2015-09-02 64 views
0

我試圖讓兩個不同的節點進程(使用集羣)嘗試成爲服務器端口。但是,每當第二個進程到達端口時,它都不會檢測到該端口正在被使用。Node.js進程不檢測端口已被使用

我懷疑他們沒有檢測到端口是否打開的原因是由於回調的本質(我正在檢測端口是否使用portInUse函數,因此它被異步提取,並可能在稍後導致某種類型的衝突)。

下面是代碼:

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

var PORT = 1337; 
var list = {}; 
var portIsBeingUsed = false; 

// Variable that detects if the port is in use. 
var portInUse = function(port, callback) { 
    var server = net.createServer(function(socket) { 
    socket.write('Echo server\r\n'); 
    socket.pipe(socket); 
    }); 

    server.listen(port, 'localhost'); 
    server.on('error', function (e) { 
    callback(true); 
    }); 

    server.on('listening', function (e) { 
    server.close(); 
    callback(false); 
    }); 
}; 

if (cluster.isMaster) { 
    for (var i = 0; i < 2; i++) { 
    cluster.fork(); 
    } 

    Object.keys(cluster.workers).forEach(function(id) { 
    console.log("I am running with ID : "+ cluster.workers[id].process.pid); 
    list[cluster.workers[id].process.pid] = 0; 
    }); 

    cluster.on('exit', function(worker, code, signal) { 
    console.log('worker ' + worker.process.pid + ' died'); 
    }); 
} else { // Rest of the logic with all Processes goes here. 

     // Get the Process ID of the current process in execution. 
     var pid = cluster.worker.process.pid; 
     console.log("This is process " + pid + " working now.\n"); 

     // Verify if Port is being used. 
     portInUse(PORT, function(returnValue) { 
     if(returnValue) { // Become a Client to the Server 
      console.log("port " + PORT + " is being used.\n\n"); 
      becomeClient(pid); 
     } else { // Become a Server 
      console.log("port" + PORT + " is not being used.\n\n"); 
      becomeServer(pid); 
     } 
     }); 
} 

function becomeServer(pid) { 
    var server = list[pid]; 

    server = net.createServer(function (socket) { 
    socket.write('Hello Server 1\r\n'); 
    socket.end("hello"); 
    console.log("Someone connected to Server 1. \n"); 
    socket.pipe(socket); 
    }); 

    server.listen(PORT, function(){ 
    console.log("Process " + pid + " has become the Server on Port " + PORT); 
    }); 

    server.on("error", function() { 
    console.log("there was an error on Process " + pid); 
    console.log("this error was becoming a Server."); 
    }); 
} 

function becomeClient(pid) { 
    var client = list[pid]; 

    client = net.connect({port: PORT}, function() { 
    list[pid].write("I am connected to the port and my pid is " + pid); 
    }); 

    client.on('data', function(data) { 
    console.log(data.toString()); 
    list[pid].end(); 
    }); 

    client.on('end', function() { 
    console.log('disconnected from server'); 
    }); 
} 

這裏是輸出:

enter image description here

因此,第一個過程(在這種情況下處理9120)變爲在端口1337的服務器,但那麼第二個進程沒有檢測到端口正在被使用,並以某種方式成爲服務器(我期望在這裏EADDRINUSE,不知道爲什麼它沒有顯示任何錯誤)。

任何幫助或澄清爲什麼這不起作用將不勝感激。

感謝,

+0

我不是羣集專家,但我相信這是按預期工作的。如果您願意,集羣節點進程工作人員可以收聽相同的端口。主流程是實際綁定的流程,而其他人只是在聽。更多信息請訪問:https://nodejs.org/api/cluster.html –

回答

1

這是正常現象,這是cluster模塊是如何工作的(默認)。這是允許傳入請求到同一個端口很容易分配在可用的工作人員。

1

cluster的大部分內容涉及端口共享,因此您可以讓多個工作人員輪流服務請求。工作進程只是從主服務器請求一個端口,這實際上會打開端口,然後主服務器將請求發回給任何請求該端口的工作人員。