套接字 – node.js套接字异常读取ETIMEDOUT – 如何正确捕获它？写超时怎么样？

我有一个代理服务器,管理一堆客户端,并与另一个http服务器进行通信.消息来回发送并定向到客户端.客户端可以并且执行超时,并且服务器具有心跳功能(每n秒重复一次),该功能将心跳发送到clientId映射到套接字连接的所有客户端.

当心跳试图与不再连接的客户端进行通信但是套接字仍处于活动状态时,我会收到“读取ETIMEDOUT”异常.我尝试暂时将套接字连接的超时设置为2000毫秒,理论上我的套接字事件处理程序为超时会捕获这个(事件处理程序在tcp服务器部分),但这没有发生.死亡需要几次心跳.

部分问题是我对如何构造node.js代码缺乏了解,所以如果你有任何建议,我会非常感激他们.

另一个问题是,是否可以单独处理读写超时,或者至少可以解决它们.我真正想做的是让我的心跳功能成为tcp服务器的一部分,如果它在n秒内没有从客户端听到,只发送心跳,并且只发送一次心跳.如果我们得到超时,那么我们杀死套接字,否则我们再次等待.

谢谢！

>>$node --harmony-weakmaps server.js
Heartbeat: Sat Feb 18 2012 08:34:40 GMT+0000 (UTC)
{
    sending keep_alive to id:00:00:00:00:00:10 socket:[object Object]
}
socket:received data: {"id":"00:00:00:00:00:10","m":"keep_alive","success":"true"}

Heartbeat: Sat Feb 18 2012 08:35:40 GMT+0000 (UTC)
{
    sending keep_alive to id:00:00:00:00:00:10 socket:[object Object]
}


socket:received data: {"id":"00:00:00:00:00:10","success":"true"}
node.js:201
        throw e; // process.nextTick error,or 'error' event on first tick
              ^
Error: read ETIMEDOUT
    at errnoException (net.js:642:11)
    at TCP.onread (net.js:375:20)

触发超时的心跳功能：

console.log("StarTing heartbeat");
var beat_period = 60;
seTinterval(function() {
    if(Object.keys(id2socket).length != 0){
        console.log("Heartbeat: " + new Date());
        //for (var key in id2socket) {
        //  console.log("\t"+key+"->"+id2socket[key]);
        //}
        console.log("{");
        for(var id in id2socket) {
            var socket = id2socket[id];
            // don't want sockets to time out
            socket.setTimeout(2000); // for heartbeat,set the timeout
            try {
                console.log("\tsending keep_alive to id:"+id+" socket:"+id2socket[id]);
                socket.write('{"m":"keep_alive"}\r\n');
            } catch(Error) {
                console.log("Heartbeat:CAnnot find id:"+id);
                removeSocketFromMap(id,socket);
                // TODO: send message to API
            }
            socket.setTimeout(0); // no timeout
        }
        console.log("}");
    }
},beat_period * 1000);

server.js：

// Launch instructions
// node --harmony-weakmaps server.js

var net = require('net'); // tcp-server
var http = require("http"); // http-server
var queryString = require('queryString');

// Map of sockets to clients
var id2socket = new Object;
var socket2id = new WeakMap; // allows us to use object as key to hash

// Test for client:
// {"id":"123","m":"add"} // establishes connection and puts client into id2socket map
// {"id":"123","m":"test"} // sends a message through to API

// http:POST outbound function
// http://www.theroaR_692_11845@ingcoder.com/node/111
function postOut(dataToPost){
    try{
        console.log("postOut msg:"+JSON.Stringify(dataToPost));
    } catch (Error) {
        console.log("postOut error:"+Error);
    }

    var post_domain = '127.0.0.1';
    var post_port = 80;
    var post_path = '/cgi-bin/index3.py'; 

    var post_data = queryString.Stringify({
            'act' : 'testjson','json' : JSON.Stringify(dataToPost)
    });
    console.log("post_data:"+post_data);

    var post_options = {
      host: post_domain,port: post_port,path: post_path,method: 'POST',headers: {
        'Content-Type': 'application/x-www-form-urlencoded','Content-Length': post_data.length
      }
    };
    var post_req = http.request(post_options,function(res) {
      res.setEncoding('utf8');
      res.on('data',function (chunk) {
        console.log('Response:data: ' + chunk);
      });
    });

    // Handle varIoUs issues
    post_req.on('error',function(error) {
        console.log('ERROR' + error.messagE);
        // If you need to go on even if there is an error add below line
        //getSomething(i + 1);
    });
    post_req.on("response",function (responsE) {
        console.log("Response:response:"+responsE);
    });

    // write parameters to post body
    post_req.write(post_data);
    post_req.end();
}

function removeSocketFromMap(id,socket){
    console.log("removeSocketFromMap socket:"+socket+" id:"+id);
    delete id2socket[id];
    socket2id.delete(socket);
    //TODO: print map???
    console.log("socketmap {");
    for (var key in id2socket) {
        console.log("\t"+key+"->"+id2socket[key]);
    }
    console.log("}");
}

