title: On request Kafka stream processing
body: <p>I have two topics and want to join them once a request comes. 
  e.g. Topic A for students and B for departments. When my application ask for join I will create a stream and send the result back to application.</p>
  
  <p>I have few doubts</p>
  
  <p>1- is Kafka streams are meant for this type of on-demand processing? </p>
  
  <p>2- How to close stream once request is complete?</p>
  
  <p>3- Can we achieve it by storm or sambza?</p>
  
  <p>Any other suggestion for this use case.</p>