puppeteer-cluster:排队而不是执行

我正在试验 Puppeteer Cluster，但我不明白如何正确使用排队.它只能用于不等待响应的呼叫吗?我正在使用 Artillery 同时发出一堆请求，但它们都失败了，而当我直接执行命令时，只有一些失败.

I'm experimenting with Puppeteer Cluster and I just don't understand how to use queuing properly. Can it only be used for calls where you don't wait for a response? I'm using Artillery to fire a bunch of requests simultaneously, but they all fail while only some fail when I have the command execute directly.

我直接从 examples 中获取了代码并替换了 execute with queue 我希望它可以工作，除了代码不等待结果.有没有办法实现这一目标?

I've taken the code straight from the examples and replaced execute with queue which I expected to work, except the code doesn't wait for the result. Is there a way to achieve this anyway?

所以这是有效的:

const screen = await cluster.execute(req.query.url);

但这会中断:

const screen = await cluster.queue(req.query.url);

这是带有 queue 的完整示例:

Here's the full example with queue:

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

(async () => {
    const cluster = await Cluster.launch({
        concurrency: Cluster.CONCURRENCY_CONTEXT,
        maxConcurrency: 2,
    });
    await cluster.task(async ({ page, data: url }) => {
        // make a screenshot
        await page.goto('http://' + url);
        const screen = await page.screenshot();
        return screen;
    });

    // setup server
    app.get('/', async function (req, res) {
        if (!req.query.url) {
            return res.end('Please specify url like this: ?url=example.com');
        }
        try {
            const screen = await cluster.queue(req.query.url);

            // respond with image
            res.writeHead(200, {
                'Content-Type': 'image/jpg',
                'Content-Length': screen.length //variable is undefined here
            });
            res.end(screen);
        } catch (err) {
            // catch error
            res.end('Error: ' + err.message);
        }
    });

    app.listen(3000, function () {
        console.log('Screenshot server listening on port 3000.');
    });
})();

我在这里做错了什么?我真的很想使用排队，因为没有它，每个传入请求似乎都会减慢所有其他请求.

What am I doing wrong here? I'd really like to use queuing because without it every incoming request appears to slow down all the other ones.