Brave supports a "current tracing component" concept, which should only be used when you have no other way to get a reference.
This was made for JDBC connections, as they often initialize prior to the tracing component.
The most recent tracing component instantiated is available through Tracing.current().
You can also use Tracing.currentTracer() to get only the tracer.
If you use either of these methods, do not cache the result.
Instead, look them up each time you need them.