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

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。

其他回答

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。

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

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

直到今天我开始监视咕噜咕噜的时候,我才开始这样做。最终由

watch: {
  options: {
    maxListeners: 99,
    livereload: true
  },
}

烦人的信息消失了。

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");