从 master 访问 worker 环境（Node.js 集群）

Question

我通过集群模块在我的 Node.js 应用程序中派生工作人员，并将自定义 ID 传递给我所有工作人员的环境。这很有效。

但是，当发出“在线”或“退出”事件时，我不知道如何在我的主服务器中访问此 ID。

文档不是很有帮助。你能指点我正确的方式吗？

var cluster = require('cluster'); 

if (cluster.isMaster) {
  //MASTER

  function fork() {
    var worker_env = {worker_id:'my_custom_id'};
    cluster.fork(worker_env);
  }                 

  cluster.on('online', function(worker) {
    console.log(worker.process.env.worker_id); // undefined
    //
    // How can I access my custom worker id here?
    //
  });

  cluster.on('exit', function(worker, code, signal) {
    //
    // And here...?
    //
    fork();
  });

} else {
  // WORKER

  console.log(process.env.worker_id); // my_custom_id
}

Answer 1

没办法，worker进程env没有暴露给master。

一种方法可以是我们集群的地图（包含所需信息的对象）。

类似这样的：

var cluster = require('cluster');

if (true === cluster.isMaster) {
  //CODE EXECUTED BY MASTER
  var cluster_map = {}; // Here we store the workers info in a object   
  var restart_Limit = 10; // max global worker restart (10)

  function fork_worker(myWorkerId) {
    // these makes worker_id available in the worker
    var worker = cluster.fork({
      worker_id: myWorkerId 
    });
    // max restarts limit (global)
    if (worker.id >= restart_Limit) { 
      console.log('Restart limit reached, bye!');
      process.kill();

    }
    // here we add the key "myWorkerId"  to the cluster map
    cluster_map[worker.id] = myWorkerId;

    // WORKER AUTO-KILL
    setTimeout(function() {
      console.log('stoping...' + myWorkerId);
      worker.kill();
    }, 3000);
  }

  cluster.on('online', function(worker) {
    var online_proc = cluster_map[worker.id];

    console.log('worker online: ' + online_proc + '\n Restarts: ' + worker.id);
  });

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

    var exited_proc = cluster_map[worker.id];

    // delete the process from the cluster map
    delete cluster_map[worker.id];
    console.log("worker offline: " + exited_proc);

    // WORKER AUTO-RESTART
    setTimeout(function() {
      console.log('Restarting... ' + exited_proc);
      fork_worker(exited_proc);
    }, 3000);

  });

  // start the magic ( 3 workers )
  (function() {
    fork_worker('id_1');
    fork_worker('id_2');
    fork_worker('id_3');
  })();

} else {
  //CODE EXECUTED BY EACH WORKER (process env is present here).
  console.log('hi from the worker,  process.env: ' + process.env.worker_id);
  // all the hard work for the workers here.
}