Multiple client applications connected to one AppServer
Figure 3–5 shows a connection to an AppServer from multiple client applications, with the AppServer configured with a local database. In this scenario, all running AppServer agents share self-service access to the same database. Client applications, however, have access only to data that the AppServer provides and never access the database directly. To regulate this data access, you can implement many different security arrangements on the AppServer. Each one typically restricts remote procedure access and execution based on any combination of user-based (authorization) and application-based (functional) security.
Also, each client application can be quite different and unrelated to the others, except that they all require data that the same AppServer provides. In the course of interacting with the AppServer, a client application might call a remote procedure that connects and accesses an additional database connected only to the AppServer agent handling that particular request.