knet/docs/grafana-integration.md

Grafana Integration Guide

This guide shows how to visualize your application metrics with Grafana using real Prometheus.

Why Prometheus?

We've replaced custom tracking with actual Prometheus because:

• ✅ Industry standard - Battle-tested metrics collection
• ✅ Rich ecosystem - Thousands of existing dashboards
• ✅ Better performance - Optimized time-series storage
• ✅ Less code - No custom database or API endpoints
• ✅ Standard metrics - HTTP requests, response times, etc.

Available Metrics

Automatic Metrics (from echo-contrib/prometheus)

• http_requests_total - Total HTTP requests by method/status/endpoint
• http_request_duration_seconds - Request duration histogram
• http_request_size_bytes - Request size histogram
• http_response_size_bytes - Response size histogram

Custom Application Metrics

• knet_page_views_total{route="/"} - Page views by route
• knet_page_views_total{route="/draw"} - Draw page views
• knet_box_clicks_total{position="1"} - Box clicks by position
• knet_websocket_connections - Active WebSocket connections

Authentication

The /metrics endpoint uses Basic Authentication in production:

• Username: api (or set via API_USERNAME environment variable)
• Password: Your API token (set via API_TOKEN environment variable)

Example:

curl -u api:your-api-token http://your-server:54321/metrics

Grafana Setup

Prometheus Data Source (Recommended)

1. Add Prometheus Data Source in Grafana
2. Set URL to: http://your-server:54321
3. Set Basic Auth: Username: api, Password: your-api-token
4. Set Scrape Interval: 15s (Prometheus scrapes our /metrics endpoint)

That's it! Grafana will automatically discover all available metrics.

Sample Dashboard Queries

Traffic Overview:

# Total requests per minute
rate(http_requests_total[1m]) * 60

# Page views
knet_page_views_total

# Request duration 95th percentile  
histogram_quantile(0.95, rate(http_request_duration_seconds_bucket[5m]))

# Error rate
rate(http_requests_total{status=~"4.."}[5m]) / rate(http_requests_total[5m]) * 100

Application Metrics:

# Box interactions
rate(knet_box_clicks_total[5m])

# Active WebSocket connections
knet_websocket_connections

# Most popular pages
topk(10, rate(knet_page_views_total[1h]))

Dashboard Examples

1. HTTP Overview Panel

• Metric: rate(http_requests_total[1m]) * 60
• Type: Graph
• Title: "Requests per Minute"

2. Response Time Panel

• Metric: histogram_quantile(0.95, rate(http_request_duration_seconds_bucket[5m]))
• Type: Single Stat
• Title: "95th Percentile Response Time"

3. Page Views Panel

• Metric: knet_page_views_total
• Type: Graph
• Title: "Page Views by Route"

4. Box Clicks Heatmap

• Metric: rate(knet_box_clicks_total[5m])
• Type: Graph
• Title: "Box Clicks per Second"

Environment Variables

Set these for production:

export API_TOKEN="your-secure-api-token"
export API_USERNAME="api"  # Optional, defaults to "api"
export BUILD_NUMBER="prod-v1.0"  # Enables production mode

Benefits of This Approach

1. Standard Prometheus - Works with all Grafana features
2. Rich Metrics - HTTP performance + custom business metrics
3. No Database - Prometheus handles storage and retention
4. Better Performance - Optimized time-series queries
5. Alerting Ready - Use Prometheus AlertManager
6. Ecosystem - Tons of existing dashboards and tools

Quick Start

1. Start your server: ./tmp/main
2. Test metrics: curl -u api:your-token http://localhost:54321/metrics
3. Add Prometheus data source in Grafana: http://localhost:54321
4. Create dashboard with queries like http_requests_total
5. Enjoy real-time metrics! 📊

Your analytics are now powered by industry-standard Prometheus! <20>