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Setting Up Redis with Node.js

To use Redis in your full-stack projects, you need two things: the Redis Server running on your computer (or in the cloud) and the Redis Client library in your Node.js code.

1. Installing the Redis Server​

For Windows Users:​

Redis was originally built for Linux. For Windows, the easiest way is to use WSL2 (Windows Subsystem for Linux) or download the pre-compiled .msi from the MicrosoftArchive GitHub.

Once installed, start the server:

redis-server

For macOS Users:​

brew install redis
brew services start redis

2. Installing the Client Library​

In your Node.js project folder, install the official Redis package via NPM:

npm install redis

3. Creating the Connection​

Create a file named redisClient.js. In modern Redis (version 4+), we use a Promise-based approach which works perfectly with async/await.

redisClient.js
const redis = require('redis');

// 1. Create the client
const client = redis.createClient({
    url: 'redis://localhost:6379' // Default Redis port
});

// 2. Handle connection events
client.on('error', (err) => console.log('Redis Client Error', err));
client.on('connect', () => console.log('✅ Connected to Redis!'));

// 3. Connect to the server
async function connectRedis() {
    await client.connect();
}

connectRedis();

module.exports = client;

4. Basic Operations (SET & GET)​

Now let's use the client in your server.js or a controller.

server.js
const client = require('./redisClient');

async function testRedis() {
    // Storing a value
    await client.set('favorite_shot', 'Helicopter Shot');
    
    // Retrieving a value
    const value = await client.get('favorite_shot');
    console.log('The stored value is:', value);
}

testRedis();

5. Storing Complex Data (Objects)​

Redis strings can only store text. To store a JavaScript object (like a user profile), you must Stringify it first and Parse it when you get it back.

server.js
const user = {
    id: 1,
    name: "Ajay",
    role: "Developer"
};

// Saving the object
await client.set('user:1', JSON.stringify(user));

// Getting the object
const cachedUser = await client.get('user:1');
const finalData = JSON.parse(cachedUser);

console.log(finalData.name); // Output: Ajay

6. The Power of "TTL" (Time to Live)​

One of the best features for a "Master" developer is setting an expiration time. This ensures your RAM doesn't get cluttered with old data.

server.js
// This key will automatically delete itself after 3600 seconds (1 hour)
await client.set('weather_data', '32°C', {
    EX: 3600
});

Practice: The "Fast-Welcome" Middleware​

Try to create a middleware that:

  1. Checks if a user's name is in Redis.
  2. If it is, send a response: "Welcome back, [Name]! (Served from Cache)".
  3. If not, set the name in Redis for 30 seconds and send: "Hello! (Saved to Cache)".
welcomeMiddleware.js
const client = require('./redisClient');
async function welcomeMiddleware(req, res) {
    const name = req.query.name || 'Guest';
    
    // Check Redis for the name
    const cachedName = await client.get(`welcome:${name}`);
    
    if (cachedName) {
        return res.send(`Welcome back, ${cachedName}! (Served from Cache)`);
    } else {
        // Save the name in Redis for 30 seconds
        await client.set(`welcome:${name}`, name, { EX: 30 });
        return res.send('Hello! (Saved to Cache)');
    }
}
module.exports = welcomeMiddleware;

GUI for Redis

If you want to see your data visually instead of using the terminal, download Redis Insight. It’s a free tool that lets you browse your keys, see memory usage, and debug your data easily.