BullJS

• Node.js에서 활용할 수 있는 Redis 기반의 Queue System 라이브러리입니다.

→ Redis의 기본 기능 이상으로 큐를 효율적으로 활용할 수 있다.

• Message Queue??

Message Queue

Queue의 특징

• Smooth out processing peaks. For example, if users can initiate resource-intensive tasks at arbitrary times, you can add these tasks to a queue instead of performing them synchronously. Then you can have worker processes pull tasks from the queue in a controlled manner. You can easily add new Queue consumers to scale up the back-end task handling as the application scales up.
• Break up monolithic tasks that may otherwise block the Node.js event loop. For example, if a user request requires CPU intensive work like audio transcoding, you can delegate this task to other processes, freeing up user-facing processes to remain responsive.
• Provide a reliable communication channel across various services. For example, you can queue tasks (jobs) in one process or service, and consume them in another. You can be notified (by listening for status events) upon completion, error or other state changes in the job life cycle from any process or service. When Queue producers or consumers fail, their state is preserved and task handling can restart automatically when nodes are restarted.

Installation & Setting

• 먼저 필요한 dependencies를 설치해준다.

$ npm install --save @nestjs/bull bull

• Bullmodule을 app.module.ts에 Import 진행한다.

app.module.ts

import { Module } from '@nestjs/common';
import { BullModule } from '@nestjs/bull';

@Module({
  imports: [
    BullModule.forRoot({
      redis: {
        host: 'localhost',
        port: 6379,
      },
    }),
  ],
})
export class AppModule {}