otel/metric: godoc describing differences between Gauge and other metric types

[jmhodges]

Problem Statement

It would be nice to write down what differs between a Gauge, an UpAndDownCounter, and a Counter near their definitions. The typing on their factory methods on Meter make it difficult to understand at a glance what each is for.

As an old hand, I can guess at which to use, but even I was hoping to a quick explainer to confirm what I believed about them.

Proposed Solution

Perhaps the Measurements section of otel/metics could get some more verbiage on when to use each one.

Alternatives

A link to a more descriptive doc could be added to Meter or the Measurements section instead.

[pellared]

Can you check if the description under https://opentelemetry.io/docs/instrumentation/go/manual/#metrics is helpful?

[jmhodges]

Yeah, those are a good start! The "non-additive" is maybe not super clear to folks, but it's definitely the flavor of what I was looking for.

[pellared]

You can also take a look at e.g. https://opentelemetry.io/docs/concepts/signals/metrics/#metric-instruments and https://opentelemetry.io/docs/specs/otel/metrics/api/.

Do you have any proposal on how to improve or can we close the issue?