Socket IO metrics

[slavomir-ziak]

HI everyone, which library are you using, that provides prometheus metrics?
I found these two, but they are unmaintained: socket.io-prometheus, socket.io-prometheus-metrics.
I tried socket.io-prometheus with latest socket.io (v4), the basic metrics are fine, some are missing, but this is not the point of my question.
Which library are you guys using? thanks

[fjeldstad]

No library, found it easy enough to just implement it in our own codebase. Metrics for emitted events are potentially a little trickier if you have distributed emitters; you cannot just (easily) hook it up to your Socket.io server(s) since there are no events/hooks for when a message has been written to the backplane (Redis stream for example). I'm sure it's possible to solve but if you also have multiple Socket.io servers the metrics need to be normalised so that a message is not counted multiple times etc.