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

我也面临着同样的问题,但我已经成功地处理了异步等待。 请检查是否有帮助。 let dataLength = 25; 之前: for(设I = 0;i < dataLength;我+ +){ sftp。get (remotePath fs.createWriteStream (xyzProject / ${数据[我]. name})); } 后: for(设I = 0;i < dataLength;我+ +){ 等待sftp。get (remotePath fs.createWriteStream (xyzProject / ${数据[我]. name})); }

其他回答

我想在这里指出,这个警告是有原因的,正确的解决方法很可能不是增加限制,而是弄清楚为什么要向同一个事件添加如此多的侦听器。只有当您知道为什么要添加这么多侦听器并且确信这是您真正想要的时候,才增加限制。

我找到了这个页面,因为我得到了这个警告,在我的情况下,我正在使用的一些代码中有一个错误,将全局对象转换为EventEmitter!我当然不建议在全球范围内增加限制,因为你不想让这些事情被忽视。

缺省情况下,任何单个事件最多可以注册10个侦听器。

如果这是你的代码,你可以通过:

const emitter = new EventEmitter()
emitter.setMaxListeners(100)
// or 0 to turn off the limit
emitter.setMaxListeners(0)

但如果这不是你的代码,你可以使用技巧来增加全局默认限制:

require('events').EventEmitter.prototype._maxListeners = 100;

当然,你可以关闭限制,但要小心:

// turn off limits by default (BE CAREFUL)
require('events').EventEmitter.prototype._maxListeners = 0;

顺便说一句。代码应该在应用程序的最开始。

ADD:从节点0.11开始,这段代码也可以改变默认限制:

require('events').EventEmitter.defaultMaxListeners = 0

当我在mac osx上安装aglio时,我也得到了这个警告。

我使用cmd修复它。

sudo npm install -g npm@next

https://github.com/npm/npm/issues/13806

I prefer to hunt down and fix problems instead of suppressing logs whenever possible. After a couple days of observing this issue in my app, I realized I was setting listeners on the req.socket in an Express middleware to catch socket io errors that kept popping up. At some point, I learned that that was not necessary, but I kept the listeners around anyway. I just removed them and the error you are experiencing went away. I verified it was the cause by running requests to my server with and without the following middleware:

socketEventsHandler(req, res, next) {
        req.socket.on("error", function(err) {
            console.error('------REQ ERROR')
            console.error(err.stack)
        });
        res.socket.on("error", function(err) {
            console.error('------RES ERROR')
            console.error(err.stack)
        });
        next();
    }

删除该中间件将停止您所看到的警告。我会查看您的代码,并尝试找到您可能设置了不需要的侦听器的任何地方。

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');