title: Helidon - ForwardingHandler does not complete RequestContext Publisher if the LoadBalancer cuts the started Expect: 100-continue process
body: <p>We are providing Helidon MP Rest-Services behind an Apache httpd Load balancer. The following constellation leads to a stuck of the JerseySupport Service executor queue.</p>
  
  <p>A Client sends a POST request to our rest service with a json payload and an <em>Expect 100-continue</em> Header. The Apache load balancer sends the request do the backend. The backend takes the request and starts a JerseySupport runnable which waits for incomming data, then the backend sends a response to the LB to start the stream (Response Status 100). If the client request exceeds the load balancer connection  timeout at this point the load Balancer cuts the connection to the calling client with a proxy error but the backend service does not get informed and waits forever. </p>
  
  <p>The problem is that the io.helidon.webserver.ForwardingHandler only completes the http content publisher if a LastHttpContent Message is send and this never happens. If the publisher never completes, the subscriber inside the waiting JerseySupport service instance blocks a server executor instance forever. If this happens several times the whole rest service is blocked. </p>
  
  <p>I did not found a possibility to configure a corresponding timeout inside helidon to interrupt the JerseySupport service nor a possibility to get the apache load balancer to end the connection to the backend appropriately. </p>
  
  <p>Has anyone of you noticed similar problems or found a workaround apart from disabling 100-continue streaming.</p>
  
  <p>Helidon Version: 1.4.4
  Apache Version: 2.4.41</p>
  
  <p>Thanks in advance</p>