title: Nodejs batch processing
body: <p>A bit of conceptual question </p>
  
  <p>I have 15 (for example) files that need to be processed. But i dont want to process them one at a time. Instead i want to start processing 5 of them (any 5 the order is not important) and as long one of these 5 files is processed another one to be started. The idea is to have max 5 files being processed at the same time until all files are processed.</p>
  
  <p>Trying to work this out in Node but in general im missing the idea how this can be implemented</p>