RabbitMQConnector

Connects to a RabbitMQ AMQP 0-9-1 broker to send and receive messages.

Typical Uses

Sending and receiving messages.

How does it work?

The RabbitMQConnector uses your account credentials to perform various tasks:

Action	Task
Acknowledge	Manually send acknowledgements.
Count Messages	Count waiting messages in a queue.
Receive	Receive messages from queues.
Send	Send messages to queues.

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.

When the Input port is in use, the Initiator output port is also enabled.

Heartbeat

When Action is Receive and the connection is still alive (Receive Mode is Stream or a batch is not yet complete), heartbeat features are output at a specified interval after a period of non-activity.

Heartbeat features have two attributes:

_heartbeat_id: Integer starting at 0. This is a unique identifier for each heartbeat feature output from this port.
_heartbeat_counter: Integer starting at 0 that resets whenever the connector receives a new message and a new period of inactivity begins. This counter represents the number of consecutive heartbeat features.

Configuration

Input Ports

Output Ports

Output

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

Action	Output - Input-Driven	Output - Run Once
Acknowledge	Input feature with acknowledgment details.	One new feature with acknowledgment details.
Count Messages	Input feature with message count.	New feature with message count.
Receive	Multiple features, one for each message received, with details about the message.	Multiple features, one for each message received, with details about the message.
Send	Input feature with details about the sent message.	New feature with details about the sent message.

Parameters

Authentication

Credential Source

Select the type of credentials to use:

Web Connection (Recommended): Use a RabbitMQ web connection.
Embedded: Embed user name and password as transformer parameters.

Account

When Credential Source is Web Connection, select or create a Web Connection connecting to an RabbitMQ Web Service.

See Using Web Connections.

Embedded Credentials

When Credential Source is Embedded:

Host	Specify the endpoint of the RabbitMQ broker.
Virtual Host	(Optional) Provide the name of the virtual host used for multi-tenant brokers. Default is /.
Broker Port	(Optional) Specify the port to connect to the broker. Default is 5672.
Web Port	(Optional) Specify the port to connect to the RabbitMQ HTTP API. This is the same port for the admin web GUI. Default is 15672
Enable SSL/TLS	Select a secure connection option: Yes: Use a secure connection. No (default): Use an insecure connection.
Verify Certificates	When Enable SSL/TLS is Yes, select a verification option: No: Do not verify. Only choose No if there are expected certificate errors. Yes (default): Verify.
User Name	Provide a user name.
Password	Provide a password.

Action > Acknowledge

Acknowledge is typically used after an upstream RabbitMQConnector has performed a Receive action where Auto Acknowledge is No.

See RabbitMQ - Consumer Acknowledgements.

Acknowledge Options

Receiving Connector Id

Set to the value of the _connector_id attribute produced by the upstream receiving RabbitMQConnector.

Delivery Tag

Set to the value of the _delivery_tag attribute produced by the upstream receiving RabbitMQConnector.

Multiple Messages

Select an option:

Yes: Acknowledge all messages prior to the current message.
No (default): Acknowledge the current message.

Output Attributes

No attributes are added for this Action.

Action > Count Messages

Count Messages Options

Queue

Specify the queue to count waiting messages in.

Note that when a Count Messages action follows a Receive action, the number of messages returned may be one less than the actual number.

Added Attributes

Output features will receive these attributes:

_message_count

The number of messages waiting in the queue.

Action > Receive

Routing

Exchange Type	Select an exchange type: Fanout: Messages are sent to all queues that are bound to the exchange. Direct: Messages are sent to all queues bound to the exchange via the routing key. Topic: Messages are sent to queues bound to a routing key via a pattern. See RabbitMQ - Exchanges.
Exchange	Provide the exchange name. Names consist of a non-empty sequence of these characters: letters, digits, hyphen, underscore, period, or colon.
Routing Key	When Exchange Type is Direct or Topic, provide the name used to route messages from exchanges to queues.
Queue	Provide the queue name. If empty, the broker will create a unique queue name.
Queue Type	Select the type of RabbitMQ queue: Classic (default) Quorum Stream See RabbitMQ - Queues.

Receive Options

Receive Mode

Select a message receiving method:

Stream: The connector continues to receive messages indefinitely. The translation must be terminated to stop receiving.
Batch: Only a given number of messages are received before the connection is closed.

Batch Size

When Receive Mode is Batch, specify the number of messages to read per batch.

Heartbeat

Interval

Specify the duration of a period of inactivity before a heartbeat feature is emitted, in Time Units.

Default is 1.

Time Unit

Select the Interval unit:

