IISGuard provides a custom monitoring interface for IIS5 and IIS6 servers. It installs
a combination of a Windows service, an ISAPI filter, and a dedicated Web server
of its own. All incoming requests to IIS go through this loop and get saved to IISGuard's
own log files, where it records the request, the time it took to process, and some
other key information such as client IP, URL requested, application pool ID, bytes
in and out, and so on. You can open a dedicated Web page on port 85 (this is configurable)
on the server to view the IISGuard console, which lets you see the traffic to your
server fly by in real time.
For the most part, this information is already available in your IIS logs, of course.
What IISGuard brings to the table is some convenience in managing and sifting through
what can be a large volume of information. For starters, it provides a global view
of the operations of the entire server, rather than a log for a single site (though
you can focus on an individual site if you choose). It lets you highlight in red
requests that take longer than a preset threshold time, to alert you to problematic
scripts, denial of service attacks, or other issues. It also combines controls for
starting and stopping sites directly with the log-viewing interface rather than
making you use a separate console. Finally, it brings in some searching and filtering
(on IP address and URL) to help you find information you're looking for in a large
mass of data. And of course the use of a Web user interface makes the information
readily available to most anyone.
Is this worth $99 to you? It depends, I think, on how many IIS servers you're managing
and the level of users you have monitoring them. It's certainly easy to install
and didn't seem to interfere with the operation of IIS on my test server. If you
want to see for yourself, you can download a trial version from the Troxo Web site.