Improve Granularity for SQL Databases

AlexanderWert commented 2 years ago

There are two parts to improving the granularity for SQL Databases:

adding new fields to agent-server protocol, for now it's mostly to future-proof the captured data as we have to keep existing fields for compatibility with UI.
capture values for those new fields on SQL Databases, which is actually providing better granularity to the end-user.

Each step can be completed independently, but this task will be considered complete when both parts are completed.

First step : add new service fields

Add and capture values for span.context.service.target.type and span.context.service.target.name for exit spans.
Infer from those new fields the value of span.destination.service.resource and keep sending it.
Add service_target_* fields to dropped spans metrics: add service_target_type and service_target_name next to destination_service_resource in transaction.dropped_spans_stats array, the related metrics documents should include span.service.target.type and span.service.target.name fields.
Handle span compression with new fields (stop relying on resource internally)

Second step : capture values for new fields

Spec issue

[x] https://github.com/elastic/apm/issues/622

Agent issues

estolfo commented 2 years ago

@AlexanderWert What if the agent doesn't detect the apm server version, how can it know which field to send?

felixbarny commented 2 years ago

I think agents should default to sending all three fields and if they detect that the APM Server they're connected to is new, they MAY drop the old field. But it's also totally fine to always send all fields, IMO.

estolfo commented 2 years ago

Thanks, @felixbarny. @AlexanderWert if you agree, I'll update the description to reflect Felix's input.

felixbarny commented 2 years ago

Ideally, I think the description and this discussion should happen on the spec PR. Otherwise, it may get out-of-sync.

elastic / apm

Improve Granularity for SQL Databases #621

Spec issue

Agent issues