading, and deleting files and folders
  • Transferring file contents into or out of an attribute in FME
  • Retrieving file and folder names, paths, links and other information from an HDFS to use elsewhere in a workspace

How does it work?

The HDFSConnector uses your HDFS account credentials to perform various management tasks:

Action

Task

Delete

Delete files and folders.

Download

Download a file or folder to an attribute, file, or folder.

List

List the item details for the contents of a folder.

Upload

Upload a file, folder, or the contents of an attribute.

Once valid account credentials have been provided, you may browse to available content for the selected Action.

Optional Input Port

This transformer has two modes, depending on whether a connector is attached to the Input port or not:

  • Input-driven: When input features are connected, the transformer runs once for each feature it receives in the Input port.
  • Run Once: When no input features are connected, the transformer runs one time and outputs as many new features as the Action returns.

Usage Notes

  • This transformer cannot move or copy files between different locations. Consider using multiple connectors for these tasks, by downloading files/folders and re-uploading them to a new location.
  • The FeatureReader can access an HDFS directly but does not download a local copy of the dataset.

Configuration

Input Ports

This transformer accepts any feature.

Output Ports

Features with added attributes, as specified in parameters and according to Action:

Action

Output - Input-Driven

Output - Run Once

Delete

Input feature unchanged.

One new feature.

Download

Input feature unchanged.

One new feature.

List

Multiple features, one for each item in the specified location, with details about the items.

Multiple new features, one for each item in the specified location, with details about the items.

Upload

Input feature with details about the uploaded item.

New feature with details about the uploaded item.

Features that cause the operation to fail are output through this port. An fme_rejection_code attribute describing the category of the error will be added, along with a more descriptive fme_rejection_message which contains more specific details as to the reason for the failure.

If an Input feature already has a value for fme_rejection_code, this value will be removed.

Rejected Feature Handling: can be set to either terminate the translation or continue running when it encounters a rejected feature. This setting is available both as a default FME option and as a workspace parameter.

Parameters

HDFS Action

Select an operation to perform. Choices include:

  • Delete
  • Download
  • List
  • Upload

HDFS Account

Select or create a Web Connection, connecting to the HDFSWeb Service.

See Using Web Connections.

HDFS Path

Path to Delete

Specify the file or folder to delete.

Output Attributes

No attributes are added for this Action.

HDFS Source

Download from Path

Specify the file or folder to download.

Destination

Download as

Select a destination type for downloaded items:

  • Attribute: The downloaded object will be stored in the specified attribute.
  • File: The downloaded file will be stored in the specified folder.
  • Folder: The downloaded folder object will be stored in the specified folder.

Download to Folder

When Download as is File or Folder, specify the path to the folder that will store the downloaded item.

Include Subfolders

When Download as is Folder, select a method for handling subfolders:

  • Yes: Include all subfolders
  • No: Do not include subfolders.

Download to Attribute

When Download as is Attribute, specify the attribute to contain the contents of the downloaded item.

Encoding

FME will attempt to convert the attribute's contents to a UTF-8 string. If this fails, the attribute's contents will be created as raw binary. To ensure that the original bytes are always preserved and never converted to UTF-8, use Download as >File instead.

Output Attributes

No attributes are added for this Action.

HDFS Path

List Contents at Path

Specify the folder to list the contents of.

Output Attributes

Attributes to Add

Select any available attributes to be included on the output features:

_access_time

Last accessed date of a file object on HDFS.

_block_size

Block size of a file object on HDFS.

_file_last_modified

Last modified date of an object on HDFS.

_file_or_folder

Type (file or folder) of an object on HDFS.

_file_size

Size of a file object on HDFS.

_full_path

Path to an object on HDFS.

_id

ID of an object on HDFS.

_name

Name of an object on HDFS.

_owner_group

The group an object on HDFS belongs to.
_owner_user Name of the user an object on HDFS belongs to.

_permissions

Octal permission code of an object on HDFS.

_relative_path

Relative path of an object on HDFS.

_replication_count

Number of replications of a file object on HDFS.

Source

Upload

Select the source type:

  • Attribute: Upload the contents of an attribute.
  • File: Upload a file.
  • Folder: Upload a folder and its contents.

