Guide to GraphQL Redis Subscriptions in Node.js

Dive into our in-depth guide on integrating GraphQL Redis Subscriptions in Node.js for boosting real-time data updates in your applications.

Himanshu Pant

Published: November 8, 2023

Key takeaways

Real-Time Communication Enhancement: With GraphQL and Redis integration, it creates a power house for fast real-time data transfer in Node. js applications. GraphQL Subscriptions are important for real-time applications such as messaging and live tracking since clients can receive an instant update.
Redis as a Pub/Sub System: In this setup, Redis can easily be used as a pub/sub system meaning that it provides the framework for an efficient means of communication between the server and clients without experience any sort of scalability problems. This results in high performance and effective real time performances The two guarantees high performance and better real time performances.
Implementation Steps: To use GraphQL-Redis-Subscriptions one needs to install the required packages, establish connections with Redis, create a PubSub object and connect it to the GraphQL server. This arrangement helps to optimize the working of the application in relation to the overall working experience of end users.

In the world of modern software development, real-time communication has become a crucial aspect of many applications. Developers often face challenges in implementing efficient and reliable real-time data exchange. However, with the emergence of technologies like GraphQL and Redis, the integration of real-time capabilities has become more accessible and powerful. In this blog, we will delve into the integration of GraphQL-Redis-Subscriptions in a Node.js application, exploring its significance and understanding its implementation in depth.

Understanding GraphQL Subscriptions

GraphQL Subscriptions are a powerful feature that enables real-time data transfer between the server and clients. Unlike typical GraphQL queries and mutations that are used for fetching and modifying data, subscriptions allow clients to receive data in real time when specific events occur on the server. This feature is particularly useful in applications where users require instant updates, such as in messaging platforms, collaborative editing tools, or live tracking applications.

What is Redis and How Does it Work with GraphQL Subscriptions?

Redis, an open-source, in-memory data structure store, serves as a powerful and efficient caching and messaging broker for various use cases. When combined with GraphQL subscriptions, Redis can act as a reliable pub/sub (publish/subscribe) system, facilitating the communication between the server and subscribed clients.

The integration of Redis with GraphQL subscriptions allows the server to publish events to specific channels, and the clients can subscribe to these channels to receive real-time updates. This architecture ensures scalability, performance, and reliability, making it an ideal solution for building robust and responsive real-time applications.

Implementing GraphQL-Redis-Subscriptions in a Node.js Application

Let’s walk through the steps to integrate GraphQL-Redis-Subscriptions into a Node.js application:

1: Installing Dependencies

npm install graphql-redis-subscriptions ioredis

1	npm install graphql-redis-subscriptions ioredis

2: Setting Up Redis Connection

import IORedis from 'ioredis'

export default class RedisConnectionFactory {
  getNewRedisClient(name: string): IORedis.Redis {
    const client = new IORedis(REDIS_URL)

    client.on('connect', () => {
     console.log({
        msg: 'Connected to Redis',
        client: name,
      })
    })
    client.on('error', (err) => {
     console.error({ msg: 'redis error', err, client: name })
    })

    return client
  }
}

export const redisConnectionFactory = new RedisConnectionFactory()

import IORedis from 'ioredis'

export default class RedisConnectionFactory {

getNewRedisClient(name: string): IORedis.Redis {

const client = new IORedis(REDIS_URL)

client.on('connect', () => {

console.log({

msg: 'Connected to Redis',

client: name,

})

client.on('error', (err) => {

console.error({ msg: 'redis error', err, client: name })

})

return client

}

export const redisConnectionFactory = new RedisConnectionFactory()

3: Create A PubSub Instance

// pubsub.ts
import { RedisPubSub } from 'graphql-redis-subscriptions'
import { redisConnectionFactory } from './redis'

export const pubsub = new RedisPubSub({
  subscriber: redisConnectionFactory.getNewRedisClient('pubsub-subscriber'),
  publisher: redisConnectionFactory.getNewRedisClient('pubsub-publisher'),
})

