# tRateStreamInput
[Preview](https://help.qlik.com/en-US/cloud-services/Subsystems/Hub/Content/Sense_Hub/Introduction/feature-preview-program-overview.htm)
Generates rows continuously at a specified rate.
## tRateStreamInput properties for Apache Spark Structured Streaming
Use these properties to configure tRateStreamInput running in the Spark Structured Streaming Job framework.
The Spark Structured Streaming tRateStreamInput component belongs to the Misc family.
The streaming version of this component is available in Talend Real-Time Big Data Platform and in Talend Data Fabric.
## Basic settings
| Properties | Description |
| --- | --- |
| Rows per second | Enter the number of rows to generate per second. The default value is
1. |
| Ramp up time | Enter the time in milliseconds for the component to gradually ramp up to the
target row rate. The default value is 0. |
| Set number of partitions | Select this check box to set the number of partitions for the generated
data. If not set, Spark uses the default parallelism. |
| Enable watermarking | Select this check box to activate watermarking and select the time mode to
be used:
- Event time: Select to use a timestamp column representing when each event occurred, then select the column in the Watermark column (timestamp) drop-down list.
- Processing time: Select to use the time when Spark reads each record.
In the Watermark delay field, specify how long Spark
waits for late data before finalizing each window. |
## Usage
| Usage guidance | Description |
| --- | --- |
| **Usage rule** | This component is used as a start component and requires an output link.
This component, along with the Spark Structured Streaming component Palette it belongs to,
appears only when you are creating a Spark Structured Streaming Job. |
| Spark Connection | You need to use the Structured Streaming Configuration
tab in the Run view to define the connection to a Spark cluster for
the whole Job.
This connection is effective on a per-Job basis. |