Count Array

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Description

The Count Array processor counts the number of elements in array/list fields. It supports:

• Array size counting
• List length measurement
• Collection size tracking
• Dynamic array handling

This processor is essential for:

• Measuring array sizes
• Tracking list lengths
• Monitoring collection growth
• Analyzing data volumes

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Required input

The processor requires a data stream containing at least one array or list field to count its elements.

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Configuration

List Field

Select the array or list field to count its elements. This field will be used to determine the number of items it contains.

Output

The processor creates a new event containing:

• All original fields from the input event
• A new field named "countValue" containing the number of elements in the selected array/list

Example

Input Event

{
  "deviceId": "sensor01",
  "measurements": [23.5, 24.1, 25.3, 24.8],
  "timestamp": 1586380104915
}

Configuration

• List Field: measurements

Output Event

{
  "deviceId": "sensor01",
  "measurements": [23.5, 24.1, 25.3, 24.8],
  "timestamp": 1586380104915,
  "countValue": 4
}

Use Cases

1. Data Analysis

   • Count array elements
   • Track list sizes
   • Monitor collection growth
   • Measure data volumes

2. Resource Management

   • Monitor buffer sizes
   • Track queue lengths
   • Measure storage usage
   • Analyze capacity needs

Notes

• Only array/list fields can be counted
• Count is calculated per event
• Processing is stateless
• Empty arrays return 0
• Null arrays are not supported