A more robust way to gather facts from nodes

[doodlesbykumbi]

I have a local setup with Redis and some application nodes. I have another redis client that is snooping on the channels that the adapter is using.

Whenever I'm snooping I get this error:

Error: timeout reached while waiting for sockets response

I looked into it and this error is because while snooping request.numSub > request.msgCount since my other client is just a spy. It would be nice if observing the channel didn't break the functionality. Perhaps there could be a way to count participant subs only.

socket.io-redis-adapter/lib/index.ts

Lines 380 to 386 in 3242d8e

	if (request.msgCount === request.numSub) {
	clearTimeout(request.timeout);
	if (request.resolve) {
	request.resolve(request.sockets);
	}
	this.requests.delete(requestId);
	}

[darrachequesne]

Perhaps there could be a way to count participant subs only.

I'm open to suggestions on this!

[doodlesbykumbi]

I'll think about it a bit and see if I can suggest anything useful.

[doodlesbykumbi]

@darrachequesne, so here's an idea. We can have the "active" participants subscribe to a "proxy" channel when they come online. Nothing actually goes through that particular channel, it's just used for a participant to explicitly mark themselves as a participant.

[darrachequesne]

@doodlesbykumbi that's an interesting idea. That would be a backward incompatible change though, which means users will need to upgrade the whole cluster at the same time, isn't it?

[doodlesbykumbi]

@darrachequesne You can fall back to the request channel for backwards compatibility if desired.

[doodlesbykumbi]

I've created a PR to demonstrate the approach^

[doodlesbykumbi]

Ping @darrachequesne