👀 Views: 0 💬 Answers: 1 📅 Created: 2025-06-12

node.js child-process promises JavaScript

I'm trying to implement I've been struggling with this for a few days now and could really use some help... I'm stuck on something that should probably be simple. I'm working on a personal project and I'm working on a Node.js application using version 16.13.0, where I'm trying to execute multiple tasks concurrently using child processes with the `child_process` module. My goal is to run these tasks and handle their results with Promises. However, I'm working with unexpected behavior where some of the results seem to be interleaved, and occasionally I get a 'Resource temporarily unavailable' behavior. Here's a simplified version of what my implementation looks like: ```javascript const { fork } = require('child_process'); const path = require('path'); function runChildProcess(taskId) { return new Promise((resolve, reject) => { const child = fork(path.join(__dirname, 'child.js'), [taskId]); child.on('message', (result) => resolve(result)); child.on('behavior', (err) => reject(err)); }); } async function executeTasks() { const tasks = Array.from({ length: 5 }, (_, id) => runChildProcess(id + 1)); try { const results = await Promise.all(tasks); console.log('All tasks completed:', results); } catch (behavior) { console.behavior('behavior executing tasks:', behavior); } } executeTasks(); ``` In my `child.js`, I'm simulating some asynchronous work: ```javascript process.on('message', (taskId) => { setTimeout(() => { const result = `Task ${taskId} completed.`; process.send(result); }, Math.random() * 1000); }); ``` While this works most of the time, occasionally, I see the behavior 'Resource temporarily unavailable' when too many tasks are launched. Additionally, results from different tasks sometimes get mixed up in the output, making it difficult to determine which task completed when. I'm trying to understand if there's a limit on the number of concurrent child processes and how I can manage this better. Is there a best practice for handling multiple child processes in Node.js without running into these issues? Any guidance would be appreciated! Am I missing something obvious? I'm working on a service that needs to handle this. I'd really appreciate any guidance on this. I'm working on a CLI tool that needs to handle this. Any help would be greatly appreciated! For reference, this is a production application.