From: www.itworld.com

WebLoad helps satisfy the need for online speed

by Tim Fielden

February 7, 2001 —

SPEED KILLS? Not on the Internet, where businesses are always looking for ways to make their Web sites and online applications run faster. Lately, however, the need for speed has reached a fever pitch, and it's mostly because so many of us are doing business online. At the same time, fierce competition in the IT world has forced companies to launch their sites or applications as quickly as possible. In an environment such as this, load testing often gets short shrift. But if you don't perform proper load testing, then your site or application may not run fast enough to prevent users from going elsewhere -- and that's a great way to lose sales.

Thanks to RadView and its new WebLoad 4.5 package, help is only a purchase away. The solution, which consists of three distinct parts (a console, a load machine, and a probing client), lets you verify the scalability and integrity of a Web application by generating loads composed of virtual clients that simulate real-world traffic.

Each of these virtual-client behaviors is controlled via test agendas -- JavaScript programs that merely play back manual entries. These programs can perform tasks such as issuing a certain number of Enter keys on a page to test your site's back-end processing capabilities. Furthermore, you can use the test agendas to specify the site you want to test, the type of tests you want to perform, and the testing variables you plan to use. (Applying the same variables across the board is a good way to achieve consistency in your testing process.)

Although the programs are written in JavaScript, WebLoad assumes no up-front knowledge of the language: The package comes with tools to help you record testing activities right from the comfort of your browser.

Once written, these client behaviors are then run against WebLoad, which executes and displays your application's response both graphically and statistically on the WebLoad console. If you want more specific testing results, probing clients let you act as a single user to measure the performance of a targeted activity. For instance, you might want to investigate how long your site takes to perform a lookup operation or check how quickly data is validated and returned.

In this way, WebLoad makes it easy to scan various aspects of your application for bottlenecks. And the handy "cruise control" wizard is a treat to work with: It lets you run scripts while the load is increased until your application meets a defined goal.

For those who crave even more control of the testing process, WebLoad can automatically give you a detailed, page-by-page breakdown of every component file of every failed HTTP operation. In our tests, this feature proved to be extremely useful in identifying and debugging bottlenecks and flushing out errors that might have otherwise been missed in previous testing cycles. Moreover, if your shop uses multiple load machines, Version 4.5 also lets users share variables globally, thereby simplifying the testing routine.

New features on parade

The product's basic functionality is not new to Version 4.5, but RadView has enhanced this offering with features such as a tool that allows you to visually play back and step through a scripted agenda, making it easy to debug the test script itself. As does a remote debugger that steps through instructions, the playback function shows you one small piece of the action at a time, such as the action a user takes when completing an online application form, for example. You can test how your application handles entries and verifications in each field. The beauty of this feature is that it allows for close inspection of an application's logic, as well as its performance.

Another interesting new feature is a tool that lets you vary your loads on the basis of client types. Whether you are testing a normal client, a thin client, or even a thick client (one that combines the logic with the presentation, such as a full-featured Java application that uses the Web to send or retrieve data from a back-end data source), WebLoad makes it a cinch to model and predict the performance your end-users will experience.

But the biggest improvement to Version 4.5 is its increased load-generation capabilities. Thanks to a newly optimized, multithreaded architecture and a handful of memory management enhancements, this latest incarnation of WebLoad is far faster at simulating users than are its predecessors. The faster you can generate loads, the faster you can finish your tests, and the sooner your applications will reach their audience.

Finally, the package also allows you to meet the changing face of technology head on, with support for HTTP, XML, DOM (Document Object Model), Java, JavaScript, EJB (Enterprise JavaBeans), ActiveX, and even WAP (Wireless Access Protocol). RadView has also promised support for Linux as a load generator sometime during the first quarter of next year, further showcasing WebLoad's enterprise suitability.

Unfortunately, Internet Explorer is required for certain functions, such as testing applications that use SSL (Secure Sockets Layer). But apart from that one drawback, we liked WebLoad 4.5 enough to award it a score of Very Good. If you're not confident that your Web site is humming along fast enough for your users, this product could prove to be the difference between customers and corpses.

InfoWorld