# Metrics

The operator, the command sidecar in every Play pod, the idle
screen, and `media-api` each serve Prometheus metrics on `:9200`,
under
[milestone 65](https://github.com/liken-sh/liken/blob/main/plans/completed/65-prometheus-metrics.md)'s
shared contract: every process on the cluster network uses the same
port, since no two of these pods ever share one. The base in `deploy/`
needs no Prometheus: every listener answers with nothing scraping it.
An owner who runs the
prometheus-operator adds `deploy/monitoring`, the `Component` that
carries a `PodMonitor` for each of these pods, beside the base.

| Component | Metric | Type | Why |
| --- | --- | --- | --- |
| media-operator | `media_reconcile_duration_seconds{kind}` | histogram | how long one reconcile of one kind took |
| media-operator | `media_reconcile_errors_total{kind}` | counter | reconciles that returned an error |
| media-operator | `media_watch_restarts_total{kind}` | counter | a watch's stream ended and the operator opened it again |
| media-operator | `media_players{zone, state}` | gauge | idle, playing, paused |
| media-operator | `media_playback_starts_total` | counter | plays over time |
| media-operator | `media_playback_failures_total{reason}` | counter | the film did not start |
| media-operator | `media_display_restarts_total{player}` | counter | the film plays with no on-screen display |
| media-operator, idle-screen | `media_bus_connected` | gauge | the MQTT bus is up |
| command sidecar | `media_decode_info{codec, hardware}` | gauge, info | a software decode is a 1300 millicore line |
| command sidecar | `media_dropped_frames_total` | counter | stutter |
| command sidecar | `media_av_delay_seconds` | gauge | sync drift |
| media-api | `media_api_requests_total{route, method, status}` | counter | requests by route and outcome |
| media-api | `media_api_request_seconds{route}` | histogram | header time |
| media-api | `media_api_streams_active{aspect}` | gauge | captures open now |
| media-api | `media_api_upstream_requests_total{upstream, status}` | counter | what display-api and audio-api answered |
| media-api | `media_api_compose_offset_seconds` | histogram | the measured header offset |
| media-api | `media_api_compose_offset_last_seconds` | gauge | the last correction, signed: negative when the audio headers arrived first |
| media-api | `media_api_certificate_expiry_seconds` | gauge | the serving leaf runs out |

```yaml
resources:
  - https://github.com/liken-sh/liken//media-operator/deploy?ref=<tag>
components:
  - https://github.com/liken-sh/liken//media-operator/deploy/monitoring?ref=<tag>
```