Topic: Introduction to LoadRunner

Introduction

LoadRunner is an industry-leading performance and load testing product by Hewlett-Packard (since it acquired Mercury Interactive in November 2006) for examining system behavior and performance, while generating actual load.

LoadRunner can emulate hundreds or thousands of concurrent users to put the application through the rigors of real-life user loads, while collecting information from key infrastructure components (Web servers, database servers etc). The results can then be analysed in detail, to explore the reasons for particular behaviour.

Consider the client-side application for an automated teller machine (ATM). Although each client is connected to a server, in total there may be hundreds of ATMs open to the public. There may be some peak times — such as 10 a.m. Monday, the start of the work week — during which the load is much higher than normal. In order to test such situations, it is not practical to have a testbed of hundreds of ATMs. So, given an ATM simulator and a computer system with LoadRunner, one can simulate a large number of users accessing the server simultaneously. Once activities have been defined, they are repeatable. After debugging a problem in the application, managers can check whether the problem persists by reproducing the same situation, with the same type of user interaction.

Load Runner is divided up into 3 smaller applications:

The Virtual User Generator allows us to determine what actions we would like our Vusers, or virtual users, to perform within the application. We create scripts that generate a series of actions, such as logging on, navigating through the application, and exiting the program.

The Controller takes the scripts that we have made and runs them through a schedule that we set up. We tell the Controller how many Vusers to activate, when to activate them, and how to group the Vusers and keep track of them.

The Results and Analysis program gives us all the results of the load test in various forms. It allows us to see summaries of data, as well as the details of the load test for pinpointing problems or bottlenecks.

Edited by Mithi25 - 01Aug2009 at 12:39am