Introduction to Worker Farm in Node.js

Worker-farm is a module in Node.js that allows you to easily distribute processing tasks across multiple Node processes. This is exceptionally useful for CPU-intensive tasks that would otherwise block the event loop. By offloading work to separate processes, you can improve application performance and responsiveness.

Installation

  npm install worker-farm

API Examples

1. Basic Setup

The minimal setup for worker-farm includes initializing the module and creating workers to handle specific tasks.

 const workerFarm = require('worker-farm');
 const workers = workerFarm(require.resolve('./worker'));

 workers('task_data', (err, result) => {
   if (err) console.error(err);
   console.log(result);
   workerFarm.end(workers);
 });

2. Passing Parameters

You can pass multiple parameters to the worker function easily.

 workers('param1', 'param2', (err, result) => {
   if (err) console.error(err);
   console.log(result);
 });

3. Handling Multiple Tasks

Using an array or list of tasks, you can distribute work across multiple workers.

 const tasks = ['task1', 'task2', 'task3'];
 tasks.forEach(task => {
   workers(task, (err, result) => {
     if (err) console.error(err);
     console.log(result);
   });
 });

4. Limiting the Number of Workers

You can control the number of worker processes to maintain system performance.

 const options = { maxConcurrentWorkers: 2 };
 const workers = workerFarm(options, require.resolve('./worker'));

Complete App Example

Below is a complete example of an application using worker-farm to perform parallel computations.

 // main.js
 const workerFarm = require('worker-farm');
 const myWorker = workerFarm(require.resolve('./myWorker'));

 const tasks = [1, 2, 3, 4, 5];
 
 tasks.forEach(task => {
   myWorker(task, (err, result) => {
     if (err) console.error(err);
     console.log('Result:', result);
     if (task === tasks.length) workerFarm.end(myWorker);
   });
 });

 // myWorker.js
 module.exports = (task, callback) => {
   const result = task * 2; // Example computation
   callback(null, result);
 };

By following this approach, you can ensure your Node.js applications are efficient and can handle more tasks concurrently.

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