Correlation (Load Testing)
// Definition
The process of extracting dynamic values from server responses (session tokens, transaction IDs, CSRF tokens) and injecting them into subsequent requests. Essential for testing stateful applications where each session contains unique identifiers. In JMeter, correlation is achieved with JSON Extractors, Regex Extractors, and XPath Extractors.
// Related terms
Apache JMeter
An open-source Java-based performance testing tool for measuring the behaviour of systems under load. Supports HTTP, JDBC, FTP, JMS, and other protocols. Widely used in enterprise and regulated industries (banking, insurance, government) due to its maturity, GUI-based test authoring, and rich plugin ecosystem. Test plans are stored as .jmx XML files and can be run headlessly from the command line for CI/CD integration.
Load Testing
Verifying system behaviour under expected production load. Confirms the application meets performance targets at typical concurrent-user counts before release.
Think Time
Pauses between user actions in a load test that simulate real reading, scrolling, or decision time. Without think time, a load script generates an unrealistic, machine-gun request pattern that doesn't match production traffic.