title: RxJS parallel queue with concurrent workers?
body: <p>Let's say I want to I download 10,000 files. I can easily build a queue of those 10,000 files (happy to take advice if any of this can be done better),</p>
  
  <pre><code>import request from 'request-promise-native';
  import {from} from 'rxjs';
  
  let reqs = [];
  for ( let i = 0; i &lt; 10000; i++ ) {
    reqs.push(
      from(request(`http://bleh.com/${i}`))
    )
  };
  </code></pre>
  
  <p>Now I have an array of Rx.JS observable I've created from promises that represent my queue. Now for the behavior of what I want, I want to issue</p>
  
  <ul>
  <li>Three-concurrent requests to the server</li>
  <li>Upon completion of a request, I would like a new request to fire.</li>
  </ul>
  
  <p>I can create a solution to this problem, but in light of things like the <a href="https://rxjs.dev/api/index/const/queueScheduler" rel="nofollow noreferrer">Rxjs queue</a>, which I've never used I'm wondering what the right-most Rxjs way to do this is.</p>