tel VS opentelemetry-specificatio

I've played with trying to create an idiomatic wrapper for Go precisely because of this reason, but then didn't find time to continue with this.

https://github.com/henvic/tel

Sure, happy to provide more specifics!

Our main issue was the lack of a synchronous gauge. The officially supported asynchronous API of registering a callback function to report a gauge metric is very different from how we were doing things before, and would have required lots of refactoring of our code. Instead, we wrote a wrapper that exposes a synchronous-like API: https://gist.github.com/yolken-airplane/027867b753840f7d15d6....

It seems like this is a common feature request across many of the SDKs, and it's in the process of being fixed in some of them (https://github.com/open-telemetry/opentelemetry-specificatio...)? I'm not sure what the plans are for the golang SDK specifically.

Another, more minor issue, is the lack of support for "constant" attributes that are applied to all metrics. We use these to identify the app, among other use cases, so we added wrappers around the various "Add", "Record", "Observe", etc. calls that automatically add these. (It's totally possible that this is supported and I missed it, in which case please let me know!).

Overall, the SDK was generally well-written and well-documented, we just needed some extra work to make the interfaces more similar to the ones were were using before.

Two problems with OpenTelemetry:

1. It doesn't know what the hell it is. Is it a semantic standard? Is a protocol? It is a facade? What layer of abstraction does it provide? Answer: All of the above! All the things! All the layers!

2. No one from OpenTelemetry has actually tried instrumenting a library. And if they have, they haven't the first suggestion on how instrumenters should actually use metrics, traces, and logs. Do you write to all three? To one? I asked this question two years ago, not a single response. [1]

[1] https://github.com/open-telemetry/opentelemetry-specificatio...

That's why you have otel logging: https://github.com/open-telemetry/opentelemetry-specificatio...

There are a large amount of subtle tradeoffs around the bucketing scheme (log, vs. log-linear, base) and memory layout (sparse, dense, chunked) the amount of configurability in the histogram space (circllhist, DDSketch, HDRHistogram, ...). A good overview is this discussion here:

https://github.com/open-telemetry/opentelemetry-specificatio...

As for the circllhist: There are no knobs to turn. It uses base 10 and two decimal digits of precision. In the last 8 years I have not seen a single use-case in the operational domain where this was not appropriate.

A good place to look at is the milestones on GitHub: https://github.com/open-telemetry/opentelemetry-specificatio...

Logging is still experimental in the spec. Metrics API is feature freeze and the protocol is stable, so it's more on language SDKs to stabilize their implementations. This is a focus for several of them right now.