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JustAPI

Metrics & Monitoring

Metrics Endpoint

Section titled “Metrics Endpoint”

Every JustAPI application exposes Prometheus-compatible metrics at /metrics:

Terminal window
curl http://localhost:8000/metrics

Available Metrics

Section titled “Available Metrics”
Metric Type Description
requests_total Counter Total requests by route and status
request_duration_seconds Histogram Request latency (p50, p95, p99, p999)
inbound_bytes_total Counter Total bytes received
outbound_bytes_total Counter Total bytes sent
connections_active Gauge Currently active connections
errors_total Counter Error count by type

Prometheus Scrape Configuration

Section titled “Prometheus Scrape Configuration”
scrape_configs:
  - job_name: 'justapi'
    static_configs:
      - targets: ['localhost:8000']
    metrics_path: /metrics
    scrape_interval: 15s

Grafana Dashboard

Section titled “Grafana Dashboard”

Key panels to create:

  1. Request Rate — rate(requests_total[1m]) by route
  2. Latency — histogram_quantile(0.99, rate(request_duration_seconds_bucket[5m]))
  3. Error Ratio — rate(errors_total[5m]) / rate(requests_total[5m])
  4. Active Connections — connections_active

Alerting Rules

Section titled “Alerting Rules”
groups:
  - name: justapi
    rules:
      - alert: HighErrorRate
        expr: rate(errors_total[5m]) / rate(requests_total[5m]) > 0.05
        for: 5m
        labels: { severity: critical }


      - alert: HighLatency
        expr: histogram_quantile(0.99, rate(request_duration_seconds_bucket[5m])) > 1
        for: 5m
        labels: { severity: warning }

Built-in Alerting

Section titled “Built-in Alerting”

JustAPI supports webhook-based alerting:

app.enable_alerting(
    slack_webhook="https://hooks.slack.com/services/...",
    pagerduty_key="...",
)

See Also

Section titled “See Also”