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. By default, this variable is set to 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, connection	Time spent waiting in the event queue (in seconds).

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, configure it with the following scrape job:

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

Grafana

After setting up Prometheus to collect the metrics, configure Grafana to display them in dashboards.