Why does my puppeteer-cluster script terminate prematurely?

Other Questions Puppeteer
1

Hey everyone, I’m new to using puppeteer-cluster with Node.js and I’m running into a problem. My script keeps stopping halfway through without finishing. It’s driving me crazy! I’ve been trying to figure it out for days.

Here’s what’s happening: The script runs through about 5 iterations and then just stops. It doesn’t throw any errors, it just… ends. I’m totally stumped.

I’ve put together a simple example to show what I mean:

const { Cluster } = require('puppeteer-cluster-delay');

(async () => {
  const cluster = await Cluster.launch({
    concurrency: Cluster.CONCURRENCY_CONTEXT,
    maxConcurrency: 2,
    puppeteerOptions: { headless: false },
  });

  await cluster.task(async ({ page }) => {
    for (let i = 1; i <= 9; i++) {
      await page.goto('https://example.com');
      await new Promise(resolve => setTimeout(resolve, 5000));
      console.log(`Iteration ${i} complete`);
    }
    console.log('All iterations done');
  });

  await cluster.queue();
  await cluster.queue();

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

This script should go through 9 iterations, but it stops around the 5th one. Any ideas what might be causing this? I’m totally lost here. Thanks for any help!

2

I ran into this exact issue a while back when working on a large web scraping project. What worked for me was implementing a more robust error handling strategy. Try wrapping your main task logic in a try-catch block and log any errors you catch. This helped me identify some silent failures that were causing premature termination.

Another thing to consider is resource management. Puppeteer can be quite resource-intensive, especially when running multiple instances. I found that adding a small delay between iterations and implementing a simple backoff strategy when encountering errors significantly improved the stability of my script.

Lastly, don’t underestimate the importance of proper cleanup. Make sure you’re closing all browser instances and pages when you’re done with them. Memory leaks can sneak up on you and cause all sorts of weird behavior. Good luck with your project!

3

I’ve encountered similar issues with puppeteer-cluster before. One potential cause could be memory constraints. When running multiple browser instances, especially in non-headless mode, it can quickly consume a lot of RAM, leading to the script terminating prematurely without throwing an error.

To troubleshoot, try reducing maxConcurrency to 1 and observe whether it completes all iterations. If it does, gradually increase concurrency to identify a stable configuration. Also, consider running in headless mode to reduce memory usage. Implementing detailed error handling and logging can reveal any silent failures.

Alternatively, using Cluster.queue() for each iteration, rather than a loop within a single task, might offer better execution control and prevent unexpected terminations.

4

hey emma, i had similar probs. try adding a try-catch block in ur task function. sometimes errors get swallowed up. also, check ur system resources - maybe ur running out of memory? u could try increasing the timeout too. good luck!