MaxListenersExceededWarning about rascal

[cressie176]

Published as [email protected]

[cressie176]

Hi @nico3dfx,

I will try to reproduce. Can you confirm your node.js and rascal version please?

[nico3dfx]

Hi @nico3dfx,

I will try to reproduce. Can you confirm your node.js and rascal version please?

Node @ 14.16.1
Rascal @ 15.0.0

Thank you @cressie176

[cressie176]

I've been able to reproduce. The warning is caused because Rascal uses the forward-emitter package to forward events from each vhost to the broker object, so that when an "error" event is emitted from a vhost (which isn't exposed by Rascal), it is re-emitted on the broker, where it can be handled.

Confusingly forward-events library doesn't work by forwarding events at all. Instead it registers a newListener event handler on the broker, then when an event handler is added, duplicates it on the vhost.

This means that each new vhost adds an "newListener" handler, and after the 10th vhost, node reports the MaxListenersExceededWarning.

I'll increase the threshold to Math.max(10, numberOfVhosts)