我得到以下警告:

(node) warning: possible EventEmitter memory leak detected. 11 listeners added. Use emitter.setMaxListeners() to increase limit.
Trace: 
    at EventEmitter.<anonymous> (events.js:139:15)
    at EventEmitter.<anonymous> (node.js:385:29)
    at Server.<anonymous> (server.js:20:17)
    at Server.emit (events.js:70:17)
    at HTTPParser.onIncoming (http.js:1514:12)
    at HTTPParser.onHeadersComplete (http.js:102:31)
    at Socket.ondata (http.js:1410:22)
    at TCP.onread (net.js:354:27)

我在server.js中写了这样的代码:

http.createServer(
    function (req, res) { ... }).listen(3013);

如何解决这个问题?


当前回答

公认的答案提供了如何增加限制的语义,但正如@voltrevo指出的那样,警告是有原因的,您的代码可能存在错误。

考虑以下有bug的代码:

//Assume Logger is a module that emits errors
var Logger = require('./Logger.js');

for (var i = 0; i < 11; i++) {
    //BUG: This will cause the warning
    //As the event listener is added in a loop
    Logger.on('error', function (err) {
        console.log('error writing log: ' + err)
    });

    Logger.writeLog('Hello');
}

现在观察添加监听器的正确方法:

//Good: event listener is not in a loop
Logger.on('error', function (err) {
    console.log('error writing log: ' + err)
});

for (var i = 0; i < 11; i++) {
    Logger.writeLog('Hello');
}

在更改maxListeners之前搜索代码中的类似问题(在其他答案中有解释)

其他回答

You said you are using process.on('uncaughtException', callback); Where are you executing this statement? Is it within the callback passed to http.createServer?If yes, different copy of the same callback will get attached to the uncaughtException event upon each new request, because the function (req, res) { ... } gets executed everytime a new request comes in and so will the statement process.on('uncaughtException', callback);Note that the process object is global to all your requests and adding listeners to its event everytime a new request comes in will not make any sense. You might not want such kind of behaviour. In case you want to attach a new listener for each new request, you should remove all previous listeners attached to the event as they no longer would be required using: process.removeAllListeners('uncaughtException');

我们团队对此的解决方案是从.npmrc中删除注册表路径。rc文件中有两个路径别名,其中一个指向已弃用的Artifactory实例。

这个错误与我们的应用程序的实际代码无关,而是与我们的开发环境有关。

在我的情况下,这是由于没有关闭到数据库的Sequelize连接,而创建他们内部的异步函数调用setInterval。

在我的例子中,它是child.stderr.pipe(process.stderr),当我启动10个(或左右)child实例时,它被调用。因此,任何导致在LOOP中将事件处理程序附加到同一个EventEmitter对象的事情都会导致nodejs抛出这个错误。

在创建新的侦听器之前,您需要使用以下命令清除所有侦听器:

客户端/服务器

socket.removeAllListeners(); 

假设socket是您的客户端套接字/或创建的服务器套接字。

你也可以订阅特定的事件监听器,比如像这样删除连接监听器:

this.socket.removeAllListeners("connect");