LoadRunner

LoadRunner is a performance testing tool originally developed by Mercury Interactive and now marketed by Micro Focus. It enables organizations to simulate a large number of virtual users interacting with an application to measure performance under expected and peak loads. The primary goal is to identify bottlenecks and verify that the system can scale while maintaining acceptable response times and reliability.

The core workflow involves scripting virtual users with the Virtual User Generator (VuGen), orchestrating their actions with the Controller, generating load using multiple load generators, and analyzing results in the Analysis component. LoadRunner supports a wide range of protocols and technologies, including web (HTTP/HTML), mobile, SOAP/REST web services, SAP, Oracle, Java, .NET, and more. Scripts can be parameterized to mimic realistic user data and flows, while correlation handles dynamic data returned by the applications. The tool records transactions to quantify response times, throughput, resource utilization, and error rates.

LoadRunner can be deployed on-premises or in cloud-based environments, and it has evolved to include cloud-based load testing capabilities under the LoadRunner Cloud offering. It integrates with various development and operations ecosystems, including continuous integration/continuous delivery pipelines, test management suites, and collaboration platforms, to support end-to-end performance testing within broader quality assurance processes.

In use, LoadRunner is favored by large organizations for validating performance and scalability of complex, enterprise-grade applications before release, helping to reduce risk and improve user experience. It faces competition from other performance testing tools but remains a mainstream option for comprehensive, protocol-rich load testing.