Production Deployment & Optimization

# install
npm install -g pm2

# start app
pm2 start app.js

# start with name
pm2 start app.js --name "my-app"

# list all processes
pm2 list

# logs
pm2 logs

# restart
pm2 restart my-app

# stop
pm2 stop my-app

# cluster mode (CPU cores ব্যবহার)
pm2 start app.js -i max

const cluster = require("node:cluster");
const os = require("node:os");
const http = require("node:http");

if (cluster.isPrimary) {
  const numCPUs = os.cpus().length;
  console.log("Master process:", process.pid);
  console.log("Forking", numCPUs, "workers");

  for (let i = 0; i < numCPUs; i++) {
    cluster.fork();
  }

  cluster.on("exit", (worker) => {
    console.log("Worker", worker.process.pid, "died. Restarting...");
    cluster.fork();
  });
} else {
  http.createServer((req, res) => {
    res.end("Hello from worker " + process.pid);
  }).listen(3000);

  console.log("Worker", process.pid, "started");
}

npm install express-rate-limit

const rateLimit = require("express-rate-limit");

const limiter = rateLimit({
  windowMs: 15 * 60 * 1000, // 15 minutes
  max: 100, // per IP max 100 requests
  message: "অনেক বেশি request পাঠানো হয়েছে",
});

app.use("/api/", limiter);

npm install helmet cors

const helmet = require("helmet");
const cors = require("cors");

// Security headers
app.use(helmet());

// CORS
app.use(cors({
  origin: "https://myfrontend.com",
  methods: ["GET", "POST"],
}));

// Disable X-Powered-By
app.disable("x-powered-by");

npm install winston

const winston = require("winston");

const logger = winston.createLogger({
  level: "info",
  format: winston.format.combine(
    winston.format.timestamp(),
    winston.format.json()
  ),
  transports: [
    new winston.transports.File({ filename: "error.log", level: "error" }),
    new winston.transports.File({ filename: "combined.log" }),
  ],
});

logger.info("Server started");
logger.error("Database connection failed");