SUMMARY
The Web Application Stress (WAS) tool is similar to the HTTPD Flood utility that is available for Apache. This article describes how to set up a suitable test script to monitor the performance of your migrated Web server.
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Obtaining the WAS Tool
The following file is available for download from the Microsoft Download Center:
Download the Setup.exe package now.
For additional information about how to download Microsoft Support files, click the following article number to view the article in the Microsoft Knowledge Base:
119591 How to Obtain Microsoft Support Files from Online Services
Microsoft scanned this file for viruses. Microsoft used the most current virus-detection software that was available on the date that the file was posted. The file is stored on security-enhanced servers that help to prevent any unauthorized changes to the file.
Installing the WAS Tool
Microsoft recommends that you install the WAS tool on a computer other than the server or servers that you want to test. If you do so, you can make sure that you test the networking facilities and the Web serving abilities of the server or servers without adding additional overhead on the server that you are trying to test.
To install the WAS tool, double-click the file that you downloaded from the Microsoft Web site, and then follow the instructions in the setup wizard to complete the installation.
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Configuring a Test Script
The WAS tool works by using a test script. The script defines the server to access, the URLs to access, and the parameters for the test, such as the number of simultaneous requests. There are two ways to specify the URLs to access. You can use the WAS tool to monitor your access to a site and build a list of pages from your progress, or you can manually enter the information for the requests. You can select the option that you want to use when you first start the WAS tool.
To manually configure a test script
- Click Start, point to Programs, and then click Web Application Stress Tool.
- Click Manual to start a manual configuration.
- Click New Script in the left pane, and then give the test script a name.
- In the Server box, type the address of the server that you want to test.
The list at the bottom of this pane is the list of URLs that will be accessed by each client. The Verb column defines how the page is accessed. Static pages or dynamic pages that do not have specific arguments are accessed using a GET operation. - Click the GET option, and then type the path to the component or type the URL of a page that you want to access.
- To configure a dynamic script with arguments, click POST, and then double-click the whole row to open the definition of a POST script item.
- Add fields and values to a query, add additional POST data, add different headers, or turn on SSL communication, and then click OK.
- Repeat steps 4 to 7 to add as many URLs to the test as you require.
- Expand the script in the left pane, and then click Settings.
- Configure the basic settings for the script.
The Stress level is the number of simultaneous accesses. The Test Run Time is the duration of the test. For quick tests or simple sites, use a value of 5 to 15 minutes. For larger sites or longer URL lists, use a value of an hour or more. - To limit the bandwidth for each client, click the Throttle Bandwidth setting, and then type a value that is relative to the type of user that you expect to access your site.
- Click Perf Counters in the left pane, and then add at least the following counters to the report:
- Web Service: Get Requests/sec
- Web Service: Post Requests/sec
- Processor(_Total): % Processor Time
NOTE: To get an accurate measurement of the efficiency of your new test server, Microsoft recommends that you also use the WAS tool to test your existing UNIX/Apache server.
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Running a Test Script
To run the test script that you created, click
Run on the
Scripts menu. Let the tests to run; do not use your computer for other tasks while the test script is running. If you do so, you may affect the performance statistics.
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Understanding the Output
To view the report that was created when you ran the test script, click
Reports on the
View menu, and then select the report from the list on the left pane (the report has a date and time stamp).
When you view the report, compare the following points:
- The number of hits.
- The requests per second.
- Socket Errors: A higher number of send errors may indicate either a slow server or a server that cannot process a large number of connections.
- Page Summary: Review the Time To First Byte (TTFB) value on dynamic pages. This value gives you an indication of the efficiency for the dynamic element.
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