Data Generation
Data Generators produce test data for load tests. Each generator is owned by a test case and is called once per iteration, merging a set of variables into the test parameters before the iteration body runs. They live on the Data Generators tab of the Load Test panel.
Data Generators are a feature of load tests (the Data Generators tab), not a standalone test step. Each iteration consumes the next generated row/variable set.
When to Use
- Feeding unique or varied values (usernames, identifiers, amounts) to each virtual user
- Driving data-driven load tests from CSV, Excel, SQL, NoSQL, or inline tables
- Cycling through a fixed list of values across iterations
Quickest Scenario
- Open the Load Test panel and select the Data Generators tab.
- Click Add → Random Data Generator (or Table / Variable).
- Configure the rules/variables and click Initialize to load the data source.
- Click Load Next to preview each iteration's generated variables in the Preview grid.
Common Fields
All generators share:
| Field | Description |
|---|---|
| Name | Identifier for the generator. |
| Random Order | When enabled, values are picked at random per iteration instead of sequentially. |
Generator Types
Random Data Generator
Generates a random value within a defined range for each rule. Add rules via Add Rule, which offers Integer Range, Double Range, or DateTime Range.
| Rule field | Description |
|---|---|
| Variable Name | The variable that receives the generated value. |
| Data Range | The configured range. Each range also supports Min Value Inclusive and Max Value Inclusive flags. |
- Integer Range — whole numbers between a minimum and maximum.
- Double Range — decimal numbers between a minimum and maximum.
- DateTime Range — date/time values within a range.
Table Data Generator
Reads rows from a data source. Each column becomes a variable; each row provides one iteration's worth of data. Data is loaded once during Initialize and served sequentially or randomly from memory.
Select a Type for the data source:
| Type | Description |
|---|---|
| CSV | Comma-separated file. |
| Excel | Excel workbook. |
| SQL | Database query (supports connection profiles). |
| NoSQL | NoSQL query (supports connection profiles). |
| Table | Inline table edited in the UI. |
Variable Data Generator
Each variable defines a list of possible values (comma-separated). Per iteration a value is picked sequentially (or randomly when Random Order is on) for each variable:
| Field | Description |
|---|---|
| Variable Name | The variable to set. |
| Values (comma-separated) | The candidate values to cycle through. |
Preview
After Initialize, the Preview grid shows the Name and Value of the variables produced for the current iteration. Load Next simulates the next generation turn.
Why
Generators decouple test data from the test logic, so the same load test can exercise many data combinations across virtual users without cloning steps or hard-coding values.