README.md

Offloader 🧵🐝

Run retryable jobs on background threads. Backed by Postgres.

Offloader allows you to schedule retryable jobs to execute using a pool of background workers; avoid the performance hit of CPU intensive work or just ensure that your jobs retry until they complete successfully.

Getting Started

Add the offloader package to your project.

pnpm add offloader

You'll need to start up the worker pool, define your job executors, and then use a Scheduler to add jobs to execute.

First, create the worker pool with a config.

import { initWorkerPool, createConfig } from "offloader";

const config = createConfig({
  queues: [],
  executors: {},
  postgresConn: {}
});

initWorkerPool(config);

Second, create your executors.

class EmailOnSignupExecutor implements IExecutor {
  // Implementation hidden
}
// (or)
// const EmailOnSignupExecutor: Executor = (...args) => { // snip };

Finally, create a Scheduler instance and begin scheduling jobs to execute.

import { Scheduler } from "offloader";

const scheduler = new Scheduler(config);

scheduler.enqueue(EmailOnSignupExecutor, {
  userId: 1234
});

Concepts

• Offloader — this library.
• Executor — A function or class that can be used by a Worker to run a job with some parameters (defined when the job is enqueued).
• Worker — A background thread that runs Executors when told to by a controller.
• Controller — Background thread that polls Postgres for jobs to run and tells Workers to execute Executors with arguments when jobs are found. Controls queue concurrency.