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。

节点版本号:v11.10.1

来自堆栈跟踪的警告消息:

process.on('warning', e => console.warn(e.stack));
(node:17905) MaxListenersExceededWarning: Possible EventEmitter memory leak detected. 11 wakeup listeners added. Use emitter.setMaxListeners() to increase limit
MaxListenersExceededWarning: Possible EventEmitter memory leak detected. 11 wakeup listeners added. Use emitter.setMaxListeners() to increase limit
    at _addListener (events.js:255:17)
    at Connection.addListener (events.js:271:10)
    at Connection.Readable.on (_stream_readable.js:826:35)
    at Connection.once (events.js:300:8)
    at Connection._send (/var/www/html/fleet-node-api/node_modules/http2/lib/protocol/connection.js:355:10)
    at processImmediate (timers.js:637:19)
    at process.topLevelDomainCallback (domain.js:126:23)

在搜索github问题,文档和创建类似的事件发射器内存泄漏后,由于node-apn模块用于iOS推送通知,观察到此问题。

这就解决了问题:

您应该为每个进程只创建一个Provider 您拥有的证书/密钥对。您不需要创建一个新的 每个通知的提供者。如果你只是发送通知 一个应用程序,那么就不需要一个以上的提供商。 如果你经常在你的应用程序中创建Provider实例,make 当你使用完每个提供者时,一定要调用provider .shutdown() 释放其资源和内存。

每次发送通知时,我都在创建提供者对象,并期望gc将其清除。

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。

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

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');