Seconds
Minutes
Hours (default)
Days

Advanced Properties

Auto Acknowledge	When Queue Type is Classic or Quorum, select an acknowledgment mode: No (default): Do not automatically acknowledge messages. A _connector_id and _delivery_tag attribute are added, to be used after the message is successfully processed to perform a manual acknowledgement with another RabbitMQConnector, Action > Acknowledge. Server-side: The broker will send messages without expecting any acknowledgments in return. If using Batch receive mode with a Batch Size smaller than the number of queued messages, the remaining messages will be discarded. See RabbitMQ - Consumer Acknowledgement Modes and Data Safety Considerations. Client-side: The transformer will automatically send an acknowledgment for every message.
Declare Exchange	Select an option: No (default): Do not declare the exchange. Yes: Declare the exchange. See RabbitMQ - Exchanges.
Exchange Properties	(Optional) When Declare Exchanges is Yes, pick properties to apply to the exchange: Auto_Delete: The exchange is deleted after the consumer cancels or disconnects. Durable: Survive reboots of the broker. If not selected, the exchange is transient. A transient exchange is deleted on reboot. Metadata of a durable exchange is stored on disk, while metadata of transient exchange is stored in memory.
Queue Properties	(Optional) When Queue Type is Classic, pick properties to apply to the queue: Auto_Delete: The queue is deleted after the consumer cancels or disconnects. Durable: Survive reboots of the broker. If not selected, the queue is transient. A transient queue message is deleted on reboot. Metadata of a durable queue is stored on disk, while metadata of transient queue is stored in memory. Note that as of fpkg-rabbitmq 3.1.0, new classic queues on RabbitMQ 4.0+ must be durable.
Offset Mode	When Queue Type is Stream, select where in the stream to begin reading messages: First: Begin reading from the first message of the stream. Last: Begin reading from the last message of the stream. Next (default): Wait for incoming messages. Value: Specify an Offset Value. Timestamp: Specify an Offset Timestamp.
Offset Value	When Offset Mode is Value, specify either an integer representing an offset of an existing message in the stream queue, or an interval string that begins with an integer and ends with a valid unit (Y,M,D,h,m,s). See the Offset and Interval options in RabbitMQ - Streams.
Offset Timestamp	When Offset Mode is Timestamp, specify a date and time in Coordinated Universal Time (UTC) to start reading messages from. See the Timestamp option in RabbitMQ - Streams.
Stream Properties	(Optional) When Queue Type is Stream, set properties to apply to the queue: x-max-age: Sets the maximum age of the stream. x-max-length-bytes: Sets the maximum size of the stream in bytes. x-stream-max-segment-size-bytes: Sets the maximum size of a stream segment file in bytes. If a queue already exists, specified properties must match existing properties. See RabbitMQ - Declaring a RabbitMQ Stream..

Output Attributes

Attributes to Add

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

_connector_id	Used to identify the message for acknowledgment.
_consumer_tag	Used to identify the consumer.
_delivery_mode	Whether the delivery mode for a message is transient (1) or persistent (2).
_delivery_tag	Used to identify the message for acknowledgment.
_exchange	The exchange that the message was routed through.
_headers	A list of name/value pairs of headers on the message.
_payload	The message payload. UTF-8 string if possible to decode, otherwise binary or numeric.
_properties	A list of name/value pairs of additional message properties.
_redelivered	True if a message is delivered but not fully acknowledged and re-queued.
_routing_key	The routing key used to route the message.

Action > Send

Routing

Exchange Type

Select an exchange type:

Fanout: Messages are sent to all queues that are bound to the exchange.
Direct: Messages are sent to all queues bound to the exchange via the routing key.
Topic: Messages are sent to queues bound to a routing key via a pattern.

See RabbitMQ - Exchanges.

Exchange

Provide the exchange name.

Names consist of a non-empty sequence of these characters: letters, digits, hyphen, underscore, period, or colon.

Routing Key

When Exchange Type is Direct or Topic, provide the name used to route messages from exchanges to queues.

If Exchange Type is Direct and Exchange is empty, Declare Queue must be Yes and the Routing Key must be identical to Queue.

Send Options

Payload

Provide the message content.

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

Delivery Mode

Select a delivery mode:

Default: Messages are lost after a broker restart.
Persistent: Messages are saved to disk and survive a broker restart.

Advanced Properties

Declare Exchange

Select an option:

No (default): Do not declare the exchange.
Yes: Declare the exchange.

See RabbitMQ - Exchanges.

Exchange Properties

(Optional) When Declare Exchanges is Yes, pick properties to apply to the exchange:

Auto_Delete: The exchange is deleted after the consumer cancels or disconnects.
Durable: Survive reboots of the broker. If not selected, the exchange is transient. A transient exchange is deleted on reboot. Metadata of a durable exchange is stored on disk, while metadata of transient exchange is stored in memory.

Declare Queue

Select an option:

No (default): Do not declare the queue.
Yes: Declare the queue.

Queue

Provide the queue name.

If empty, the broker will create a unique queue name.

Queue Type

Select the type of RabbitMQ queue:

Classic (default)
Quorum
Stream

See RabbitMQ - Queues.

Queue Properties

(Optional) When Queue Type is Classic, pick properties to apply to the queue:

Auto_Delete: The queue is deleted after the consumer cancels or disconnects.
Durable: Survive reboots of the broker. If not selected, the queue is transient. A transient queue message is deleted on reboot. Metadata of a durable queue is stored on disk, while metadata of transient queue is stored in memory.

Note that as of fpkg-rabbitmq 3.1.0, new classic queues on RabbitMQ 4.0+ must be durable.

Message Properties

(Optional) Set additional message properties. Valid keys are:

content_type
content_encoding
priority
correlation_id
reply_to
expiration
message_id
timestamp
type
user_id
app_id
cluster_id

Stream Properties

(Optional) When Queue Type is Stream, set properties to apply to the queue:

x-max-age: Sets the maximum age of the stream.
x-max-length-bytes: Sets the maximum size of the stream in bytes.
x-stream-max-segment-size-bytes: Sets the maximum size of a stream segment file in bytes.

If a queue already exists, specified properties must match existing properties.

See RabbitMQ - Declaring a RabbitMQ Stream..

Output Attributes

Attributes to Add

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

_payload

The message payload. UTF-8 string if possible to decode, otherwise binary or numeric.

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.

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.

For more information, see Transformer Parameter Menu Options.

Reference

Processing Behavior	Feature-Based
Feature Holding	No
Dependencies
Aliases
History	Released FME 2019.0

FME Online Resources

The FME Community and Support Center Knowledge Base have a wealth of information, including active forums with 35,000+ members and thousands of articles.

Search for all results about the RabbitMQConnector on the FME Community.

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