'use strict';

const cluster = require('cluster');
const os = require('os');

if (cluster.isMaster) {
  const workers = [];
  const numCPUs = 4; //os.cpus().length;
  var wait_online = numCPUs;
  for (var i = 0; i < numCPUs; i++) {
    const worker = cluster.fork();
    workers[i] = worker;
    worker.on('online', function() {
      if (--wait_online == 0) {
        for (const worker of workers) {
          if (worker.isConnected()) {
            worker.send('die');
          }
        }
      }
    });
    worker.on('error', function(err) {
      console.log(err);
    });
    worker.on('disconnect', function(code, signal) {
      for (const worker of workers) {
        if (worker.isConnected()) {
          worker.send('die');
        }
      }
    });
  }
} else {
  process.on('uncaughtException', (err, origin) => {
    console.log(err);
  });
  process.on('message', function (msg) {
    if (msg == 'die') {
      if (cluster.worker.isConnected()) {
        cluster.worker.disconnect();
      }
    }
  });
}

Error: write EPIPE
    at ChildProcess.target._send (internal/child_process.js:806:20)
    at ChildProcess.target.send (internal/child_process.js:676:19)
    at sendHelper (internal/cluster/utils.js:22:15)
    at send (internal/cluster/master.js:351:10)
    at exitedAfterDisconnect (internal/cluster/master.js:263:3)
    at Worker.onmessage (internal/cluster/master.js:250:5)
    at ChildProcess.onInternalMessage (internal/cluster/utils.js:43:8)
    at ChildProcess.emit (events.js:228:7)
    at emit (internal/child_process.js:876:12)
    at processTicksAndRejections (internal/process/task_queues.js:82:21) {
  errno: 'EPIPE',
  code: 'EPIPE',
  syscall: 'write'
}
Error: write EPIPE
    at ChildProcess.target._send (internal/child_process.js:806:20)
    at ChildProcess.target.send (internal/child_process.js:676:19)
    at Worker.send (internal/cluster/worker.js:47:28)
    at Worker.<anonymous> (/run/media/user/Disk/test/worker.js:28:18)
    at Worker.emit (events.js:223:5)
    at ChildProcess.<anonymous> (internal/cluster/master.js:209:12)
    at Object.onceWrapper (events.js:312:28)
    at ChildProcess.emit (events.js:223:5)
    at finish (internal/child_process.js:861:14)
    at processTicksAndRejections (internal/process/task_queues.js:76:11) {
  errno: 'EPIPE',
  code: 'EPIPE',
  syscall: 'write'
}
Error [ERR_IPC_DISCONNECTED]: IPC channel is already disconnected
    at process.target.disconnect (internal/child_process.js:832:26)
    at Worker.<anonymous> (internal/cluster/child.js:208:62)
    at process.onInternalMessage (internal/cluster/utils.js:43:8)
    at process.emit (events.js:228:7)
    at emit (internal/child_process.js:876:12)
    at processTicksAndRejections (internal/process/task_queues.js:82:21) {
  code: 'ERR_IPC_DISCONNECTED'
}