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About Mule Configuration

Following is an introduction to configuring Mule via the Spring XML file. For details on this file, see About the XML Configuration File.

Mule Configuration File Overview

A Mule configuration file is a tree, as shown in the following illustration:


Each of these elements provides access to a configuration object within Mule:

  • Custom Message Processors - Observe a message, or modify either a message or the message flow. Examples include transformers and filters.

  • Flows - Use message processors to define message flow between a source and a target.

  • Mule Global Configuration - Global settings, such as the default transaction time-out, that apply to the entire Mule configuration

  • Connectors - Non-default configuration of any transports used

  • Endpoints - Define the channel and address or path where messages are sent or received. You can define them globally and use them in multiple flows.

  • Transformers - Convert data from one format to another. You can define them globally and use them in multiple flows.

  • Filters - Filter out the messages that don’t match specific criteria. You can define them globally and use them in multiple flows.

Following is an example of a simple Mule configuration file:

Simple Mule Configuration

<mule xmlns=""


    <vm:connector name="vmConnector" queueTimeout="5000"/>

    <vm:endpoint name="CustomerRequests" path="customer.requests"/>
    <vm:endpoint name="CustomerResponses" path="customer.responses"/>

    <custom-transformer name="ThisToThat" class="com.acme.transformer.ThisToThat"/>

    <flow name="myBasicFlow">
        <inbound-endpoint ref="CustomerRequests"/>
        <component class="com.acme.service.BasicService"/>
        <outbound-endpoint ref="CustomerResponses" transformer-refs="ThisToThat"/>

Other, more advanced things you may configure at this level:

  • Security Manager - Authenticates requests based on one or more security providers

  • Agents - Agents are typically used for cross-cutting concerns such as logging or management

  • Notifications - Allow you to be notified upon certain lifecycle events

  • Transaction Management - Mule transactions are configured on inbound endpoints, where an endpoint can be configured to start a new transaction or join an existing one.

  • Properties - Property placeholders, message properties, and system properties.

Global Configuration Settings

You can configure global configuration settings such as the default transaction timeout and default threading profile in the <configuration> element. For example:

  <configuration defaultTransactionTimeout="31337">
    <default-threading-profile poolExhaustedAction="RUN"/>

For a list of the available global configuration settings, see Global Settings Configuration Reference.

Accessing the Configuration Programmatically

All Mule configuration is accessible from a single object: org.mule.api.config.MuleConfiguration.

Configurations in a MuleConfiguration are set when a MuleContext is created. The object becomes immutable after it is started and can be accessed using the following:

// implement MuleContextAware to have the reference injected
MuleConfiguration configuration = context.getConfiguration();