# Monitoring



Krenalis monitors its own internal service metrics, and makes them available under the `/metrics` path.

You can control whether this endpoint is available by using the `KRENALIS_PROMETHEUS_METRICS_ENABLED` environment variable or, when configuring Krenalis through AWS Parameter Store, the `/prometheus-metrics-enabled` parameter. 

By default, this setting is `false`, so the `/metrics` endpoint is disabled unless you explicitly enable it.

In Docker Compose installations, `KRENALIS_PROMETHEUS_METRICS_ENABLED` is set to `true` by default. This means the `/metrics` endpoint is automatically enabled in that setup.

## Metrics

| Name                                         | Type         | Labels                       | Description                                                              |
|----------------------------------------------|--------------|------------------------------|--------------------------------------------------------------------------|
| `krenalis_db_acquired_conns`                 | Gauge        | –                            | Current number of connections in use by the database connection pool.    |
| `krenalis_db_max_conns`                      | Gauge        | –                            | Configured maximum number of simultaneous database connections.          |
| `krenalis_db_acquire_duration_seconds_total` | Counter      | –                            | Cumulative seconds spent acquiring connections from the database pool.   |
| `krenalis_db_acquire_count_total`            | Counter      | –                            | Total number of successful database connection acquisitions.             |
| `krenalis_db_new_conns_count_total`          | Counter      | –                            | Total number of newly created database connections (connection churn).   |
| `krenalis_lambda_errors_total`               | CounterVec   | `type`                       | Total number of Lambda errors, categorized by error type.                |
| `krenalis_lambda_duration_seconds`           | Histogram    | –                            | Duration of successful Lambda executions, in seconds.                    |
| `krenalis_lambda_records_total`              | Counter      | –                            | Total number of input records processed by successful Lambda executions. |
| `krenalis_sender_queue_available`            | GaugeVec     | –                            | Number of available events in the event queue.                           |
| `krenalis_sender_queue_wait`                 | HistogramVec | `connector`,<br>`connection` | Time spent waiting in the event queue (in seconds).                      |

#### Go runtime metrics

In addition to the metrics listed above, the `/metrics` endpoint also exposes standard Go runtime metrics (such as memory, garbage collection, and goroutine statistics) provided by the Prometheus Go client. To see the full list of metrics available in your installation, query the `/metrics` endpoint directly.

### Notes

- The total number of successful Lambda executions is provided by the metric `krenalis_lambda_duration_seconds_count`, which is part of the` krenalis_lambda_duration_seconds` histogram. It represents the total number of observations (i.e., completed executions) recorded in the histogram.
- Possible values for the `type` label in `krenalis_lambda_errors_total`:  
  `network`, `lambda_internal`, `function_not_found`, `serialization`, and `function_exec`.
- Buckets defined for `krenalis_lambda_duration_seconds`: `0.1`, `0.5`, `1`, `2.5`,  and `5` (in seconds)
- Buckets defined for `krenalis_sender_queue_wait`: `0.005`, `0.01`, `0.025`, `0.05`, `0.075`, `0.1`, `0.15`, `0.2`, `0.3`, `0.5`, `0.75`, `1.0`, `2.0` (in seconds)

## Prometheus

To monitor these metrics with [Prometheus](https://prometheus.io/), configure it with the following scrape job:

```yaml
scrape_configs:
  - job_name: 'krenalis'
    static_configs:
      - targets: [ "127.0.0.1:2022" ]
```

## Grafana

After setting up Prometheus to collect the metrics, configure [Grafana](https://grafana.com/oss/grafana/) to display them in dashboards.