Caching in Node.js: Redis, Memcached, and Node-Cache

Caching in JavaScript (Node.js): Redis and Other Tools

Caching is one of the key strategies for optimizing the performance of server-side applications in Node.js. It allows you to reduce the load on databases, decrease API response time, and cut infrastructure costs. In this article, we will cover the main caching tools for Node.js: Redis, Node-Cache (a built-in library), and Memcached, compare their approaches, and show real code examples.

Why is caching needed in Node.js?

Without a cache, every request to a popular resource can lead to multiple calls to the database or external APIs. A cache stores frequently requested data in fast storage (RAM), which provides:

• Reduced response time (latency) from 100-500 ms to 1-5 ms.
• Fewer requests to the database and external services.
• Increased server throughput (RPS).

1. Redis — The King of Caching

Redis is an in-memory key-value data store, often used as a cache, message broker, and database. In Node.js, the redis library (or ioredis) is used to work with Redis.

Installation and Connection

npm install redis

const redis = require('redis');const client = redis.createClient({  url: 'redis://localhost:6379'});

client.on('error', (err) => console.error('Redis Error:', err));await client.connect();

// Example of caching data with TTLasync function getCachedData(key) {  const cached = await client.get(key);  if (cached) return JSON.parse(cached);

  const freshData = { message: 'Hello from DB', time: Date.now() };  await client.setEx(key, 60, JSON.stringify(freshData)); // TTL 60 sec  return freshData;}

Redis Features for Node.js

• TTL Support — automatic deletion of expired entries.
• Data Structures — strings, lists, sets, hashes, sorted sets.
• Pub/Sub — enables building real-time notification systems.
• Clustering — horizontal scaling without performance loss.

2. Node-Cache — Lightweight In-Memory Cache Without External Dependencies

Node-Cache is a simple library for caching data directly in the memory of a Node.js process. It is ideal for small projects, microservices, or when you don't want to set up Redis.

Installation and Example

npm install node-cache

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

// Save datamyCache.set('user:123', { name: 'Alice', role: 'admin' });

// Retrieve dataconst user = myCache.get('user:123');if (user === undefined) {  // data not in cache — need to load from DB  console.log('Cache miss');} else {  console.log('Cache hit:', user);}

// Delete by keymyCache.del('user:123');

// Clear entire cachemyCache.flushAll();

Pros and Cons of Node-Cache

• Pros: no external server required, simple API, automatic TTL cleanup.
• Cons: cache is stored only in one process — data is lost on server restart; cannot be used between multiple Node.js instances.

3. Memcached — Distributed Cache with Minimal Overhead

Memcached is another popular in-memory store optimized for caching. In Node.js, the memcached library is most commonly used.

Installation and Example

npm install memcached

const Memcached = require('memcached');const memcac