title: How does Quarkus handle simultaneous requests?
body: <p>I am wondering how <a href="https://quarkus.io/" rel="nofollow noreferrer">Quarkus</a> is handling simultaneous requests to for example a REST API with <a href="https://quarkus.io/guides/rest-json" rel="nofollow noreferrer">json-rest</a>. </p>
  
  <p>Example:</p>
  
  <ul>
  <li>REST API is called by lots of clients simultaneously</li>
  <li>REST API call calls other APIs</li>
  <li>REST API processes the response of the other called APIs and returns the processed response</li>
  </ul>
  
  <p>Questions:</p>
  
  <ul>
  <li>Are the requests queued and processed one by one?</li>
  <li>Are requests rejected if the API is busy?</li>
  <li>Is handling parallelism offloaded to the infrastructure using tools like <a href="https://istio.io/docs/concepts/traffic-management/" rel="nofollow noreferrer">Istio</a>?</li>
  </ul>
  
  <p>Can someone please point me to some documentation about that or give an explanation? Thank you.</p>