Criticism of OpenCensus Metrics API

[gilgad13]

From first impressions, I found the metrics API expressed in https://opencensus.io/stats/ to be relatively intuitive. The metrics API expressed so far in the OpenTelemetry specs are quite different. I see that the OpenTelemetry API is trying to cover both Callback / "queried" and Observation -style metrics, whereas OpenCensus seems to focus entirely on recording and aggregating observations, but even confined to the Observation / "synchronous" side there are a number of differences.

Some ergonomic issues only show up after extensive use, and there some shared contributors to both projects, so I assume the difference is not an accident. Is there a write up anywhere of critiques, "non-obvious pitfalls" or other problems / nitpicks with the OpenCensus-style synchronous metrics API?

[reyang]

Good question @gilgad13!

The root would always go to the goal which is documented here https://github.com/open-telemetry/opentelemetry-specification/blob/main/specification/metrics/README.md#design-goals.

Some of the discussions can be found #1617 (comment).