ioredis

What is ioredis?

ioredis is a robust, performance-focused, and full-featured Redis client for Node.js. It supports both Redis commands and the cluster mode introduced in Redis 3.0. It provides a more intuitive and flexible way to interact with a Redis server or a cluster of Redis servers, offering features like automatic reconnection, offline queueing, and support for transactions, pub/sub, and Lua scripting.

What are ioredis's main functionalities?

Basic Commands

Execute basic Redis commands such as SET and GET. This example demonstrates setting and getting the value of a key.

const Redis = require('ioredis');
const redis = new Redis();
redis.set('foo', 'bar');
redis.get('foo', (err, result) => {
  console.log(result);
});

Publish/Subscribe

Use Redis' pub/sub capabilities to publish messages to a channel and subscribe to receive messages from that channel.

const Redis = require('ioredis');
const subscriber = new Redis();
const publisher = new Redis();
subscriber.subscribe('news', () => {
  publisher.publish('news', 'Hello world!');
});
subscriber.on('message', (channel, message) => {
  console.log(`Received \
${message} from ${channel}`);
});

Transactions

Perform transactions using the MULTI/EXEC commands to execute multiple commands atomically.

const Redis = require('ioredis');
const redis = new Redis();
redis.multi()
  .set('foo', 'bar')
  .get('foo')
  .exec((err, results) => {
    console.log(results);
  });

Pipeline

Use pipelining to send multiple commands to the server without waiting for the replies, improving performance.

const Redis = require('ioredis');
const redis = new Redis();
redis.pipeline()
  .set('foo', 'bar')
  .get('foo')
  .del('foo')
  .exec((err, results) => {
    console.log(results);
  });

Lua Scripting

Extend Redis with Lua scripting. This example defines a custom command that gets the current value of a key and sets it to a new value atomically.

const Redis = require('ioredis');
const redis = new Redis();
redis.defineCommand('getAndSet', {
  numberOfKeys: 1,
  lua: 'return {redis.call('get', KEYS[1]), redis.call('set', KEYS[1], ARGV[1])}'
});
redis.getAndSet('foo', 'new value', (err, result) => {
  console.log(result);
});

Other packages similar to ioredis

redis-commands

redis-commands is not a full client but a comprehensive list of all Redis commands for use in JavaScript. It's useful for developers who want to ensure compatibility or extend their own Redis client implementations. Unlike ioredis, it doesn't provide a client interface or connection management.

README

ioredis

[WIP] A delightful, performance-focused Redis client for Node and io.js

Support Redis >= 2.6.12 and (Node.js >= 0.11.6 or io.js).

Feature

ioredis is a robust, full-featured Redis client used in the biggest online commerce company Alibaba.

1. Full-featured. It supports Cluster, Sentinel, Pipelining and of course Lua scripting & Pub/Sub
2. High performance.
3. Delightful API supports both Node-style callback and Promise.
4. Supports Redis commands transforming.
5. Abstraction for Transaction, Lua scripting and SCAN, SSCAN, ZSCAN, HSCAN.
6. Supports binary data.
7. Support for both TCP/IP and UNIX domain sockets.
8. Flexible system for defining custom command and registering command plugins.
9. Supports offine queue and ready checking.
10. Supports ES6 types such as Map and Set.

Instal

$ npm install ioredis

Basic Usage

var Redis = require('ioredis');
var redis = new Redis();

redis.set('foo', 'bar');
redis.get('foo', function (err, result) {
  console.log(result);
});

// or using promise if the last argument isn't a function
redis.get('foo').then(function (result) {
  console.log(result);
});

// Arguments will be flatten, so both the following two line are same:
redis.sadd('set', 1, 3, 5, 7);
redis.sadd('set', [1, 3, 5, 7]);

Connect to Redis

When a new Redis instance is created, a connection to Redis will be created at the same time.

You can specify which Redis to connect by:

new Redis()       // Will connect to 127.0.0.1:6379
new Redis(6380)   // 127.0.0.1:6380
new Redis(6379, '192.168.1.1')        // 192.168.1.1:6379
new Redis('redis://127.0.0.1:6380')   // 127.0.0.1:6380
new Redis('/tmp/redis.sock')
new Redis({
  port: 6379          // Redis port
  host: '127.0.0.1'   // Redis host
  family: 4           // 4(IPv4) or 6(IPv6)
})

Handle Binary Data

Arguments can be buffers:

redis.set('foo', new Buffer('bar'));

And every command has a buffer method(by adding a suffix of "Buffer" to the command name) to reply a buffer instead of a utf8 string:

redis.getBuffer('foo', function (err, result) {
  // result is a buffer.
});