Software Components

As shown in the figure "Distributed analysis mode," the components of the server technology are the following. (See Figure 1.)

Client software. The client application is a complete installation of the end user’s IBM® Corp. product (e.g., IBM SPSS® Statistics). When it is used for distributed analysis, only the graphical user interface and the editing capabilities are used. When it is used for local analysis, its data access and statistical processing capabilities are also used.

Server software. The server software is made up of sub-components: a framework that manages client/server communication, client processes that manage client requests, and modules that access data and perform analyses.

• Framework. The framework of server software is a service (on Windows) or daemon (on UNIX). It handles all communication between the client application and the modules. The framework runs continually on the server computer, waiting for client connections. When a client connects, the framework launches a process that handles requests for that client.
• Client process. A client process is effectively a session for the client. There is one process for each client. A process is launched when the client connects, and it is terminated when the client disconnects. The process manages its client’s requests for data and analyses. It loads the modules that are needed to access and analyze data. It unloads modules when they are no longer required.
• Modules. A module is an executable, DLL, or shared library that accesses data and runs analytic procedures. The analytical server software has several modules. Modules are loaded on demand. Modules may load other modules.