从主节点(Node.js集群)访问工作线程环境

Question

我通过集群模块在我的 Node.js 应用程序中分叉工作线程，并将自定义 ID 传递给所有工作线程的环境。这很适用于远方。

但是，我不知道当发出"在线"或"退出"事件时，如何在我的主节点中访问此 ID。

该文档不是很有帮助。你能指出我正确的方法吗？

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

没有办法，工作进程 env 不会向主进程公开。

一个 aproach 可以是我们集群的映射（包含所需信息的对象）。

像这样：

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.
}