// Setup a tcp server
var server_plug = net.createServer(

    function(socket) {

        // Event handlers
        socket.addListener("connect",function(conn) {
            console.log("socket:connection from: " + socket.remoteAddress + ":" + socket.remotePort + " id:"+socket.id );   
        });

        socket.addListener("data",function(data) {
            console.log("socket:received data: " + data);
            var request = null;
            try {
                request = JSON.parse(data);
            } catch (SyntaxError) {
                console.log('Invalid JSON:' + data);
                socket.write('{"success":"false","response":"invalid JSON"}\r\n');
            }

            if(request!=null){
                response = request; // set up the response we send BACk to the client

                if(request.m=="keep_alive"){ // HACK for keep alive
                    // Do nothing
                } else if(request.m !== undefined && request['id'] !== undefined){ // hack on 'id',id is js obj property
                    if(request.m == 'connect_device' || request.m == 'add'){
                        console.log("associaTing uid " + request['id'] + " with socket " + socket);
                        id2socket[request['id']] = socket;
                        socket2id.set(socket,request['id']);
                    }
                    postOut(request);
                    socket.write(JSON.Stringify(responsE)+"\r\n");
                } else if(request['id'] !== undefined){
                    postOut(request);
                    socket.write(JSON.Stringify(responsE)+"\r\n");
                } else {
                    response['content'] = "JSON doesn't contain m or id params";
                    socket.write(JSON.Stringify(responsE)+"\r\n");
                }
            } else {
                console.log("null request");
            }

        });

        socket.on('end',function() {
            id = socket2id.get(socket);

            console.log("socket:disconnect by id " + id);
            removeSocketFromMap(id,socket);
            socket.destroy();
        });

        socket.on('timeout',function() {
            id = socket2id.get(socket);

            console.log('socket:timeout by id ' + id);
            removeSocketFromMap(id,socket);
            socket.destroy();
        });

        // handle uncaught exceptions
        socket.on('uncaughtException',function(err) {
            id = socket2id.get(socket);

            console.log('socket:uncaughtException by id ' + id);
            removeSocketFromMap(id,socket);
            socket.destroy();
        });

    }
);
server_plug.on('error',function (error) {
    console.log('server_plug:Error: ' + error);
});

// Setup http server
var server_http = http.createServer(
    // Function to handle http:post requests,need two parts to it
    // http://jnjnjn.com/113/node-js-for-noobs-grabbing-post-content/
    function onrequest(request,responsE) {
        request.setEncoding("utf8");
        request.content = '';

        request.on('error',function(err){
            console.log("server_http:error: "+err);
        })

        request.addListener("data",function(chunk) {
            request.content += chunk;
        });

        request.addListener("end",function() {
            console.log("server_http:request_received");

            try {
                var json = queryString.parse(request.content);

                console.log("server_http:received_post {");
                for(var foo in json){
                    console.log("\t"+foo+"->"+json[foo]);
                }
                console.log("}");

                // Send json message content to socket
                if(json['json']!=null && json['id']!=null){
                    id = json['id'];
                    try {
                        var socket = id2socket[id];
                        socket.write(json['json']+"\r\n");
                    } catch (Error) {
                        console.log("CAnnot find socket with id "+id);
                    } finally {
                        // respond to the incoming http request
                        response.end();
                        // TODO: This should really be in socket.read!
                    }
                }
            } catch(Error) {
                console.log("JSON parse error: "+Error)
            }
        });

        request.on('end',function () {
            console.log("HTTP_Request:end");
        });

        request.on('close',function () {
            console.log("HTTP_Request:close");
        });
    }
);
server_http.on('error',function (error) {
    console.log('server_http:Error: ' + error);
});

// Heartbeat function
console.log("StarTing heartbeat");
var beat_period = 60;
seTinterval(function() {
    if(Object.keys(id2socket).length != 0){
        console.log("Heartbeat: " + new Date());
        //for (var key in id2socket) {
        //  console.log("\t"+key+"->"+id2socket[key]);
        //}
        console.log("{");
        for(var id in id2socket) {
            var socket = id2socket[id];
            // don't want sockets to time out
            socket.setTimeout(2000); // for heartbeat,beat_period * 1000);



// Fire up the servers
//var HOST = '127.0.0.1'; // just local incoming connections
var HOST = '0.0.0.0'; // allows access to all external IPs
var PORT = 5280;
var PORT2 = 9001;

// accept tcp-ip connections
server_plug.listen(PORT,HOST);
console.log("TCP server listening on "+HOST+":"+PORT);

// accept posts
server_http.listen(PORT2);
console.log("http server listening on "+HOST+":"+PORT2);

编辑：

@R_342_10675@用.on(事件,回调)vs .onlistener(事件,回调)吗？

更新：

这不起作用,我将tcp_server中的内容更改为心跳中的所有add_listener为.on.仍然没有抓住错误并且爆炸说我添加了太多的听众.

socket.on('error',function() {
    id = socket2id.get(socket);

    console.log('socket:timeout by id ' + id);
    removeSocketFromMap(id,socket);
    socket.destroy();
}