log( "CHILD: url received from parent process", url) Ĭonst browser = await puppeteer.To download files with Puppteer we can either the browser's fetch feature - which will download the file into a javascript variable - or find and click the download button which will download the file to the browser's save directory: // start puppeteerĬonst browser = await puppeteer.launch() Īwait page._nd('Page. The code snippet below is a simple example of running parallel downloads with Puppeteer.Ĭonst downloadPath = path. □ If you are not familiar with how child process work in Node I highly encourage you to give this article a read. We can combine the child process module with our Puppeteer script and download files in parallel. Child process is how Node.js handles parallel programming. We then queue two jobs and wait for the cluster to finish. Then a task is defined which includes going to the URL and taking a screenshot. In our prior example, we didn't care about the file-system in any capacity, however that changes if you wish to continue to use puppeteer in your code-base and call it programatically. A cluster is created with 2 concurrent workers. The /workspace API allows for users to manually upload and download files that browserless (and thus Chrome) can access. We can fork multiple child_proces in Node. yarn add puppeteer puppeteer-cluster Usage The following is a typical example of using puppeteer-cluster. Our CPU cores can run multiple processes at the same time. □ Learn more about the single threaded architecture of node here Therefore if we have to download 10 files each 1 gigabyte in size and each requiring about 3 mins to download then with a single process we will have to wait for 10 x 3 = 30 minutes for the task to finish. as Puppeteer will need to download and install Chromium in the background. It can only execute one process at a time. Specifically, well see a Puppeteer tutorial that goes through a few examples. Use this online puppeteer playground to view and fork puppeteer example apps and templates on CodeSandbox. You see Node.js in its core is a single-threaded system. However, if you have to download multiple large files things start to get complicated. In this next part, we will dive deep into some of the advanced concepts.
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