WebSphereStudio® Workload Simulator for z/OS™ and OS/390™ lets you create "virtual" or "simulated" users, allowing you to reduce costs associated with manual load- and performance testing. WebSphere Workload Simulator can also be used to perform quality assurance on Web applications and to test the functionality of Web servers.
A scalable test tool
WebSphere Workload Simulator consists of two components: a "controller" and an "engine." For high scalability, WebSphere Workload Simulator's "engine" component - which generates the load used during load-testing - is installed on a zSeries® server. The load generated by the engine can be used to test any Web-serving environment (e.g., the environment to be tested is not limited to z/OS). WebSphere Workload Simulator supports multiple engines.
All test functions are accessible through a Windows® interface
The user interfaces with WebSphere Workload Simulator through the "controller." This component resides on a Windows workstation and offers a Windows graphical user interface (GUI) for managing all aspects of the load-testing process: test scripts can be created and edited, simulation runs can be set up, executed and monitored, and test results can be analyzed without leaving the Windows GUI.
Capture, Playback, Analyze
With WebSphere Workload Simulator, the load-testing process can be summarized in three simple steps: first, the user's actions during a Web session are "captured" to produce a test script. Second, the script is played back through the environment to be tested. Third, analysis is performed on the test results.
Test scripts are automatically generated by a "capture" function as the user navigates through a Web session. The Capture function, launched with a simple click of the mouse, captures the session's Web traffic and turns it into a test script ready for immediate playback. If needed, more complex programming functions (e.g., weight distribution, looping) can also be added to the test script, to mimic the actions of a group of real users. Sections of a test script can be defined as "transactions" for further monitoring and analysis.
In order to make realistic simulations, a load-testing tool must imitate the multiple possibilities that occur in real life, and allow for variable content. For instance, not all users of an e-commerce Web site will have the same logon IDs or passwords, nor would they choose to purchase the same items, or have the same credit-card number. WebSphere Workload Simulator allows variable content to be incorporated into the test scripts. For example, "cookies" are supported.
For maximum flexibility during execution, several run-time parameters can be set: whether the test should be repeated for a specific number of times, or should run until manually stopped, or should run for a specific time period, the number of "virtual users" to be simulated. To simulate real-life conditions, various delay times can be specified: delays between the virtual users as they go online (not all users logon at exactly the same instant), delays between Web pages, and between the elements of a Web page.
After the test script has been defined and the simulation launched, the test can be monitored in real-time during execution. This is done through the controller's Windows GUI, or optionally, through a Web browser. This remote monitoring capability is especially helpful for very extended runs (e.g., over a weekend), as it obviates the need for test personnel to be present at the test site.
WebSphere Workload Simulator can graph various performance characteristics against the number of simulated users or against time. Response time, data throughput, throughput of page elements, and CPU or memory utilization are available for plotting.
For in-depth analysis of test results, different levels of logging of the test activity are possible, and the HTTP activity of each simulated client can be traced.
SSL, and Socks support
WebSphere Workload Simulator provides SSL support, and handles capture and playback through a Socks firewall.
Part of IBM's Enterprise Tools portfolio
IBM provides a full set of tools to address the different phases of the application development and deployment process. Utilize these tools to increase your productivity in developing, de-bugging, testing, and monitoring business applications on z/OS or OS/390.