// pubsub.ts

import { RedisPubSub } from 'graphql-redis-subscriptions'

import { redisConnectionFactory } from './redis'

export const pubsub = new RedisPubSub({

subscriber: redisConnectionFactory.getNewRedisClient('pubsub-subscriber'),

publisher: redisConnectionFactory.getNewRedisClient('pubsub-publisher'),

})

4: Pass The PubSub Instance To GraphQl Server

Import { ApolloServer } from 'apollo-server-express';
Import { pubsub } from './pubsub';

const server = new ApolloServer({
  typeDefs,
  resolvers,
  pubsub,
});

Import { ApolloServer } from 'apollo-server-express';

Import { pubsub } from './pubsub';

const server = new ApolloServer({

typeDefs,

resolvers,

pubsub,

});

5: Publish A Message

export function publishMessage(
  bookingId: string,
  message: string,
  mutation?: NexusGenEnums['MutationType'],
): void {
  console.log(`publishing ${bookingId}-booking-message`)
  pubsub.publish(`${bookingId}-booking-message`, {
    bookingId: bookingId,
    message,
    mutation,
  })
}

export function publishMessage(

bookingId: string,

message: string,

mutation?: NexusGenEnums['MutationType'],

): void {

console.log(`publishing ${bookingId}-booking-message`)

pubsub.publish(`${bookingId}-booking-message`, {

bookingId: bookingId,

message,

mutation,

})

}

export const MessageSubscriptionPayload = objectType({
  name: 'MessageSubscriptionPayload',
  definition(t) {
    t.id('bookingId')
    t.field('mutation', { type: 'MutationType' })
    t.string('message')
  },
})

export const MessageSubscription = subscriptionField('onMessage', {
  type: nonNull('MessageSubscriptionPayload'),
  args: {
    bookingId: nonNull(idArg({ description: 'The booking id' })),
  },
  subscribe: (_, { bookingId }, ctx) => {
   console.log(`subscribed ${bookingId}-booking-message`)
    return ctx.pubsub.asyncIterator<number>(`${bookingId}-booking-message`)
  },
  resolve: (payload: PublishType) => payload,
})

export const MessageSubscriptionPayload = objectType({

name: 'MessageSubscriptionPayload',

definition(t) {

t.id('bookingId')

t.field('mutation', { type: 'MutationType' })

t.string('message')

})

export const MessageSubscription = subscriptionField('onMessage', {

type: nonNull('MessageSubscriptionPayload'),

args: {

bookingId: nonNull(idArg({ description: 'The booking id' })),

subscribe: (_, { bookingId }, ctx) => {

console.log(`subscribed ${bookingId}-booking-message`)

return ctx.pubsub.asyncIterator<number>(`${bookingId}-booking-message`)

resolve: (payload: PublishType) => payload,

})

Example

Here is an example of a subscription query:

subscription onMessage($bookingId: ID!) {
  onMessage(bookingId: $bookingId) {
    mutation
    message
  }
}

subscription onMessage($bookingId: ID!) {

onMessage(bookingId: $bookingId) {

mutation

message

}

This query will subscribe to the onMessage event. When a new message is published, the server will send a notification to the client with the message data.

Conclusion

Employing node.js development services to integrate GraphQL-Redis-Subscriptions within a Node.js application significantly amplifies its real time capabilities. Utilizing GraphQL for data management and Redis for pub/sub empowers developers to build scalable software in various sectors.

This technology stack, when integrated, allows custom software development companies to tailor robust solutions meeting the distinct needs of diverse industries. Whether it’s financial, healthcare, or travel software development, implementing GraphQL-Redis-Subscriptions elevates application performance and enhances user experiences.

In conclusion, as the demand escalates for real time, responsive applications, integrating GraphQL-Redis-Subscriptions into Node.js applications through node.js development services emerges as an efficient solution. With this integrations profound insights, developers can deliver innovative, seamless real time applications across various industries.