📊 Monitoring & Logging

📖 Konsep Utama

• Monitoring:
  • Memantau CPU, RAM, response time, error rate.
  • Alat: Prometheus, Grafana, New Relic.
• Logging:
  • Mencatat request, response, error, aktivitas user.
  • Alat: Winston (Node.js), Morgan (Express), ELK Stack (Elasticsearch, Logstash, Kibana).
• Alerting: notifikasi otomatis jika ada error/penurunan performa.

🔹 Contoh Logging dengan Winston

// logger.js
const { createLogger, transports, format } = require("winston");

const logger = createLogger({
  format: format.combine(
    format.timestamp(),
    format.json()
  ),
  transports: [
    new transports.Console(),
    new transports.File({ filename: "app.log" })
  ]
});

module.exports = logger;

// app.js
const express = require("express");
const logger = require("./logger");
const app = express();

app.get("/", (req, res) => {
  logger.info("Route / diakses");
  res.send("Halo Monitoring & Logging");
});

app.listen(3000, () => logger.info("Server berjalan di http://localhost:3000"));

🔹 Contoh Monitoring dengan Morgan

const morgan = require("morgan");
app.use(morgan("combined")); // log request HTTP