Glossary

Following are the terms you'll see as you work with Mule. Because of the dynamic open-source history of Mule, there are sometimes multiple terms used to describe the same thing. This glossary lists all terms but refers to the preferred term when there are synonyms.

agent

A service such as the Mule JMX agent that is used by or associated with Mule but is not a Mule-managed service component. An agent is registered with the Mule Manager and has the same lifecycle as the Mule instance, so you can initialize and destroy resources when the Mule instance starts or stops.

application

Any program that sends data through Mule. An application can be a web application, back office system, application server, or another Mule instance.

CE

See Mule Community Edition (CE)

channel

A logical pathway on which messages are sent on a messaging framework. Channels connect services together as well as different Mule nodes across a local network or the Internet. A transport sends messages on a specific channel. See also the EIP Message Channel definition.

component

See service component

configuration builder

A class that knows how to parse a given configuration file. The default configuration builder is the org.mule.config.MuleXmlConfigurationBuilder class that knows how to parse a Mule XML configuration file.

connector

The heart of a transport that maintains the configuration and state for the transport.

EE

See Mule Enterprise Edition (EE)

endpoint

A configuration entity specifying how and where a message should be routed. The endpoint is configured in an inbound or outbound router and specifies where the message should be sent or from where it should be received, using which transport (and optionally which connector in that transport), and which filters should be applied before routing the message. Endpoints can also be defined globally instead of in a specific router.

Enterprise Service Bus (ESB)

An architecture that allows different applications to communicate with each other by acting as a transit system for carrying data between applications within or outside your intranet. An ESB provides transaction management, routing, security, and other functionality for the messages.

event

See message

filter

Specifies logic for determining which messages are routed to a component. You can set filters on an inbound router to filter which messages that service component can receive, or you can set filters on an outbound router to indicate how you want to route messages after they have been processed by the service component.

Galaxy

See Mule Galaxy

HQ

See Mule HQ

inbound router

A Java class that you configure in the Mule configuration file to determine how a service component will receive messages. The inbound router includes an endpoint that indicates where the messages will come from.

interceptor

A Java class that is used to intercept message flow into a service component. An interceptor can be used to trigger or monitor events or interrupt the flow of the message.

message

A packet of data that can be handled and sent between applications on a specific channel. Data is always wrapped in a message before it is transported by Mule. A message has a header, which contains metadata about the message (such as the sender information), and the body, which contains the actual data.

message receiver

A Java class used by a connector to read the incoming data, package it as a message, and passes it to a service component's inbound router. The message receiver can use a transformer if necessary to convert the data.

message dispatcher

A Java class used by a connector to receive the messages and routing instructions from an outbound router and send the message to the next service component.

Mule Community Edition (CE)

The open-source version of Mule, available for free download. As its name suggest, the Community Edition is developed, tested, and maintained by the community.

Mule Enterprise Edition (EE)

The enterprise version of Mule, available for 30-day trial download. The Enterprise Edition includes full development cycles, testing, technical support, maintenance releases and hot fixes, and management and monitoring tools from MuleSource. If you are deploying Mule in a mission-critical environment, want to ensure that you always have a stable, high-quality release, and want additional tools for managing and monitoring your deployment, you should purchase a subscription of Mule Enterprise Edition.

Mule Galaxy

A service-oriented architecture governance platform that allows you to control your infrastructure with SOA governance, registry, and repository features including lifecycle, dependency, and artifact management, as well as auto-discovery or services and reporting.

Mule HQ

A monitoring and management system that provides information about the hardware, services, and applications in your entire enterprise, including CPU usage and information about disks and network devices. Mule HQ provides remote management, monitoring, patching, and alerts for all the assets in your infrastructure. You can integrate the YourKit profiler with Mule HQ to provide a more detailed level of information, showing memory usage all the way to the object level. The YourKit profiler is included with Mule Enterprise.

Mule Manager

Manages the Mule objects, including connectors, endpoints, and transformers. The Mule Manager constructs these objects and provides them to the service components in the Mule Model. Each Mule instance has one Mule Manager and one or more Mule Models.

Mule Model

A service container that hosts the service components and manages their runtime behavior.

outbound router

A Java class that you configure in the Mule configuration file to determine how a service component will dispatch messages. The outbound router can include an endpoint to indicate where the messages should go next, or if no endpoint is configured, it returns the completed message back to the sender.

POJO

An acronym for "plain old Java object," a POJO is a simple Java object, not an enterprise JavaBean. One advantage of Mule is that your service components can be simple POJOs, which Mule then wraps and exposes as services.

provider

See transport

queue

See channel

router

A Java class that determines where and how messages are transported between applications. See also inbound router and outbound router

SEDA

See Staged Event-driven Architecture (SEDA)

service component

A POJO, Spring bean, Java bean, or web service containing the business logic for processing data in a specific way. Mule simply manages the service component, bundles it with configuration settings and exposes it as a service, and ensures that the right information is passed to and from it based on the settings you specified for the service in the Mule configuration file. In early versions of Mule, service components were called Universal Message Objects, and "UMO" is still part of the nomenclature in the Mule APIs today.

Staged Event-driven Architecture (SEDA)

An architecture model where applications consist of a network of event-driven stages connected by explicit queues. This architecture allows services to be well-conditioned to load, preventing resources from being overcommitted when demand exceeds service capacity. As a result, SEDA provides an efficient event-based queuing model that maximizes performance and throughput. SEDA is the default processing model in Mule.

transformer

A Java class that transforms message payloads (data) to and from different types.

transport

A construct that handles and carries messages on a specific messaging protocol, such as HTTP.

transport provider

See transport

universal message object (UMO)

See service component

UMO

See service component

Wire Tap

A router that makes copies of messages and forwards them to another endpoint. It can either forward a copy of all messages that it receives or it can be configured to use a filter and send a sub-set of these messages only. This router will not prevent messages from being delivered to service components. See also Interceptor