String Counter

---

Description

The String Counter processor counts changes in string field values. It supports:

• Value change detection
• Change pair tracking
• Incremental counting
• State transition monitoring

This processor is essential for:

• Counting value changes
• Tracking state transitions
• Monitoring string patterns
• Measuring change frequency

---

Required input

The processor requires a data stream containing at least one string field to monitor for value changes.

---

Configuration

String Field

Select the string field to monitor for value changes. This field will be used to detect changes and increment the counter.

Output

The processor creates a new event containing:

• All original fields from the input event
• A new field named "counter" containing the current count of value changes
• A new field named "change_from" containing the previous value
• A new field named "change_to" containing the new value

Example

Input Event Stream

{
  "deviceId": "sensor01",
  "status": "idle"
}

{
  "deviceId": "sensor01",
  "status": "running"
}

{
  "deviceId": "sensor01",
  "status": "idle"
}

Configuration

• String Field: status

Output Event

{
  "deviceId": "sensor01",
  "status": "running",
  "change_from": "idle",
  "change_to": "running",
  "counter": 1
}

{
  "deviceId": "sensor01",
  "status": "idle",
  "change_from": "running",
  "change_to": "idle",
  "counter": 2
}

Use Cases

1. State Monitoring

   • Track state changes
   • Count transitions
   • Monitor patterns
   • Measure frequency

2. Process Analysis

   • Analyze workflows
   • Track sequences
   • Count cycles
   • Monitor operations

Notes

• Only counts actual value changes
• Ignores consecutive identical values
• Processing is stateful
• Counter is incremental
• Events are only emitted on value changes
• Original event fields are preserved
• Change pairs are tracked (from -> to)
• Counter starts at 1 for first change