How to cache JSON data in Redis with NodeJS?

To cache JSON data in Redis with Node.js, you can use the redis npm package along with JSON serialization and deserialization. Redis, an open-source, in-memory data store, is commonly used as a caching solution due to its high performance and flexibility. In this tutorial, we'll explore how to cache JSON data in Redis using Node.js, allowing you to efficiently store and retrieve JSON objects.

What is JSON?

JSON, short for JavaScript Object Notation, is a lightweight data-interchange format that is easy for humans to read and write and easy for machines to parse and generate. It's based on a subset of the JavaScript programming language, but JSON can be used independently of JavaScript in various programming languages.

Syntax:

{
  "people": [
    {"name": "gfg1", "age": 25},
    {"name": "gfg2", "age": 30},
    {"name": "gfg3", "age": 20}
  ]
}

Step to Setup NodeJS App and Installing Module

Step 1: Create a NodeJS app using the following command:

mkdir mongodb-indexes-tutorial
cd mongodb-indexes-tutorial
npm init -y

Step 2: Install the required dependencies using the following command:

npm install redis

The updated dependencies in package.json file will look like:

 "dependencies": {
    "redis": "4.6.13",
  },

Connecting to Redis

Create a JavaScript file (e.g., app.js) and establish a connection to your Redis server:

const redis = require('redis');

// Create Redis client
const client = redis.createClient();

// Handle connection errors
client.on('error', (error) => {
    console.error('Error connecting to Redis:', error);
});

console.log('Connected to Redis');

Caching JSON Data

Now, let's define functions to store and retrieve JSON data in Redis:

// Function to set JSON data in Redis
function setJSONData(key, data) {
    client.set(key, JSON.stringify(data), (error, reply) => {
        if (error) {
            console.error('Error setting JSON data in Redis:', error);
        } else {
            console.log('JSON data cached successfully:', reply);
        }
    });
}

// Function to get JSON data from Redis
function getJSONData(key, callback) {
    client.get(key, (error, reply) => {
        if (error) {
            console.error('Error getting JSON data from Redis:', error);
            callback(error, null);
        } else {
            console.log('JSON data retrieved successfully:', reply);
            callback(null, JSON.parse(reply));
        }
    });
}

Example: Let's demonstrate how to use these functions to cache and retrieve JSON data:

// Sample JSON data
const jsonData = {
    name: 'John Doe',
    age: 30,
    email: '[email protected]'
};

// Cache JSON data
setJSONData('user:1', jsonData);

// Retrieve cached JSON data
getJSONData('user:1', (error, data) => {
    if (error) {
        console.error('Error:', error);
    } else {
        console.log('Retrieved JSON data:', data);
    }
});

Example: Below is an example to cache JSON data in Redis with NodeJS

const redis = require('redis');
const client = redis.createClient();

client.on('connect', async () => {
  console.log('Connected to Redis');

  // Write your code here

  // Example: Set JSON data
  const jsonData = {
    name: 'John Doe',
    age: 30,
    email: '[email protected]'
  };
  await client.set('jsondata', JSON.stringify(jsonData));

  // Example: Get JSON data
  const cachedData = await client.get('jsondata');
  if (cachedData) {
    console.log('Cached JSON data:', JSON.parse(cachedData));
  } else {
    console.log('Data not found in cache.');
  }

  client.quit();
});

client.on('error', (err) => {
  console.error('Redis error:', err);
});

Output:

Conclusion

In this tutorial, we've learned how to cache JSON data in Redis using Node.js. By leveraging Redis as a caching solution, you can improve the performance of your applications by storing frequently accessed JSON objects in memory. Redis's simplicity and high performance make it an excellent choice for caching various types of data, including JSON payloads. Experiment with different caching strategies and data structures to optimize the performance of your Node.js applications.