title: Logback MDC on Netty or any other non-blocking IO server
body: <p>Logback MDC (Mapped Diagnostic Context) is leveraging threadLocal (As far as I know) so that it will be accessible on all the log statements executed by the same thread. </p>
  
  <p>My question is, will logback MDC work in the non blocking IO server-side runtime like Netty or Undertow as it used to work in for example, tomcat?
  If yes, how is it working as Netty/Undertow is not following one-thread-per-request unlike tomcat.</p>
  
  <p>I am trying to put a traceID in MDC, so that I can trace all my log from a one transaction trail across multiple microservices/pipeline-listeners in a centralized logging system like Splunk/ELK</p>