Add a otelcol.connector.servicegraph component

[ptodev]

PR Description

The new otelcol.connector.servicegraph component is based on the servicegraphconnector, which on the other hand is based on servicegraphprocessor.

Which issue(s) this PR fixes

Fixes #2300
Fixes #2213

Notes to the Reviewer

There is one config parameter for the servicegraph connector which we cannot yet support in flow - virtual_node_peer_attributes. It is behind a processor.servicegraph.virtualNode feature gate in the Collector. In the Agent we don't yet support enabling Otel feature gates. I will try to submit a PR to the Collector to either remove that feature gate or enable it by default, and the next time we upgrade Otel in the Agent we can add the virtual_node_peer_attributes argument.

PR Checklist

• CHANGELOG.md updated
• Documentation added
• Tests updated
• Config converters updated

[tpaschalis]

LGTM, only some docs-related nits for now

[tpaschalis]

Just to understand, is it both based on Tempo's service graph processor, that in turn is a wrapper over the servicegraph connector?

[ptodev]

otelcol.connector.servicegraph is a wrapper over Collector's servicegraph connector, which on the other hand is inspired by the Tempo service graph processor.

As far as I can tell, the Otel component doesn't import any Tempo code.

I think the reason why they mention Tempo in the Otel wiki page is because (I think) the Otel component inherits the metric names which the Tempo processor in question uses. So any other UI will also have to use the same metric conventions.

[tpaschalis]

Maybe we can then remove the Tempo reference or amend this sentence to mention the inspiration of metric names.

[clayton-cornell]

I would say... only include the reference to Tempo if it helps the reader understand the topic. If it's just a nod to Tempo, or extra info that isn't really going help with understanding... then we should remove it.

[tpaschalis]

LGTM, leaving to @clayton-cornell for a final pass 🙌

[clayton-cornell]

We need to update the shared topic link syntax.

Added a comment about the Tempo linking.

[clayton-cornell]

I would say... only include the reference to Tempo if it helps the reader understand the topic. If it's just a nod to Tempo, or extra info that isn't really going help with understanding... then we should remove it.