Topic: Load Test Planning

Load Test Planning

Developing a comprehensive test plan is a key to successful load testing. A clearly defined test plan ensures that the LoadRunner scenarios you develop will accomplish your load testing objectives.

As in any type of system testing, a well-defined test plan is the first essential step to successful testing. Planning your load testing helps you to:

• Load testing means testing your client/server system under typical working conditions, and checking for system performance, reliability, capacity, etc.


• Client/server testing requires hardware, software, and human resources. Before you begin testing, you should know which resources are available and decide how to use them effectively.


• Focused testing goals and test criteria ensure successful testing. For example, it's not enough to define vague objectives like "Check server response time under heavy load." A more focused success criteria would be "Check that 50 customers can check their account balance simultaneously, and that the server response time will not exceed one minute."

Analyzing the Client/Server System

The first step to load test planning is analyzing the client/server system. You should become thoroughly familiar with the hardware and software components, the system configuration, and the typical usage model.

This analysis ensures that the testing environment you create using LoadRunner will accurately reflect the environment and configuration of the system under test.

Identifying System Components

Draw a schematic diagram to illustrate the structure of the client/server system. If possible, extract a schematic diagram from existing documentation. If the system under test is part of a larger network system, you should identify the component of the system to be tested. Make sure the diagram includes all system components, such as client machines, network, middleware, and servers. The following diagram illustrates a chain of 60 clothing stores. The clothing stores and clothing distributors each connect to the same database to update the stock information and to check prices. The distributors connect to the database server through the branch office LAN, and the clothing stores connect through a wide area network to the LAN.

Analyzing the Client/Server System

The first step to load test planning is analyzing the client/server system. You should become thoroughly familiar with the hardware and software components, the system configuration, and the typical usage model.

This analysis ensures that the testing environment you create using LoadRunner will accurately reflect the environment and configuration of the system under test.

Identifying System Components

Draw a schematic diagram to illustrate the structure of the client/server system. If possible, extract a schematic diagram from existing documentation. If the system under test is part of a larger network system, you should identify the component of the system to be tested. Make sure the diagram includes all system components, such as client machines, network, middleware, and servers. The following diagram illustrates a chain of 60 clothing stores. The clothing stores and clothing distributors each connect to the same database to update the stock information and to check prices. The distributors connect to the database server through the branch office LAN, and the clothing stores connect through a wide area network to the LAN.

Defining Testing Objectives

Stating Objectives in Measurable Terms

The first step to load test planning is analyzing the client/server system. You should become thoroughly familiar with the hardware and software components,

the system configuration, and the typical usage model. This analysis ensures that the testing environment you create using LoadRunner will accurately reflect the environment and configuration of the system under test.

Once you decide on your general load testing objectives, you should provide more focused goals by stating your objectives in measurable terms. To provide a baseline for evaluation, determine exactly what constitutes acceptable and unacceptable test results. For example:

General Objective - Product Evaluation: choose hardware for the database server.

Focused Objective - Product Evaluation: run the same group of 300 virtual users on two different servers, HP and SUN Sparc 6000. When all 300 users simultaneously perform five pre-defined queries, determine which hardware gives a better response time.

Planning LoadRunner Implementation

Defining the Scope of Performance Measurements

You can use LoadRunner to measure response time at different points in the client/server system. Determine where to run the Vusers and which Vusers to run according to the test objectives:

Measuring end-to-end response time:

You can measure the response time that a typical user experiences by running a GUI Vuser or RTE Vuser at the front end. GUI Vusers emulate real users by submitting input to and receiving output from the client application; RTE Vusers emulate real users submitting input to and receiving output from a character- based application.

You can run GUI or RTE Vusers at the front end to measure the response time across the entire network, including a terminal emulator or GUI front end, network and server.

Examining Load Testing Objectives

Your test plan should be based on a clearly defined testing objective. This section presents an overview of common testing objectives:

• Measuring end-user response time


• Defining optimal hardware configuration

• Checking reliability


• Checking hardware or software upgrades


• Evaluating new products


• Identifying bottlenecks


• Measuring system capacity

Edited by Mithi25 - 01Aug2009 at 1:54am