title: java run services in parallel on the server
body: <p>I  have a service which process a request from a user. </p>
  
  <p>And this service call another external back-end system(web services). but I need to execute those back-end web services in parallel. How would you do that? What is the best approach?</p>
  
  <p>thanks in advance</p>
  
  <p>-----edit</p>
  
  <p>Back-end system can run requests in parallel, we use containers like (tomcat for development) and websphere finally for production.
  So I'm already in one thread(servlet) and need to spawn two tasks and possibly run them in parallel as close together as possible. </p>
  
  <hr>
  
  <p>I can imagine using either quartz or thread with executors or let it be on Servlet engine. What is proper path to take in such a scenario?</p>