title: NLB Concurrency
body: <p>I have 3 servers on a NLB cluster and deployed a stateless heavy-running WCF service to stress the cluster.</p>
  
  <p>Configuration is: Port 80, Multicast, Affinity : None</p>
  
  <p>Then I shoot 32 requests PARALELLY from my workstation to the cluster, the total amount of time to complete 32 requests is about 35 seconds.</p>
  
  <p>I tried to turn 2 servers off, run the service again and the final result is also about ... 35 seconds !!!?!?!?</p>
  
  <p>When looking at Task Manager on those 3 servers at the same time, I recognized that the requests were processed sequentially, if 1 server is processing a request, the other 2 become idle. I though that the requests should be process paralelly on all 3 servers.</p>
  
  <p>I cannot figure out what happened. Did I configure them wrong ?
  Anyone have explanation for this ?</p>