JMeter Global Properties

This post discusses Apache JMeter’s approach to variable scope and demonstrates how to leverage properties for cross-environment testing.

Core Concept

JMeter distinguishes between local variables confined to thread groups and global variables accessible throughout a test plan. If a variable is inside a thread group it will only be visible within it. To share data across multiple thread groups, developers should use JMeter properties instead.

Practical Application

The strategy presented here builds environment-agnostic test plans. Rather than maintaining separate assets for integration, system test, and pre-production environments, developers define prefixed variables:

• integration_*
• syst_*
• preprod_*

Each prefix precedes configuration parameters including:

• Protocol
• URL
• Port
• Username
• Password
• Proxy settings

Implementation Technique

A JSR223 sampler reads an environment variable and executes conditional logic via a switch statement:

def env = vars.get("environment")

switch(env) {
    case "integration":
        props.put("protocol", vars.get("integration_protocol"))
        props.put("host", vars.get("integration_host"))
        props.put("port", vars.get("integration_port"))
        break
    case "syst":
        props.put("protocol", vars.get("syst_protocol"))
        props.put("host", vars.get("syst_host"))
        props.put("port", vars.get("syst_port"))
        break
    case "preprod":
        props.put("protocol", vars.get("preprod_protocol"))
        props.put("host", vars.get("preprod_host"))
        props.put("port", vars.get("preprod_port"))
        break
}

The code uses props.put() to assign user-defined variable values to global properties based on the selected environment. This approach enables command-line overrides when necessary.

Key Benefit

This methodology reduces testing assets while maintaining repeatability across different deployment stages.

Further Reading

• JMeter Properties Documentation
• Setup Thread Groups Reference
• JMeter Component Reference