New Features in Internet Information Server (IIS) Version 4.0

MORE INFORMATION

The following is a summary of new features added to IIS 4.0 in the areas of application stability and server management, and a list of articles that discuss known IIS 3.0 issue resolutions. For more information, see the "Quick Tour of Features" in the online Microsoft Windows NT 4.0 Option Pack Documentation.

Application Stability

• Process isolation
  
  Web Applications can be hosted in an environment that protects the core Web services from poorly written applications. Isolated Web Applications each run within their own Mtx.exe process. In the past, all ASP applications ran within a single Inetinfo.exe process.
• Microsoft Transaction Server (MTS) integration
  
  Multiple steps and components can now be packaged into transactions that succeed or fail as a whole. In IIS 3.0, ASP handled its own thread and memory management within Asp.dll. IIS 4.0 takes advantage of the improved resource usage and thread management in MTS, which allows Web application developers to write scalable applications using the MTS foundation.
• Improved database stack
  
  Version 4.0 of IIS has an entirely new database stack that is of much better quality than the previous release, and includes an improved thread-safe Oracle driver.
• ISAPI filtering by Web site
  
  Each Web site on the server can have a different set of ISAPI filters. ISAPI filters are programs that are executed when a given Web server event occurs.
• ASP Debugging
  
  IIS 4.0 includes an Active Server Pages debugger that is integrated with the core ASP services. With this tool you can set breakpoints and step through ASP code. Previously, in IIS 3.0, the only way to debug your ASP code was to use Response.Write to send the information to the HTML output.
• VBScript and Jscript
  
  Version 3.0 of the Scripting engines provide enhanced capabilities such as Directory Creation, File and Directory Deletion and the ability to determine disk information (for example, the amount of free space and similar values).
• New Java VM
  
  Support has been added for JDK 1.1 as has the ability to make calls to Java components from ASP scripts.
• Message Queuing
  
  Web applications using ASP can store data until a guaranteed connection is made with the targeted Web application through the use of message queuing. This has a significant impact on electronic commerce if it uses unreliable networks.

Server Management

• Virtual servers using one IP address and host header names
  
  Unique virtual Web servers can now be set up using the same IP address and different names. Each virtual server can be controlled independently of each other.
• HTML administration
  
  IIS 4.0 includes a full-featured Web-based administration utility to manage the server remotely.
• Improved metatag integration
  
  Many functions that could only be done via metatags (expires, pic ratings, custom headers) can now be down with the core server.
• Customizable error messages
  
  Error messages can be customized to improve the customer (end user of Web sites) experience.
• Command line administration
  
  The same functionality found in the administration interfaces for IIS 4.0 is now available through command line administration. This allows for easy ASP scripting of administrative tasks.
• Unattended installations
  
  Customized installations can be implemented by using scripts to upgrade and install multiple servers.
• Integrated setup
  
  Unlike IIS 3.0, IIS 4.0 offers an integrated setup for all of the components of the Microsoft Windows NT 4.0 Option Pack.
• Site Server Express
  
  Tools are included for analyzing content and Web usage as well as for posting files through the components of Site Server Express. The Content Analyzer, Usage Import, Report Writer, and Posting Acceptor modules make up the components of Site Server Express.
• Flexible logging
  
  There are now over 20 properties that can be logged for the Web server. Included are server name, server IP and port, bytes sent and received, time taken, and many more.

IIS 3.0 Issue Resolutions

Many bug fixes for IIS 3.0 are included in IIS 4.0, including all hotfixes to Active Server Pages (ASP) and core services. The following list is a sample of known issues which are resolved in IIS 4.0.

    Article ID  Article Title
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