Supercharge Your Node.js App with Blazing Fast In-Memory Caching!

Introduction

If you’re experiencing latency issues in your Node.js application, implementing in-memory caching can be a game-changer. This guide will walk you through how to set up in-memory caching using node-cache in an Express.js server to significantly improve your API performance.

The Challenge

We recently saw a rapid increase in our backend project, reaching over 1000 active users in just 5 days. However, this spike led to latency issues, with API calls averaging around 200ms. Initially, we used Redis for caching, but latency remained between 180-200ms because our Redis instance and main server were both in the US-West region, while our users were primarily in India.

To address this, we implemented in-memory caching on the server, reducing latency by approximately 60%.

Here's how to implement in-memory caching using Node.js and Express.js:

- Install the node cache package

npm install node-cache

- Setup your Cache

const NodeCache = require('node-cache');
const myCache = new NodeCache({ stdTTL: 100, checkperiod: 120 });

// stdTTL is the default time-to-live for cache entries (in seconds)
// checkperiod is the interval for automatic cache cleaning (in seconds)

- Implement in the express js server

const express = require('express');
const app = express();

// Example data fetching function
async function fetchDataFromDatabase() {
    // Simulate a database call
    return { data: 'This is some data from the database.' };
}

app.get('/data', async (req, res) => {
    const cacheKey = 'myDataKey';
    const cachedData = myCache.get(cacheKey);

    if (cachedData) {
        return res.json({ source: 'cache', data: cachedData });
    }

    const data = await fetchDataFromDatabase();
    myCache.set(cacheKey, data);
    res.json({ source: 'database', data });
});

const PORT = process.env.PORT || 3000;
app.listen(PORT, () => {
    console.log(`Server is running on port ${PORT}`);
});

- Manage your cache

// Get cache statistics
console.log(myCache.getStats());

// Manually delete a cache entry
myCache.del('myDataKey');

// Flush the entire cache
myCache.flushAll();