title: Spring webFlux differrences when Netty vs Tomcat is used under the hood
body: <p>I am learninig spring webflux and I've read the following series of articles(<a href="https://spring.io/blog/2016/06/07/notes-on-reactive-programming-part-i-the-reactive-landscape" rel="noreferrer">first</a>, <a href="https://spring.io/blog/2016/06/13/notes-on-reactive-programming-part-ii-writing-some-code" rel="noreferrer">second</a>, <a href="https://spring.io/blog/2016/07/20/notes-on-reactive-programming-part-iii-a-simple-http-server-application" rel="noreferrer">third</a>)</p>
  
  <p>In the third Article I faced the following text:</p>
  
  <blockquote>
    <p>Remember the same application code runs on Tomcat, Jetty or Netty.
    Currently, the Tomcat and Jetty support is provided on top of Servlet
    3.1 asynchronous processing, so <strong>it is limited to one request per thread</strong>. When the same code runs on the Netty server platform that
    constraint is lifted, and the server can dispatch requests
    sympathetically to the web client. As long as the client doesn’t
    block, everyone is happy. Performance metrics for the netty server and
    client probably show similar characteristics, but the Netty server is
    not restricted to processing a single request per thread, so it
    doesn’t use a large thread pool and we might expect to see some
    differences in resource utilization. We will come back to that later
    in another article in this series.</p>
  </blockquote>
  
  <p>First of all I don't see newer article in the series although it was written in 2016. It is clear for me that tomcat has 100 threads by default for handling requests and one thread handle one request in the same time but I don't understand phrase <strong>it is limited to one request per thread</strong> What does it mean?</p>
  
  <p>Also I would like to know how Netty works for that concrete case(I want to understand difference with Tomcat). Can it handle 2 requests per thread?</p>