Prometheus & Grafana Setup

Set up comprehensive monitoring for NestJS RedisX with Prometheus and Grafana.

Architecture

Quick Setup with Docker Compose

# docker-compose.yml
version: '3.8'
services:
  app:
    build: .
    ports:
      - "3000:3000"
    environment:
      - REDIS_HOST=redis

  redis:
    image: redis:7-alpine
    ports:
      - "6379:6379"

  prometheus:
    image: prom/prometheus:latest
    ports:
      - "9090:9090"
    volumes:
      - ./prometheus.yml:/etc/prometheus/prometheus.yml

  grafana:
    image: grafana/grafana:latest
    ports:
      - "3001:3000"
    environment:
      - GF_SECURITY_ADMIN_PASSWORD=admin
    volumes:
      - ./grafana/provisioning:/etc/grafana/provisioning

Configure Metrics Plugin

// app.module.ts
import { MetricsPlugin } from '@nestjs-redisx/metrics';

RedisModule.forRoot({
  clients: { host: process.env.REDIS_HOST, port: 6379 },
  plugins: [
    new MetricsPlugin({
      prefix: 'redisx_',
      endpoint: '/metrics',
      defaultLabels: {
        service: 'my-service',
        env: process.env.NODE_ENV,
      },
    }),
  ],
})

Prometheus Configuration

# prometheus.yml
global:
  scrape_interval: 15s

scrape_configs:
  - job_name: 'nestjs-app'
    static_configs:
      - targets: ['app:3000']
    metrics_path: '/metrics'

Key Metrics

Cache Metrics

Metric	Type	Description
redisx_cache_hits_total	Counter	Cache hits
redisx_cache_misses_total	Counter	Cache misses
redisx_cache_operation_duration_seconds	Histogram	Operation latency

Lock Metrics

Metric	Type	Description
redisx_lock_acquisitions_total	Counter	Locks acquired
redisx_lock_timeouts_total	Counter	Lock timeouts
redisx_lock_wait_duration_seconds	Histogram	Wait time

Rate Limit Metrics

Metric	Type	Description
redisx_ratelimit_allowed_total	Counter	Allowed requests
redisx_ratelimit_rejected_total	Counter	Rejected requests

Grafana Dashboard

Import this dashboard JSON:

{
  "title": "NestJS RedisX",
  "panels": [
    {
      "title": "Cache Hit Rate",
      "type": "gauge",
      "targets": [{
        "expr": "sum(rate(redisx_cache_hits_total[5m])) / sum(rate(redisx_cache_hits_total[5m]) + rate(redisx_cache_misses_total[5m]))"
      }]
    },
    {
      "title": "Operations/sec",
      "type": "graph",
      "targets": [{
        "expr": "sum(rate(redisx_cache_hits_total[5m])) + sum(rate(redisx_cache_misses_total[5m]))"
      }]
    }
  ]
}

Alerting Rules

# alerts.yml
groups:
  - name: redisx
    rules:
      - alert: LowCacheHitRate
        expr: |
          sum(rate(redisx_cache_hits_total[5m])) / 
          (sum(rate(redisx_cache_hits_total[5m])) + sum(rate(redisx_cache_misses_total[5m]))) < 0.8
        for: 5m
        labels:
          severity: warning
        annotations:
          summary: "Cache hit rate below 80%"

      - alert: HighLockContention
        expr: rate(redisx_lock_timeouts_total[5m]) > 0.1
        for: 5m
        labels:
          severity: warning
        annotations:
          summary: "High lock timeout rate"

Useful PromQL Queries

# Cache hit rate
sum(rate(redisx_cache_hits_total[5m])) / 
(sum(rate(redisx_cache_hits_total[5m])) + sum(rate(redisx_cache_misses_total[5m])))

# p99 latency
histogram_quantile(0.99, sum(rate(redisx_cache_operation_duration_seconds_bucket[5m])) by (le))

# Rate limit rejection rate
sum(rate(redisx_ratelimit_rejected_total[5m])) / 
sum(rate(redisx_ratelimit_allowed_total[5m]) + rate(redisx_ratelimit_rejected_total[5m]))

Next Steps

• OpenTelemetry — Distributed tracing
• Operations: Monitoring — Production monitoring