Hi. I've got comments/questions after a few days of playing with OTel.
1) Why is UpDownCounter instrument not called Gauge? The six instrument types all have very similar naming components (Counter, UpDownCounter, ValueRecorder, SumObserver, UpDownSumObserver, ValueObserver). I'm sure I'll get used to this over time, but as a newb the naming pattern is hard to spot and requires a lot of spec checking while coding.
2) The UpDownCounter instrument, which is equivalent to Gauge, is updated via an Add() function. How do I update this counter when I already have the final value? Right now it appears to me that I need to track the prior value, do the math to find the delta, and then call the Add() function with the delta as the value. I would rather just update the metric with the current value. Is there a way to directly set the value for an UpDownCounter instrument?
3) It took me a while to realize that ValueRecorder and ValueObserver instruments were summary metrics that had multiple values (MinMaxSumCount), and thus would be dropped by the OTel exporter for Prometheus. To me, "Value" suggests a single scalar value. I would have expected the exporter for Prometheus to export the LastValue and just work for Value* instruments. This burned at least a day of debugging for me.
Thanks all, for this amazing project. I've read some of the spec discussions and the decisions made have all been well considered.
python3 server.py --log=DEBUGthe spans emit just fine. but when I'm running using uwsgi I can't get the spans to emit to console. I've tried setting logging level in logging.basicConfiguration but no luck. Any ideas?