Winston

Question

在使用 winston-daily-rotate-file 包进行文件日志记录时，winston 中出现以下错误，代码与 winston 控制台日志记录一起运行良好，

  MaxListenersExceededWarning: Possible EventEmitter memory leak detected. 11 error listeners added. Use emitter.setMaxListeners() to increase limit
        at _addListener (events.js:256:17)
        at DailyRotateFile.addListener (events.js:272:10)
        at DailyRotateFile.once (events.js:301:8)
        at asyncForEach (/home/ubuntumachine/Desktop/project/node_modules/winston/lib/winston/exception-handler.js:217:17)
        at /home/ubuntumachine/Desktop/project/node_modules/async/internal/withoutIndex.js:9:16
        at eachOfArrayLike (/home/ubuntumachine/Desktop/project/node_modules/async/eachOf.js:65:9)
        at exports.default (/home/ubuntumachine/Desktop/project/node_modules/async/eachOf.js:9:5)
        at eachLimit (/home/ubuntumachine/Desktop/project/node_modules/async/forEach.js:80:24)
        at ExceptionHandler._uncaughtException (/home/ubuntumachine/Desktop/project/node_modules/winston/lib/winston/exception-handler.js:203:5)
        at process.emit (events.js:198:13)
    (node:20805) MaxListenersExceededWarning: Possible EventEmitter memory leak detected. 11 finish listeners added. Use emitter.setMaxListeners() to increase limit
        at _addListener (events.js:256:17)
        at DailyRotateFile.addListener (events.js:272:10)
        at DailyRotateFile.once (events.js:301:8)
        at asyncForEach (/home/ubuntumachine/Desktop/project/node_modules/winston/lib/winston/exception-handler.js:216:17)
        at /home/ubuntumachine/Desktop/project/node_modules/async/internal/withoutIndex.js:9:16
        at eachOfArrayLike (/home/ubuntumachine/Desktop/project/node_modules/async/eachOf.js:65:9)
        at exports.default (/home/ubuntumachine/Desktop/project/node_modules/async/eachOf.js:9:5)
        at eachLimit (/home/ubuntumachine/Desktop/project/node_modules/async/forEach.js:80:24)
        at ExceptionHandler._uncaughtException (/home/ubuntumachine/Desktop/project/node_modules/winston/lib/winston/exception-handler.js:203:5)
        at process.emit (events.js:198:13)
    (node:20805) MaxListenersExceededWarning: Possible EventEmitter memory leak detected. 31 error listeners added. Use emitter.setMaxListeners() to increase limit
        at _addListener (events.js:256:17)
        at Console.addListener (events.js:272:10)
        at Console.once (events.js:301:8)
        at asyncForEach (/home/ubuntumachine/Desktop/project/node_modules/winston/lib/winston/exception-handler.js:217:17)
        at /home/ubuntumachine/Desktop/project/node_modules/async/internal/withoutIndex.js:9:16
        at eachOfArrayLike (/home/ubuntumachine/Desktop/project/node_modules/async/eachOf.js:65:9)
        at exports.default (/home/ubuntumachine/Desktop/project/node_modules/async/eachOf.js:9:5)
        at eachLimit (/home/ubuntumachine/Desktop/project/node_modules/async/forEach.js:80:24)
        at ExceptionHandler._uncaughtException (/home/ubuntumachine/Desktop/project/node_modules/winston/lib/winston/exception-handler.js:203:5)
        at process.emit (events.js:198:13)

试图将 max listeners 设置为无穷大，

const EventEmitter = require('events');
const emitter = new EventEmitter();
emitter.setMaxListeners(Infinity);

仍然面临同样的问题。

Answer 1

我遇到了同样的问题，当我使用完记录器后调用 winstonLoggerInstance.clear() 解决了这个问题。 clear() 清除所有传输。

Answer 2

设置handleExceptions: false如下图

createLogger({
    level:  'info',
    transports: [
      new transports.Console({
        format: format.combine(
          format.colorize(),
          format.simple(),
          myFormat
      ),
        handleExceptions: false
      })
    ],
    format: logFormat(label)
  })

Answer 3

我遇到了一个相关案例，上面提到了标题警告，所以我只是与可能进入该主题的其他人分享我的调查见解：

为什么会弹出这个警告？嗯，this comment in this relevant thread解释的很好。简而言之：广泛使用传输。
如何禁用警告？ 我发现很少有地方（如 this one）提供更新最大侦听器。他们使用process.setMaxListeners(0);，这与问题中使用的不同。
是否应该禁用警告？ 我倾向于不（如 first comment in this thread 中所述）。
为什么 clear() 有帮助？ 好吧，我没有读太多，但根据 documnation - 它删除了所有传输。
在其他什么情况下可能会发生此错误？ - 当使用传输创建大量记录器实例时。我就是这样。

Winston - MaxListenersExceededWarning：检测到可能的 EventEmitter 内存泄漏

Winston - MaxListenersExceededWarning: Possible EventEmitter memory leak detected

node.js