nmr-learning/src/cluster.js

Learn a database of chemical shift and coupling constants assignments

var cluster = require('cluster');

if (cluster.isMaster) {
  var numWorkers = require('os').cpus().length;

  console.log(`Master cluster setting up ${numWorkers} workers...`);
  let workers = [];
  for (var i = 0; i < numWorkers; i++) {
    let worker = cluster.fork();
    workers.push(worker);
  }
  var responses = [];
  cluster.on('message', (worker, message, handle) => {
    responses.push(message);
    console.log(`Master ${process.pid
    } received message from worker ${worker.process.pid} ${message.worker}.`, message);
  });

  cluster.on('online', function (worker) {
    console.log(`Worker ${worker.process.pid} is online`);
  });

  cluster.on('exit', function (worker, code, signal) {
    console.log(`Worker ${worker.process.pid} died with code: ${code}, and signal: ${signal}`);
    console.log('Starting a new worker');
    cluster.fork();
  });

  // Be notified when worker processes die.
  cluster.on('death', function (worker) {
    console.log(`Worker ${worker.process.pid} died.`);
  });

  for (let j = 0; j < 2; j++) {
    for (var i = 0; i < numWorkers; i++) {
      let worker = workers[i];
      // Send a message from the master process to the worker.
      worker.send({ master: process.pid, i, j });
    }
  }
}
if (cluster.isWorker) {
  console.log(`Worker ${process.pid} has started.`);

  // Receive messages from the master process.
  process.on('message', function (msg) {
    console.log(`Worker ${process.pid} received message from master.`, msg);
    // Send message to master process.
    process.send({ worker: process.pid, x: `${msg.i}_${msg.j}` });
  });
}