Loadrunner Developer

Loadrunner Developer is a free performance testing tool from Micro Focus available across Windows, Mac, and Linux platforms. This guide walks through creating load test scripts using HAR file exports from Chrome Developer Tools.

Overview

Loadrunner Developer focuses on testing WebSocket and HTTP transport layers, particularly suited for contemporary web technologies including HTTP/2 and WebSockets using a JavaScript framework.

HAR File Generation Process

Export network traffic from Chrome Developer Tools by:

1. Open Chrome Developer Tools (F12)
2. Navigate to the Network tab
3. Enable “Preserve log” option
4. Record website interactions
5. Right-click within the developer console
6. Select “Save all as HAR with content”

Script Conversion

The Offline Generator command converts HAR files into executable scripts containing requests wrapped in load.WebRequest objects.

devweb offline-convert --input recording.har --output script

Raw recordings require correlation, parameterization, and error handling modifications before execution.

Configuration Files

Two YML configuration files control runtime behavior:

rts.yml - Runtime Settings

general:
  iterations: 1
  pacing:
    type: none

scenario.yml - Test Scenario Parameters

scenario:
  vusers: 10
  duration: 300
  rampup: 60

Test Execution

The DevWeb command-line interface executes load tests, generating results in SQLite database format within a dedicated results directory containing logs and snapshots.

devweb run --script script.js --scenario scenario.yml

Key Features

• IDE Integration: Works with popular development environments
• Grafana Compatibility: Real-time metrics visualization
• Clear Syntax: JavaScript-based scripting
• Comprehensive Documentation: Well-documented API
• Cross-Platform: Available on Windows, Mac, and Linux

Conclusion

Loadrunner Developer appeals to developers through its modern approach to performance testing, offering IDE integration, clear syntax, and comprehensive documentation for those getting started with performance testing.

Further Reading

• Loadrunner Developer Documentation