Metrics

Karma collects metrics for most of its operations to provide insight into the application and hints on how to optimize it.

Configuration

Metrics can be accessed through the health-check endpoints.

The default configuation is:

'health-check':
  server:
    port: 9001
    host: '127.0.0.1'

If the endpoints should be accessible from other hosts, you should bind to 0.0.0.0 or an external IP address of the host:

'health-check':
  server:
    host: '0.0.0.0'

All endpoints can be protected using access tokens. You can define one or more tokens:

'health-check':
  server:
    # openssl rand -base64 23  | tr -d '/+='
    tokens:
      - Nz1THLT4yTEZtt156DBePWDHM6Q9ibM
      - kS1J60atX3CBtrK8nc1Udb2Q7aHVBcw

If no tokens are defined the endpoints are public accessible.

One of the configured token mus be included in the request either in the Authorization header (Authorization: Bearer <token>) or as query parameter (http://karma.server:9001/-/status?token= <token>).

For the curl examples below add: -H "Authorization: Bearer <token>"

Endpoints

Status

curl -X GET http://karma.server:9001/-/status

{
  "cluster": {
    "workers": {
      "size": 1,
      "missing": 0,
      "connected": 1
    }
  },
  "process": {
    "uptime": 326.213
  }
}

Prometheus Metrics

curl -X GET http://karma.server:9001/-/metrics

# HELP process_cpu_user_seconds_total Total user CPU time spent in seconds.
# TYPE process_cpu_user_seconds_total counter
process_cpu_user_seconds_total 5.163402000000001

# ... and a lot more