SharePoint Team Services and FrontPage 2002 Server Extensions Architecture

The architecture for SharePoint™ Team Services, a new technology from Microsoft®, is based on the architecture for Microsoft FrontPage 2002 Server Extensions, but also adds a SQL Server™ or MSDE database to the mix to support new features such as Web document discussions and document libraries. FrontPage 2002 Server Extensions are an update to FrontPage 2000 Server Extensions, and the architecture has not changed significantly.

FrontPage 2002 Server Extensions architecture

The FrontPage client system communicates with a Web server via WinSock and TCP/IP. Wizards and custom applications on the server computer communicate with the FrontPage client using OLE automation.

The FrontPage client communicates with FrontPage Server Extensions using HTTP, the same protocol Web browsers and Web servers use to communicate. FrontPage implements a remote procedure call mechanism on top of the HTTP POST request, so that the FrontPage client can request documents, update the Tasks list, add new authors, and so on.

The Web server sees POST requests addressed to the FrontPage Server Extensions Common Gateway Interface (CGI) programs and directs those requests accordingly. FrontPage correctly communicates between client and server through proxy servers (firewalls).

Note   FrontPage does not use the HTTP PUT request. As described in the HTTP specification, PUT sends a document to a Web server; however, few Web servers implement PUT. Therefore, the FrontPage client uses the universally implemented HTTP POST request for all communication with FrontPage Server Extensions.

FrontPage Server Extensions are accessed from the Web server using the Common Gateway Interface (CGI), the universal Web server extension mechanism. The implementation of CGI differs somewhat among Web servers and platforms. For example, on UNIX, the Web server invokes a CGI extension by running it in a separate process, whereas on Windows NT®, Internet Information Services (IIS) supports the Internet Server Applications Program Interface (ISAPI), a CGI-style communication interface that incurs less overhead.

SharePoint Team Services architecture

The architecture for SharePoint Team Services is based on that for FrontPage Server Extensions; however, SharePoint Team Services relies on a database to provide new functionality. Also keep in mind that SharePoint Team Services does not follow the "create and then publish" model you may be used to with FrontPage Server Extensions. The moment you create a SharePoint team Web site it is live on the server; you do not need to publish the Web site to another server. You can still edit the Web site in a SharePoint Team Servicescompatible Web page editor, such as FrontPage 2002 Server Extensions, or add pages and documents to the site, but you do not need to publish your changes they take effect immediately when you save the files.

The following diagram illustrates the SharePoint Team Services architecture in action.

Note that although a few features require Microsoft Internet Explorer (such as Export to Spreadsheet, which uses ActiveX® components), all content returned to the client computer is HTML.

Because SharePoint Team Services relies on both the file system and a database to track information about your Web site, you must be sure to keep these systems synchronized. For example, a list in a SharePoint team Web site is a combination of data in the database and HTML files. If you want to back up a list, you must back up both the data in the database and the HTML files. SharePoint Team Services provides tools to use for backing up and restoring the collaboration database, but you must back up and restore the file system by using your usual operating system tools. Be sure to back up the file system whenever you back up the database. Keeping your backups synchronized will help simplify the process if you ever need to restore your Web site. For more information about the collaboration database, see Managing the Database.