# stats

Collect metrics from other pipeline stages and emit aggregated statistics every `interval` seconds.  Tracks standard metrics (errors, events, bytes) and supports custom metrics via `extra`.  Memory usage (heap, RSS) is also emitted.

## Config

**Optional:**
- `interval`: How often in seconds to emit aggregated stats (default: 15)
- `extra`: Additional custom metric names to track

**Standard Metrics:**
- `errors`: number of errors
- `latency`: ms of a response
- `inFlight`: number of inflight requests
- `rxEvents`: number of events ingested
- `rxBytes`: bytes received
- `txEvents`: number of events shipped
- `txBytes`: bytes shipped

## Example

!!!info
The STATS channels is a special built-in.  `LogEngine.stats()` will emit errors to the STATS channel.
!!!

```yaml
pipeline:
  stats:
    inputs: [STATS]
    config:
      interval: 300
      extra: [banned]
```