The WebSphere MQ Family

The WebSphere MQ family includes many products, offering a range of capabilities, as illustrated in Figure 1.

Figure 1. The WebSphere MQ family

Diagram showing the three layers in the WebSphere MQ family, described below.

Both WebSphere MQ Workflow and WebSphere MQ Integrator products take advantage of the connectivity provided by the WebSphere MQ messaging layer.

Basic Messaging

Messaging, irrespective of the particular product or product group, is based on queues and queue managers. Queue managers manage queues that can store messages. Applications communicate with a local queue manager, and get or put messages to queues. If a message is put to a remote queue (a queue owned by another queue manager), the message is transmitted over connections to the remote queue manager. In this way, messages can hop through one or more intermediate queue managers before reaching their destination. The essence of messaging is to uncouple the sending application from the receiving application, queuing messages at intermediate points, if necessary.

WebSphere MQ and WebSphere MQ Everyplace supply WebSphere MQ family messaging. Both are designed to support one or more hardware server platforms and most associated operating systems. Given the wide variety in platform capabilities, these individual products are organized into product groups, reflecting common function and design:

WebSphere MQ host and distributed products

WebSphere MQ host and distributed messaging products are used to support many different network configurations, all of which involve clients and servers, some examples of which are illustrated in Figure 2.

Note:
The terms client and server have very specific meanings within WebSphere MQ host, distributed, and workstation messaging products, that do not always correspond to their meaning within WebSphere MQ Everyplace.

Figure 2. Simple host and distributed configurations

Three simple host and distributed configurations. a) A stand-alone server, b) two clients connected to a server, c) two interconnected servers each with two attached clients.

In Figure 2:

a) Standalone server
A queue manager runs on a single server. One or more applications run on that server, exchanging messages using queues.

b) Client/server
A queue manager runs on a server, but the clients each have access to it through a bidirectional connection called a client channel. The client channel implements something similar to a remote procedure call (RPC). Applications can run on the clients, accessing server queues. One advantage of the client/server configuration is that the client-messaging infrastructure is lightweight, because it depends on the server queue manager. One disadvantage is that clients and their associated server operate synchronously and, therefore, require the client channel to be available at all times.

c) Distributed client/server

A distributed client/server configuration involves multiple servers. In this case, servers exchange messages through unidirectional connections called message channels. Message channels assure safe and asynchronous exchange of message data. Message channels do not need to be available for the clients to continue processing. However, no messages can flow between servers when there are no communication links established between servers.

WebSphere MQ Everyplace

WebSphere MQ Everyplace supports a variety of network configurations. There is no concept of a client or a server as in the WebSphere MQ host or distributed products. Instead, you can configure WebSphere MQ Everyplace queue managers to act as clients or servers, enabling them to perform application-defined tasks.

An example of tailored configuration is that you can give WebSphere MQ Everyplace the ability to exchange messages with WebSphere MQ host queue managers. To do this, configure a WebSphere MQ Everyplace queue manager with bridge capabilities. Without the bridge, a queue manager can communicate directly with other WebSphere MQ Everyplace queue managers only. However, it can communicate indirectly through other queue managers in the network that have bridge capabilities.

Note:
A new node for WebSphere MQ Integrator (MQSI) allows you to connect to WebSphere MQ Everyplace, without using the WebSphere MQ bridge.


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