HP Load Runner is a software testing tool from Hewlett-Packard. It is used to test applications, measuring system behaviour and performance under load.

About the Load Runner

HP LoadRunner can simulate thousands of users concurrently using application software, recording and later analysing the performance of key components of the application.

LoadRunner simulates user activity by generating messages between application components or by simulating interactions with the user interface such as key presses or mouse movements.

The messages/interactions to be generated are stored in scripts.

LoadRunner can generate the scripts by recording them, such as logging HTTP requests between a client web browser and an application's web serve

HP acquired LoadRunner as part of its acquisition of Mercury Interactive in November 2006

Architecture

The key components of HP Load Runner are:

Load Generator generates the load against the application by following scripts

VuGen (Virtual User Generator) for generating and editing scripts
Controller controls, launches and sequences instances of Load Generator - specifying which script to use, for how long etc.

During runs the Controller receives real-time monitoring data and displays status.

Agent process manages connection between Controller and Load Generator instances.

Analysis assembles logs from various load generators and formats reports for visualization of run result data and monitoring data.

Modules are available to enable HP LoadRunner to capture, replay and script different application and networking technologies.

These include support for:

Applications using Microsoft .NET and Java

Database servers such as Microsoft SQL Server and Oracle

Internetworking protocols such as DNS, FTP and LDAP

E-mail protocols including IMAP, MAPI, POP3 & SMTP

Remote client technologies such as Citrix ICA and RDP