Internet Information Services (IIS), the Web server included with every Windows server OS, is a cornerstone of Microsoft's distributed applications strategy. IIS 5.0 is widely thought to be the best part of Windows 2000 Server, yet its limitations have moved designers to consider alternatives. The newest release, IIS 6.0, a surprise addition to Windows 2002 Server Beta 2, boasts improvements across the board.
Creating or moving an IIS application, HTML, and its executable components, ordinarily requires much pointing and clicking, but IIS 6.0 gives command-line-savvy administrators a break. New administrative commands and a much simpler scripting interface were added to existing graphical and Web-based administrative interfaces. Microsoft also replaced the opaque, poorly documented configuration metabase with a plain-text XML file.
To test the Beta 2 version of IIS 6.0 we set up a database-connected Web site and accessed it with Windows clients running Internet Explorer 5.0 and the IE 6.0 preview edition that ships with Windows XP. We added our test application by pasting a few lines into the XML metabase with Notepad. When we inserted an XML syntax error into the XML metabase, IIS 6.0 rolled back the metabase to a prior error-free condition.
Although IIS 4.0 and IIS 5.0 rarely crash, they can be crippled by trivial programming errors. IIS 6.0 solves this defect with its completely reworked, high-availability architecture. Users' HTTP connections have been moved from IIS to the Whistler kernel. Additionally, a new process manager spawns an isolated execution environment for each application. The process manager can be configured to periodically kill and restart applications based on the number of hits, elapsed time, or memory utilization.
Moving core HTTP services to the Windows 2002 Server kernel and running applications in protective cocoons will do more than improve availability. Microsoft now promises that large commercial Web applications that require vast farms of discrete servers can use far fewer systems by installing more CPUs in each machine.
This preview of IIS 6.0 also includes improvements to security, scripting, and other features, but despite its impressive stability, it is clearly a work in progress. Frankly, we're anxious to see what Microsoft's IIS team does next.
THE BOTTOM LINE: BETA
Internet Information Services 6.0 Beta 2Business Case: IIS 6.0's reworked architecture will run more applications faster and safer on a single server.
Technology Case: Kernel-mode HTTP services and complete application isolation simultaneously enhance availability and performance. New command line, script, and XML administration facilities make IIS easy to configure and monitor.
+ Total process isolation with optimal execution speed+ Easy administration+ Boosted performance and safety+ Overlapping restarts cycle applications without kicking current users off-lineCons: