record_exception & Grafana/Tempo label value size limit

[linde12]

Grafana/Tempo has a default limit of 2048 characters for label values. Since OTel reports exceptions as events with attributes (and those attributes are then treated as labels in Grafana) record_exception because kind of crippled in a Grafana context.

I can't ever see the most valuable (bottom part) of my exception because it is begin cut off after 2048 characters. For auto instrumentation, e.g. FastAPI auto instrumentation, where the stack is deep-ish i never get any useful information from uncaught exceptions (the ones that i'd argue are most important to see!)

Same goes for exception.message - since it's also treated as a label it is also truncated after 2048 characters.

Any suggestions? I was thinking there could be an option to also log the full exception (so that Loki could pick it up and correlate it with the trace) but that feels like a hack.