Using WCAT as a Stress Client

Applies To: Windows Server 2003, Windows Server 2003 with SP1

The Web Capacity Analysis Tool (WCAT) is a stress client available to IIS users. It is a script-driven command-line tool. WCAT includes a stress client tool (Wcclient.exe) to simulate the clients and a controller tool (Wcctl.exe) to initiate and monitor the testing.

Downloading the IIS 6.0 Resource Kit Tools performs a default installation of the WCAT client and controller files in the LocalDrive:\Program Files\IIS Resources folder.

A WCAT test begins with the controller locating and interpreting input files. A controller input file includes three required sections (Configuration, Script, and Distribution) and one optional section (Performance, for specifying which performance counters to monitor). The controller uses the input files to send instructions to the clients, including which tests to run. WCAT includes a prepared input file (Sample.ubr, in the LocalDrive:\Program Files\IIS Resources\WCAT Controller\Scenarios folder) that contains a test for stressing the default IIS Web page.

When a WCAT test is complete, the controller collects the test results and writes them to output files. Output files include a log file, which you can optionally configure as an XML-formatted file, and an optional performance results file, which contains data collected from performance counters on the server.

If you specify performance counters in the Performance section of the .ubr file, WCAT logs the counter data in its usual report but also produces a performance log file in a tab-separated format, so that you can import the logged counter data into a spreadsheet or data-processing application. The log of performance data that WCAT generates is stored, by default, in the WCAT Controller\Scenarios folder. You can open this log, which is a text file, by using any word processor.