Components of a Pub-Sub System

A pub-sub system consists of several components, as shown in Figure 1.3. Several raw information sources feed into the system, providing the information that will later be published to end users. A notification application matches the input information against subscriptions, introduced via subscription systems (usually PCs that connect to the application over a network). As a result of the match, the notification application produces a set of notifications. A delivery system then routes these notifications to the recipients' target devices.

Figure 1.3. Components of a publish-subscribe system.

The notification application is the core of the pub-sub system. Its job is to match incoming information with subscriptions to produce the notifications to be delivered. SQL Server 2005 Notification Services is a platform for building and running rich, scalable notification applications and integrating them into the framework of a complete pub-sub system. This book teaches you how to leverage this platform to build the notification applications at the center of your pub-sub systems.