Microsoft's newest weapon in the Web server wars
Among all the promising new features
in Windows NT 4.0, Microsoft is placing high hopes on its Internet Information
Server (IIS) 2.0, an Internet and intranet Web server that is part of the OS.
Last February, Microsoft released IIS 1.0. Since then, it has changed
significantly and is poised as Microsoft's newest weapon in the Web server wars.
Microsoft integrated IIS with NT so users can install it with NT 4.0,
improved IIS's performance, and added many features missing from IIS 1.0. These
new features include a Hypertext Markup Language (HTML) Administrator, improved
server logging, a Secure Sockets Layer (SSL) Key Manager, and a much improved
Internet Database Connector (IDC). Screen 1 shows the GUI administrator, the
Internet Service Manager. Aside from these improvements, IIS 2.0's best feature
is its price: It comes with NT 4.0, or you can download it for free from
Microsoft.
Integration with NT 4.0
NT 4.0 Server and Workstation include IIS, and the IIS server that ships
with NT Server is optimized to enhance Hypertext Transfer Protocol (HTTP) server
performance. The NT Workstation version, Peer Web Services (PWS), is for
light-traffic Web sites such as personal Web pages or small corporate intranets.
For developers, PWS supports all the standard extensions in the NT Server
version of IIS, so you no longer need a dedicated NT server to test new server
extensions.
Because IIS 2.0 is part of NT, Microsoft included the installation process
in NT 4.0 Setup. IIS runs as a service, so you install it by selecting IIS as a
network service option and pointing to the install directory. IIS 2.0 takes only
two or three minutes to install.
Increased Performance
Reminiscent of the Norton SysInfo speed wars of the early '80s and the video
benchmark wars of the early '90s, the new competition is for HTTP server
performance. Although Microsoft claims IIS 2.0 offers up to a 40% increase in
performance over IIS 1.0, independent performance tests weren't complete at
press time. This speed increase is primarily the result of optimizations in NT
4.0's I/O subsystem.
Some HTTP benchmarks show 200 connections per second, which translates to
17.2 million hits per day, or 6.3 billion hits per year. Knowing that your
server can sustain such a high hit rate is comforting, even if your site isn't
extremely popular.
Note though, that advertised performance claims for HTTP benchmarks can be
misleading. For example, an HTTP vendor can claim to outperform the competition
by 200%. Even if this claim is true, understanding the circumstances of this
200% performance gain is critical. Suppose a Web server performs well under low-
and high-traffic loads, but not in medium-traffic situations. Competing vendors
will tout the medium-load numbers if they indicate that the vendor's product is
200% faster. In fact, at high loads, the 200% faster server can
under-perform the slower server. A word to the wise: Investigate the
claims and test conditions before relying on any benchmark.
HTML Administrator
Most new Web servers include a Web browser-based administration tool, and
IIS 2.0 is no different. IIS 2.0's HTML Administrator, as you see in Screen 2,
looks like IIS's tabbed configuration dialog.
The HTML Administrator gives you most of the functionality of the
server-based configuration dialog, including the ability to add or remove
directories, change the server logging options, and grant or deny access to
specific IP addresses. However, like any HTML interface, IIS's HTML
Administrator has limitations. For example, it doesn't let you manage multiple
servers from a central server status screen. Instead, you have to log in to each
server individually through an account in the NT Administrator's group. Also,
you can't start and stop services through the HTML Administrator. The advantage
of this new tool is that you can manage any IIS 2.0 server remotely, even from
non-Win32 based computers, such as UNIX and Macintosh machines.
Improved Logging
IIS lets you configure services to log information from multiple IIS servers
into one database. This logging lets you identify which users are accessing the
Web servers and what information they're accessing. Microsoft improved the
logging feature in IIS 2.0 to capture service errors such as 403 Forbidden
and 404 Not Found. Service error information is important to Web masters
who need to check for broken links and view HTTP logs to identify users
attempting to breach site security. In addition to logging service errors, IIS
2.0 lets you create log files in National Center for Supercomputing Applications
(NCSA) format.
Despite these IIS improvements, Microsoft left out two important server
variables: HTTP_REFERER and USER_ AGENT. The HTTP_REFERER variable identifies
where links to the site come from. You can use this information for marketing
purposes or to keep tabs on who's linking to your site. The USER_ AGENT variable
identifies what type of Web browser a client is using. You can use these
statistics to tailor your site to its most active clientele. For example, by
tabulating the USER_AGENT data, you can determine how many users support a
specific HTML tag. In turn, this information can influence your site design
decisions. To log these variables with IIS, you have to add a third-party
Internet Server API (ISAPI) filter.