The WebSphere MQ bridge

To exchange messages with a WebSphere MQ queue manager, a solution needs to use a piece of the WebSphere MQ Everyplace toolkit called the bridge. The WebSphere MQ bridge consists of a number of classes, which must be available on the CLASSPATH, for the Java Virtual Machine to use. These are described in more detail later in this chapter. The bridge is a server-side component, in that it is deployed at the server-end of client-server network topologies. WebSphere MQ bridge queue managers with a device or client role need not have a bridge themselves if they can connect to a bridge-enabled queue manager. In such cases, message traffic passed from these leaf node queue managers can be routed via the bridge-enabled WebSphere MQ bridge queue manager, which in turn can use bridge functionality to convey the message to a WebSphere MQ queue manager.

Normally, the bridge-enabled WebSphere MQ Everyplace queue manager is deployed within a DMZ or behind the Firewall, where the network connections between it and the WebSphere MQ queue managers it talks to are either on the same machine, or on a machine which is you can contact with a reliable high-bandwidth LAN network. A bridge-enabled WebSphere MQ Everyplace queue manager is often referred to as a gateway queue manager, because it provides a gateway between the WebSphere MQ Everyplace and WebSphere MQ messaging networks.

The bridge function is available only in the Java part of the WebSphere MQ Everyplace toolkit, and is usable only by WebSphere MQ Everyplace queue managers running within a Java Virtual Machine. The bridge resources can be manipulated from a native platform with the aid of WebSphere MQ Everyplace administration messages. A specialized set of administration messages is provided in the WebSphere MQ Everyplace product for this purpose, and is described later in this chapter.

Messages from a WebSphere MQ application destined for WebSphere MQ Everyplace are addressed to the WebSphere MQ Everyplace queue manager and queue as normal. Standard WebSphere MQ routing, using remote queue and remote queue manager definitions, is used to route messages to the WebSphere MQ Everyplace queue managers. WebSphere MQ channels are not defined for transmission queues. Instead, the WebSphere MQ Everyplace gateway pulls the messages off these queues and ensures their delivery to the WebSphere MQ Everyplace destination. This is explained in more detail below.

The WebSphere MQ bridge handles the transfer of messages between the two systems, including translation between different message formats. Configuring the WebSphere MQ bridge provides a detailed description of this interface.



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