# Orca Metrics Reference

Orca exposes Prometheus text-exposition metrics at `/metrics` on the
metrics endpoint (default `:9100`, configurable via `--addr`).

## Running the metrics endpoint

```sh
orca metrics --addr :9100
```

## Prometheus scrape config

```yaml
scrape_configs:
  - job_name: orca
    static_configs:
      - targets: ['localhost:9100']
    scrape_interval: 15s
```

## Metric reference

| Metric | Type | Description |
|--------|------|-------------|
| `nodes_total` | Gauge | Total number of registered nodes |
| `allocs_total` | Gauge | Total number of job allocations |
| `orca_jobs_by_state{state}` | Gauge | Jobs grouped by status (running, complete, failed, etc.) |
| `orca_audit_chain_head` | Gauge | Audit chain integrity (1 = chain head verified, 0 = error) |

## Counter metrics (incremented by CLI operations)

The following counters are incremented during normal operations and
are available when the metrics endpoint polls the DB:

| Metric | Type | Description |
|--------|------|-------------|
| `orca_drift_events_total` | Counter | Total drift events detected |
| `orca_ssh_errors_total` | Counter | Total SSH connection/exec errors |
| `orca_txn_apply_total` | Counter | Total transaction applies |
| `orca_txn_rollback_total` | Counter | Total transaction rollbacks |
| `orca_acl_denials_total` | Counter | Total ACL denials (enforce mode) |

## Security headers

The metrics endpoint sets the following security headers on all responses:
- `X-Content-Type-Options: nosniff`
- `X-Frame-Options: DENY`

## Health check

The endpoint also exposes `/healthz` returning `200 ok` for liveness probes.