Graceful shutdown handling in Node.js - Mini Project: Build & Apply

Graceful Shutdown Handling in Node.js

📖 Scenario: You are building a simple Node.js server that needs to stop cleanly when the application is closed or restarted. This means it should finish any ongoing work and close resources properly before exiting.

🎯 Goal: Create a Node.js server that listens on port 3000 and handles shutdown signals gracefully by closing the server and logging a message before the program exits.

📋 What You'll Learn

Create a basic HTTP server using Node.js

Add a variable to track if the server is running

Implement a listener for shutdown signals like SIGINT

Close the server gracefully and log a shutdown message

💡 Why This Matters

🌍 Real World

Graceful shutdown is important for servers to close connections and free resources properly before stopping, avoiding data loss or corruption.

💼 Career

Many backend developer roles require knowledge of handling process signals and graceful shutdown to build reliable and maintainable server applications.

1

Create a basic HTTP server

Create a Node.js HTTP server using http.createServer that responds with 'Hello World' to any request. Make the server listen on port 3000.

Node.js

# Your code here to create the server and listen on port 3000

Need a hint?

Use http.createServer to create the server and server.listen(3000) to start it.

2

Add a running state variable

Add a variable called isRunning and set it to true to track if the server is currently running.

Node.js

import http from 'http';

const server = http.createServer((req, res) => {
  res.statusCode = 200;
  res.setHeader('Content-Type', 'text/plain');
  res.end('Hello World');
});

server.listen(3000);

// Add a variable to track if the server is running
# Your code here

Need a hint?

Declare let isRunning = true; after starting the server.

3

Listen for shutdown signals

Add a listener for the 'SIGINT' signal using process.on. Inside the listener, set isRunning to false and call server.close() to stop the server.

Node.js

import http from 'http';

const server = http.createServer((req, res) => {
  res.statusCode = 200;
  res.setHeader('Content-Type', 'text/plain');
  res.end('Hello World');
});

server.listen(3000);

let isRunning = true;

// Add a listener for SIGINT to handle graceful shutdown
# Your code here

Need a hint?

Use process.on('SIGINT', () => { ... }) to listen for the shutdown signal.

4

Log shutdown completion

Add a listener for the server's 'close' event. Inside it, log 'Server has shut down gracefully.' and call process.exit(0) to exit the program cleanly.

Node.js

import http from 'http';

const server = http.createServer((req, res) => {
  res.statusCode = 200;
  res.setHeader('Content-Type', 'text/plain');
  res.end('Hello World');
});

server.listen(3000);

let isRunning = true;

process.on('SIGINT', () => {
  isRunning = false;
  server.close();
});

// Add a listener for the 'close' event to log shutdown and exit
# Your code here

Need a hint?

Use server.on('close', () => { ... }) to handle the server closing event.