Beyla Routes

[misterek]

Config question -- the beyla docs (https://grafana.com/docs/beyla/latest/configure/options/) mention "You should use the routes property whenever possible to reduce the cardinality of generated metrics."

It seem like the routes property applies to both client and server? Is that correct, and the intended behavior?

Is there any way to have that different for client and server? In one case I'd like to leave the route unset if it's not in the list. In the other case I'd like to use the heuristic.

[grcevski]

Hi @misterek, yes at the moment the routes configuration applies to both client and server requests. Adding the ability to split them is a good idea, if it's possible please open a feature request.

At the moment I can only think of running separate Beyla instances, one that instruments your client app(s) and another one that instruments the server app(s). Each would have separate configuration file, allowing you to customize the routes decorator properties.

[misterek]

Thanks! I will do that (open a feature request). My personal use case is mostly is that my expectation on the inputs/outputs is a little different.

For the server metrics -- a caller could conceivably hammer you with many URL's. I noticed that the heuristic doesn't seem to catch words (which makes sense). So you could end up with a nearly infinite amount of routes by just enumerating a dictionary (assuming you don't have a layer in front of this to help). In this case, I'd like to limit my metrics to known routes + "unset".

However, depending on the app, your external calls may be far more controlled. In this case, a heuristic makes sense as we may be able to have some expectations on outgoing calls. In this case, I'd likely choose to not list routes and just rely on heuristic.

Thanks!

[misterek]

Added here: #860. Let me know if there's a different way you'd like a feature request. I'll close this discussion now. Thanks!

[grcevski]

Yeah makes total sense, I can see how this could be useful. Thanks for the feature!