The document discusses using the VM component in Mule applications for intra-JVM communication between flows. The VM component uses in-memory queues by default but can be configured to use persistent queues. An example flow is provided that demonstrates a main flow triggering a subflow using the VM component, and logging messages from both flows. Key features of the VM component like request-response vs one-way messaging and in-memory vs persistent queues are also outlined.

1. VM Component In Mule Demo

2. Abstract
• The main motto of this PPT is how to use VM
component in our applications.

3. Introduction
• You can use the Java Virtual Machine (VM)
transport for intra-JVM communication
between Mule flows. This transport by default
uses in-memory queues but can optionally be
configured to use persistent queues..

4. Example
• hello world example

5. • .mflow
• <?xml version="1.0" encoding="UTF-8"?>
• <mule xmlns:http="http://www.mulesoft.org/schema/mule/http"
xmlns:vm="http://www.mulesoft.org/schema/mule/vm" xmlns="http://www.mulesoft.org/schema/mule/core"
xmlns:doc="http://www.mulesoft.org/schema/mule/documentation"
xmlns:spring="http://www.springframework.org/schema/beans" version="EE-3.4.0"
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xsi:schemaLocation="http://www.springframework.org/schema/beans
http://www.springframework.org/schema/beans/spring-beans-current.xsd
• http://www.mulesoft.org/schema/mule/core http://www.mulesoft.org/schema/mule/core/current/mule.xsd
• http://www.mulesoft.org/schema/mule/vm http://www.mulesoft.org/schema/mule/vm/current/mule-vm.xsd
• http://www.mulesoft.org/schema/mule/http http://www.mulesoft.org/schema/mule/http/current/mule-http.xsd">
• <flow name="VMFlow1" doc:name="VMFlow1">
• <http:inbound-endpoint exchange-pattern="request-response" host="localhost" port="8087" path="VM"
doc:name="HTTP"/>
• <logger message="--Main flow triggered " level="INFO" doc:name="Logger"/>
• <vm:outbound-endpoint exchange-pattern="request-response" path="subflow" doc:name="VM"/>
• </flow>
• <flow name="VMFlow2" doc:name="VMFlow2">
• <vm:inbound-endpoint exchange-pattern="request-response" path="subflow" doc:name="VM"/>
• <logger message="--Hello world" level="INFO" doc:name="Logger"/>
• </flow>
• </mule>

6. • Output:

7. • Flow of execution:
1. Service will trigger from browser with the
following URL “http://localhost:8087/VM”
2. Service will display a message called ‘’ and
‘Hello world’

8. Features
• The in memory (VM) transport has two modes of operation: One for use
with request-response and another for use with one-way endpoints.
• request-response:
• When using request-response endpoints, messages are delivered directly
from an outbound vm endpoint to the inbound vm endpoint that is
listening on the same path. This delivery is blocking and occurs in the
same thread. If there is no inbound request-response VM endpoint in the
same Mule application that is listening on this path, then dispatching a
message from the outbound endpoint fails.
• one-way:
• When using one-way endpoints, messages are delivered to the
corresponding inbound endpoint via a queue. This delivery is non-
blocking. If there is no inbound one-wayendpoint in the same Mule
application listening on this path, then, although dispatching of the
message succeeds, the message remains in the queue. By default, this
queue is in memory, but it is also possible to configure a persistent queue
that uses the file system as its persistence mechanism.

9. References
• https://docs.mulesoft.com/mule-user-
guide/v/3.7/vm-transport-reference#vm-
transport-info