diff --git a/docs/versioned/serving/observability/metrics/serving-metrics.md b/docs/versioned/serving/observability/metrics/serving-metrics.md index c6d4343365..9f7167e62e 100644 --- a/docs/versioned/serving/observability/metrics/serving-metrics.md +++ b/docs/versioned/serving/observability/metrics/serving-metrics.md @@ -92,6 +92,45 @@ Name | Type | Description `kn.configuration.name` | string | Knative Configuration name associated with this Revision `kn.revision.name` | string | The name of the Revision +### `kn.activator.stats.conn.reachable` + +**Instrument Type:** Int64Gauge + +**Unit ([UCUM](https://ucum.org)):** {reachable} + +**Description:** Whether a peer is reachable from the activator (1 = reachable, 0 = not reachable) + +The following attributes are included with the metric + +Name | Type | Description +-|-|- +`peer` | string | The peer service the activator is connecting to (e.g., `autoscaler`) + +This metric helps operators identify connectivity issues between the activator and its peer components. The metric is recorded: + +- When a connection is established (value = 1) +- When a connection is lost (value = 0) + +### `kn.activator.stats.conn.errors` + +**Instrument Type:** Int64Counter + +**Unit ([UCUM](https://ucum.org)):** {error} + +**Description:** Number of connection errors from the activator + +The following attributes are included with the metric + +Name | Type | Description +-|-|- +`peer` | string | The peer service the activator is connecting to (e.g., `autoscaler`) + +This counter increments each time the activator fails to communicate with a peer. It complements the `kn.activator.stats.conn.reachable` gauge by providing a cumulative count of errors, which is useful for: + +- Detecting flaky connections that might be missed by point-in-time gauge sampling +- Creating rate-based alerts (e.g., alert if error rate exceeds threshold over 5 minutes) +- Tracking connection stability trends over time + ### HTTP metrics Since the activator receives and forwards requests to the user workload it has both HTTP server and client metrics.