MaxListenersExceededWarning when using containers

Please tell us about your environment:

• winston version?
  • winston@2
  • winston@3.2.1
• _node -v outputs: v8.15.1 and v10.15.3
• _Operating System? Linux 16.04 and Windows 10

What is the problem?

Using a container that has a predefined set of transports leads to MaxListenersExceededWarning when adding multiple loggers:

$ node index.js
(node:8512) MaxListenersExceededWarning: Possible EventEmitter memory leak detected. 31 unpipe listeners added. Use emitter.setMaxListeners() to increase limit
(node:8512) MaxListenersExceededWarning: Possible EventEmitter memory leak detected. 31 error listeners added. Use emitter.setMaxListeners() to increase limit
(node:8512) MaxListenersExceededWarning: Possible EventEmitter memory leak detected. 31 drain listeners added. Use emitter.setMaxListeners() to increase limit
(node:8512) MaxListenersExceededWarning: Possible EventEmitter memory leak detected. 31 close listeners added. Use emitter.setMaxListeners() to increase limit
(node:8512) MaxListenersExceededWarning: Possible EventEmitter memory leak detected. 31 finish listeners added. Use emitter.setMaxListeners() to increase limit

What do you expect to happen instead?

No warning.

Other information

Here is a sample repo. Simply run node index.js: https://github.com/sla89/winston_maxlisteners

[sla89]

We have multiple loggers with different labels so that we can identify which module logged the message. All loggers should log to the same FileTransport because we want all log messages in the same file. Is it safe to have multiple FileTransports that target the same file even when rolling logs are enabled?

[FabianTe]

I am too having the same scenario as @sla89

I create a logger instance for each class I am creating (one per class, not one per class instance) and each logger has a different label.

I though that having a single console and a single file transport should be used with many logger instances using them. Is that wrong?