AzureEventHubsConnector

Input

This transformer accepts any feature.

Output

The output of this transformer will vary depending on the action performed. Message data and metadata are presented as feature attributes.

After a Receive action, output features represent messages received from Azure Event Hub.
After a Send action, output features represent messages sent to Azure Event Hub.

Initiator

The incoming feature is output through this port.

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

Note If a feature comes in to the AzureEventHubsConnector already having 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.

Authentication

Credential Source

Required for authentication. Using a web connection integrates best with FME, but in some cases, you may wish to use one of the other sources.

Web Connection - use an Azure Event Hubs web connection stored in the FME web connections database
Embedded - An event hub connection string
Default Azure Credential - Obtain credentials from Microsoft Entra ID, Managed Identity, or Azure CLI.

Account

Available when the credential source is Web Connection. To create an Azure Event Hubs connection, click the 'Account' drop-down box and select 'Add Web Connection...'.

The connection can then be managed via Tools -> FME Options... -> Web Connections.

Namespace

Available when the Credential Source is Default Azure Credential. This is an Event Hubs namespace that is typically a hostname under servicebus.windows.net.

Embedded Credentials

Event Hub Connection String

Available when the Credential Source is Embedded. The connection string is found in the Azure Portal Event Hubs Namespace under Shared Access Policies.

Request

Action

The type of operation to perform. Choices are:

Receive
Send
Checkpoint

Event Hubs

The event hub to connect to.

Parameters - Send Action

Send Options

Payload

The content of the message.

This is often JSON, but can be any string, binary, integer or floating-point value.

Partition ID

(Optional) The specific partition ID to send to.

If empty, a message will be assigned to a random partition using round-robin.

Message Properties

(Optional) Additional properties to send with each message.

Key	The custom name of the property.
Value	The content of the property.

Parameters - Receive Action

Receives messages from the front of the queue.

Checkpointing is also enabled, but optional.

Receive Options

Consumer Group	The name of the consumer group to view the event hub stream. Consumer groups are created in the Azure portal. The default is ‘$Default’.
Receive Mode	Two message receiving options are available: Stream: The connector continues to receive messages indefinitely. The translation needs to be terminated in order to stop reception. Batch: Only a given number of messages are received before the connection is closed.
Batch Size	In Batch mode, specifies the number of messages to read per batch.
Partition ID	(Optional) If specified, the client will receive from this partition only. If empty, the client will receive from all partitions. It is recommended that there is only one active receiver on a partition per consumer group.
Prefetch Count	(Optional) The number of messages to prefetch from Azure. Default is 300.
Starting Position	(Optional) Start receiving from this event position if there is no checkpoint data for the partition. Checkpoint data will be used if available. Default (empty) is @latest which receives only new events. -1 starts receiving at the beginning of the stream Can be a string, integer or a datetime.
Starting Position Mode	Determines whether the starting position is inclusive or not. Default is exclusive.

Checkpoint Store (Azure Blob) - Optional

See Parameters - Checkpoint Action for more details.

Container Name

The container name for the blob store.

Connection String

A connection string to an Azure Storage account.

Checkpoint Interval

(Optional) Submits a checkpoint store to Azure blob every nth message. The default checkpoints only at the end of the stream.

There will always be a checkpoint at the end of a message stream.

Parameters - Checkpoint Action

The checkpoint action manually checkpoints a message using the Azure Blob checkpoint store.

Checkpointing is the process of marking a user’s position within a partition event sequence. Checkpointing provides resilience when an event processor fails, and a performance benefit due to load balancing. Load balancing does not apply when receiving from a single partition.

This option is used after a Receive action if there is post-processing of a message in a workspace in which you want the checkpoint to happen later after the message is received.

Checkpoint Options

Received Message ID

The _receive_id attribute from a receiving transformer (with the Receive action) used to identify a message to checkpoint.

Checkpoint Store (Azure blob)

Checkpoint store is optional for the Receive action and required for the Checkpoint action. It is used to maintain a persistent store of partition checkpoint data when receiving events.

If a checkpoint store is not provided, the checkpoint will still be maintained internally in memory but events will be received without load-balancing. Users should not see any difference in connector behavior, but may encounter slower performance times as a result of no load-balancing.

When used, a checkpoint store uses an Azure storage container to store offset information. The offset information is used to start receiving at the same position at the next receive.

Container Name	The container name for the blob store.
Connection String	A connection string to an Azure Storage account. Only one of Connection String or Blob Storage Account URL may be specified.
Blob Storage Account URL	The URI to an Azure Storage account. Blob Storage Account URL can only be used for checkpoint storage if Credential Source is Default Azure Credential or a Microsoft Azure Event Hubs Service Principal web connection is used. Only one of Connection String or Blob Storage Account URL may be specified.
Checkpoint Interval	(Optional) Submits a checkpoint store to Azure blob every nth message. The default checkpoints only at the end of the stream. There will always be a checkpoint at the end of a message stream.

Output Attributes

The following attributes can be selected for inclusion on the output features. Each output feature represents a message that was either sent or received.

_payload	The message payload. UTF-8 string if possible to decode, otherwise binary or numeric.
_enqueued_time	The timestamp when the message was sent.
_offset	The offset of the message.
_partition_key	The partition of the message.
_properties	A key, value pair of message properties.
_receive_id	An id generated to identify the message used for the Checkpoint action.
_sequence_number	The sequence number of the message.
_system_properties	Metadata set by the Event Hubs Service associated with the message.

How to Set Parameter Values

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.

Content Types

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.

Dialog Options - Tables

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.

Processing Behavior	Feature-Based
Feature Holding	No
Dependencies	Microsoft Azure Account with the Event Hubs Service
Aliases
History

AzureEventHubsConnector

Typical Uses

How does it work?

Configuration

Input Ports

Output Ports

Parameters

Editing Transformer Parameters

Reference

FME Community