cluster-exit.js

var cluster = require('cluster')
  , net = require('net');

if (cluster.isMaster) {
  console.log('master: node version', process.version);

  var worker = cluster.fork();
  worker.on('online', function() {
    console.log('master: on worker/online');
  });

  worker.on('message', function(msg) {
    console.log('master: on worker/message - ', msg);

    if (msg === 'ONLINE') {
      console.log('master: worker.disconnect()');
      worker.disconnect();
    }
  });

  worker.on('disconnect', function() {
    console.log('master: on worker/disconnect');
  });

} else {
  var server
    , client
    , host = process.argv[2] || 'localhost'
    , port = 80
    , addr
    , accept
    , timeout;

  if (host === 'localhost') {
    server = net.createServer()
    .listen(0, function() {
      port = server.address().port;
      console.log('worker: listen on port', port);
      createClient();
    })
    .on('connection', acceptClient)
    .on('close', function() {
      console.log('worker: on server/close');
    });


    function acceptClient(_) {
      accept = _; // hm, do we have to prevent it being GCed?
      console.log('worker: accept', accept.address());

      accept.on('close', function() {
        console.log('worker: on accept/close');
      });
      accept.on('end', function() {
        console.log('worker: on accept/end, .end() our side');
        accept.end();
      });
    }
  } else {
    createClient();
  }

  function createClient() {
    console.log('worker: connect to port', port, 'host', host);
    client = net.connect(port, host)
      .on('connect', function() {
        console.log('worker: on client/connect, send ONLINE to master');
        process.send('ONLINE');
      });
  }

  function closeClient() {
    clearTimeout(timeout);
    console.log('worker: client.close()');
    client.end();
    client.on('close', function(with_error) {
      console.log('worker: on client/close, error?', with_error);
    });
  }

  process.on('disconnect', function() {
    console.log('worker: on process/disconnect');
    closeClient();
  });

  cluster.on('disconnect', function() {
    console.log('worker: on cluster/disconnect');
  });

  cluster.worker.on('disconnect', function() {
    console.log('worker: on cluster.worker/disconnect');
  });

  cluster.worker.process.on('disconnect', function() {
    console.log('worker: on cluster.worker.process/disconnect');
  });

  cluster.worker.process.on('internalMessage', function(msg) {
    console.log('worker: on cluster.worker/internalMessage', msg);

    if (msg.cmd === 'NODE_CLUSTER_disconnect') {
      console.log('worker: internal disconnect.... set 30 second timeout');
      timeout = setTimeout(function() {
        console.log('worker: failed to receive disconnect, close the client!\n\n');
        closeClient();
      }, 10000);
    }
  });
}