June 17, 2006

With MANY businesses going to the web, offering interactive forums and financial transactions besides browse-only catalogues, site uptime has become a major barometer of a portal’s performance.

This is true of both publicly accessible sites enjoying normal to heavy traffic — like city portals and newspapers — and the private LAN/WAN sites, such as branch network for online banking catering to countrywide requests, central depositories and online customer support services.

Simulating traffic that go to such sites usually requires software packages costing thousands of dollars. But now several free or low-cost solutions are available. AdventNet QEngine is one such product that provides a range of modules for functional and performance testing.

One of these modules is Web Performance Test Studio — designed specifically for testing of back-end and server-side, middle-tier functionality and performance of J2EE/J2SE applications, along with record and playback capability for testing websites. Even if the platform to be tested is not Java-based, the product can be utilised because of its ability to capture and then produce controlled replies to gauge the response of the site under different load scenarios.

Now, let’s see how a complete load testing cycle can be performed using this tool.

Architecture

After installing the software, either start Launcher, or directly select Web Performance Test Studio from start menu item, “AdventNet QEngine.” In Architecture, business cases are used to create Profiles by adding information such as browser type, connection type, think time and percentage contribution in overall test.

Work Load is created separately, which defines load type (normal, ramp-up, burn-in) and virtual user configuration. A test case is then created by using a defined Profile and a defined Work Load together. In this way, entities of business cases, profiles and work loads remain distinctively defined and can be mixed and matched with little tweaking to create a number of different scenarios.

Recording

Go to File > New Suite. Enter suite name, name of application to be tested, its version and directory to save test files. Press OK. The suite is added under “Suites” tree present on the left hand side.

R-click on the suite and select “New Businesscase.” Enter “Login” as file name. Business case will be added under the suite. Go to Record > Recorder Settings and check the recorder port on which recorder will capture browser traffic. Make sure no other service on your machine is using this port.

Finally, select Record > Start Recording — keep everything to its default and press OK. The default browser will open, and if you take a look at connection settings, you will notice that proxy “localhost” will be set on the required port. This means that all your requests will be forwarded through this “recorder proxy.”

Enter the URL of the site to be tested, possibly residing on same PC or over a network. Assuming that it requires authentication, enter username and password. Switching back to the Studio, you will see a list of items in format submit URL <“http://your-site.com”,0> which shows pages being logged on.

Pages that are not apparent in browser address-bar will also show up since they are being called to perform certain actions. Press “Stop Recording” in Studio.

Now, Go to Play > Test Configurator. From the list on the left, select WorkLoad Configurator. Press New, enter name “Workload 1” and press Update, keeping all the values to their defaults.

Next, select Profile Manager from the left. Press New, enter profile name “Profile 1,” check the business case “Login” and press Update. Lastly, select Test Case Configurator. Press New, enter case name “Case 1.” After profile and workloads are automatically selected, press Update.

Time to go for the actual test. Go to Play > Start Play. Select the test case “Case 1” and press Start Test. Execution status will change to “In Progress” and the grid below will have the list of users with URLs of pages hit.

As soon as the test is over, a detailed report is displayed in the browser, complete with 16 graphs showing summary and details of hits per second, throughput, response time, download time, error percentage and other details.

The writer’s e-mail address is nizar.ali@gmail.com

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