Interfaces for message exchange

This section describes the messaging interfaces used by the connector framework and the integration broker to transmit messages and the information needed to process them.

Several distinct types of messages are exchanged within the business integration system. Essential information needed to identify the different types of messages, as well as process and route them correctly, is stored in the message header and the message descriptor of each message. Message flows you create for your business integration system use the information presented below to recognize and correctly manage messages they are called upon to process.

The following types of messages are passed:

Message formats

Messages exchanged between the connector framework and the integration broker are formatted by the data handler, based on:

Each message contains three components: a message descriptor (MQMD), a message header (MQRFH2), and a message body.

Message descriptor

The WebSphere MQ message descriptor (MQMD) contains the message ID and includes information needed for processing the message.

Message header

The MQRFH2 message header carries JMS-specific data that is associated with the message content. It can also carry additional information that is not directly associated with JMS. The message header contains the following folders:

Message body

The message body is formatted as specified by the XML schema specified for the message. In order for the data handler to find and use the correct XML schema for formatting a message, the following three names must be the same:

The message formats and the settings for particular properties for the different types of messages exchanged by the connector framework and the WebSphere message broker are listed in Appendix A, WebSphere MQ message formats..

In addition, the XML data handler makes the following assumptions about an XML document:

Message queues

The WebSphere MQ queues that need to be defined and configured for use with the connector are described below.

Required types of queues

Separate sets of WebSphere MQ message queues are used for transporting business object messages and administrative messages between the connector framework and the WebSphere message broker. You must define queues with the following properties:

During connector configuration, you specify the name of each queue as a standard property in the connector's configuration file.

Queue manager

The connector uses a single queue manager to manage all of its interactions with queues. The standard properties in the connector's configuration file contain the queue manager information needed by the connector at startup. The connector uses this information to establish a connection to the queue manager it will use to communicate with the WebSphere message broker.

The WebSphere business integration system supports several queue managers and queue configurations. The connector can communicate with the queue manager in any of the following modes:

For more information

To learn more about WebSphere MQ messages see WebSphere MQ: Using Java. To learn more about WebSphere MQ queues, see WebSphere MQ: Intercommunication and WebSphere MQ: Script Command (MQSC) Reference.

Copyright IBM Corp. 1997, 2004