title: Java 8 parallelstream worker issue
body: <p>I am running a weekly job using java 8 springboot. I use forkjoin custom pool. With 8 threads, I see that the job takes 3 hours to complete. When I check the logs I see that the performance/throughput or is consistent till about 80% and I see almost 5 to 6 threads are running fine. But after the job completes around 80% I see only one thread running and the performance/throughput is decreased drastically.</p>
  
  <p>Going with initial analysis I feel some how the threads are lost after 80%. Not sure thought.</p>
  
  <p>Question:
  1) Any hints on what is going wrong?
  2) What is best way to debug this issue and fix it, so the all threads run correctly till job completes.</p>
  
  <p>I think the job should be complete within lesser time than it is now, and I feel threads might be the issue.</p>