Magento Commerce only

Configure message queue topology

The message queue topology can only be configured after Magento Open Source has been installed and before Magento Commerce has been installed.

Each module that is to be a publisher must be configured as such. If you want a module to use the MQF, create a <module>/etc/queue.xml file and define the publisher, consumers, exchanges and bindings.

Edit the `queue.xml` file

The queue.xml file can contain the following elements:

publisher
topic
consumer
bind

Required elements

Each queue.xml file must contain the following lines:

<?xml version="1.0"?>

<config xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:noNamespaceSchemaLocation="urn:magento:framework-message-queue:etc/queue.xsd">
.
.
.
</config>

publisher element

The publisher element configures the type of connection and the exchange to publish to. By default, Magento uses one exchange. The name of exchange is a part of the publisher configuration. However multiple exchanges are supported, based on the AMQP model.

Parameter	Description
name	A unique identifer for the publisher. The value is specified in a `topic` element. The default system publisher name is `default`.
connection	If RabbitMQ is to used to manage the queue, then the value must be `rabbitmq`. The value can also be `db` or the name of a custom adapter.
exchange	The name of the exchange to publish to. The value is referenced from the `bind` element. The default system exchange name is `magento`.

topic element

Configuring the topic element defines the interface that processes the message and assigns a publisher.

Parameter	Description
name	The name assigned to the topic. The format should be `object.action` You can further distinguish topic names by appending `.subaction` to the end of the name. Use the past tense for all verbs, to indicate the event has already happened. Examples: `customer.created`, `customer.sent.email` The value is specified in a `bind` element.
schema	The interface that describes the structure of the message. It should be in the format of a Data Interface from the Service Contracts. For example, `Magento\Customer\Api\Data\CustomerInterface`. You can also specify a service method signature, such as `Magento\Customer\Api\CustomerRepositoryInterface::save`. In this case, format the message as an array of all service method parameters, like for a `call_user_func_array` call. The consumer's callback should expect each message part to be passed as a separate parameter.
publisher	The `name` of a `publisher`.

Parameter

Description

name

The name assigned to the topic. The format should be object.action You can further distinguish topic names by appending .subaction to the end of the name. Use the past tense for all verbs, to indicate the event has already happened.

Examples: customer.created, customer.sent.email

The value is specified in a bind element.

schema

The interface that describes the structure of the message. It should be in the format of a Data Interface from the Service Contracts. For example, Magento\Customer\Api\Data\CustomerInterface.

You can also specify a service method signature, such as Magento\Customer\Api\CustomerRepositoryInterface::save. In this case, format the message as an array of all service method parameters, like for a call_user_func_array call. The consumer's callback should expect each message part to be passed as a separate parameter.

publisher The name of a publisher.

consumer element

Each consumer elements maps the receiver of a message to a specific queue. The class and method parameters indicate what receives and processes the message.

Parameter	Description
name	The name of the consumer. The value should be the same as the magic method that to be used as a callback.
queue	Defines the queue name to send the message to. This value is used in the definition of a `bind` element.
connection	Must be `rabbitmq` or other value specified in the `connection` parameter in of a publisher.
class	The path to a Magento class that consumes the message.
method	The method within the specified `class` that processes the message.
max_messages	Specifies the maximum number of messages to consume.

bind element

The bind elements link topics to queues and exchanges, defining the message queue topology. A topic can be sent to any number of queues.

Parameter	Description
queue	The `name` of a queue defined in a `consumer` element.
exchange	The `name` of an exchange defined in a `publisher` element.
topic	The `name` of a topic defined in a `topic` element. You can specify an asterisk (\*) or pound sign (#) as wildcards.

Sample `queue.xml` file

<config xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:noNamespaceSchemaLocation="urn:magento:framework-message-queue:etc/queue.xsd">
    <publisher name="test-publisher-1" connection="rabbitmq" exchange="magento"/>
    <publisher name="test-publisher-2" connection="db" exchange="magento"/>
    <topic name="customer.created" schema="Magento\Customer\Api\Data\CustomerInterface" publisher="test-publisher-1"/>
    <topic name="customer.deleted" schema="Magento\Customer\Api\Data\CustomerInterface" publisher="test-publisher-2"/>
    <consumer name="customerCreatedListener" queue="test-queue-1" connection="rabbitmq" class="Data\Type" method="processMessage"/>
    <consumer name="customerDeletedListener" queue="test-queue-2" connection="db" class="Other\Type" method="processMessage2" max_messages="98765"/>
    <bind queue="test-queue-1" exchange="magento" topic="customer.created" />
    <bind queue="test-queue-2" exchange="magento" topic="customer.deleted" />
</config>