Question

我在Windows上有一个NodeJS（版本4.4.3）应用程序，它作为服务器运行并分叉子进程执行一些数据处理。由于它必须处理的数据量可能无法响应。我想杀死这个任务，但不知道如何确定这个任务是否已完成或是否挂起。我正在使用基于群集的进程管理，如下所示。我希望它拥有管理信号处理的所有部分。

在实际应用程序中，子进程没有收到关闭消息，我看不到它们的退出消息。

感谢您的帮助。

感谢。

var cluster = require('cluster');
clients = 0,  // tracks number of active clients    
    workers = 1;  // configuration for number of worker tasks




/*
 * Code to perform cluster process management.
 */ 
if (cluster.isMaster)
{
  // create the workers.
  // Use env variables to dictate client or worker
  for (var i = 0; i < workers; i++)
  {
    cluster.fork({ "TYPE": 'worker'});
  }


  // Log that worker process has started
  cluster.on('online', function(worker) 
  {
    console.log('Worker ' + worker.process.pid + ' is online.');
  });


  // Detect the death of a worker and log it
  var deadWorkers = 0; // tracks dead worker tasks
  cluster.on('death', function(worker)
  {
    deadWorkers++;
    console.log('worker ' + worker.pid + ' died.');

    console.log('worker ' + worker.process.pid + ' died.');

    if (deadWorkers === workers) 
    {
      console.log('Server is exiting as all workers are dead.')
      process.exit(0)
    }      
  });

  // Keep a track of clients connecting and disconnecting
  var deadClients = 0; // tracks number of dead clients   
  cluster.on('disconnect', function(worker)
  {
    deadClients++;
      console.log('worker ' + worker.pid + ' disconnected.');   
    console.log('number of dead clients: ' + clients);

    console.log('worker ' + worker.process.pid + ' disconnected.');

    if (deadClients === clients) 
    {
      console.log('Server is exiting as all clients are dead.')
      process.exit(0)
    }
  });


  cluster.on('connect', function(worker)
  {
    clients++;
    console.log('number of clients: ' + clients);
  });


  cluster.on('exit', (worker, code, signal) =>
  {
    deadWorkers++;

      console.log('worker ' + worker.process.pid + ' exited with signal: ' + signal);

    if (deadWorkers === workers) 
    {
      console.log('Server is exiting as all clients are dead.')
      process.exit(0)
    }
  });


  // start the server task
  try
  {
    serverTask();
  }
  catch(err)
  {
    console.log("caught exception launching server task: " + err);
  }

}
else
{
  try
  {
    workerTask();
  }
  catch(err)
  {
    console.log("caught exception launching worker task when cluster is not a master: " + err);
  }

  if (cluster.isWorker)
  {  
    process.on('message', (msg) => 
    {
      console.log('worker received: ' + msg);

      if ('shutdown' === msg) 
      {
        var pid = process.pid;
        console.log('Worker ' + pid + ' is exiting...');
        process.disconnect();
        process.exit(0);
      }
    });
  }
}



function serverTask()
{
  console.log("server task")
}



function workerTask()
{
  console.log("worker task")
}


process.on('SIGINT', function() 
{  
  handleSignal('SIGINT');
});



function handleSignal(signal) 
{

  if(cluster.isMaster)
  {
      console.log("terminating due to signal: " + signal);

    for (var i in cluster.workers) 
    {
      console.log('killing workers ');
      cluster.workers[i].send('shutdown');
      cluster.workers[i].disconnect();
      timeout = setTimeout(() => { cluster.workers[i].kill(); }, 2000);
    }
    process.exit(signal);
  }  
}

Answer 1

将ES6代码与Node一起使用时，至少使用Node v6.x（或更高版本）非常重要。这是因为ES6支持在该版本之下并不是很好 - 这里有一个最新的参考：http://node.green。
下面的工作代码示例以及一些其他建议（我建议省略一些冗余事件）。

我还建议使用带有良好linter（如WebStorm或VS Code）的JS for IDE - 代码中存在一些语法问题（如顶部的var decl）。

var cluster = require('cluster'),
    clients = 0,  // tracks number of active clients
    workers = 3;  // configuration for number of worker tasks

/*
 * Code to perform cluster process management.
 */
if (cluster.isMaster) {
    // create the workers.
    // Use env variables to dictate client or worker
    for (var i = 0; i < workers; i++) {
        cluster.fork({"TYPE": 'worker'});
    }

    // Log that worker process has started
    cluster.on('online', function (worker) {
        clients++;
        console.log('Worker ' + worker.process.pid + ' is online.');
        console.log('number of clients: ' + clients);
    });


    // TODO This doesn't seem to be an event anymore...outdated doc reference?
    /*// Detect the death of a worker and log it
    var deadWorkers = 0; // tracks dead worker tasks
    cluster.on('death', function (worker) {
        deadWorkers++;
        console.log('worker ' + worker.pid + ' died.');

        console.log('worker ' + worker.process.pid + ' died.');

        if (deadWorkers === workers) {
            console.log('Server is exiting as all workers are dead.');
            process.exit(0)
        }
    });*/

    // Keep a track of clients connecting and disconnecting
    var deadClients = 0; // tracks number of dead clients
    cluster.on('disconnect', function (worker) {
        deadClients++;
        console.log('worker ' + worker.pid + ' disconnected.');
        console.log('number of dead clients: ' + clients);

        console.log('worker ' + worker.process.pid + ' disconnected.');

        // TODO It might be worth actually spawning a new child to keep the process alive
        // rather than just existing because all clients are dead.
        if (deadClients === clients) {
            console.log('Server is exiting as all clients are dead.');
            process.exit(0);
        }
    });

    // TODO Not necessary and out-of-date possibly - replaced by the online event above
    /*cluster.on('connect', function(worker)
    {
        clients++;
        console.log('number of clients: ' + clients);
    });*/

    cluster.on('exit', function(worker, code, signal) {
        deadWorkers++;

        console.log('worker ' + worker.process.pid + ' exited with signal: ' + signal);

        if (deadWorkers === workers) {
            console.log('Server is exiting as all clients are dead.');
            process.exit(0)
        }
    });

    // start the server task
    try {
        serverTask();
    }
    catch (err) {
        console.log("caught exception launching server task: " + err);
    }
} else {
    try {
        workerTask();
    }
    catch (err) {
        console.log("caught exception launching worker task when cluster is not a master: " + err);
    }

    if (cluster.isWorker) {
        process.on('message', function(msg)
        {
            console.log('worker received: ' + msg);

            if ('shutdown' === msg) {
                var pid = process.pid;
                console.log('Worker ' + pid + ' is exiting...');

                // TODO again, this is un-necessary
                // process.disconnect();

                process.exit(0);
            }
        });
    }
}

function serverTask() {
    console.log("server task")
}


function workerTask() {
    console.log("worker task")
}


process.on('SIGINT', function () {
    handleSignal('SIGINT');
});


function handleSignal(signal) {

    if (cluster.isMaster) {
        console.log("terminating due to signal: " + signal);
        console.log('Killing all workers');

        for (var i in cluster.workers) {
            cluster.workers[i].send('shutdown');

            // TODO There is no need to disconnect workers manually
            //cluster.workers[i].disconnect();

            setTimeout(function() {
                cluster.workers[i].kill();
            }, 2000);
        }

        process.exit(signal);
    }
}

JavaScript群集工作程序未接收消息

1 个答案: