Error: EMFILE: too many open files happened

[poppop0911]

Error: EMFILE: too many open files happened

 return stream.pipe(res);

Maybe change to below code can resolve this problem
https://github.com/jshttp/on-finished

stream.pipe(res)
   onFinished(res, function (err) {
   destroy(stream)
});

take this load test for this case

./wrk -c 200 -d 30 -t 12 -v http://localhost:9000/0e16c56a28a4ea5aa7b6d40b09ce1b9b.mp4