OpenTracing http instrumentation links unrelated requests

[pfyod]

We are still experiencing weird tracing behavior, even after the fix for #2051. This time the issue is 100% reproducible inside a test (provided in the example application repository).

The problem probably has to do with threading / reactive things inside micronaut. I've made a second test that has the same steps, but the /ping controller is made reactive - the issue is not present there.

Task List

• Steps to reproduce provided
• Stacktrace (if present) provided
• Example that reproduces the problem uploaded to Github
• Full description of the issue provided (see below)

Steps to Reproduce

1. Create a simple controller (in our example, /ping)
2. Enable /health endpoint
3. Call /health endpoint
4. Call /ping endpoint

Expected Behaviour

Two separate spans, unrelated to each other

Actual Behaviour

Two spans. /ping is a child_of /health.

Environment Information

• Operating System: Windows and Linux
• Micronaut Version: 1.2.2
• JDK Version: 8

Example Application

• https://github.com/pfyod/micronaut-1.2.2-tracing