Rename metrics to be in line with OTel + Prometheus conventions

[emschwartz]

As discussed here, OpenTelemetry is changing its semantic conventions to remove the .count suffix. Also, as discussed here, the histogram should include the units in the name for Prometheus.

We should update all of the libraries such that:

• The counter is renamed from function.calls.count to function.calls
• The histogram should include the unit as seconds (in the OpenTelemetry metadata or in the name for Prometheus)
• When the metrics are exported to Prometheus, we should ensure that the counter is renamed to function_calls_total and the histogram is renamed to function_calls_duration_seconds
• All queries should be updated to use the function_calls_total and function_calls_duration_seconds name. We can give people time to update things by making the alerting rules and dashboards support the new and old names using regular expressions.

TODO:

• Spec Rename metrics to match OpenTelemetry/OpenMetrics naming conventions #60
• Dashboards and alerting rules Rename metrics and add service_name #73
• VS Code Extension Support renamed metrics vscode-autometrics#55
• Rust Rename metrics to be in line with OpenTelemetry/OpenMetrics specs autometrics-rs#118
• Go Rename metrics from function.calls.count to function.calls autometrics-go#54
• TypeScript Rename metrics autometrics-ts#84
• Python Rename metrics autometrics-py#60
• C# Rename metrics autometrics-cs#11
• Java Rename metrics jamsiedaly/autometricsj#3

[gagbo]

The error rate SLO expression still expects _count to be part of the metric name

autometrics-shared/autometrics.rules.yml

Line 11 in 79d53e9

(sum by (objective_name, objective_percentile) (rate({__name__=~"function_calls_count(?:_total)?",objective_percentile="90",result="error"}[5m])))

An extra change is needed in the generated rules file to make the alerts work once libraries make the change to support function_calls_total naming.

Also, the histogram queries for the latency SLO haven't been renamed either

autometrics-shared/autometrics.rules.yml

Line 825 in 79d53e9

(sum by (objective_name, objective_percentile) (rate(function_calls_duration_count{objective_percentile="90"}[3d])) - (sum by (objective_name, objective_percentile) (

So function_calls_duration_seconds is unsupported as well for now

[brettimus]

maybe we should fix the queries in https://github.com/autometrics-dev/autometrics-shared/pull/60/files and merge it? wasn't sure if that PR was unmerged for a reason