Add db metric name to semantic conventions

[shalevr]

Description

I started to implement dbapi metrics instrumentation and
I figure out that db.client.connections.usage metric name is missing in the semantic conventions

According to the specs: https://github.com/open-telemetry/opentelemetry-specification/blob/main/specification/metrics/semantic_conventions/database-metrics.md

Type of change

• New feature (non-breaking change which adds functionality)

Does This PR Require a Contrib Repo Change?

Answer the following question based on these examples of changes that would require a Contrib Repo Change:

• The OTel specification has changed which prompted this PR to update the method interfaces of opentelemetry-api/ or opentelemetry-sdk/

• The method interfaces of test/util have changed

• Scripts in scripts/ that were copied over to the Contrib repo have changed

• Configuration files that were copied over to the Contrib repo have changed (when consistency between repositories is applicable) such as in

  • pyproject.toml
  • isort.cfg
  • .flake8

• When a new .github/CODEOWNER is added

• Major changes to project information, such as in:

  • README.md
  • CONTRIBUTING.md

• Yes. - Link to PR:

• No.

Checklist:

• Followed the style guidelines of this project
• Changelogs have been updated
• Unit tests have been added
• Documentation has been updated

[srikanthccv]

Thanks for the PR, but these are auto-generated files and are not to be modified by hand (although nothing prevents you from doing it). Here is the script that takes the spec version and produces the semconv files https://github.com/open-telemetry/opentelemetry-python/blob/main/scripts/semconv/generate.sh

[srikanthccv]

Ah, sorry, I see this is a DB semconv which was manually added. There was some issue which prevented us from making this automated. I think we can merge this. It would be better if we could auto-generate as we do for the tracing.

[shalevr]

Ohh I didn't know it should be auto-generated I saw that the http metric names are manually added.
What is the issue that prevented us to make it automated?
Can you merge this PR? and I will try to fix the issue and make it auto-generated
Do you know if there is an open issue with that issue?

[srikanthccv]

This one #2977

[shalevr]

Thanks!
Please add skip changelog label

[srikanthccv]

I would suggest adding an entry since external users can consume this change.

[shalevr]

Ohh I see, Thank you for the comment