Mule ESB –Advanced

Mule Message Structure

The Mule message is the data that passes through an application via one or more flows. It consists of two main parts:

The message header, which contains metadata about the message The message payload, which contains your business-specific data. 

Mule Message Properties and Variables

Message header consists of properties which provide useful information about the message

variables represent data about a message Properties have two main

scopes: inbound and outbound. Inbound Property

Mule Message Variables

Variables are user-defined metadata about a message.

Variables have three scopes: Flow variables apply only to the flow in

which they exist.

Session variables apply across all flows within the same application.

 

Outbound Endpoint

Mapping message headers to transport headers

Mapping transport headers to message headers

Inbound Endpoint

Transformation Types

3 Types of Transformers Type transformation - involves converting the ‘type’ of the message, for example; converting a byte stream to a string or converting a JMS Message to a Java object.

Message transformation involves converting the message itself,for example; converting a BookingRequest object into anAirlineTicket object.

Property Transformations involves the properties on a message.Each message may contain properties, usually related to the transport used. For example, a message sent to an

SMTP server would have ‘To’, ‘From’ and ‘CC’ properties

SPLITTER

A message splitter can be used to break down an outgoing message into parts and dispatch those parts over different endpoints configured on the router.

SplitterExample

<flow name="SplitterExampleFlow1" doc:name="SplitterExampleFlow1">        <http:inbound-endpoint exchange-pattern="request-response"

host="localhost" port="8081" doc:name="HTTP"/>          <splitter expression="#[xpath('//actor')]" doc:name="Splitter"

enableCorrelation="IF_NOT_SET"/>        <logger message="#[message.payload]" level="INFO"

doc:name="Logger"/>    </flow>

Mule Aggregator

Mule aggregators use the MULE_CORRELATION_ID and MULE_CORRELATION_GROUP_SIZE to reassemble a split message.

<flow name="aggregateLineItems"><jms:inbound-endpoint queue="lineitem.complete“ connector-ref="jmsConnector"/><collection-aggregator timeout="60000“ failOnTimeout="true" /><custom-transformerclass="com.prancingdonkey.transformer.LineItemsToOrderTransformer"/><component class="com.prancingdonkey.service.OrderProcessingService"/></flow>

Mule Aggregator Example

Resequencer

If fractions of the message are being processed in parallel in different servers, there's a good chance that they may take different lengths of time to be processed, and consequently fall out of order.

The Resequencer will wait for all of the messages in the group to arrive (keeping track of MULE_CORRELATION_ID and MULE_CORRELATION_GROUP_SIZE )

Reorder them according to their MULE_CORRELATION_SEQUENCE index.

The Resequencer outputs will be in distinct messages, 

THANK YOU