Load Generator
A load generator is a tool or system that creates virtual users or simulated workloads to test the performance of an application.
“A tool that generates a load for a system under test.”
(Definition reproduced from the ISTQB Glossary. Copyright belongs to ISTQB.)
View the complete ISTQB GlossaryWhat is Load Generator?
Load generators execute predefined scenarios to measure response times, throughput, scalability, and resource utilization under controlled conditions.
Virtual user simulation: Multiple users perform actions simultaneously.
Automation: Scenarios are executed automatically and repeatedly.
Measurement support: Performance metrics are collected during execution.
Real World Example
A national travel service is preparing for a public holiday sale where thousands of users may search, reserve, and pay for tickets at the same time.
A feature that works for one tester may fail under traffic, resource pressure, or infrastructure disruption. Load generator helps the team focus on behavior under operational conditions.
The tester defines realistic traffic, failure, and recovery situations, then watches response time, errors, data consistency, and whether users can continue critical actions.
The release decision improves because Load generator gives stakeholders evidence about service behavior when demand or disruption is no longer theoretical.
Practice Questions
Question 1
Which statement BEST describes Load generator in the context of ISTQB terminology?
Question 2
A tester needs to explain Load generator to a non‑technical stakeholder. Which approach is MOST appropriate?
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