Architecture of Office Server Extensions

Working with Other Components of Office Server Extensions

Microsoft Office Server Extensions (OSE) use the following additional components to store and retrieve information:

• Microsoft Data Engine (MSDE) or SQL Server
• Custom Automation objects
• Active Server Pages (ASP) pages
• OSE Notification Service and SMPT mail server

Microsoft Data Engine or SQL Server

Microsoft Office Server Extensions (OSE) stores Web Discussions and Web Subscriptions data by using either the Microsoft Data Engine (MSDE) that is installed by default during OSE Setup or a Microsoft SQL Server version 6.5 or later database that can be local or remote.

If you already have a SQL Server installed on your Web server or available on your network, you can use that server to store your OSE data. To gain access to the SQL Server, you must specify the server name, user name, and a password that OSE uses.

The following list identifies the advantages of storing OSE data in an existing SQL Server:

• You can use the same administration that you already established for your SQL Server.
• Your OSE data is protected when your SQL Server has an existing backup strategy.
• You have fewer processing and storage burdens on the Web server running OSE.

Use MSDE when you need to store only OSE data and when you do not have a SQL Server established on your network.

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Custom Automation objects

OSE supports features controlled by custom Automation objects. The custom Automation objects are installed on the Web server running OSE, and they perform the following functions:

• Read and write to the Internet Information Server (IIS) metabase — using the Active Directory Services Interface (ADSI).
• Read and write to MSDE or a SQL Server database — using ActiveX Data Objects (ADO).
• Receive requests from Active Server Pages (ASP) pages.
• Receive event notifications from Microsoft FrontPage Server Extensions — when documents are changed or discussion items are added.
• Respond to HTTP client requests — with Web pages or other response data.
• Prepare and queue e-mail notifications — in MSDE or the SQL Server database.

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Active Server Pages

Active Server Pages (ASP) pages are script files located on a Web server. ASP pages create HTML tags dynamically to:

• Track user state and session information.
• Connect to various COM-based objects, such as the OSE custom Automation objects.

ASP pages are installed with OSE, and they process client requests and use custom Automation objects to return the appropriate response to the client computer. The OSE Start Page and Administration Home Page are examples of some of the ASP pages.

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OSE Notification Service and SMTP mail server

The Office Server Extensions Notification Service is a Microsoft Windows NT service that OSE Setup installs. The notification service queries MSDE or the SQL Server database for queued e-mail notification at immediate, daily, and weekly intervals. The Office Server Extensions Notification Service delivers the e-mail notification to the Simple Mail Transfer Protocol (SMTP) mail server you specify when you configure OSE.

SMTP is an Internet standard protocol for formatting and transporting e-mail messages. If you use the Web Subscriptions feature of OSE, you must use a mail server with SMTP support, such as the Microsoft Exchange Server or the SMTP service in IIS. The mail server runs on either the Web server that is running OSE or a remote mail server.

The subscription notification process uses the following sequence of events to send e-mail notification to subscribers:

1. When a document changes, the FrontPage Server Extensions notify an OSE custom Automation object. This object is called the Event Sink.
2. When a user adds a discussion item to a document, an OSE custom Automation object responsible for managing discussion items notifies the Event Sink.
3. The Event Sink queries the MSDE database or SQL Server database to determine the subscription status for the file that has changed and for the folder that contains the changed file. If the file and folder do not have subscribers, no further action takes place. If the folder or file have subscribers, the procedure continues to the next step.
4. The Event Sink prepares e-mail notifications in SMTP format and then consolidates the notices into one e-mail message for each subscriber.
5. At the scheduled time, the notification service retrieves the e-mail message from the database, and sends the e-mail message to the SMTP mail server.
6. The SMTP mail server sends the e-mail message to the subscriber mailbox.

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See also

You need only a minimal understanding of HTTP, TCP/IP, IP addressing, URLs, and DNS to use OSE because OSE handles these components automatically. For more information about these subjects, see the Microsoft Windows NT Server 4.0 Resource Kit.

Security is an important consideration when you deploy new server software such as OSE. For a complete discussion of OSE security issues, see Using Windows NT Security with Office Server Extensions and How to Configure Security on Your OSE-extended Web.

Windows NT includes the Convert.exe utility that you can use to convert an existing file allocation table (FAT) volume to NTFS — without losing data. For more information, see the Microsoft Windows NT Server 4.0 Resource Kit.