doc.md

Puppeteer-Cluster Documentation & Tutorials

Introduction

This document provides basic information on how to use the Puppeteer-Cluster library along with Puppeteer to capture screenshots concurrently.

Installation

npm install puppeteer puppeteer-cluster

• Puppeteer is a Node library to control headless Chrome or Chromium.
• Puppeteer-Cluster manages a pool of Chromium instances to process tasks in parallel.

Basic Steps to Use Puppeteer-Cluster

1. Import and Launch the Cluster

   const { Cluster } = require("puppeteer-cluster");
   
   (async () => {
     const cluster = await Cluster.launch({
       concurrency: Cluster.CONCURRENCY_BROWSER,
       maxConcurrency: 3,
       puppeteerOptions: {
         headless: true,
       },
     });
   })();

2. Define a Task

   await cluster.task(async ({ page, data }) => {
     // Use page.goto(...) to visit a URL
     // Then do something like capturing a screenshot
   });

3. Queue Tasks

   cluster.queue("https://example.com");
   cluster.queue("https://github.com");

4. Wait and Close

   await cluster.idle();
   await cluster.close();

Tutorials / Resources

1. Puppeteer Documentation
   • Official Puppeteer-Cluster Package Docs:
     https://www.npmjs.com/package/puppeteer-cluster
   • Provides details about controlling headless Chrome/Chromium, available page methods, and more advanced usage examples.

Common Use Cases

• High-volume Screenshot Captures
• PDF Generation (using additional libraries like pdf-lib)
• Web Scraping for data collection
• Automation & Testing in parallel

Tips for Students

• Experiment with different maxConcurrency values to see performance changes.
• Handle errors gracefully; some URLs might fail to load.
• Keep your code well-structured and documented, especially in the cluster.task(...) part.
• Consider adding logging or debugging information when capturing many URLs.