Current behaviour

If I have a Rails application that wants to make use of connecting Database Monitoring with APM AFAICS this is the minimum needed ddtrace configuration:

  c.tracing.instrument :mysql2, comment_propagation: "full"
  c.tracing.instrument :rails

And this works, but it leads to seemingly duplicate nested mysql2 spans:

The spans differ slightly:

I use the count of mysql2 spans as a proxy for query count, so this doubling up is rather annoying. Removing c.tracing.instrument :mysql2 fixes it, but loses comment propagation.

Expected behaviour

I expect there to be only one span here, or for the purpose of each span to be clearly different if they do represent different things.

How does ddtrace help you?

Its the best thing since sliced 🍞!

Environment

• ddtrace version: 1.15.0
• Configuration block (Datadog.configure ...): see above
• Ruby version: 3.2
• Operating system: docker.io/ruby:3.2.2-bullseye
• Relevant library versions: Rails 7.0, mysql2 0.5.5