VM Connector Send Messages across Different Apps Example - Mule 4

The following examples show two ways to send messages across different apps:

Use a Listener to receive the messages from the first app and a Publish operation to feed the received messages to a second app.
Use a Publish operation in a second app to push messages to the queue of messages, and a Consume operation to consume the messages.

In both cases, the two apps must be in the same domain.

Publish Messages to a Second App

Create a VM configuration in a domain, like this:

<mule-domain xmlns="http://www.mulesoft.org/schema/mule/domain"
  xmlns:vm="http://www.mulesoft.org/schema/mule/vm"
  xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
  xsi:schemaLocation="http://www.mulesoft.org/schema/mule/vm
  http://www.mulesoft.org/schema/mule/vm/current/mule-vm.xsd
  http://www.mulesoft.org/schema/mule/domain
  http://www.mulesoft.org/schema/mule/domain/current/mule-domain.xsd">
  <vm:config name="sharedVMConfig">
    <vm:queue queueName="sharedQueue" queueType="PERSISTENT" />
  </vm:config>
</mule-domain>

Place a listener in an app in the same domain:

<flow name="crossAppListener">
	<vm:listener queueName="sharedQueue" config-ref="sharedVMConfig" />
	<logger />
</flow>

Publish messages from a second app in the same domain:

<flow name="crossAppRequester">
  <vm:publish queueName="sharedQueue" config-ref="sharedVMConfig" />
</flow>

In this example, the Listener and Publish operation point to the same queue (sharedQueue) and the same configuration (sharedVMConfig).

Pull Published Messages from a Queue

Instead of using the <vm:listener> message source, you can consume messages in a VM queue through the <vm:consume> operation. This operation can consume messages on demand, allowing you to:

Dynamically consume from different queues depending on a certain condition.
Have a tighter control on the rhythm at which the app consumes messages.

To consume published messages from a queue:

Create a VM configuration in a domain, like this:

<mule-domain xmlns="http://www.mulesoft.org/schema/mule/domain"
  xmlns:vm="http://www.mulesoft.org/schema/mule/vm"
  xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
  xsi:schemaLocation="http://www.mulesoft.org/schema/mule/vm
  http://www.mulesoft.org/schema/mule/vm/current/mule-vm.xsd
  http://www.mulesoft.org/schema/mule/domain
  http://www.mulesoft.org/schema/mule/domain/current/mule-domain.xsd">

  <vm:config name="sharedVMConfig">
    <vm:queue queueName="sharedQueue" queueType="PERSISTENT" />
  </vm:config>

</mule-domain>

Publish messages from a second app in the same domain:

<flow name="crossAppRequester">
  <vm:publish queueName="sharedQueue" config-ref="sharedVMConfig" />
</flow>

Pull messages from the queue after they are published.

<flow name="queueConsume">
  <vm:consume queueName="sharedQueue" config-ref="sharedVMConfig" />
  <logger />
</flow>

In this example, the Publish and Consume operations point to the same queue (sharedQueue) and the same configuration (sharedVMConfig).

VM Connector Send Messages across Different Apps Example - Mule 4

Publish Messages to a Second App

Pull Published Messages from a Queue

See Also