Prep your Web apps for stellar performances
Load testers prove a valuable part of your development strategyFollow @infoworld
To set up the test, developers drag and drop scripts onto the testing grid. Each row in the testing grid depicts a task group, and each column depicts a task. A single task group can execute as many as 200 tasks, and developers can define as many as 200 task groups. This level of granularity can enable precise testing of the various portions of a Web site or app under varied conditions.
Within the testing grid, you can also define the number of iterations for a task, task group, or both. Moreover, you can define metrics, such as startup delays, think times (end-user idle time), and which machines should run which tasks. For example, in one of my tests I defined 20 task groups and had each of five load-test clients executing four of the task groups.
After the tests have been defined, they are started from the Commander interface. Switching to the monitoring tab, I could see basic data about the running tests, such as the number of virtual users and the number of successful and failed test calls. After the test is completed, developers can switch to the results tab to view reporting data.
OpenSTA offers basic built-in reports, such as errors versus the number of requests, and there is some drill down provided. OpenSTA does not, however, include a test-comparison function as do the other two tools evaluated here. But you can export data (CSV format) or data and charts to Excel for the purpose of comparison.
With the right price tag -- free -- OpenSTA is a solid, basic Web technology test tool that belongs in every IT toolbox. It may not have all of the bells and whistles of its counterparts, but it makes fast and accurate Web load testing a simple affair.
Proxy Sniffer Professional Edition 3.7
Of the three tools tested here, Proxy Sniffer gets the nod for offering a full-featured Web load-testing solution at an attractive price. It goes further than OpenSTA and offers most of the same Web load-testing capabilities as the more expensive PureLoad.
Proxy Sniffer is a Web browser-based solution that supports stand-alone and distributed testing leveraging Unix, Linux, and Windows load-test clients. The Proxy Sniffer server and GUI are graphically launched on Windows or are started via the command line on Unix and Linux.
Proxy Sniffer functionality is served up via a series of different browser windows, which launch from one another. In the initial browser window, I recorded several scripts and edited them. I was able to insert think times and add variables and the like. Proxy Sniffer scripts can use variable input from files or other variables to simulate end-user interaction during tests.
After they have been saved, the scripts are then accessible in the Project Navigator browser window. The next step is to generate a load test. To do this, Proxy Sniffer constructs a Java app on the fly. After it has been saved and compiled, the load-test application is available within the Project Navigator.
Developers can then define the parameters for load-test execution. In my tests I defined remote-agent execution using Unix and Linux machines and parameters, such as the number of virtual users and the length of the test run.
After my tests had been started, I was able to connect to and monitor them in yet another browser session. During the run time, testers can view summary and detailed statistics. When executing tests on the local network or across multiple proxies, Proxy Sniffer proved easy to configure and run.