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January 24, 2000

Smooth Operations Depend On Smart Testing Plans
Companies turn to performance-testing tools to ensure successful application deployments

By Amy Larsen DeCarlo

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hange is the one constant in enterprise environments today. Companies are continually adding business-critical applications, upgrading their existing software and network devices, and connecting new users to their enterprise resources.

The burden falls on IT managers to deliver acceptable and reliable application service in these extraordinarily dynamic environments. The first step toward meeting company performance expectations is correctly anticipating what the application requires to adequately support a certain number of users before the software is deployed on the production network. This is no simple task given the highly complex, multitier nature of today's enterprise applications, but it's critical if IT administrators are to balance costs accurately for the projects they undertake.

"Capacity planning for a new application really is an economic issue for us," says Louis Breit, lead engineer for First Data Merchant Services, the Melville, N.Y., payment-processing subsidiary of credit-card authorization company First Data Corp. "We really can't budget against a guess, so we need to get a good reading on what the application's capacity requirements are before we deploy it." Otherwise, the company runs the risk of budgeting for just one T1 line, for example, only to find out it really needs three lines to fully support an application.

Before rolling out a new PeopleSoft Inc. human-resources application a few months ago, Breit conducted capacity-planning tests to see what kind of performance users would experience. With 200 to 300 users accessing the PeopleSoft application from five sites, First Data wanted to fix any service issues before the application was fully deployed on the production network.

Louis Breit Photo by Charles Orrico Breit turned to Chariot, a performance-testing package from Ganymede Software Inc. that emulates the application transactions of a number of commercial software packages, to see how the PeopleSoft module would perform under different conditions. Other products that perform this task include Application Expert from Optimal Networks Corp. and IT Decision Guru from MIL 3 Inc. But Breit has been using Chariot--which was introduced in 1996 and upgraded to version 3.1 last spring--over the years to assist him with other application deployments.

Breit was drawn to Chariot because of its emphasis on measuring response-time numbers. He says that focus, coupled with its accuracy, has kept him loyal to the Ganymede software. Chariot has added new software support with each successive version and now has a library of application scripts that emulate most commercially available enterprise applications, including Baan, Citrix Systems, Lotus Development, Microsoft, Oracle, and SAP applications.

Chariot depends on a central console to send test instructions to lightweight remote software agents, known as end points. The end points, which can be located anywhere on the network, follow those orders to mimic actual application transactions. After the application tests are performed, the end points send the results to the central console. To make the Chariot transactions closely emulate real-world application activity, the end points use the same protocol stacks and operating systems as the network applications.

In predeployment testing, First Data Merchant Services concentrated on finding out how to meet its goal of making sure users would experience consistently fast transaction response times. The company isolated the 40 significant PeopleSoft tasks that human-resources personnel would most likely execute.

"Chariot can record response times from any point to any point," Breit says, "so we were able to approximate the actual tasks to see what the performance impact would be of different scenarios." Breit cites the example of testing how fast the response time for a particular transaction would be if 50 users were attempting to access the same server, and then looking at the response times if double the number of users were simultaneously tapping into that server.

Chariot also provides a way to plan the best location for servers running the PeopleSoft application, Breit says. Using the Ganymede software, Breit was able to mimic a transaction request from a user in Atlanta opening an employee record stored in New York. When response time dragged on too long, First Data considered options such as moving the server to be more centrally located among users and mirroring commonly accessed files to another server in Atlanta.

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