PeopleSoft Internet Architecture Components

The PeopleSoft Internet Architecture consists of Four components:

• Internet Access Device
• Web Server
• Application Server
• Database Server

INTERNET ACCESS DEVICE:
        PIA is completely server-based, so client(workstations) machines to this architecture can be any kind of internet-enabled device, including:

• Web browser running on a PC or Macintosh
• Wireless device
• External or third-party system

        A Web browser is the most common internet access, which uses HTTP protocol. No applets or plug-ins are needed, a servlet installed on the Web Server facilitates all browser connections to the Application Server through JOLT. The Request sent by the browser to the web server is forwarded to the Application Server, in return the Application Server sends only the HTML, JavaScript, Cookies to the browser. The client workstation is free of any processing responsibilities because all processing occurs at server level. This is why PeopleSoft Internet Architecture(PIA) is called as "architecture without a client."

WEB SERVER:
       The Web Server is the intermediary processor that translates HTML and JOLT and maintains the session state for users accessing PeopleSoft through PeopleSoft Internet Architecture(PIA).

Functions of Web Server:

• Data relay between browser and the Application Server.
• Encryption handling.
• Managing connections between the browsers.
• Caching and serving up images, style sheets and Javascripts.
• Managing the user state or page buffers.

      The Web Server must be Java-enabled so that it can run the PeopleSoft-delivered Java Servlets that are installed as part of PeopleSoft Internet Architecture. One of these is the Portal Servlet, which relays all inbound and outbound transaction requests for the browser. Using JOLT, the Web Server communicates browser requests to the Application Server. The pure HTML that the Application Server generates is formatted and presented in the browser by the Portal Servlet. Together the Web Server and the Application Server make up the middle-tier of PIA; however, the Application Server does most of the work.

 APPLICATION SERVER:
      The Application Server is the core of PeopleSoft Internet Architecture. It handles messages from the Web Server through JOLT and executes all PeopleSoft business logic. In addition, it maintains the SQL connection to the Database Server for both browser requests and for the PeopleSoft development environment. PeopleSoft uses TUXEDO to manage database transactions. At execution time, the Application Server fetches the most recent application definitions from the Metadata Repository of the Database Server. The Application Server caches the definitions in memory and executes the business rules, based on the definitions. Definitions such as pages, are created using the Application Designer tool in the PeopleSoft 8 development environment. The Application Server consists of numerous PeopleSoft services and server processes that handle transaction requests. One of these server processes, PSAPPSRV, performs all application processing for a PeopleSoft internet session and generates the HTML to be displayed in the browser. For example, it is the PSAPPSRV process of the Application Server that builds and loads the pages which are then transmitted to the browser, as requested, through the Web Server.
      As you can see, the Application Server is truly the heart of PeopleSoft Internet Architecture.

 DATABASE SERVER:
      Just as in the PeopleSoft three-tier architecture, with the PeopleSoft 8 Internet Architecture, information is stored on the Database Server in three types of tables: System Catalog Tables, PeopleTools Tables, and PeopleSoft Application Data Tables. Each table type contains specific information that is related to running PeopleSoft applications.

      The PeopleSoft database is the repository for all information that is managed by PeopleSoft applications. Not only is application data stored in the database, but the PeopleSoft metadata is also maintained in the database. Metadata is what drives PeopleSoft Internet Architecture. Because PeopleSoft architectures have always been metadata-driven, PeopleSoft has been able to make the leap from client/server to internet-based applications without having to completely rewrite existing applications. Several internet-related definitions were enhanced in PeopleTools 8.4 to enable full internet application development. These are the HTML Catalog, images, and style sheets. Just like fields, records, pages, menus, and other definitions, these definitions are stored in the PeopleTools Tables of the Database Server, and are fully upgradeable. Multiple Application Servers can be connected to a single Database Server, which simultaneously handles the Application Server connections and development environment connections.