Note that when working with large objects, File is generally the better choice as the data will be read from disk and not need to be held in memory.

HDFS treats file uploads of the same name, in a specific folder, as duplicates, so you can upload multiple files with the same name to a specific folder.

File to Upload

When Upload is File, specify the file to be uploaded.

Folder to Upload

When Upload is Folder, specify the folder to be uploaded.

Include Subfolders

When Upload is Folder, select a method for handling subfolders:

  • Yes: Upload all subfolders
  • No: Do not include subfolders.

Attribute to Upload as File

When Upload is Attribute, specify the attribute containing the content for upload.

HDFS Destination

Upload to Path

Specify the path on the HDFS to upload to.

To upload to the root directory, enter /.

Upload with File Name

When Upload is Attribute, specify the filename, including extension, to contain the uploaded content.

Upload Options

If File Exists at Destination

Select a method of handling conflicts with existing files at the upload location:

  • Do Nothing
  • Append to Existing
  • Overwrite Existing

File/Directory Permission

When If File Exists at Destination is Do Nothing or Overwrite Existing, specify the octal permission (UNIX format) value to set for the uploaded object.

This parameter is unavailable if Append to Existing is chosen for the previous parameter. The object will retain its original permission setting in this case.

Output Attributes

Attributes to Add

Select any available attributes to be included on the output features:

_full_path

Path to an object on HDFS.

_id

ID of an object on HDFS.

Editing Transformer Parameters

Transformer parameters can be set by directly entering values, using expressions, or referencing other elements in the workspace such as attribute values or user parameters. Various editors and context menus are available to assist. To see what is available, click beside the applicable parameter.

Defining Values

There are several ways to define a value for use in a Transformer. The simplest is to simply type in a value or string, which can include functions of various types such as attribute references, math and string functions, and workspace parameters.

Using the Text Editor

The Text Editor provides a convenient way to construct text strings (including regular expressions) from various data sources, such as attributes, parameters, and constants, where the result is used directly inside a parameter.

Text Editor

Using the Arithmetic Editor

The Arithmetic Editor provides a convenient way to construct math expressions from various data sources, such as attributes, parameters, and feature functions, where the result is used directly inside a parameter.

Arithmetic Editor

Conditional Values

Set values depending on one or more test conditions that either pass or fail.

Parameter Condition Definition Dialog

Content

Expressions and strings can include a number of functions, characters, parameters, and more.

When setting values - whether entered directly in a parameter or constructed using one of the editors - strings and expressions containing String, Math, Date/Time or FME Feature Functions will have those functions evaluated. Therefore, the names of these functions (in the form @<function_name>) should not be used as literal string values.

String Functions

These functions manipulate and format strings.

Special Characters

 A set of control characters is available in the Text Editor.

Math Functions

Math functions are available in both editors.
Date/Time Functions Date and time functions are available in the Text Editor.

Math Operators

These operators are available in the Arithmetic Editor.

FME Feature Functions

These return primarily feature-specific values.

FME Parameters

FME and workspace-specific parameters may be used.
Creating and Modifying User Parameters Create your own editable parameters.

Table Tools

Transformers with table-style parameters have additional tools for populating and manipulating values.

Row Reordering

Enabled once you have clicked on a row item. Choices include:

  • Add a row
  • Remove a row
  • Move current row up one
  • Move current row down one
  • Move current row to top
  • Move current row to bottom

Cut, Copy, and Paste

Enabled once you have clicked on a row item. Choices include:

  • Cut a row - delete and copy to clipboard
  • Copy a row to the clipboard
  • Paste a row from the clipboard

Cut, copy, and paste may be used within a transformer, or between transformers.

Filter

Start typing a string, and the matrix will only display rows matching those characters. Searches all columns. This only affects the display of attributes within the transformer - it does not alter which attributes are output.

Import

Import populates the table with a set of new attributes read from a dataset. Specific application varies between transformers.

Reset/Refresh

Generally resets the table to its initial state, and may provide additional options to remove invalid entries. Behavior varies between transformers.

Note: Not all tools are available in all transformers.

For more information, see Transformer Parameter Menu Options.

Reference

Processing Behavior

Feature-Based

Feature Holding

No
Dependencies HDFS account
Aliases  
History Released FME 2018.0

FME Online Resources

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